3D Bioplotter Research Papers

Displaying all papers about Bone Regeneration (123 results)

3D printing of silk fibroin-based hybrid scaffold treated with platelet rich plasma for bone tissue engineering

Bioactive Materials 2019 Volume 4, Pages 256-260

3D printing/bioprinting are promising techniques to fabricate scaffolds with well controlled and patient-specific structures and architectures for bone tissue engineering. In this study, we developed a composite bioink consisting of silk fibroin (SF), gelatin (GEL), hyaluronic acid (HA), and tricalcium phosphate (TCP) and 3D bioprinted the silk fibroin-based hybrid scaffolds. The 3D bioprinted scaffolds with dual crosslinking were further treated with human platelet-rich plasma (PRP) to generate PRP coated scaffolds. Live/Dead and MTT assays demonstrated that PRP treatment could obviously promote the cell growth and proliferation of human adipose derived mesenchymal stem cells (HADMSC). In addition, the treatment of PRP…

Design of a new 3D‐printed joint plug

Asia‐Pacific Journal of Chemical Engineering 2019

This paper introduces a kit of parts as a novel three‐dimensional (3D)–printed joint plug, in which each of the parts function cooperatively to treat cartilage damage in joints of the human body (e.g., hips, wrists, elbow, knee, and ankle). Three required and one optional parts are involved in this plug. The first part is a 3D‐printed hard scaffold (bone portion) to accommodate bone cells, and the second is a 3D‐printed soft scaffold (cartilage portion) overlying the bone portion to accommodate chondrocytes. The third part of joint plug is a permeable membrane, termed film, to cover the entire plug to provide…

3D printing of layered mesoporous bioactive glass/sodium alginate-sodium alginate scaffolds with controllable dual-drug release behaviors

Biomedical Materials 2019 Volume 14, Article 065011

Scaffolds with controlled drug release are valuable for bone tissue engineering, but constructing the scaffolds with controllable dual-drug release behaviors is still a challenge. In this study, layered mesoporous bioactive glass/sodium alginate-sodium alginate (MBG/SA–SA) scaffolds with controllable dual-drug release behaviors were fabricated by 3D printing. The porosity and compressive strength of three-dimensional (3D) printed MBG/SA–SA scaffolds by cross-linking are about 78% and 4.2 MPa, respectively. As two model drugs, bovine serum albumin (BSA) and ibuprofen (IBU) were separately loaded in SA layer and MBG/SA layer, resulting in a relatively fast release of BSA and a sustained release of IBU. Furthermore,…

Silicone resin derived larnite/C scaffolds via 3D printing for potential tumor therapy and bone regeneration

Chemical Engineering Journal 2019

Three dimensional (3D) printing has been used to fabricate bioceramic scaffolds for treating the tumor-related defects in recent years, but the fabrication process and the introduction of anti-tumor agents are still challenging. In this study, porous free carbon-embedding larnite (larnite/C) scaffolds have been successfully fabricated by 3D printing of the silicone resin loaded with CaCO3 filler and high temperature treatment under an inert atmosphere. The fabricated larnite/C scaffolds had uniform interconnected macropores (ca. 400 μm), and exhibited excellent photothermal effect, which was able to kill human osteosarcoma cells (MNNG/HOS) and inhibit the tumor growth in nude mice. Moreover, the larnite/C scaffolds…

3D-Printed Ceramic-Demineralized Bone Matrix Hyperelastic Bone Composite Scaffolds for Spinal Fusion

Tissue Engineering: Part A 2019

Although numerous spinal biologics are commercially available, a cost-effective and safe bone graft substitute material for spine fusion has yet to be proven. In this study, “3D-Paints” containing varying volumetric ratios of hydroxyapatite (HA) and human demineralized bone matrix (DBM) in a poly(lactide-co-glycolide) elastomer were three-dimensional (3D) printed into scaffolds to promote osteointegration in rats, with an end goal of spine fusion without the need for recombinant growth factor. Spine fusion was evaluated by manual palpation, and osteointegration and de novo bone formation within scaffold struts were evaluated by laboratory and synchrotron microcomputed tomography and histology. The 3:1 HA:DBM composite…

3D printed HUVECs/MSCs cocultures impact cellular interactions and angiogenesis depending on cell-cell distance

Biomaterials 2019 Volume 222, Article 119423

Vascularization is a crucial process during the growth and development of bone 1, yet it remains one of the main challenges in the reconstruction of large bone defects. The use of in vitro coculture of human umbilical vein endothelial cells (HUVECs) and human mesenchymal stem cells (hMSCs) has been one of the most explored options. Both cell types secrete specific growth factors that are mutually beneficial, and studies suggested that cell-cell communication and paracrine secretion could be affected by a number of factors. However, little is known about the effect of cell patterning and the distance between cell populations on…

Effect of Polymer Binder on the Synthesis and Properties of 3D-Printable Particle-Based Liquid Materials and Resulting Structures

ACS Omega 2019 Volume 4, Issue 7, Pages 12088-12097

Recent advances have demonstrated the ability to 3D-print, via extrusion, solvent-based liquid materials (previously named 3D-Paints) which solidify nearly instantaneously upon deposition and contain a majority by volume of solid particulate material. In prior work, the dissolved polymer binder which enables this process is a high molecular weight biocompatible elastomer, poly(lactic-co-glycolic) acid (PLGA). We demonstrate in this study an expansion of this solvent-based 3D-Paint system to two additional, less-expensive, and less-specialized polymers, polystyrene (PS) and polyethylene oxide (PEO). The polymer binder used within the 3D-Paint was shown to significantly affect the as-printed and thermal postprocessing behavior of printed structures. This…

The application of BMP-12-overexpressing mesenchymal stem cells loaded 3D-printed PLGA scaffolds in rabbit rotator cuff repair

International Journal of Biological Macromolecules 2019

This study investigates if the application of bone marrow-derived mesenchymal stem cells (BM-MSCs) loaded 3D-printed scaffolds could improve rotator cuff repair. The polylactic-co-glycolic acid (PLGA) scaffolds were fabricated by 3D print technology. Rabbit BM-MSCs were transfected with a recombinant adenovirus encoding bone morphogenic protein 12 (BMP-12). The effect of BM-MSCs loaded PLGA scaffolds on tendon-bone healing was assessed by biomechanical testing and histological analysis in a rabbit rotator cuff repair model. We found that the PLGA scaffolds had good biocompatible and biodegradable property. Overexpression of BMP-12 increased the mRNA and protein expression of tenogenic genes in BM-MSCs cultured with DMEM…

3D Printing of Tissue Engineering Scaffolds with Horizontal Pore and Composition Gradients

Tissue Engineering Part C: Methods 2019

This work investigated a new 3D-printing methodology to prepare porous scaffolds containing horizontal pore and composition gradients. To achieve that, a multimaterial printing technology developed in our laboratory was adapted to incorporate pore gradients. Fibers were printed by welding segments with unique material compositions and fiber diameters. Particularly, we focused on the preparation of model composite poly(ε-caprolactone)-based scaffolds with radial gradients of particulate hydroxyapatite (HA) content (higher concentrations in the outer region of the scaffold) and porosity (higher in the inner region). The morphology of the scaffolds revealed that the methodology allowed the fabrication of discrete regions with compressive mechanical…

3D printing of mesoporous bioactive glass/silk fibroin composite scaffolds for bone tissue engineering

Materials Science & Engineering C 2019 Volume 103, Article 109731

The fabrication of bone tissue engineering scaffolds with high osteogenic ability and favorable mechanical properties is of huge interest. In this study, a silk fibroin (SF) solution of 30 wt% was extracted from cocoons and combined with mesoporous bioactive glass (MBG) to fabricate MBG/SF composite scaffolds by 3D printing. The porosity, compressive strength, degradation and apatite forming ability were evaluated. The results illustrated that MBG/SF scaffolds had superior compressive strength (ca. 20 MPa) and good biocompatibility, and stimulated bone formation ability compared to mesoporous bioactive glass/polycaprolactone (MBG/PCL) scaffolds. We subcutaneously transplanted hBMSCs-loaded MBG/SF and MBG/PCL scaffolds into the back of nude mice…

3D printed β-TCP scaffold with sphingosine 1-phosphate coating promotes osteogenesis and inhibits inflammation

Biochemical and Biophysical Research Communications 2019

Traditional treatments for bone repair with allografts and autografts are limited by the source of bone substitutes. Bone tissue engineering via a cell-based bone tissue scaffold is a new strategy for treatment against large bone defects with many advantages, such as the accessibility of biomaterials, good biocompatibility and osteoconductivity; however, the inflammatory immune response is still an issue that impacts osteogenesis. Sphingosine 1-phosphate (S1P) is a cell-derived sphingolipid that can mediate cell proliferation, immunoregulation and bone regeneration. We hypothesised that coating S1P on a β-Tricalcium phosphate (β-TCP) scaffold could regulate the immune response and increase osteogenesis. We tested the immunoregulation…

Novel Strategy to Accelerate Bone Regeneration of Calcium Phosphate Cement by Incorporating 3D Plotted Poly(lactic‐co‐glycolic acid) Network and Bioactive Wollastonite

Advanced Healthcare Materials 2019

Inefficient bone regeneration of self‐hardening calcium phosphate cement (CPC) increases the demand for interconnected macropores and osteogenesis‐stimulated substances. It remains a challenge to fabricate porous CPC with interconnected macropores while maintaining its advantages, such as plasticity. Herein, pastes containing CPC and wollastonite (WS) are infiltrated into a 3D plotted poly(lactic‐co‐glycolic acid) (PLGA) network to fabricate plastic CPC‐based composite cement (PLGA/WS/CPC). The PLGA/WS/CPC recovers the plasticity of CPC after being heated above the glass transition temperature of PLGA. The presence of the 3D PLGA network significantly increases the flexibility of CPC in prophase and generates 3D interconnected macropores in situ upon…

3D-printed ternary SiO2CaOP2O5 bioglass-ceramic scaffolds with tunable compositions and properties for bone regeneration

Ceramics International 2019 Volume 45, Issue 8, Pages 10997-11005

Simple ternary SiO2CaOP2O5 bioglasses proved sufficient osteogenesis capacity. In this study, the bioglasses were 3D printed into porous scaffolds and SiO2/CaO molar ratio was altered (from 90/5 to 60/35) to achieve tunable glass-ceramic compositions after thermal treatment. Scaffolds possessed interconnected porous structure with controllable porosities via 3D printing technique. In addition, microstructure and properties of mechanical strength, degradation, ion dissolution and apatite formation were investigated. Characterization results showed that higher content of SiO2 produced more homogeneous crystalline particles and sintering compactness, thus led to higher strength. For scaffolds with higher CaO content, more glasses were maintained and faster degradation rate…

