3D Bioplotter Research Papers

Displaying all papers about Coating (Collagen) (16 results)

Angiogenic effects of mesenchymal stem cells in combination with different scaffold materials

Microvascular Research 2019

Tissue survival in regenerative tissue engineering requires rapid vascularization, which is influenced by scaffold material and seeded cell selection. Poly-l-lactide-co-glycolide (PLGA) and beta-tricalcium phosphate (β-TCP) are well-established biomaterials with angiogenic effects because of their material properties. Given the importance of the seeded cell type as a co-factor for vascularization, mesenchymal stem cells (MSCs) are known to have high angiogenic potential. We hypothesized that PLGA and β-TCP scaffolds seeded with MSCs would effectively induce a potent angiogenic response. Therefore, we studied the angiogenic effects after implanting PLGA and β-TCP scaffolds seeded with isogeneic MSCs in vivo. Fifty-six BALB/c mice were equally…

Achieving Molecular Orientation in Thermally Extruded 3D Printed Objects

Biofabrication 2019

3D printing is used to fabricate tissue scaffolds. The polymer chains in these objects are typically unoriented. The mechanical properties of these scaffolds can be significantly enhanced by proper alignment of the polymer chains. But, post-processing routes to increase orientation can be limited by the geometry of the printed object. Here we show that it is possible to orient the polymer chains during printing by optimizing the printing parameters to take advantage of the flow characteristics of the polymer. This is demonstrated by printing a polymeric scaffold for meniscus regeneration using poly(desaminotyrosyl-tyrosine dodecyl dodecanedioate), poly(DTD DD). Alignment of the polymer…

Extraction and characterization of collagen from Antarctic and Sub-Antarctic squid and its potential application in hybrid scaffolds for tissue engineering

Materials Science and Engineering: C 2017 Volume 78, 1 September 2017, Pages 787–795

Collagen is the most abundant protein found in mammals and it exhibits a low immunogenicity, high biocompatibility and biodegradability when compared with others natural polymers. For this reason, it has been explored for the development of biologically instructive biomaterials with applications for tissue substitution and regeneration. Marine origin collagen has been pursued as an alternative to the more common bovine and porcine origins. This study focused on squid (Teuthoidea: Cephalopoda), particularly the Antarctic squid Kondakovia longimana and the Sub-Antarctic squid Illex argentinus as potential collagen sources. In this study, collagen has been isolated from the skins of the squids using…

Pyrintegrin Induces Soft Tissue Formation by Transplanted or Endogenous Cells

Scientific Reports 2017 Issue 7, Article number: 36402

Focal adipose deficiency, such as lipoatrophy, lumpectomy or facial trauma, is a formidable challenge in reconstructive medicine, and yet scarcely investigated in experimental studies. Here, we report that Pyrintegrin (Ptn), a 2,4-disubstituted pyrimidine known to promote embryonic stem cells survival, is robustly adipogenic and induces postnatal adipose tissue formation in vivo of transplanted adipose stem/progenitor cells (ASCs) and recruited endogenous cells. In vitro, Ptn stimulated human adipose tissue derived ASCs to differentiate into lipid-laden adipocytes by upregulating peroxisome proliferator-activated receptor (PPARγ) and CCAAT/enhancer-binding protein-α (C/EBPα), with differentiated cells increasingly secreting adiponectin, leptin, glycerol and total triglycerides. Ptn-primed human ASCs seeded…

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…

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…

In situ forming collagen–hyaluronic acid membrane structures: mechanism of self-assembly and applications in regenerative medicine

Acta Biomaterialia 2013 Volume 9, Issue 2, Pages 5153–5161

Bioactive, in situ forming materials have the potential to complement minimally invasive surgical procedures and enhance tissue healing. For such biomaterials to be adopted in the clinic, they must be cost-effective, easily handled by the surgeon and have a history of biocompatibility. To this end, we report a novel and facile self-assembling strategy to create membranes and encapsulating structures using collagen and hyaluronic acid (HA). Unlike membranes built by layer-by-layer deposition of oppositely charged biomolecules, the collagen–HA membranes described here form a diffusion barrier upon electrostatic interaction of the oppositely charged biomolecules, which is further driven by osmotic pressure imbalances….

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…

Hierarchical scaffold design for mesenchymal stem cell-based gene therapy of hemophilia B

Biomaterials 2011 Volume 32, Issue 1, Pages 295-305

Gene therapy for hemophilia B and other hereditary plasma protein deficiencies showed great promise in pre-clinical and early clinical trials. However, safety concerns about in vivo delivery of viral vectors and poor post-transplant survival of ex vivo modified cells remain key hurdles for clinical translation of gene therapy. We here describe a 3D scaffold system based on porous hydroxyapatite-PLGA composites coated with biomineralized collagen 1. When combined with autologous gene-engineered factor IX (hFIX) positive mesenchymal stem cells (MSCs) and implanted in hemophilic mice, these scaffolds supported long-term engraftment and systemic protein delivery by MSCs in vivo. Optimization of the scaffolds…

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…

Accelerated Angiogenic Host Tissue Response to Poly(L-Lactide-co-Glycolide) Scaffolds by Vitalization with Osteoblast-like Cells

