3D Bioplotter Research Papers

Displaying all papers from 2015 (29 results)

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…

Three Dimensional Printing of High-Content Graphene Scaffolds for Electronic and Biomedical Applications

ACS Nano 2015 Volume 9, Issue 4, Pages 4636–4648

The exceptional properties of graphene enable applications in electronics, optoelectronics, energy storage, and structural composites. Here we demonstrate a 3D printable graphene (3DG) composite consisting of majority graphene and minority polylactide-co-glycolide, a biocompatible elastomer, 3D-printed from a liquid ink. This ink can be utilized under ambient conditions via extrusion-based 3D printing to create graphene structures with features as small as 100 μm composed of as few as two layers (10 cm thick object). The resulting 3DG material is mechanically robust and flexible while retaining electrical conductivities greater than 800 S/m, an order of magnitude increase over previously reported 3D-printed carbon…

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….

Spatiotemporal proliferation of human stromal cells adjusts to nutrient availability and leads to stanniocalcin-1 expression in vitro and in vivo

Biomaterials 2015 Volume 61, Pages 190–202

Cells and tissues are intrinsically adapted to molecular gradients and use them to maintain or change their activity. The effect of such gradients is particularly important for cell populations that have an intrinsic capacity to differentiate into multiple cell lineages, such as bone marrow derived mesenchymal stromal cells (MSCs). Our results showed that nutrient gradients prompt the spatiotemporal organization of MSCs in 3D culture. Cells adapted to their 3D environment without significant cell death or cell differentiation. Kinetics data and whole-genome gene expression analysis suggest that a low proliferation activity phenotype predominates in stromal cells cultured in 3D, likely due…

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…

Characterization of Material–Process–Structure Interactions in the 3D Bioplotting of Polycaprolactone

3D Printing and Additive Manufacturing 2015 Volume 2, Issue 1, Pages 20-31

Three-dimensional (3D) bioplotting is a melt-extrusion-based additive manufacturing process used to fabricate 3D scaffolds for tissue engineering applications. This study investigates the relationship between material rheology, process parameters, and scaffold characteristics during 3D bioplotting of polycaprolactone (PCL). The effects of two process parameters, extrusion temperature and nozzle diameter, on resultant scaffold structure and compression strength were studied using design of experiments. PCL scaffolds designed for a 24-well culture plate (Ø 14 mm × 2 mm) were bioplotted in a 0°/90° laydown pattern at three levels of extrusion temperature (80°C, 90°C, and 100°C) and two levels of nozzle inner diameter (0.3 and 0.4 mm) at…


Fabrication of Force Sensor Circuits on Wearable Conductive Textiles

Procedia Technology 2015 Volume 20, Pages 263–269

This paper discusses design and fabrication processes in the development of a wearable and flexible conductive resistive sensor. The design and development of the sensor involve the use of Sn-Ag-Cu (SAC)plated Nylon fabric, precisionfused deposition modeling(FDM) using silicone and petrolatum for etch-resistant masks using the EnvisionTEC GmbH Bioplotter, and wet etching using Chromium, Ammonium Persulphate, and Salt-Vinegar etching solutions. Preliminary testing with other mask types, development processes, and sensor design approaches for various applications are discussed.

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…

From nanoparticles to fibres: effect of dispersion composition on fibre properties

Journal of Nanoparticle Research 2015 Volume 17, Issue 237, Pages 237ff

A polyvinyl alcohol (PVA)-stabilized polypyrrole nanodispersion has been optimised for conductivity and processability by decreasing the quantity of PVA before and after synthesis. A reduction of PVA before synthesis leads to the formation of particles with a slight increase in dry particle diameter (51 ± 6 to 63 ± 3 nm), and conversely a reduced hydrodynamic diameter. Conductivity of the dried nanoparticle films was not measureable after a reduction of PVA prior to synthesis. Using filtration of particles after synthesis, PVA content was sufficiently reduced to achieve dried thin film conductivity of 2 S cm−1, while the electroactivity of the…