Osteostatin potentiates the bioactivity of mesoporous glass scaffolds containing Zn2+ ions in human mesenchymal stem cells

Acta Biomaterialia 2019

There is an urgent need of biosynthetic bone grafts with enhanced osteogenic capacity. In this study, we describe the design of hierarchical meso-macroporous 3D-scaffolds based on mesoporous bioactive glasses (MBGs), enriched with the peptide osteostatin and Zn2+ ions, and their osteogenic effect on human mesenchymal stem cells (hMSCs) as a preclinical strategy in bone regeneration. The MBG compositions investigated were 80%SiO2–15%CaO–5%P2O5 (in mol-%) Blank (BL), and two analogous glasses containing 4% ZnO (4ZN) and 5% ZnO (5ZN). By using additive fabrication techniques, scaffolds exhibiting hierarchical porosity: mesopores (around 4 nm), macropores (1–600 μm) and big channels (∼1000 μm), were prepared. These MBG scaffolds…

3D Bioprinted Scaffolds Containing Viable Macrophages and Antibiotics Promote Clearance of Staphylococcus aureus Craniotomy-Associated Biofilm Infection

ACS Apllied Materials & Interfaces 2019 Volume 11, Issue 13, Pages 12298-12307

Craniotomy involves the removal of a skull fragment to access the brain, such as during tumor or epilepsy surgery, which is immediately replaced intraoperatively. The infection incidence after craniotomy ranges from 0.8 to 3%, with approximately half caused by Staphylococcus aureus (S. aureus). To mitigate infectious complications following craniotomy, we engineered a three-dimensional (3D) bioprinted bone scaffold to harness the potent antibacterial activity of macrophages (MΦs) together with antibiotics using a mouse S. aureus craniotomy-associated biofilm model that establishes a persistent infection on the bone flap, subcutaneous galea, and brain. The 3D scaffold contained rifampin and daptomycin printed in a…

Fabrication and mechanical characterization of 3D printed vertical uniform and gradient scaffolds for bone and osteochondral tissue engineering

Acta Biomaterialia 2019

Recent developments in 3D printing (3DP) research have led to a variety of scaffold designs and techniques for osteochondral tissue engineering; however, the simultaneous incorporation of multiple types of gradients within the same construct remains a challenge. Herein, we describe the fabrication and mechanical characterization of porous poly(ε-caprolactone) (PCL) and PCL-hydroxyapatite (HA) scaffolds with incorporated vertical porosity and ceramic content gradients via a multimaterial extrusion 3DP system. Scaffolds of 0 wt% HA (PCL), 15 wt% HA (HA15), or 30 wt% HA (HA30) were fabricated with uniform composition and porosity (using 0.2 mm, 0.5 mm, or 0.9 mm on-center fiber spacing), uniform composition and gradient porosity, and…

Hydroxyapatite /Collagen 3D printed Scaffolds and their Osteogenic Effects on hBMSCs

Tissue Engineering Part A 2019

3D printing provides a novel approach to repair bone defects using customized biomimetic tissue scaffolds. To make a bone substitute closest to natural bone structure and composition, two different types of hydroxyapatite, Nano hydroxyapatite (nHA) and deproteinized bovine bone (DBB), were dispersed into collagen (CoL) to prepare the bio-ink for 3D printing. In doing so, a porous architecture was manufactured with 3D printing technology. The physical and chemical properties of the materials were evaluated, including biocompatibility and effect on the osteogenic differentiation of the human bone marrow-derived mesenchyme stem cells (hBMSCs). The XPS, XRD, FTIR, and the mechanical analysis of…

Development of 3D-printed PLGA/TiO2 nanocomposite scaffolds for bone tissue engineering applications

Materials Science and Engineering: C 2019 Volume 96, Pages 105-113

Porous scaffolds were 3D-printed using poly lactic-co-glycolic acid (PLGA)/TiO2 composite (10:1 weight ratio) for bone tissue engineering applications. Addition of TiO2 nanoparticles improved the compressive modulus of scaffolds. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) revealed an increase in both glass transition temperature and thermal decomposition onset of the composite compared to pure PLGA. Furthermore, addition of TiO2 was found to enhance the wettability of the surface evidenced by reducing the contact angle from 90.5 ± 3.2 to 79.8 ± 2.4 which is in favor of cellular attachment and activity. The obtained results revealed that PLGA/TiO2 scaffolds significantly improved osteoblast proliferation compared to…

3D-printed scaffolds of biomineralized hydroxyapatite nanocomposite on silk fibroin for improving bone regeneration

Applied Surface Science 2019 Volumes 467–468, Pages 345-353

In an attempt to fabricate biomimetic bone repair scaffolds and improve bone regeneration point of view, we have three dimensionally printed porous scaffolds with biomineralized hydroxyapatite/silk fibroin nanocomposites. SF/HA composite particles were firstly produced via an in-situ mineral precipitation process when SF molecules were served as templates.. Microscopy observations of SF/HA showed homogeneous morphology and narrowly distributed size. By using sodium alginate (SA) as paste binder, scaffolds with different contents of SF/HA were subsequently 3D-printed under proper conditions. All the scaffolds were porous with 3D interconnected large pores (size ~400 μm) and an overall porosity about 70%, combined with a relative…

I-Optimal Design of Hierarchical 3D Scaffolds Produced by Combining Additive Manufacturing and Thermally Induced Phase Separation

ACS Apllied Bio Materials 2019

The limitations in the transport of oxygen, nutrients, and metabolic waste products pose a challenge to the development of bioengineered bone of clinically relevant size. This paper reports the design and characterization of hierarchical macro/microporous scaffolds made of poly(lactic-co-glycolic) acid and nanohydroxyapatite (PLGA/nHA). These scaffolds were produced by combining additive manufacturing (AM) and thermally induced phase separation (TIPS) techniques. Macrochannels with diameters of ∼300 μm, ∼380 μm, and ∼460 μm were generated by embedding porous 3D-plotted polyethylene glycol (PEG) inside PLGA/nHA/1,4-dioxane or PLGA/1,4-dioxane solutions, followed by PEG extraction using deionized (DI) water. We have used an I-optimal design of experiments…

Homogeneous hydroxyapatite/alginate composite hydrogel promotes calcified cartilage matrix deposition with potential for three-dimensional bioprinting

Biofabrication 2019 Volume 11, Issue 1, Article 015015

Calcified cartilage regeneration plays an important role in successful osteochondral repair, since it provides a biological and mechanical transition from the unmineralized cartilage at the articulating surface to the underlying mineralized bone. To biomimic native calcified cartilage in engineered constructs, here we test the hypothesis that hydroxyapatite (HAP) stimulates chondrocytes to secrete the characteristic matrix of calcified cartilage. Sodium citrate (SC) was added as a dispersant of HAP within alginate (ALG), and homogeneous dispersal of HAP within ALG hydrogel was confirmed using sedimentation tests, electron microscopy, and energy dispersive spectroscopy. To examine the biological performance of ALG/HAP composites, chondrocyte survival…

Precision lattice parameter determination from transmission diffraction of thick specimens with irregular cross sections

Journal of Applield Crystallography 2019 Volume 52, Pages 40-46

Accurate determination of lattice parameters from X-ray diffraction requires that the diffraction angles be measured very precisely, and significant errors result if the sample–detector separation differs from that assumed. Transmission diffraction from bones, which have a complex cross section and must be left intact, is a situation where this separation is difficult to measure and it may differ from position to position across the specimen. This article describes a method for eliminating the effect of variable sample cross section. Diffraction patterns for each position on the specimen are collected before and after 180° rotation about an axis normal to the…

Multimaterial Segmented Fiber Printing for Gradient Tissue Engineering

Tissue Engineering Part C: Methods 2019

In this work, we present a printing method to fabricate scaffolds consisting of multimaterial segmented fibers. Particularly, we developed a reproducible printing process to create single fibers with multiple discrete compositions and control over the distribution of particulate ceramics—namely hydroxyapatite (HA) and β-tricalcium phosphate (TCP)—within poly(ɛ-caprolactone)-based composite scaffolds. Tensile testing revealed that the mechanical integrity of individual segmented fibers was preserved compared with nonsegmented fibers, and microcomputed tomography and thermal analysis confirmed the homogeneous distribution of ceramics incorporated in the fiber compositions. Moreover, we printed and characterized composite scaffolds containing model inverse radial gradients of HA and TCP that could…

Coating 3D Printed Polycaprolactone Scaffolds with Nanocellulose Promotes Growth and Differentiation of Mesenchymal Stem Cells

Biomacromolecules 2018 Voluem 19, Issue 11, Pages 4307-4319

3D printed polycaprolactone (PCL) has potential as a scaffold for bone tissue engineering, but the hydrophobic surface may hinder optimal cell responses. The surface properties can be improved by coating the scaffold with cellulose nanofibrils material (CNF), a multiscale hydrophilic biocompatible biomaterial derived from wood. In this study, human bone marrow-derived mesenchymal stem cells were cultured on tissue culture plates (TCP) and 3D printed PCL scaffolds coated with CNF. Cellular responses to the surfaces (viability, attachment, proliferation, and osteogenic differentiation) were documented. CNF significantly enhanced the hydrophilic properties of PCL scaffolds and promoted protein adsorption. Live/dead staining and lactate dehydrogenase…

Collagen/hydroxyapatite bone grafts manufactured by homogeneous/ heterogeneous 3D printing

Materials Letters 2018 Volume 231, Pages 179-182

This paper presents a new way to obtain collagen/hydroxyapatite (COLL/HA) composite materials by 3D printing. Because of high tendency of segregation of COLL/HA composite materials, printing was done using COLL/Ca2+ gel (even COLL/Ca(OH)2) followed by precipitation of HA and crosslinking of COLL. The HA precipitation occurs simultaneously with crosslinking of COLL molecules, these processes being assured by the presence of glutaraldehyde supplemented PBS solution. By printing with COLL/Ca2+ at acidic pH homogeneity was increased. FTIR spectroscopy and microscopy reveal HA formation as the main inorganic phase these nanoparticles being homogeneously dispersed in the volume. In vitro biocompatibility assays were performed…

