ABSTRACT
Background: In bone tissue engineering segment, numerous approaches have been investigated to address critically sized bone defects via 3D scaffolds, as the amount of autologous bone grafts are limited, accompanied with complications on harvesting. Moreover, the use of bone-marrow-derived stem cells is also a limiting factor owing to the invasive procedures involved and the low yield of stem cells. Hence, research is ongoing on the search for an ideal bone graft system promoting bone growth and regeneration. Purpose of the Study: This study aims to develop a unique platform for tissue development via stem cell differentiation towards an osteogenic phenotype providing optimum biological cues for cell adhesion, differentiation and proliferation using biomimetic gelatin-based scaffolds. The use of adipose-derived mesenchymal stem cells in this study also offers an ideal approach for the development of an autologous bone graft. Methods: A gelatin-vinyl acetate-based 3D scaffold system incorporating Bioglass was developed and the osteogenic differentiation of adipose-derived mesenchymal stem cells (ADMSCs) on the highly porous freeze-dried gelatin-vinyl acetate/ Bioglass scaffold (GB) system was analyzed. The physicochemical properties, cell proliferation and viability were investigated by seeding rat adipose tissue-derived mesenchymal stem cells (ADSCs) onto the scaffolds. The osteogenic differentiation potential of the ADMSC seeded GeVAc/bioglass system was assessed using calcium deposition assay and bone-related protein and genes and comparing with the 3D Gelatin vinyl acetate coppolymer (GeVAc) constructs. Results and Conclusion: According to the findings, the 3D porous GeVAc/bioglass scaffold can be considered as a promising matrix for bone tissue regeneration and the 3D architecture supports the differentiation of the ADMSCs into osteoblast cells and enhances the production of mineralized bone matrix.
ABSTRACT
Gel-type autologous chondrocyte implantation (GACI) is the fourth-generation therapeutic strategy that has been introduced to address the limitations of earlier generation strategies, especially problems related to cell leakage upon implantation and loss of chondrocyte functionality owing to the dedifferentiation of cells in culture and fibrocartilage formation. In GACI, an injectable gel system is used, which acts as the cell carrier. However, the maintenance of the morphology and redifferentiation of chondrocytes with appropriate biofunctionality are major challenges in this technique. In this study, we prepared a photocrosslinkable injectable hydrogel based on carboxymethyl cellulose-methacrylate (CMC-MA) and polyethylene glycol diacrylate (PEGDA) and evaluated chondrocyte-matrix interactions and biofunctionality on different blend ratios of the gels with varying stiffness. Cell-matrix interaction was evaluated by immunostaining for actin filaments via phalloidin and cell adhesion markers such as focal adhesion kinase (FAK), integrin ß1, and integrin αV. This study indicates that the stiffness of the substrates, along with the material chemistry, is a crucial factor when selecting an injectable gel-based system. Stiffer gels (2:8 CMC-MA/PEGDA) showed good chondrocyte cell attachment and growth with maintenance of the redifferentiated phenotype; therefore, they can be considered as an ideal matrix for GACI technique.