Decelerated vascularization in tissue-engineered constructs in association with diabetes mellitus in vivo

Journal of Diabetes and its Complications 2015 Volume 29, Issue 7, Pages 855–864

Aims Rapid blood vessel ingrowth in transplanted tissue engineering constructs is the key factor for successful incorporation, but many potential patients who may use engineered tissues suffer from widespread diseases that limit the capacity of neovascularization (e.g. diabetes). Thus, in vivo vascularization analyses of tissue-engineered constructs in angiogenically affected organisms are required. Methods We therefore investigated the in vivo incorporation of collagen-coated and cell-seeded poly-L-lactide-co-glycolide scaffolds in diabetic B6.BKS(D)-Leprdb/J mice using repetitive intravital fluorescence microscopy over a time period of two weeks. For this purpose, scaffolds were seeded with osteoblast-like or bone marrow mesenchymal stem cells and implanted into the…

Modular Small Diameter Vascular Grafts with Bioactive Functionalities

PloS One 2015 Volume 10, Issue 7, Article e0133632

We report the fabrication of a novel type of artificial small diameter blood vessels, termed biomimetic tissue-engineered blood vessels (bTEBV), with a modular composition. They are composed of a hydrogel scaffold consisting of two negatively charged natural polymers, alginate and a modified chitosan, N,O-carboxymethyl chitosan (N,O-CMC). Into this biologically inert scaffold two biofunctionally active biopolymers are embedded, inorganic polyphosphate (polyP) and silica, as well as gelatin which exposes the cell recognition signal, Arg-Gly-Asp (RGD). These materials can be hardened by exposure to Ca2+ through formation of Ca2+ bridges between the polyanions, alginate, N,O-CMC, and polyP (alginate-Ca2+-N,O-CMC-polyP). The bTEBV are formed…

Use of the polycation polyethyleneimine to improve the physical properties of alginate-hyaluronic acid hydrogel during fabrication of tissue repair scaffolds

Journal of Biomaterials Science, Polymer Edition 2015 Volume 26, Issue 7, Pages 433-445

Recently alginate-based tissue repair scaffolds fabricated using 3D printing techniques have been extensively examined for use in tissue engineering applications. However, their physical and mechanical properties are unfavorable for many tissue engineering applications because these properties are poorly controlled during the fabrication process. Some improvement of alginate gel properties can be realized by addition of hyaluronic acid (HA), and this may also improve the ability of cells to interact with the gel. Here, we report improvement of the physical properties of alginate–HA gel scaffolds by the addition of the polycation polyethyleneimine (PEI) during the fabrication process in order to stabilize…

A Multimaterial Bioink Method for 3D Printing Tunable, Cell-Compatible Hydrogels

Advanced Materials 2015 Volume 27, Issue 9, Pages 1607–1614

A multimaterial bio-ink method using polyethylene glycol crosslinking is presented for expanding the biomaterial palette required for 3D bioprinting of more mimetic and customizable tissue and organ constructs. Lightly crosslinked, soft hydrogels are produced from precursor solutions of various materials and 3D printed. Rheological and biological characterizations are presented, and the promise of this new bio-ink synthesis strategy is discussed.

A bio-friendly, green route to processable, biocompatible graphene/polymer composites

RSC Advances 2015 Volume 5, Issue 56, 45284-45290

Graphene-based polymer composites are a very promising class of compounds for tissue engineering scaffolds. However, in general the methods of synthesis are environmentally hazardous and residual toxic materials can affect the biocompatibility significantly. In this paper a simple, scalable, environmentally-friendly, microwave-assisted synthesis is described that results in conducting graphene/polycaprolactone composites that retain the processability and biocompatibility of the pristine polymer without introducing possibly hazardous reducing agents. Composites of polycaprolactone and graphene oxide were synthesised in a single step by the ring-opening polymerisation of ε-caprolactone in the presence of dispersed graphene oxide nanosheets under microwave irradiation. The graphene oxide provides 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…