Heparin/Poly-L-lysine-coated 3D-printed PLGA scaffolds as drug carriers for local immune modulation in bone regeneration

Society for Biomaterials Annual Meeting and Exposition 2018 Presentation 584

Immune responses after injury play a critical role in bone regeneration. Initiation of inflammation at early stages of repair triggers tissue formation and remodeling; however, uncontrolled inflammation underlies a catabolic effect on tissues as commonly seen in arthritis where inflammation breaks down tissues and hinders regeneration. Our ultimate goal is to design a novel approach on bone scaffolds for which biodegradable scaffolds are loaded with inflammatory cytokines for local immunomodulation as well as bone regeneration. We employed nanoparticles (NPs) composed of heparin (Hep) and poly-L-lysine (PLL) as cytokine drug carriers adhered on 3D-printed poly(lactic-co-glycolic acid) (PLGA) scaffolds. The entire drug…

3D Printing Nanoscale Bioactive Glass Scaffolds Enhance Osteoblast Migration and Extramembranous Osteogenesis through Stimulating Immunomodulation

Advanced Healthcare Materials 2018 Volume 7, Article 1800361

Bioactive glass (BG) can repair bone defects, however, it is not clear whether BG has the ability for bone augmentation without making any bone defect. Unlike the intramembranous osteogenesis in bone defect repair, the extramembranous osteogenesis occurs outside the cortical bone and the osteoprogenitor cells show the reversed migration. Herein, nanoscale bioactive glass scaffolds (BGSs) are fabricated, and their role and immunomodulation‐related mechanism in the extramembranous osteogenesis are investigated. The in vitro migration and differentiation of calvaria preosteoblasts are studied by culturing with peripheral macrophage‐conditioned medium after stimulating with BGSs. The results indicate that the proinflammatory environment significantly promotes preosteoblast…

Zein regulating apatite mineralization, degradability, in vitro cells responses and in vivo osteogenesis of 3D-printed scaffold of n-MS/ZN/PCL ternary composite

RSC Advances 2018 Volume 8, Pages 18745-18756

Bioactive and degradable scaffolds of nano magnesium silicate (n-MS)/zein (ZN)/poly(caprolactone) (PCL) ternary composites were prepared by 3D-printing method. The results showed that the 3D-printed scaffolds possessed controllable pore structure, and pore morphology, pore size, porosity and pore interconnectivity of the scaffolds can be efficiently adjusted. In addition, the apatite-mineralization ability of the scaffolds in simulated body fluids was obviously improved with the increase of ZN content, in which the scaffold with 20 w% ZN (C20) possessed excellent apatite-mineralization ability. Moreover, the degradability of the scaffolds was significantly enhanced with the increase of ZN content in the scaffolds. The degradation of…

Response of hPDLSCs on 3D printed PCL/PLGA composite scaffolds in vitro

Molecular Medicine Reports 2018 Volume 18 Issue 2, Pages 1335-1344

Three‑dimensional printed (3DP) scaffolds have become an excellent resource in alveolar bone regeneration. However, selecting suitable printable materials remains a challenge. In the present study, 3DP scaffolds were fabricated using three different ratios of poly (ε‑caprolactone) (PCL) and poly‑lactic‑co‑glycolic acid (PLGA), which were 0.1PCL/0.9PLGA, 0.5PCL/0.5PLGA and 0.9PCL/0.1PLGA. The surface characteristics and degradative properties of the scaffolds, and the response of human periodontal ligament stem cells (hPDLSCs) on the scaffolds, were assessed to examine the preferable ratio of PCL and PLGA for alveolar bone regeneration. The results demonstrated that the increased proportion of PLGA markedly accelerated the degradation, smoothed the surface…

3D printed mesoporous bioactive glass/metal-organic framework scaffolds with antitubercular drug delivery

Microporous and Mesoporous Materials 2018 Volume 272, Pages 24-30

Three-dimensional (3D) porous scaffolds with sustained drug delivery are pursued for osteoarticular tuberculosis therapy after surgery. In this study, mesoporous bioactive glass/metal-organic framework (MBG/MOF) scaffolds with sustained antitubercular drug release have been fabricated by 3D printing. The results showed that the MBG/MOF scaffolds possess macropores of ca. 400 μm and enhanced compressive strength of 3–7 MPa, also exhibited good biocompatibility and apatite forming ability in vitro. Furthermore, the drug release rate and pH microenvironment of the MBG/MOF scaffolds could be controlled due to the MOF degradation. These results indicated that the 3D printed MBG/MOF scaffolds are promising for treating osteoarticular tuberculosis.

Vascularization of Natural and Synthetic Bone Scaffolds

Cell transplantation 2018 Volume 27, Issue 8, Pages 1269–1280

Vascularization of engineered bone tissue is critical for ensuring its survival after implantation. In vitro pre-vascularization of bone grafts with endothelial cells is a promising strategy to improve implant survival. In this study, we pre-cultured human smooth muscle cells (hSMCs) on bone scaffolds for 3 weeks followed by seeding of human umbilical vein endothelial cells (HUVECs), which produced a desirable environment for microvasculature formation. The sequential cell-seeding protocol was successfully applied to both natural (decellularized native bone, or DB) and synthetic (3D-printed Hyperelastic “Bone” scaffolds, or HB) scaffolds, demonstrating a comprehensive platform for developing natural and synthetic-based in vitro vascularized…

Three-dimensional printing of β-tricalcium phosphate/calcium silicate composite scaffolds for bone tissue engineering

Bio-Design and Manufacturing 2018 Volume 1, Issue 2, Pages 146-156

Bioactive scaffolds with interconnected porous structures are essential for guiding cell growth and new bone formation. In this work, we successfully fabricated three-dimensional (3D) porous β-tricalcium phosphate (β-TCP)/calcium silicate (CS) composite scaffolds with different ratios by 3D printing technique and further investigated the physiochemical properties, in vitro apatite mineralization properties and degradability of porous β-TCP/CS scaffolds. Moreover, a series of in vitro cell experiments including the attachment, proliferation and osteogenic differentiation of mouse bone marrow stromal cells were conducted to testify their biological performances. The results showed that 3D printed β-TCP/CS scaffolds possessed of controllable internal porous structures and external…

3D-printed IFN-γ-loading calcium silicate-β-tricalcium phosphate scaffold sequentially activates M1 and M2 polarization of macrophages to promote vascularization of tissue engineering bone

Acta Biomaterialia 2018 Volume 71, Pages 96-107

To promote vascularization of tissue-engineered bone, IFN-γ polarizing macrophages to M1 was loaded on 5% calcium silicate/β-tricalcium phosphate (CaSiO3-β-TCP) scaffolds. IFN-γ and Si released from the scaffold were designed to polarize M1 and M2 macrophages, respectively. β-TCP, CaSiO3-β-TCP, and IFN-γ@CaSiO3-β-TCP were fabricated and biocompatibilities were evaluated. Polarizations of macrophages were detected by flow cytometry. Human umbilical vein endothelial cells with GFP were cultured and induced on Matrigel with conditioned culture medium extracted from culture of macrophages loaded on scaffolds for evaluating angiogenesis. Four weeks after the scaffolds were subcutaneously implanted into C57B1/6, vascularization was evaluated by visual observation, hematoxylin and…

3D Bio-Plotted Tricalcium Phosphate/Zirconia Composite Scaffolds to Heal Large Size Bone Defects

Molecular & Cellular Biomechanics 2017 Vol. 14, No. 2, pages 125-136

β-TCP-Zirconia scaffolds with different architectures were fabricated by means of 3D-Bioplotting in order to enhance the mechanical and in-vitro ability of the scaffold to heal large size bone defects. In the present study scaffold architecture with different strand orientations (0o-90o, 0o-45o-135o-180o, 0o-108o-216o and 0o-72o-144o-36o-108o) were fabricated, characterized and evaluated for mechanical strength and cell proliferation ability. β-TCP powder (25µm) and PVA (Polyvinyl Alcohol) was acquired from Fisher Scientific, India. Zirconia (18 to 32 µm) was procured from Lobachemie, India. In brief 7.5%, PVA in distilled water was used as a binder and was mixed with 10 grams of (70/30) TCP-Zirconia…

3D printing of hybrid biomaterials for bone tissue engineering: Calcium-polyphosphate microparticles encapsulated by polycaprolactone

Acta Biomaterialia 2017 Volume 64, Pages 377-388

Here we describe the formulation of a morphogenetically active bio-ink consisting of amorphous microparticles (MP) prepared from Ca2+ and the physiological inorganic polymer, polyphosphate (polyP). Those MP had been fortified by mixing with poly-ε-caprolactone (PCL) to allow 3D-bioprinting. The resulting granular PCL/Ca-polyP-MP hybrid material, liquefied by short-time heating to 100 °C, was used for the 3D-printing of tissue-like scaffolds formed by strands with a thickness of 400 µm and a stacked architecture leaving ≈0.5 mm2-sized open holes enabling cell migration. The printed composite scaffold turned out to combine suitable biomechanical properties (Young’s modulus of 1.60 ± 0.1 GPa; Martens hardness of 153 ± 28 MPa), matching those of cortical…

Imaging stem cell distribution, growth, migration, and differentiation in 3-D scaffolds for bone tissue engineering using mesoscopic fluorescence tomography

Biotechnology and Bioengineering 2017 Volume 115, Issue 1, Pages 257-265

Regenerative medicine has emerged as an important discipline that aims to repair injury or replace damaged tissues or organs by introducing living cells or functioning tissues. Successful regenerative medicine strategies will likely depend upon a simultaneous optimization strategy for the design of biomaterials, cell-seeding methods, cell-biomaterial interactions and molecular signaling within the engineered tissues. It remains a challenge to image three-dimensional (3-D) structures and functions of the cell-seeded scaffold in mesoscopic scale (>2∼3 mm). In this study, we utilized angled fluorescence laminar optical tomography (aFLOT), which allows depth-resolved molecular characterization of engineered tissues in 3-D to investigate cell viability, migration and…

Prevascularization of 3D printed bone scaffolds by bioactive hydrogels and cell co-culture

Journal of Biomedical Materials Research Part B: Applied Biomaterials 2017 Volume 106B, Pages 1788–1798

