RGD-conjugated UV-crosslinked chitosan scaffolds inoculated with mesenchymal stem cells for bone tissue engineering

Biomimetic chitosan scaffolds were prepared using two types of chitosan derivatives, one containing photoreactive azides for UV-crosslinking and the other tethered with RGD peptides. Mesenchymal stem cells (MSCs) isolated from rat bone marrow were cultured in the RGD-conjugated, UV-crosslinked chitosan scaffolds for bone tissue engineering. RGD-incorporation to the chitosan-based scaffolds increased the cell contents from 2.4 × 104 to 3.8 × 104 cells/scaffold and 3.4 × 104 to 5.1 × 104 cells/scaffold after 1 and 10 days of culture, respectively. Furthermore, osteogenic differentiation of MSCs, indicated by ALP activity and expression of Runx2 and osteocalcin genes, was enhanced on the RGD-conjugated surface compared with the unmodified surfaces. After 14 days of osteogenic culture, calcium deposition in the RGD-conjugated scaffolds (711 nmol Ca/scaffold) was significantly higher than the control (390 nmol Ca/scaffold). The results demonstrate a potential application of RGD-immobilized, crosslinked chitosan scaffolds for bone tissue engineering applications.