Collagen-glycosaminoglycan scaffold and mesenchymal stem cells for bone tissue engineering

Abstract

Tissue engineering using cell-seeded biodegradable scaffolds offers a new bone regenerative approach that might circumvent many of the limitations of current therapeutic modalities. This thesis reports on a number of in vitro and in vivo aspects of bone tissue engineering using collagen-glycosaminoglycan scaffolds and bone marrow derived, murine mesenchymal stem cells. The work presented in chapter 3 quantified the dimensional changes as a result of cell- mediated contraction in mesenchymal stem cell-seeded collagen-glycosaminoglycan scaffolds when cultured in osteoinductive factor-supplemented medium. The effect of cells originating from different donors on the scaffold contraction was also examined. Three experimental groups were used; non-seeded scaffolds (Group 1), seeded scaffolds which were maintained in standard culture medium for 4 weeks (Group 2), and seeded scaffolds which were maintained in osteoinductive factor-supplemented medium for 4 weeks (Group 3) i.e. a tissue engineered group which allowed matrix deposition and mineralisation upon the scaffolds prior to implantation. Each group comprised 3 scaffolds of each of the following diameters (6 mm, 10 mm, 13 mm, and 16 mm) for a total of 12 scaffolds in each group. After 4 weeks in culture, seeded scaffolds displayed significantly greater contraction than the cell-free scaffolds (P < 0.0001). However, the difference between the percentage reduction in diameter of scaffolds in group 2 (49.11 ± 2.36 %) and in group 3 (44.26 ± 2.68 %) was not significant. Scaffolds with larger diameters showed substantially more contraction than scaffolds with smaller diameters (P < 0.001). Similar amounts of contraction were reached when the scaffolds were seeded with cells originating from different donors (P < 0.32).