Vascularization is a fundamental prerequisite for large bone construct development and remains one of the main challenges of bone tissue engineering. Our current study presents the combination of 3D printing technique with a hydrogel-based prevascularization strategy to generate prevascularized bone constructs. Human adipose derived mesenchymal stem cells (ADMSC) and human umbilical vein endothelial cells (HUVEC) were encapsulated within our bioactive hydrogels, and the effects of culture conditions on in vitro vascularization were determined. We further generated composite constructs by forming 3D printed polycaprolactone/hydroxyapatite scaffolds coated with cell-laden hydrogels and determined how the co-culture affected vascularization and osteogenesis. It was demonstrated…

Evaluation of 3D-Printed Polycaprolactone Scaffolds Coated with Freeze-Dried Platelet-Rich Plasma for Bone Regeneration

Materials 2017 Volume 10, Issue 7, Article 831

Three-dimensional printing is one of the most promising techniques for the manufacturing of scaffolds for bone tissue engineering. However, a pure scaffold is limited by its biological properties. Platelet-rich plasma (PRP) has been shown to have the potential to improve the osteogenic effect. In this study, we improved the biological properties of scaffolds by coating 3D-printed polycaprolactone (PCL) scaffolds with freeze-dried and traditionally prepared PRP, and we evaluated these scaffolds through in vitro and in vivo experiments. In vitro, we evaluated the interaction between dental pulp stem cells (DPSCs) and the scaffolds by measuring cell proliferation, alkaline phosphatase (ALP) activity,…

Tailorable Surface Morphology of 3D Scaffolds by Combining Additive Manufacturing with Thermally Induced Phase Separation

Macromolecular Rapid Communications 2017 Volume 38, Article 1700186

The functionalization of biomaterials substrates used for cell culture is gearing towards an increasing control over cell activity. Although a number of biomaterials have been successfully modified by different strategies to display tailored physical and chemical surface properties, it is still challenging to step from 2D substrates to 3D scaffolds with instructive surface properties for cell culture and tissue regeneration. In this study, additive manufacturing and thermally induced phase separation are combined to create 3D scaffolds with tunable surface morphology from polymer gels. Surface features vary depending on the gel concentration, the exchanging temperature, and the nonsolvent used. When preosteoblasts…

Short-term hypoxic preconditioning promotes prevascularization in 3D bioprinted bone constructs with stromal vascular fraction derived cells

RSC Advances 2017 Volume 7, Pages 29312-29320

Reconstruction of complex, craniofacial bone defects often requires autogenous vascularized bone grafts, and still remains a challenge today. In order to address this issue, we isolated the stromal vascular fraction (SVF) from adipose tissues and maintained the phenotypes and the growth of endothelial lineage cells within SVF derived cells (SVFC) by incorporating an endothelial cell medium. We 3D bioprinted SVFC within our hydrogel bioinks and conditioned the constructs in either normoxia or hypoxia. We found that short-term hypoxic conditioning promoted vascularization-related gene expression, whereas long-term hypoxia impaired cell viability and vascularization. 3D bioprinted bone constructs composed of polycaprolactone/hydroxyapatite (PCL/HAp) and…

Fabrication and Evaluation of Electrospun, 3D-Bioplotted, and Combination of Electrospun/3D-Bioplotted Scaffolds for Tissue Engineering Applications

BioMed Research International 2017 Volume 2017, Article ID 6956794

Electrospun scaffolds provide a dense framework of nanofibers with pore sizes and fiber diameters that closely resemble the architecture of native extracellular matrix. However, it generates limited three-dimensional structures of relevant physiological thicknesses. 3D printing allows digitally controlled fabrication of three-dimensional single/multimaterial constructs with precisely ordered fiber and pore architecture in a single build. However, this approach generally lacks the ability to achieve submicron resolution features to mimic native tissue. The goal of this study was to fabricate and evaluate 3D printed, electrospun, and combination of 3D printed/electrospun scaffolds to mimic the native architecture of heterogeneous tissue. We assessed their…

Polycaprolactone-and polycaprolactone/ceramic-based 3D-bioplotted porous scaffolds for bone regeneration: A comparative study

Materials Science and Engineering: C 2017 Volume 79, Issue 1, Pages 326–335

One of the critical challenges that scaffolding faces in the organ and tissue regeneration field lies in mimicking the structure, and the chemical and biological properties of natural tissue. A high-level control over the architecture, mechanical properties and composition of the materials in contact with cells is essential to overcome such challenge. Therefore, definition of the method, materials and parameters for the production of scaffolds during the fabrication stage is critical. With the recent emergence of rapid prototyping (RP), it is now possible to create three-dimensional (3D) scaffolds with the essential characteristics for the proliferation and regeneration of tissues, such…

Three dimensional printing of calcium sulfate and mesoporous bioactive glass scaffolds for improving bone regeneration in vitro and in vivo

Scientific Reports 2017 Volume 7, Article number: 42556

In the clinic, bone defects resulting from infections, trauma, surgical resection and genetic malformations remain a significant challenge. In the field of bone tissue engineering, three-dimensional (3D) scaffolds are promising for the treatment of bone defects. In this study, calcium sulfate hydrate (CSH)/mesoporous bioactive glass (MBG) scaffolds were successfully fabricated using a 3D printing technique, which had a regular and uniform square macroporous structure, high porosity and excellent apatite mineralization ability. Human bone marrow-derived mesenchymal stem cells (hBMSCs) were cultured on scaffolds to evaluate hBMSC attachment, proliferation and osteogenesis-related gene expression. Critical-sized rat calvarial defects were applied to investigate the…

3D printing of pearl/CaSO4 composite scaffolds for bone regeneration

Journal of Materials Chemistry B 2017 Volume 6, Issue 3, Pages 499-509

The development of biomaterials with high osteogenic ability for fast osteointegration with a host bone is of great interest. In this study, pearl/CaSO4 composite scaffolds were fabricated using three-dimensional (3D) printing, followed by a hydration process. The pearl/CaSO4 scaffolds showed uniform interconnected macropores (∼400 μm), high porosity (∼60%), and enhanced compressive strength. With CaSO4 scaffolds as a control, the biological properties of the pearl/CaSO4 scaffolds were evaluated in vitro and in vivo. The results showed that the pearl/CaSO4 scaffolds possessed a good apatite-forming ability and stimulated the proliferation and differentiation of rat bone mesenchymal stem cells (rBMSCs), as well as…

Three-dimensional printing of cerium-incorporated mesoporous calcium-silicate scaffolds for bone repair

Journal of Materials Science 2016 Volume 51, Issue 2, Pages 836-844

In the study, we developed hierarchical composite scaffolds by 3D printing technique with mesoporous CaSiO3 containing controlled amounts of Ce substitution in Ca–Si system. The scaffolds were porous with 3D interconnected large pores (size ~400 μm) and an overall porosity above 70 %, combined with a relative high compressive strength (~7 MPa). These properties are essential for enhancing bone ingrowth in tissue engineering. The in vitro biological properties of apatite formation, cell proliferation, and differentiation were characterized on CeO2-MCS scaffolds and MCS scaffolds. Results indicated that CeO2-MCS scaffolds induced similar apatite deposition and cell attachment of human bone marrow stromal…

Hyperelastic “bone”: A highly versatile, growth factor–free, osteoregenerative, scalable, and surgically friendly biomaterial

Science Translational Medicine 2016 Volume 8, Issue 358, Pages 358ra127

Despite substantial attention given to the development of osteoregenerative biomaterials, severe deficiencies remain in current products. These limitations include an inability to adequately, rapidly, and reproducibly regenerate new bone; high costs and limited manufacturing capacity; and lack of surgical ease of handling. To address these shortcomings, we generated a new, synthetic osteoregenerative biomaterial, hyperelastic “bone” (HB). HB, which is composed of 90 weight % (wt %) hydroxyapatite and 10 wt % polycaprolactone or poly(lactic-co-glycolic acid), could be rapidly three-dimensionally (3D) printed (up to 275 cm3/hour) from room temperature extruded liquid inks. The resulting 3D-printed HB exhibited elastic mechanical properties (~32…

Osteogenic Differentiation of Three-Dimensional Bioprinted Constructs Consisting of Human Adipose-Derived Stem Cells In Vitro and In Vivo

PloS One 2016 Volume 11, Issue 6, e0157214

Here, we aimed to investigate osteogenic differentiation of human adipose-derived stem cells (hASCs) in three-dimensional (3D) bioprinted tissue constructs in vitro and in vivo. A 3D Bio-plotter dispensing system was used for building 3D constructs. Cell viability was determined using live/dead cell staining. After 7 and 14 days of culture, real-time quantitative polymerase chain reaction (PCR) was performed to analyze the expression of osteogenesis-related genes (RUNX2, OSX, and OCN). Western blotting for RUNX2 and immunofluorescent staining for OCN and RUNX2 were also performed. At 8 weeks after surgery, osteoids secreted by osteogenically differentiated cells were assessed by hematoxylin-eosin (H&E) staining,…

Accelerated vascularization of tissue engineering constructs in vivo by preincubated co-culture of aortic fragments and osteoblasts

Biochemical Engineering Journal 2016 Volume 105, Part A, Pages 230–241

There is an urgent critical need for the development of clinically relevant tissue-engineered large bone substitutes that can promote early vascularization after transplantation. To promote rapid blood vessel growth in the engineered tissue, we preincubated aortic fragments, as well as, co-cultures of aortic fragments and osteoblast-like cells in matrigel-filled PLGA scaffolds before implantation into the dorsal skinfold chambers of balb/c mice. Despite an acceptable and low inflammatory response, preincubated aortic fragments accelerate early angiogenesis of tissue-engineered constructs; the angiogenesis was found to occur faster than that observed in previous studies. Thus, the time-period for achieving a denser microvascular network could…

[Osteogenesis of human adipose-derived mesenchymal stem cells-biomaterial mixture in vivo after 3D bio-printing]

Journal of Peking University. Health Sciences 2016 Volume 48, Issue 1, Pages 45-50

To construct human adipose-derived mesenchymal stem cells (hASCs)-biomaterial mixture 3D bio-printing body and detect its osteogenesis in vivo, and to establish a guideline of osteogenesis in vivo by use of 3D bio-printing technology preliminarily.P4 hASCs were used as seed cells, whose osteogenic potential in vitro was tested by alkaline phosphatase (ALP) staining and alizarin red staining after 14 d of osteogenic induction. The cells were added into 20 g/L sodium alginate and 80 g/L gelatin mixture (cell density was 1×10(6)/mL), and the cell-sodium alginate-gelatin mixture was printed by Bioplotter 3D bio-printer (Envision company, Germany), in which the cells’survival rate was…