Multiscale fabrication of biomimetic scaffolds for tympanic membrane tissue engineering

Biofabrication 2015 Volume 7, Number 2, Article 025005

The tympanic membrane (TM) is a thin tissue able to efficiently collect and transmit sound vibrations across the middle ear thanks to the particular orientation of its collagen fibers, radiate on one side and circular on the opposite side. Through the combination of advanced scaffolds and autologous cells, tissue engineering (TE) could offer valuable alternatives to autografting in major TM lesions. In this study, a multiscale approach based on electrospinning (ES) and additive manufacturing (AM) was investigated to fabricate scaffolds, based on FDA approved copolymers, resembling the anatomic features and collagen fiber arrangement of the human TM. A single scale…

Metallic Architectures from 3D‐Printed Powder‐Based Liquid Inks

Advanced Functional Materials 2015 Volume 25, Issue 45, Pages 6985–6995

A new method for complex metallic architecture fabrication is presented, through synthesis and 3D-printing of a new class of 3D-inks into green-body structures followed by thermochemical transformation into sintered metallic counterparts. Small and large volumes of metal-oxide, metal, and metal compound 3D-printable inks are synthesized through simple mixing of solvent, powder, and the biomedical elastomer, polylactic-co-glycolic acid (PLGA). These inks can be 3D-printed under ambient conditions via simple extrusion at speeds upwards of 150 mm s–1 into millimeter- and centimeter-scale thin, thick, high aspect ratio, hollow and enclosed, and multi-material architectures. The resulting 3D-printed green-bodies can be handled immediately, are…

The Application of Three-Dimensional Printing in Animal Model of Augmentation Rhinoplasty

Annals of Biomedical Engineering 2015 Volume 43, Issue 9, Pages 2153-2162

The role of three-dimensional (3D) printing has expanded in diverse areas in medicine. As plastic surgery needs to fulfill the different demands from diverse individuals, the applications of tailored 3D printing will become indispensable. In this study, we evaluated the feasibility of using 3D-printed polycaprolactone (PCL) scaffold seeded with fibrin/chondrocytes as a new dorsal augmentation material for rhinoplasty. The construct was surgically implanted on the nasal dorsum in the subperiosteal plane of six rabbits. The implants were harvested 4 and 12 weeks after implantation and evaluated by gross morphological assessment, radiographic imaging, and histologic examination. The initial shape of the…

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….

Dielectric spectroscopy for monitoring human pancreatic islet differentiation within cell-seeded scaffolds in a perfusion bioreactor system

Analyst 2015 Volume 140, Issue 18, Pages 6295-6305

The long-term in vitro culture and differentiation of human pancreatic islets is still hindered by the inability to emulate a suitable microenvironment mimicking physiological extracellular matrix (ECM) support and nutrient/oxygen perfusion. This is further amplified by the current lack of a non-invasive and rapid monitoring system to readily evaluate cellular processes. In this study, we realized a viable method for non-invasively monitoring isolated human pancreatic islets in vitro. Islets are induced to dedifferentiate into proliferative duct-like structures (DLS) in preparation for potential and subsequent re-differentiation into functional islet-like structures (ILS) in a process reminiscent of islet regeneration strategies. This long-term…

3D Printed Biocompatible Enclosures for an Implantable DBS Microdevice

Procedia Technology 2015 Volume 20, Pages 155–161

A number of methods have been used to make electronic medical microdevices biocompatible. This paper presents a novel approach for design and fabrication of biocompatible silicone enclosures for implantable medical microdevices. The approach involves design and formation of a 3D model of the enclosure using a computer-aided design software tool, followed by 3D printing of the enclosures using a bioplotter. Three different implantable enclosure designs are presented. The fabrication of the three enclosures is given. An evaluation of the suitability of the enclosures for implantation of a deep brain stimulation microdevice is discussed through submersion and operation tests. The evaluation…

