Influence of growth factors on mesenchymal stem cell differentiation for later annulus fibrosus tissue engineering
Date of Issue2016-05-25
School of Chemical and Biomedical Engineering
Intervertebral disc (IVD) degeneration is one of the most prevalent health concerns, debilitating, and economically significant causes of morbidity worldwide. Its incidence is growing exponentially with current demographic changes and an ageing population. In addition, cartilage itself has limited self-regeneration capability due to lack of vascularity and scarce number of cells Use of stem cells and regenerative medicine is thought to be next hallmark of modern tissue engineering; the technology promising in-vitro construction of whole transplantable tissue. This study investigated the effect of exogenously added growth factors: TGF-β3, PDGF-BB, FGF-2, FGF-18, during development of scaffold-free mesenchymal stem cell (MSC) differentiated cartilage and fibrocartilage-like tissue for future applications in engineering of annulus fibrosus-like tissue of IVD. FGF-18 induced and PDGF-BB induced groups showed a higher cell population at the end of 2 weeks of culture into monolayer cell sheet, while TGF-β3 induced groups displayed slowest growth. Annulus fibrosus-related gene expression data of monolayer cell sheet suggested that TGF-β3 is a significant growth factor in the differentiation of MSC cells towards fibrocartilaginous tissue, a feature of annulus fibrosus-like tissue. Study of 3D cell pellet cultures showed that groups pre-exposed to growth factors expressed low annulus fibrosus-related gene levels whereas control group exhibited enhanced gene expression. The up-regulation of COL II and down-regulation of COL I gene expression by cell pellets when compared with cell sheets could possibly explain that development of more cartilage-like tissue is favorable in 3D microenvironment.
Final Year Project (FYP)
Nanyang Technological University