Material design and photo-regulated hydrolytic degradation behavior of tissue engineering scaffolds fabricated via 3D fiber deposition

Journal of Materials Chemistry B 2016 Volume 5, Pages 329-340

An ideal behavior of a tissue engineering scaffold is that it degrades and reshapes at a rate that matches the formation of new tissues. However, this ideal situation may not occur as the scaffold often undergoes too slow or too fast degradation. To test the promise of the active control of scaffold degradation, in this work, a photo/water dual-degradable porous scaffold was designed and fabricated using a 3D fiber deposition (3DF) system from a linear biopolymer (named PLANB) that combined the o-nitrobenzyl linkages and hydrolysable ester bone in the polymer chains. The chemical structure, molecular weight and polydispersity of PLANB…

The effect of calcium sulfate incorporation on physiochemical and biological properties of 3D-printed mesoporous calcium silicate cement scaffolds

Microporous and Mesoporous Materials 2016 Volume 241, Issue 15, Pages 11–20

Development of 3D porous scaffolds with proper mechanical strength is crucial in bone tissue engineering. In this study, calcium sulfate hemihydrate (CSH) cement was functionally incorporated into mesoporous calcium silicate (MCS) through a 3D printing technique in order to improve the scaffold strength. Compared to printed MCS scaffolds, the characterizations revealed that 20% CSH incorporation had enhanced their compressive strength by 2 times via 4 weeks’ hydration. Furthermore, CSH incorporation prevented the fast pH value rise and achieved a balanced degradation rate. SEM observations showed a good apatite formation on the surfaces of both MCS and MCS/CSH scaffolds. Cellular experiments…

Three-dimensional printing of tricalcium silicate/mesoporous bioactive glass cement scaffolds for bone regeneration

Journal of Materials Chemistry B 2016 Volume 4, Pages 7452-7463

Bone defects, particularly large bone defects resulting from infections, trauma, surgical resection or genetic malformations, maintain a significant challenge for clinicians. In this study, the tricalcium silicate/mesoporous bioactive glass (C3S/MBG) cement scaffolds were successfully fabricated for the first time by 3D printing with a curing process, which combined the hydraulicity of C3S with the excellent biological property of MBG together. The C3S/MBG scaffolds exhibited 3D interconnected macropores (~400μm), high porosity (~70%), enhanced mechanical strength (>12MPa) and excellent apatite mineralization ability. Human bone marrow-derived mesenchymal stem cells (hBMSCs) were cultured on the scaffolds to evaluate their cell responses, and the results…

3D silicon doped hydroxyapatite scaffolds decorated with Elastin-like Recombinamers for bone regenerative medicine

Acta Biomaterialia 2016 Volume 45, Pages 349–356

The current study reports on the manufacturing by rapid prototyping technique of three-dimensional (3D) scaffolds based on silicon substituted hydroxyapatite with Elastin-like Recombinamers (ELRs) functionalized surfaces. Silicon doped hydroxyapatite (Si-HA), with Ca10(PO4)5.7(SiO4)0.3(OH)1.7h0.3 nominal formula, was surface functionalized with two different types of polymers designed by genetic engineering: ELR-RGD that contain cell attachment specific sequences and ELR-SNA15/RGD with both hydroxyapatite and cells domains that interact with the inorganic phase and with the cells, respectively. These hybrid materials were subjected to in vitro assays in order to clarify if the ELRs coating improved the well-known biocompatible and bone regeneration properties of calcium…

Fabrication and characterization of bioactive glass/alginate composite scaffolds by a self-crosslinking processing for bone regeneration

RSC Advances 2016 Volume 6, Pages 91201-91208

The aim of this study was to synthesize and characterize self-crosslinked bioactive glass/alginate composite scaffolds, as a kind of potential biomaterial for bone regeneration. The scaffolds were fabricated through a self-crosslinking process of alginate by bioactive glass microspheres provided Ca2+ completely, without any organic solvent, crosslinking agent or binder. The microstructure, mechanical properties, apatite-forming ability, ionic release, adhesion, proliferation and ALP activity of human bone marrow-derived mesenchymal stem cells (hBMSCs) of the scaffolds were evaluated. The results showed that uniform films could be obtained on the surface as well as abundant of crosslinking bridges in the interior of scaffolds. The…

In vitro colonization of stratified bioactive scaffolds by pre-osteoblast cells

Acta Biomaterialia 2016 Volume 44, Issue 15, Pages 73–84

Mesoporous bioactive glass-polycaprolactone (MBG-PCL) scaffolds have been prepared by robocasting, a layer by layer rapid prototyping method, by stacking of individual strati. Each stratus was independently analyzed during the cell culture tests with MC3T3-E1 preosteblast-like cells. The presence of MBG stimulates the colonization of the scaffolds by increasing the cell proliferation and differentiation. MBG-PCL composites not only enhanced pre-osteoblast functions but also allowed cell movement along its surface, reaching the upper stratus faster than in pure PCL scaffolds. The cells behavior on each individual stratus revealed that the scaffolds colonization depends on the chemical stimuli supplied by the MBG dissolution…

Multi‐and mixed 3D‐printing of graphene‐hydroxyapatite hybrid materials for complex tissue engineering

Journal of Biomedical Materials Research Part A 2016 Volume 105, Issue 1, Pages 274–283

With the emergence of 3D-printing (3DP) as a vital tool in tissue engineering and medicine, there is an ever growing need to develop new biomaterials that can be 3D-printed and also emulate the compositional, structural, and functional complexities of human tissues and organs. In this work, we probe the 3D-printable biomaterials spectrum by combining two recently established functional 3D-printable particle-laden biomaterial inks: one that contains hydroxyapatite microspheres (Hyperelastic Bone, HB) and another that contains graphene nanoflakes (3D-Graphene, 3DG). We demonstrate that not only can these distinct, osteogenic and neurogenic inks be co-3D-printed to create complex, multi-material constructs, but that composite…

A new printable and durable N,O-carboxymethyl chitosan–Ca2+–polyphosphate complex with morphogenetic activity

Journal of Materials Chemistry B 2015 Volume 3, Issue 8, Pages 1722-1730

Biomimetic materials have been gaining increasing importance in tissue engineering since they may provide regenerative alternatives to the use of autologous tissues for transplantation. In the present study, we applied for bioprinting of a functionalized three-dimensional template, N,O-carboxymethyl chitosan (N,O-CMC), mimicking the physiological extracellular matrix. This polymer, widely used in tissue engineering, has been provided with functional activity by integration of polyphosphate (polyP), an osteogenically acting natural polymer. The two polymers, N,O-CMC and polyP, are linked together via Ca2+ bridges. This N,O-CMC + polyP material was proven to be printable and durable. The N,O-CMC + polyP printed layers and tissue…

3D fibre deposition and stereolithography techniques for the design of multifunctional nanocomposite magnetic scaffolds

Journal of Materials Science: Materials in Medicine 2015 Volume 26, Issue 250, Pages 250ff

Magnetic nanocomposite scaffolds based on poly(ε-caprolactone) and poly(ethylene glycol) were fabricated by 3D fibre deposition modelling (FDM) and stereolithography techniques. In addition, hybrid coaxial and bilayer magnetic scaffolds were produced by combining such techniques. The aim of the current research was to analyse some structural and functional features of 3D magnetic scaffolds obtained by the 3D fibre deposition technique and by stereolithography as well as features of multimaterial scaffolds in the form of coaxial and bilayer structures obtained by the proper integration of such methods. The compressive mechanical behaviour of these scaffolds was investigated in a wet environment at 37…

3D-printed hierarchical scaffold for localized isoniazid/rifampin drug delivery and osteoarticular tuberculosis therapy

Acta Biomaterialia 2015 Volume 16, Pages 145–155

After surgical treatment of osteoarticular tuberculosis (TB), it is necessary to fill the surgical defect with an implant, which combines the merits of osseous regeneration and local multi-drug therapy so as to avoid drug resistance and side effects. In this study, a 3D-printed macro/meso-porous composite scaffold is fabricated. High dosages of isoniazid (INH)/rifampin (RFP) anti-TB drugs are loaded into chemically modified mesoporous bioactive ceramics in advance, which are then bound with poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) through a 3D printing procedure. The composite scaffolds show greatly prolonged drug release time compared to commercial calcium phosphate scaffolds either in vitro or in vivo….

Three-dimensional printed strontium-containing mesoporous bioactive glass scaffolds for repairing rat critical-sized calvarial defects

Acta Biomaterialia 2015 Volume 12, Pages 270–280

The development of a new generation of biomaterials with high osteogenic ability for fast osseointegration with host bone is being intensively investigated. In this study, we have fabricated three-dimensional (3-D) strontium-containing mesoporous bioactive glass (Sr-MBG) scaffolds by a 3-D printing technique. Sr-MBG scaffolds showed uniform interconnected macropores (∼400 μm), high porosity (∼70%) and enhanced compressive strength (8.67 ± 1.74 MPa). Using MBG scaffolds as a control, the biological properties of Sr-MBG scaffolds were evaluated by apatite-forming ability, adhesion, proliferation, alkaline phosphatase activity and osteogenic gene expression of osteoblast-like cells MC3T3-E1. Furthermore, Sr-MBG scaffolds were used to repair critical-sized rat calvarial…

The preliminary performance study of the 3D printing of a tricalcium phosphate scaffold for the loading of sustained release anti-tuberculosis drugs

Journal of Materials Science 2015 Volume 50, Issue 5, Pages 2138-2147

In the surgical treatment of tuberculosis of the bones, excision of the lesion site leaves defects in the bone structure. Recent research has shown benefits for bone tissue support, such as tricalcium phosphate, as regrowth materials. These biocompatible engineering materials have good bone inductivity and biologic mechanical performance. The goal of this study was to evaluate the use of 3D printing, a new technology, to design and build 3-dimensional support structures for use in grafting at lesion sites and for use in embedding the sustained release anti-tuberculosis drugs Rifampin and Isoniazid and determine the in vivo performance of these structures….

