Adhesion, proliferation, and osteogenic differentiation of a mouse mesenchymal stem cell line (BMC9) seeded on novel melt-based chitosan/polyester 3D porous scaffolds

The aim of the present work was to study the biological behavior of a mouse mesenchymal stem cell line when seeded and cultured under osteogenic conditions onto novel processed melt-based chitosan scaffolds. Scaffolds were produced by compression molding, followed by salt leaching. Scanning electron microscopy (SEM) observations and lCT analysis showed the pore sizes ranging between 250 and 500 lm and the interconnectivity of the porous structure. The chitosan–poly(butylenes succinate) scaffolds presented high mechanical properties, similar to the ones of trabecular bone (E1%*75 MPa). Cytotoxicity assays were carried out using standard tests (accordingly to ISO/EN 10993 part 5 guidelines), namely, MTS test with a 24 h extraction period, revealing that L929 cells had similar metabolic activities to that obtained for the negative control. Cell culture studies were conducted using a mouse mesenchymal stem cell line (BMC9). Cells were seeded onto the scaffold and allowed to proliferate for 3 weeks under osteogenic conditions. SEM observations demonstrated that cells were able to proliferate and massively colonize the scaffolds structure. The cell viability assay MTS demonstrated that BMC9 cells were viable after 3 weeks of culture. The cells clearly evidenced a positive differentiation toward the osteogenic lineage, as confirmed by the high ALP activity levels. Moreover, energy dispersive spectroscopy (EDS) analysis revealed the presence of Ca and P in the elaborated extracellular matrix (ECM). These combined results indicate that the novel melt-based chitosan/polyester scaffolds support the adhesion, proliferation, and osteogenic differentiation of the mouse MSCs and shows adequate physicochemical and biological properties for being used as scaffolds in bone tissue engineering–related strategies

Evaluation of polycaprolactone-poly-D,L-lactide copolymer as biomaterial for breast tissue engineering

The potential of the copolymer polycaprolactone-co-poly-d,l-lactic acid (PCLLA) as a biomaterial for scaffold-based therapy for breast tissue engineering applications was assessed. First, the synthesized PCLLA was evaluated for its processability by means of additive manufacturing (AM). We found that the synthesized PCLLA could be fabricated into scaffolds with an overall gross morphology and porosity similar to that of polycaprolactone. The PCLLA scaffolds possessed a compressive Young's modulus (ca 46 kPa) similar to that of native breast (0.5-25 kPa), but lacked thermal stability and underwent thermal degradation during the fabrication process. The PCLLA scaffolds underwent rapid degradation in vitro which was characterized by loss of the scaffolds' mechanical integrity and a drastic decrease in mass-average molar mass (M-w) and number-average molar mass (M-n) after 4 weeks of immersion in phosphate buffer solution maintained at 37 degrees C. The tin-catalysed PCLLA scaffold was also found to have cytotoxic effects on cells. Although the initial mechanical properties of the PCLLA scaffolds generally showed potential for applications in breast tissue regeneration, the thermal stability of the copolymer for AM processes, biocompatibility towards cells and degradation rate is not satisfactory at this stage. Therefore, we conclude that research efforts should be geared towards fine-tuning the copolymer synthesizing methods

Osteogenic induction of human bone marrow-derived mesenchymal progenitor cells in novel synthetic polymer-hydrogel matrices

10.1089/107632703768247386Tissue Engineering94689-702TIEN

The Periosteum as a Cellular Source for Functional Tissue Engineering

The periosteum, a specialized fibrous tissue composed of fibroblast, osteoblast, and progenitor cells, may be an optimal cell source for tissue engineering based on its accessibility, the ability of periosteal cells to proliferate rapidly both in vivo and in vitro, and the observed differentiation potential of these cells. However, the functional use of periosteum-derived cells as a source for tissue engineering requires an understanding of the ability of such cells to elaborate matrix of different tissues. In this study, we subjected a population of adherent primary periosteum-derived cells to both adipogenic and osteogenic culture conditions. The commitment propensity of periosteal cells was contrasted with that of well-characterized phenotypically pure populations of NIH3T3 fibroblast and MC3T3-E1 osteoblast cell lines. Our results demonstrate that the heterogeneous populations of periosteal cells and NIH3T3 fibroblasts have the ability to express both osteoblast-like and adipocyte-like markers with similar potential. This raises the question of whether fibroblasts within the periosteum may, in fact, have the potential to behave like progenitor cells and play a role in the tissue's multilineage potential or whether there are true stem cells within the periosteum. Further, this study suggests that expanded periosteal cultures may be a source for tissue engineering applications without extensive enrichment or sorting by molecular markers. Thus, this study lays the groundwork for future investigations that will more deeply enumerate the cellular sources and molecular events governing periosteal cell differentiation

The evaluation of a biphasic osteochondral implant coupled with an electrospun membrane in a large animal model

Conventional clinical therapies are unable to resolve osteochondral defects adequately, hence tissue engineering solutions are sought to address the challenge. A biphasic implant which was seeded with Mesenchymal Stem Cells (MSC) and coupled with an electrospun membrane was evaluated as an alternative. This dual phase construct comprised of a Polycaprolactone (PCL) cartilage scaffold and a Polycaprolactone - Tri Calcium Phosphate (PCL - TCP) osseous matrix. Autologous MSC was seeded into the entire implant via fibrin and the construct was inserted into critically sized osteochondral defects located at the medial condyle and patellar groove of pigs. The defect was resurfaced with a PCL - collagen electrospun mesh that served as a substitute for periosteal flap in preventing cell leakage. Controls either without implanted MSC or resurfacing membrane were included. After 6 months, cartilaginous repair was observed with a low occurrence of fibrocartilage at the medial condyle. Osteochondral repair was promoted and host cartilage degeneration was arrested as shown by the superior Glycosaminoglycan (GAG) maintenance. This positive morphological outcome was supported by a higher relative Young's modulus which indicated functional cartilage restoration. Bone in growth and remodeling occurred in all groups with a higher degree of mineralization in the experimental group. Tissue repair was compromised in the absence of the implanted cells or the resurfacing membrane. Moreover healing was inferior at the patellar groove as compared to the medial condyle and this was attributed to the native biomechanical features