Hierarchical polymeric scaffolds support the growth of MC3T3-E1 cells

Journal of Materials Science: Materials in Medicine 2015 Volume 26, Issue 116, Pages 116ff

Tissue engineering makes use of the principles of biology and engineering to sustain 3D cell growth and promote tissue repair and/or regeneration. In this study, macro/microporous scaffold architectures have been developed using a hybrid solid freeform fabrication/thermally induced phase separation (TIPS) technique. Poly(lactic-co-glycolic acid) (PLGA) dissolved in 1,4-dioxane was used to generate a microporous matrix by the TIPS method. The 3D-bioplotting technique was used to fabricate 3D macroporous constructs made of polyethylene glycol (PEG). Embedding the PEG constructs inside the PLGA solution prior to the TIPS process and subsequent extraction of PEG following solvent removal (1,4-dioaxane) resulted in a macro/microporous…

4D Printing with Mechanically Robust, Thermally Actuating Hydrogels

Macromolecular Rapid Communications 2015 Volume 36, Issue 12, Pages 1211–1217

A smart valve is created by 4D printing of hydrogels that are both mechanically robust and thermally actuating. The printed hydrogels are made up of an interpenetrating network of alginate and poly(N-isopropylacrylamide). 4D structures are created by printing the “dynamic” hydrogel ink alongside other static materials.

Characterization of Mechanical Properties of Tissue Scaffolds by Phase Contrast Imaging and Finite Element Modeling

Journal of Biomechanical Engineering 2015 Volume 137, Issue 8, Article 081004

In tissue engineering, the cell and scaffold approach has shown promise as a treatment to regenerate diseased and/or damaged tissue. In this treatment, an artificial construct (scaffold) is seeded with cells, which organize and proliferate into new tissue. The scaffold itself biodegrades with time, leaving behind only newly formed tissue. The degradation qualities of the scaffold are critical during the treatment period, since the change in the mechanical properties of the scaffold with time can influence cell behavior. To observe in time the scaffold’s mechanical properties, a straightforward method is to deform the scaffold and then characterize scaffold deflection accordingly….

PDMS Imaging

3D Bioprinting of Carboxymethylated-Periodate Oxidized Nanocellulose Constructs for Wound Dressing Applications

BioMed Research International 2015 Volume 2015, Article ID 925757

Nanocellulose has a variety of advantages, which make the material most suitable for use in biomedical devices such as wound dressings. The material is strong, allows for production of transparent films, provides a moist wound healing environment, and can form elastic gels with bioresponsive characteristics. In this study, we explore the application of nanocellulose as a bioink for modifying film surfaces by a bioprinting process. Two different nanocelluloses were used, prepared with TEMPO mediated oxidation and a combination of carboxymethylation and periodate oxidation. The combination of carboxymethylation and periodate oxidation produced a homogeneous material with short nanofibrils, having widths

Alginate Microspheroid Encapsulation and Delivery of MG-63 Cells Into Polycaprolactone Scaffolds: A New Biofabrication Approach for Tissue Engineering Constructs

Journal of Nanotechnology in Engineering and Medicine 2015 Volume 6, Issue 2, 021003

Scaffolds play an important role in tissue engineering by providing structural framework and a surface for cells to attach, proliferate, and secrete extracellular matrix (ECM). In order to enable efficient tissue formation, delivering sufficient cells into the scaffold three-dimensional (3D) matrix using traditional static and dynamic seeding methods continues to be a critical challenge. In this study, we investigate a new cell delivery approach utilizing deposition of hydrogel-cell encapsulated microspheroids into polycaprolactone (PCL) scaffolds to improve the seeding efficiency. Three-dimensional-bioplotted PCL constructs (0 deg/90 deg lay down, 284 ± 6 μm strand width, and 555 ± 8 μm strand separation) inoculated with MG-63 model bone cells encapsulated within…