Glasses in bone regeneration: A multiscale issue

Journal of Non-Crystalline Solids 2015 Volume 432, Part A, Pages 9–14

3D scaffolds based in mesoporous bioactive glasses (MBGs) are being widely investigated to use in bone tissue engineering (TE) applications. These scaffolds are often obtained by rapid prototyping (RP) and exhibit an array of interconnected pores in a hierarchy of sizes. The ordered mesopore network (around 4 nm in diameter) is optimal for the adsorption and release of bone inductor biomolecules, and the arrangement of macropores over 100 μm facilitates the bone cell ingrowths and angiogenesis. Nevertheless MBG composition can be varied almost infinitely at the atomic scale by including in the glass network oxides of inorganic elements with a…

Fabrication of novel Si-doped Hydroxyapatite/Gelatine scaffolds by rapid prototyping for drug delivery and bone regeneration

Acta Biomaterialia 2015 Volume 15, Pages 200–209

Porous 3-D scaffolds consisting of gelatine and Si-doped hydroxyapatite were fabricated at room temperature by rapid prototyping. Microscopic characterization revealed a highly homogeneous structure, showing the pre-designed porosity (macroporosity) and a lesser in-rod porosity (microporosity). The mechanical properties of such scaffolds are close to those of trabecular bone of the same density. The biological behavior of these hybrid scaffolds is greater than that of pure ceramic scaffolds without gelatine, increasing pre-osteoblastic MC3T3-E1 cell differentiation (matrix mineralization and gene expression). Since the fabrication process of these structures was carried out at mild conditions, an antibiotic (vancomycin) was incorporated in the slurry…

3D-printed dimethyloxallyl glycine delivery scaffolds to improve angiogenesis and osteogenesis

Biomaterials Science 2015 Voulme 3, Issue 8, Pages 1236-1244

Angiogenesis–osteogenesis coupling processes are vital in bone tissue engineering. Normal biomaterials implanted in bone defects have issues in the sufficient formation of blood vessels, especially in the central part. Single delivery of vascular endothelial growth factors (VEGF) to foci in previous studies did not show satisfactory results due to low loading doses, a short protein half-life and low efficiency. Development of a hypoxia-mimicking microenvironment for cells by local prolyl-4-hydroxylase inhibitor release, which can stabilize hypoxia-inducible factor 1α (HIF-1α) expression, is an alternative method. The aim of this study was to design a dimethyloxallyl glycine (DMOG) delivering scaffold composed of mesoporous…

Three-dimensionally plotted MBG/PHBHHx composite scaffold for antitubercular drug delivery and tissue regeneration

Journal of Materials Science: Materials in Medicine 2015 Volume 26, Issue 102, 102ff

A suitable drug-loaded scaffold that can postoperatively release an antituberculosis drug efficiently in a lesion area and help repair a bone defect is very important in the clinical treatment of bone tuberculosis (TB). In this study, a composite drug-loaded cylindrical scaffold was prepared by using three-dimensional printing technology in combination with the mesoporous confinement range, surface chemical groups, and gradual degradation of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate). This achieves the slow release of a drug for as long as possible. We implanted the drug-loaded compound scaffold into New Zealand rabbits’ femur defect model to study the in vivo drug release performance and osteogenic ability….

Hyperthermia Induced in Magnetic Scaffolds for Bone Tissue Engineering

IEEE Transactions on Magnetics 2014 Volume 50, Issue 11, Pages 1-7

The design and fabrication of advanced biocompatible and bioresorbable materials able to mimic the natural tissues present in the human body constitutes an important challenge in regenerative medicine. The size-dependent properties that materials exhibit at the nanoscale as a consequence of their higher surface-to-volume ratio have opened a wide range of opportunities for applications in almost every imaginable field. In this regard, the incorporation of magnetic nanoparticles (MNPs) into biocompatible scaffold formulations provides final materials with additional multifunctionality and reinforced mechanical properties for bone tissue engineering applications. In addition to the biological implications due to their magnetic character (i.e., magnetic…

3D-Printed Magnetic Fe3O4/MBG/PCL Composite Scaffolds with Multifunctionality of Bone Regeneration, Local Anticancer Drug Delivery and Hyperthermia

Journal of Materials Chemistry B 2014 Volume 2, Issue 43, Pages 7583-7595

In this study, three-dimensional (3D) magnetic Fe3O4 nanoparticles containing mesoporous bioactive glass/polycaprolactone (Fe3O4/MBG/PCL) composite scaffolds have been fabricated by the 3D-printing technique. The physiochemical properties, in vitro bioactivity, anticancer drug delivery, mechanical strength, magnetic heating ability and cell response of Fe3O4/MBG/PCL scaffolds were systematically investigated. The results showed that Fe3O4/MBG/PCL scaffolds had uniform macropores of 400 μm, high porosity of 60% and excellent compressive strength of 13–16 MPa. The incorporation of magnetic Fe3O4 nanoparticles into MBG/PCL scaffolds did not influence their apatite mineralization ability but endowed excellent magnetic heating ability and significantly stimulated proliferation, alkaline phosphatase (ALP) activity, osteogenesis-related gene…

Accelerating the early angiogenesis of tissue engineering constructs in vivo by the use of stem cells cultured in matrigel

Journal of Biomedical Materials Research Part A 2014 Volume 102, Issue 6, Pages 1652–1662

In tissue engineering research, generating constructs with an adequate extent of clinical applications remains a major challenge. In this context, rapid blood vessel ingrowth in the transplanted tissue engineering constructs is the key factor for successful incorporation. To accelerate the microvascular development in engineered tissues, we preincubated osteoblast-like cells as well as mesenchymal stem cells or a combination of both cell types in Matrigel-filled PLGA scaffolds before transplantation into the dorsal skinfold chambers of balb/c mice. By the use of preincubated mesenchymal stem cells, a significantly accelerated angiogenesis was achieved. Compared with previous studies that showed a decisive increase of…

Biocalcite, a multifunctional inorganic polymer: Building block for calcareous sponge spicules and bioseed for the synthesis of calcium phosphate-based bone

Beilstein Journal of Nanotechnology 2014 Volume 5, Pages 610–621

Calcium carbonate is the material that builds up the spicules of the calcareous sponges. Recent results revealed that the calcium carbonate/biocalcite-based spicular skeleton of these animals is formed through an enzymatic mechanism, such as the skeleton of the siliceous sponges, evolutionarily the oldest animals that consist of biosilica. The enzyme that mediates the calcium carbonate deposition has been identified as a carbonic anhydrase (CA) and has been cloned from the calcareous sponge species Sycon raphanus. Calcium carbonate deposits are also found in vertebrate bones besides the main constituent, calcium phosphate/hydroxyapatite (HA). Evidence has been presented that during the initial phase…

Effect of Bioglass on Growth and Biomineralization of SaOS-2 Cells in Hydrogel after 3D Cell Bioprinting

PloS One 2014 Volume 9, Issue 11, Article e112497

We investigated the effect of bioglass (bioactive glass) on growth and mineralization of bone-related SaOS-2 cells, encapsulated into a printable and biodegradable alginate/gelatine hydrogel. The hydrogel was supplemented either with polyphosphate (polyP), administered as polyP•Ca2+-complex, or silica, or as biosilica that had been enzymatically prepared from ortho-silicate by silicatein. These hydrogels, together with SaOS-2 cells, were bioprinted to computer-designed scaffolds. The results revealed that bioglass (nano)particles, with a size of 55 nm and a molar ratio of SiO2∶CaO∶P2O5 of 55∶40∶5, did not affect the growth of the encapsulated cells. If silica, biosilica, or polyP•Ca2+-complex is co-added to the cell-containing alginate/gelatin…

Three-dimensional printing of strontium-containing mesoporous bioactive glass scaffolds for bone regeneration

Acta Biomaterialia 2014 Volume 10, Issue 5, Pages 2269–2281

In this study, we fabricated strontium-containing mesoporous bioactive glass (Sr-MBG) scaffolds with controlled architecture and enhanced mechanical strength using a three-dimensional (3-D) printing technique. The study showed that Sr-MBG scaffolds had uniform interconnected macropores and high porosity, and their compressive strength was ∼170 times that of polyurethane foam templated MBG scaffolds. The physicochemical and biological properties of Sr-MBG scaffolds were evaluated by ion dissolution, apatite-forming ability and proliferation, alkaline phosphatase activity, osteogenic expression and extracelluar matrix mineralization of osteoblast-like cells MC3T3-E1. The results showed that Sr-MBG scaffolds exhibited a slower ion dissolution rate and more significant potential to stabilize the…

Additive effect of mesenchymal stem cells and VEGF to vascularization of PLGA scaffolds

Microvascular Research 2013 Volume 90, Pages 71–79

Bone marrow derived mesenchymal stem cells (bmMSCs) are widely used for the generation of tissue engineering constructs, since they can differentiate into different cell types occurring in bone tissues. Until now their use for the generation of tissue engineering constructs is limited. All cells inside a tissue engineering construct die within a short period of time after implantation of the construct because vascularization and establishment of connections to the recipient circulatory system is a time consuming process. We therefore compared the influences of bmMSC, VEGF and a combination of both on the early processes of vascularization, utilizing the mice skinfold…

Combining technologies to create bioactive hybrid scaffolds for bone tissue engineering

Biomatter 2013 Volume 3, Issue 2, e23705

Combining technologies to engineer scaffolds that can offer physical and chemical cues to cells is an attractive approach in tissue engineering and regenerative medicine. In this study, we have fabricated polymer-ceramic hybrid scaffolds for bone regeneration by combining rapid prototyping (RP), electrospinning (ESP) and a biomimetic coating method in order to provide mechanical support and a physico-chemical environment mimicking both the organic and inorganic phases of bone extracellular matrix (ECM). Poly(ethylene oxide terephthalate)-poly(buthylene terephthalate) (PEOT/PBT) block copolymer was used to produce three dimensional scaffolds by combining 3D fiber (3DF) deposition, and ESP, and these constructs were then coated with a…

Advanced composites for hard-tissue engineering based on PCL/organic–inorganic hybrid fillers: From the design of 2D substrates to 3D rapid prototyped scaffolds

Polymer Composites 2013 Volume 34, Issue 9, Pages 1413–1417

The bioactivity of sol–gel synthesized poly(ε-caprolactone) (PCL)/TiO2 or poly(ε-caprolactone)/ZrO2 particles was already known. In designing innovative 2D composite substrates for hard-tissue engineering, the possibility to embed PCL/TiO2 or PCL/ZrO2 hybrid fillers into a PCL matrix was previously proposed. In the present study, the potential of 3D fiber-deposition technique to design morphologically controlled scaffolds consisting of PCL reinforced with PCL/TiO2 or PCL/ZrO2 hybrid fillers was demonstrated. Finite element analysis was initially carried out on 2D substrates to find a correlation between the previously obtained results from the small punch test and the Young’s modulus of the materials, whilst mechanical and biological…

