The Effect of Bone Morphogenic Protein-2 (BMP-2)-Immobilizing Heparinized-Chitosan Scaffolds for Enhanced Osteoblast Activity

The aim of orthopedic and dental tissue engineering is to generate synthetic bone-graft tissue substitutes. It is generally comprised through the combination of viable cells, a scaffolding material, and sometimes the inclusion of bone morphogenic proteins. The object of this study is to develop novel bone-grafting scaffolds that enhance osteoblast activity. We were fabricated the chitosan scaffolds with channel-shaped and spherically shaped pore morphologies. Also, Bone morphogenic protein-2 (BMP-2) was sequentially immobilized to the heparinized-chitosan (Hep-chitosan) scaffolds. Osteoblast activities of all chitosan scaffolds were investigated by a cell proliferation assay, alkaline phosphatase (ALP) activity, calcium deposition, and the expression of osteogenic markers. The results showed that BMP-2-immobilizing heparinized-chitosan (BMP-2/Hep-chitosan) scaffolds significantly enhanced ALP activity and calcium deposition of the osteoblast cells when compared with chitosan scaffolds only. Also, mRNA expressions of osteocalcin and osteopontin of osteoblast cells cultured on BMP-2 (100 ng)/Hep-chitosan scaffolds were increased versus chitosan scaffolds only. Taken together, BMP-2 (100 ng)/Hep-chitosan scaffolds could achieve the functions of excellent osteoblast promotion. Therefore, osteoinductive protein-functionalizing scaffold substrates such as BMP-2/Hepchitosan scaffolds are a promising material for the enhanced osteoblast activity in orthopedic and dental fields.