Tissue Engineering Part A 2010 Volume 16, Issue 7, Pages 2265-2279

Background: Bone substitutes should ideally promote rapid vascularization, which could be accelerated if these substitutes were vitalized by autologous cells. Although adequate engraftment of porous poly(L-lactide-co-glycolide) (PLGA) scaffolds has been demonstrated in the past, it has not yet been investigated how vascularization is influenced by vitalization or, more precisely, by seeding PLGA scaffolds with osteoblast-like cells (OLCs). For this reason, we conducted an in vivo study to assess host angiogenic and inflammatory responses after the implantation of PLGA scaffolds vitalized with isogeneic OLCs. Materials and Methods: OLCs were seeded on collagen-coated PLGA scaffolds that were implanted into dorsal skinfold chambers…

Effects of VEGF loading on scaffold-confined vascularization

Journal of Biomedical Materials Research Part A 2010 Volume 95A, Issue 3, Pages 783-792

Adequate vascularization of tissue-engineered constructs remains a major challenge in bone grafting. In view of this, we loaded ß-tricalcium-phosphate (ß-TCP) and porous poly(L-lactide-co-glycolide) (PLGA) scaffolds via collagen coating with vascular endothelial growth factor (VEGF) and studied whether the VEGF loading improves scaffold angiogenesis and vascularization. Dorsal skinfold chambers were implanted into 48 balb/c mice, which were assigned to 6 groups (n = 8 each). Uncoated (controls), collagen-coated, and additionally VEGF-loaded PLGA and ß-TCP scaffolds were inserted into the chambers. Angiogenesis, neovascularization, and leukocyte-endothelial cell interaction were analyzed repeatedly during a 14-day observation period using intravital fluorescence microscopy. Furthermore, VEGF release…

Regeneration of the articular surface of the rabbit synovial joint by cell homing: a proof of concept study

The Lancet 2010 Volume 376, Issue 9739, Pages 440-448

Background A common approach for tissue regeneration is cell delivery, for example by direct transplantation of stem or progenitor cells. An alternative, by recruitment of endogenous cells, needs experimental evidence. We tested the hypothesis that the articular surface of the synovial joint can regenerate with a biological cue spatially embedded in an anatomically correct bioscaffold. Methods In this proof of concept study, the surface morphology of a rabbit proximal humeral joint was captured with laser scanning and reconstructed by computer-aided design. We fabricated an anatomically correct bioscaffold using a composite of poly-ɛ-caprolactone and hydroxyapatite. The entire articular surface of unilateral…

Anatomically shaped tooth and periodontal regeneration by cell homing

Journal of Dental Research 2010 Volume 89, Issue 8, Pages 842-847

Tooth regeneration by cell delivery encounters translational hurdles. We hypothesized that anatomically correct teeth can regenerate in scaffolds without cell transplantation. Novel, anatomically shaped human molar scaffolds and rat incisor scaffolds were fabricated by 3D bioprinting from a hybrid of poly-ε-caprolactone and hydroxyapatite with 200-µm-diameter interconnecting microchannels. In each of 22 rats, an incisor scaffold was implanted orthotopically following mandibular incisor extraction, whereas a human molar scaffold was implanted ectopically into the dorsum. Stromal-derived factor-1 (SDF1) and bone morphogenetic protein-7 (BMP7) were delivered in scaffold microchannels. After 9 weeks, a putative periodontal ligament and new bone regenerated at the interface…

Bone repair by cell-seeded 3D-bioplotted composite scaffolds made of collagen treated tricalciumphosphate or tricalciumphosphate-chitosan-collagen hydrogel or PLGA in ovine critical-sized calvarial defects

Journal of Biomedical Materials Research Part B: Applied Biomaterials 2010 Volume 93B, Issue 2, Pages 520-530

The aim of this study was to investigate the osteogenic effect of three different cell-seeded 3D-bioplotted scaffolds in a ovine calvarial critical-size defect model. The choice of scaffold-materials was based on their applicability for 3D-bioplotting and respective possibility to produce tailor-made scaffolds for the use in cranio-facial surgery for the replacement of complex shaped boneparts. Scaffold raw-materials are known to be osteoinductive when being cell-seeded [poly(L-lactide-co-glycolide) (PLGA)] or having components with osteoinductive properties as tricalciumphosphate (TCP) or collagen (Col) or chitosan. The scaffold-materials PLGA, TCP/Col, and HYDR (TCP/Col/chitosan) were cell-seeded with osteoblast-like cells whether gained from bone (OLB) or from…

Consequences of seeded cell type on vascularization of tissue engineering constructs in vivo

Microvascular Research 2009 Volume 78, Issue 2, Pages 180-190

Implantation of tissue engineering constructs is a promising technique to reconstruct injured tissue. However, after implantation the nutrition of the constructs is predominantly restricted to vascularization. Since cells possess distinct angiogenic potency, we herein assessed whether scaffold vitalization with different cell types improves scaffold vascularization. 32 male balb/c mice received a dorsal skinfold chamber. Angiogenesis, microhemodynamics, leukocyte–endothelial cell interaction and microvascular permeability induced in the host tissue after implantation of either collagen coated poly (l-lactide-co-glycolide) (PLGA) scaffolds (group 4), additionally seeded with osteoblast-like cells (OLCs, group 1), bone marrow mesenchymal stem cells (bmMSCs, group 2) or a combination of OLCs…