Physiologic load-bearing characteristics of autografts, allografts, and polymer-based scaffolds in a critical sized segmental defect of long bone: an experimental study

International Journal of Nanomedicine 2013 Volume 8, Pages 1637-1643

Background To address the challenge of treating critical sized intercalary defects, we hypothesized that under physiologic cyclic loading, autografts, allografts, and scaffolds loaded with and without human mesenchymal stem cells (hMSCs) would have different biomechanical characteristics. Methods Using a rat femoral defect model, 46 rats were assigned to four groups, ie, autograft (n = 12), allograft (n = 10), scaffold (n = 13), and scaffold with hMSCs (n = 11). The scaffold groups used a 5 mm segment of scaffold composed of 80% poly-ε-caprolactone and 20% hydroxyapatite. Rats were sacrificed 4 months postoperatively, and the repairs were assessed radiographically and…

Monolithic and assembled polymer–ceramic composites for bone regeneration

Acta Biomaterialia 2013 Volume 9, Issue 3, Pages 5708–5717

The rationale for the use of polymer–ceramic composites for bone regeneration stems from the natural composition of bone, with collagen type I and biological apatite as the main organic and inorganic constituents, respectively. In the present study composite materials of PolyActive™ (PA), a poly(ethylene oxide terephthalate)/poly(butylene terephtalate) co-polymer, and hydroxyapatite (HA) at a weight ratio of 85:15 were prepared by rapid prototyping (RP) using two routes. In the first approach pre-extruded composite filaments of PA–HA were processed using three-dimensional fibre deposition (3DF) (conventional composite scaffolds). In the second approach PA scaffolds were fabricated using 3DF and combined with HA pillars…

Poly(ester-urethane) scaffolds: effect of structure on properties and osteogenic activity of stem cells

Journal of Tissue Engineering and Regenerative Medicine 2013 Volume 9, Issue 8, Pages 930–942

The present study aimed to investigate the effect of structure (design and porosity) on the matrix stiffness and osteogenic activity of stem cells cultured on poly(ester-urethane) (PEU) scaffolds. Different three-dimensional (3D) forms of scaffold were prepared from lysine-based PEU using traditional salt-leaching and advanced bioplotting techniques. The resulting scaffolds were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), mercury porosimetry and mechanical testing. The scaffolds had various pore sizes with different designs, and all were thermally stable up to 300 °C. In vitro tests, carried out using rat bone marrow stem cells (BMSCs) for bone tissue…

Systematic analysis of injectable materials and 3D rapid prototyped magnetic scaffolds: from CNS applications to soft and hard tissue repair/regeneration

Procedia Engineering 2013 Volume 59, Pages 233–239

Over the past years, polymer-based materials have attracted research interest in the field of tissue repair and regeneration. As reported in literature, different injectable systems have been proposed, trying to reduce surgical invasiveness. In a first step of the current research, the rheological and functional features of injecatble hydrogel-based materials for central nervous system applications or soft tissue regeneration (collagen/PEG semi-IPNs) as well as for hard tissue engineering (alginate/iron-doped hydroxyapatite) were evaluated. Then, the study was also devoted to the development of 3D nanocomposite poly(ɛ- caprolactone)/iron-doped hydroxyapatite scaffolds for bone tissue engineering, providing a preliminary approach to assess magnetic attraction…

Benefits of Spine Stabilization with Biodegradable Scaffolds in Spinal Cord Injured Rats

Tissue Engineering Part C: Methods 2013 Volume 19, Issue 2, 101-108

Spine stabilization upon spinal cord injury (SCI) is a standard procedure in clinical practice, but rarely employed in experimental models. Moreover, the application of biodegradable biomaterials for this would come as an advantage as it would eliminate the presence of a nondegradable prosthesis within the vertebral bone. Therefore, in the present work, we propose the use of a new biodegradable device specifically developed for spine stabilization in a rat model of SCI. A 3D scaffold based on a blend of starch with polycaprolactone was implanted, replacing delaminated vertebra, in male Wistar rats with a T8-T9 spinal hemisection. The impact of…

Hierarchical Fibrillar Scaffolds Obtained by Non-conventional Layer-By-Layer Electrostatic Self-Assembly

Advanced Healthcare Materials 2013 Volume 2, Issue 3, pages 422–427

A new application of layer-by-layer assembly is presented, able to create nano/micro fibrils or nanocoatings inside 3D scaffolds using non-fibrillar polyelectrolytes for tissue-engineering applications. This approach shows promise for developing advanced scaffolds with controlled nano/micro environments, and nature and architectures similar to the natural extracellular matrix, leading to improved biological performance.

Design and preparation of biocompatible zwitterionic hydroxyapatite

Journal of Materials Chemistry B 2013 Volume 11, Issue 1, Pages 1595-1606

This study reports the design and preparation of zwitterionic nanocrystalline hydroxyapatite (HA) capable of inhibiting bacterial adhesion while allowing osteoblast cell colonization. The surface functionalization of HA powders was carried out by post-synthesis grafting of 3-aminopropyltriethoxysilane (APTES) and carboxyethylsilanetriol sodium salt (CES) as amine and carboxylate precursors, respectively. The successful functionalization of HA surfaces was assessed by elemental chemical analysis, FTIR, 29Si, 31P and 13C solid state CP/MAS NMR and ζ-potential measurements, and the zwitterionic nature of the synthesized HA was proved through the presence of –NH3+/–COO− pairs on the material surfaces. With the aim of evaluating the feasibility of…

Mesoporous bioactive scaffolds prepared with cerium-, gallium- and zinc-containing glasses

Acta Biomaterialia 2013 Volume 9, Issue 1, Pages 4836–4844

Mesoporous bioactive glass scaffolds (MBG_Scs), based on 80% SiO2–15% CaO–5% P2O5 (in mol.%) mesoporous sol–gel glasses substituted with Ce2O3, Ga2O3 (both 0.2% or 1.0%) and ZnO (0.4% or 2.0%), were synthesized by combination of evaporation-induced self-assembly and rapid prototyping techniques. Cerium, gallium and zinc trace elements were selected because of their inherent beneficial biological properties. Fabricated scaffolds were characterized and compared with unsubstituted scaffold (B_Sc). All of them contained well interconnected ultralarge pores (pores >400 μm) ideal for vascular ingrowth and proliferation of cells. Macropores of size 100–400 μm were present inside the scaffolds. In addition, low-angle X-ray diffraction showed…

An in vivo study on the effect of scaffold geometry and growth factor release on the healing of bone defects

Journal of Tissue Engineering and Regenerative Medicine 2013 Volume 7, Issue 9, Pages 687–696

The hypothesis of this study was that the extent of bone regeneration could be enhanced by using scaffolds with appropriate geometry, and that such an effect could be further increased by mimicking the natural timing of appearance of bone morphogenetic proteins BMP-2 and BMP-7 after fracture. Bioplotted poly(ε-caprolactone) (PCL) disks with four different fibre organizations were used to study the effect of 3D scaffold architecture on the healing of bone defects in a rat pelvis model. Moreover, one PCL construct was further modified by introducing a nanoparticulate sequential BMP-2/BMP-7 delivery system into this scaffold. Scaffolds and functionalized construct along with…

In‐vivo behavior of Si‐hydroxyapatite/polycaprolactone/DMB scaffolds fabricated by 3D printing

Journal of Biomedical Materials Research Part A 2013 Volume 101A, Issue 7, Pages 2038–2048

Scaffolds made of polycaprolactone and nanocrystalline silicon-substituted hydroxyapatite have been fabricated by 3D printing rapid prototyping technique. To asses that the scaffolds fulfill the requirements to be considered for bone grafting applications, they were implanted in New Zealand rabbits. Histological and radiological studies have demonstrated that the scaffolds implanted in bone exhibited an excellent osteointegration without the interposition of fibrous tissue between bone and implants and without immune response after 4 months of implantation. In addition, we have evaluated the possibility of improving the scaffolds efficiency by incorporating demineralized bone matrix during the preparation by 3D printing. When demineralized bone…

A biomimetic growth factor delivery strategy for enhanced regeneration of iliac crest defects

Biomedical Materials 2013 Volume 8, Number 4, 045009

The importance of provision of growth factors in the engineering of tissues has long been shown to control the behavior of the cells within the construct and several approaches were applied toward this end. In nature, more than one type of growth factor is known to be effective during the healing of tissue defects and their peak concentrations are not always simultaneous. One of the most recent strategies includes the delivery of a combination of growth factors with the dose and timing to mimic the natural regeneration cascade. The sequential delivery of bone morphogenetic proteins BMP-2 and BMP-7 which are…

Peripheral mineralization of a 3D biodegradable tubular construct as a way to enhance guidance stabilization in spinal cord injury regeneration

Journal of Materials Science: Materials in Medicine 2012 Volume 23, Issue 11, Pages 2821-2830

Spinal cord injuries (SCI) present a major challenge to therapeutic development due to its complexity. Combinatorial approaches using biodegradable polymers that can simultaneously provide a tissue scaffold, a cell vehicle, and a reservoir for sustained drug delivery have shown very promising results. In our previous studies we have developed a novel hybrid system consisting of starch/poly-e-caprolactone (SPCL) semi-rigid tubular porous structure, based on a rapid prototyping technology, filled by a gellan gum hydrogel concentric core for the regeneration within spinal-cord injury sites. In the present work we intend to promote enhanced osteointegration on these systems by pre-mineralizing specifically the external…

Degradable amorphous scaffolds with enhanced mechanical properties and homogeneous cell distribution produced by a three‐dimensional fiber deposition method

Journal of Biomedical Materials Research Part A 2012 Volume 100A, Issue 10, Pages 2739-2749

The mechanical properties of amorphous, degradable, and highly porous poly(lactide-co-caprolactone) structures have been improved by using a 3D fiber deposition (3DF) method. Two designs of 3DF scaffolds, with 45° and 90° layer rotation, were printed and compared with scaffolds produced by a salt-leaching method. The scaffolds had a porosity range from 64% to 82% and a high interconnectivity, measured by micro-computer tomography. The 3DF scaffolds had 8–9 times higher compressive stiffness and 3–5 times higher tensile stiffness than the salt-leached scaffolds. There was a distinct decrease in the molecular weight during printing as a consequence of the high temperature. The…

Three-Dimensional Poly(ε-caprolactone) Bioactive Scaffolds with Controlled Structural and Surface Properties

Biomacromolecules 2012 Volume 13, Issue 11, Pages 3510-3521

The requirement of a multifunctional scaffold for tissue engineering capable to offer at the same time tunable structural properties and bioactive interface is still unpaired. Here we present three-dimensional (3D) biodegradable polymeric (PCL) scaffolds with controlled morphology, macro-, micro-, and nano-mechanical performances endowed with bioactive moieties (RGD peptides) at the surface. Such result was obtained by a combination of rapid prototyping (e.g., 3D fiber deposition) and surface treatment approach (aminolysis followed by peptide coupling). By properly designing process conditions, a control over the mechanical and biological performances of the structure was achieved with a capability to tune the value of…

A route toward the development of 3D magnetic scaffolds with tailored mechanical and morphological properties for hard tissue regeneration: Preliminary study

Virtual and Physical Prototyping 2011 Volume 6, Issue 4, Pages 189-195

A basic approach toward the design of three-dimensional (3D) rapid prototyped magnetic scaffolds for hard-tissue regeneration has been proposed. In particular, 3D scaffolds consisting of a poly(ε-caprolactone) (PCL) matrix and iron oxide (Fe3O4) or iron-doped hydroxyapatite (FeHA) nanoparticles were fabricated through a 3D fibre deposition technique. As a first approach, a polymer to nanoparticle weight ratio of 90/10 (wt/wt) was used. The effect of the inclusion of both kinds of nanoparticles on the mechanical, magnetic, and biological performances of the scaffolds was studied. The inclusion of Fe3O4 and FeHA nanoparticles generally improves the modulus and the yield stress of the…

A basic approach toward the development of nanocomposite magnetic scaffolds for advanced bone tissue engineering

Jounal of Applied Polymer Science 2011 Volume 122, Issue 6, Pages 3599-3605

Magnetic scaffolds for bone tissue engineering based on a poly(ε-caprolactone) (PCL) matrix and iron oxide (Fe3O4) magnetic nanoparticles were designed and developed through a three-dimensional (3D) fiber-deposition technique. PCL/Fe3O4 scaffolds were characterized by a 90/10 w/w composition. Tensile and magnetic measurements were carried out, and nondestructive 3D imaging was performed through microcomputed tomography (Micro-CT). Furthermore, confocal analysis was undertaken to investigate human mesenchymal stem cell adhesion and spreading on the PCL/Fe3O4 nanocomposite fibers. The results suggest that nanoparticles mechanically reinforced the PCL matrix; the elastic modulus and the maximum stress increased about 10 and 30%, respectively. However, the maximum strain…

Comparably accelerated vascularization by preincorporation of aortic fragments and mesenchymal stem cells in implanted tissue engineering constructs

Journal of Biomedical Materials Research Part A 2011 Volume 97A, Issue 4, Pages 383-394

The demanding need for tissue replacement resulted in manifold approaches for the construction of different tissues. One common problem which hampers the clinical usage of tissue engineering constructs is a limited vascularization. In an attempt to accelerate the vascularization of tissue engineering constructs we compared the usage of bone marrow mesenchymal stem cells (bmMSCs) and fragments derived from the aorta in vivo. Tissue engineering constructs composed of PLGA scaffolds containing Matrigel (n = 8), aortic fragments embedded in Matrigel (n = 8), bmMSCs embedded in Matrigel (n = 8), and aortic fragments embedded in Matrigel combined with bmMSCs (n =…

Calvaria bone chamber-A new model for intravital assessment of osseous angiogenesis

Journal of Biomedical Materials Research Part A 2011 Volume 99A, Issue 2, pages 151-157

The faith of tissue engineered bone replacing constructs depends on their early supply with oxygen and nutrients, and thus on a rapid vascularization. Although some models for direct observation of angiogenesis are described, none of them allows the observation of new vessel formation in desmal bone. Therefore, we developed a new chamber model suitable for quantitative in vivo assessment of the vascularization of bone substitutes by intravital fluorescence microscopy. In the parietal calvaria of 32 balb/c mice a critical size defect was set. Porous 3D-poly(L-lactide-co-glycolide) (PLGA)-blocks were inserted into 16 osseous defects (groups 3 and 4) while other 16 osseous…

A Novel Approach for Studying Microcirculation in Bone Defects by Intravital Fluorescence Microscopy

Tissue Engineering Part C: Methods 2011 Volume 17, Issue 12, Pages 1151-1159

Angiogenic and inflammatory responses to biodegradable scaffolds were previously studied using the dorsal skinfold chamber for testing different scaffold materials. In this model, the angiogenic response originates from the soft tissue of the skin. Herein, we introduce a new model that allows the study of developing microcirculation of bone defects for testing tissue-engineered constructs. A bone defect was prepared in the femur of Balb/c mice by inserting a pin for intramedullary fixation, and a custom-made observation window fixed over the defect allowed constant observation. This study included three different groups: empty defect (control), defect filled with porous poly(l-lactide-co-glycolide), and beta-tricalcium-phosphate…

Three-dimensional plotted scaffolds with controlled pore size gradients: Effect of scaffold geometry on mechanical performance and cell seeding efficiency

Acta Biomaterialia 2011 Volume 7, Issue 3, Pages 1009-1018

Scaffolds produced by rapid prototyping (RP) techniques have proved their value for tissue engineering applications, due to their ability to produce predetermined forms and structures featuring fully interconnected pore architectures. Nevertheless, low cell seeding efficiency and non-uniform distribution of cells remain major limitations when using such types of scaffold. This can be mainly attributed to the inadequate pore architecture of scaffolds produced by RP and the limited efficiency of cell seeding techniques normally adopted. In this study we aimed at producing scaffolds with pore size gradients to enhance cell seeding efficiency and control the spatial organization of cells within the…

Comparison of the osteoblastic activity conferred on Si-doped hydroxyapatite scaffolds by different osteostatin coatings

Acta Biomaterialia 2011 Volume 7, Issue 10, Pages 3555-3562

Parathyroid hormone-related protein (107-111) (osteostatin) induces osteogenic effects in osteoblasts in vitro and in regenerating bone in mice and rabbits. In this study we used osteoblastic MC3T3-E1 cell cultures to evaluate and compare the bioactivity of this peptide either adsorbed or covalently bound (by its C-terminus) to Si-doped hydroxyapatite (Si-HA) scaffolds after organic (-NH2) functionalization. By these means osteostatin can be locally released or kept anchored to the scaffold surface. This was confirmed by chemical analysis and by testing the efficiency of osteostatin-loaded Si-HA scaffolds (placed in Transwell chambers) in healing a scratch wound in mouse pluripotent mesenchymal C3H10T1/2 cells….

Preparation of 3-D scaffolds in the SiO2–P2O5 system with tailored hierarchical meso-macroporosity

Acta Biomaterialia 2011 Volume 7, Issue 3, Pages 1265-1273

Herein we report for the first time the synthesis of three-dimensional scaffolds in the binary system SiO2–P2O5 exhibiting different scales of porosity: (i) highly ordered mesopores with diameters of ca. 4 nm; (ii) macropores with diameters in the 30–80 μm range with interconnections of ca. 2–4 and 8–9 μm; and (iii) ultra-large macropores of ca. 400 μm. The hierarchical porosity of the resulting scaffolds makes them suitable for bone tissue engineering applications. The chemical nature and mesoporosity of these matrices would allow these scaffolds to act as local controlled delivery systems of biologically active molecules, such as certain drugs to…

Comparison of bacterial adhesion and cellular proliferation on newly developed three-dimensional scaffolds manufactured by rapid prototyping technology

Journal of Biomedical Materials Research Part A 2011 Volume 98A, Issue 2, pages 303-311

Scaffolds used in the field of tissue engineering should facilitate the adherence, spreading, and ingrowth of cells as well as prevent microbial adherence. For the first time, this study simultaneously deals with microbial and tissue cell adhesion to rapid prototyping-produced 3D-scaffolds. The cell growth of human osteosarcoma cells (CAL-72) over a time period of 3-11 days were examined on three scaffolds (PLGA, PLLA, PLLA-TCP) and compared to the adhesion of salivary microorganisms and representative germs of the oral flora (Porphyromonas gingivalis, Prevotella nigrescens, Candida albicans, Enterococcus faecalis, Streptococcus mutans, and Streptococcus sanguinis). Scanning electron microscopy (SEM), cell proliferation measurements, and…

Prolongated Survival of Osteoblast-Like Cells on Biodegradable Scaffolds by Heat Shock Preconditioning

Tissue Engineering Part A 2011 Volume 17, Issue 15-16, Pages 1935-1943

The implantation of tissue-engineered constructs leads to hypoxic and physical stress to the seeded cells until they were reached by a functional microvascular system. Preconditioning of cells with heat shock induced heat shock proteins, which can support the cells to survive a subsequent episode of stress that would otherwise be lethal. Preconditioning of tissue-engineered constructs resulted in significantly higher number of surviving osteoblast-like cells (OLC). At the 6th and 10th day, angiogenic response was found comparative to poly(L-lactide-co-glycolide) (PLGA) scaffolds vitalized with either unconditioned or preconditioned OLC. However, they were significantly enhanced compared with the nonvitalized collagen-labeled PLGA scaffolds. This…

Immobilization and bioactivity evaluation of FGF-1 and FGF-2 on powdered silicon-doped hydroxyapatite and their scaffolds for bone tissue engineering

Journal of Materials Science: Materials in Medicine 2011 Volume 22, Issue 2, pp 405-416

Fibroblast growth factors (FGFs) are polypeptides that control the proliferation and differentiation of various cell types including osteoblasts. FGFs are also strong inducers of angiogenesis, necessary to obtain oxygen and nutrients during tissue repair. With the aim to incorporate these desirable FGF biological properties into bioceramics for bone repair, silicon substituted hydroxyapatites (Si-HA) were used as materials to immobilize bioactive FGF-1 and FGF-2. Thus, the binding of these growth factors to powdered Si-HA and Si-HA scaffolds was carried out efficiently in the present study and both FGFs maintained its biological activity on osteoblasts after its immobilization. The improvement of cell…

An approach in developing 3D fiber‐deposited magnetic scaffolds for tissue engineering

AIP Conference Proceedings 2010 1255, 420

Scaffolds should possess suitable properties to play their specific role. In this work, the potential of 3D fiber deposition technique to develop multifunctional and well‐defined magnetic poly(ε‐caprolactone)/iron oxide scaffolds has been highlighted, and the effect of iron oxide nanoparticles on the biological and mechanical performances has been assessed.