Improvement of osteoblast functions by sustained release of bone morphogenetic protein-2 (BMP-2) from heparin-coated chitosan scaffold

The aim of this study was to investigate the improvement in osteoblast functions by using bone morphogenetic protein-2 (BMP-2) immobilized heparin-coated chitosan scaffolds and comparing it with that using chitosan scaffold or BMP-2/chitosan scaffold in vitro. BMP-2 was released from the heparin-coated chitosan scaffold in a sustained manner compared to that released from the chitosan scaffold. The osteoblast functions of MG-63 cells grown on the chitosan scaffold, the BMP-2/chitosan scaffold, the BMP-2/Hep/chitosan scaffold were investigated by assessing cell proliferation, alkaline phosphatase (ALP) activity, calcium deposition, and gene expression. The results of the in vitro studies demonstrated that MG-63 cells grown on the BMP-2/Hep/chitosan scaffold showed a significant increment in ALP activity, and calcium deposition as compared to those grown on the chitosan scaffold by sustained release of BMP-2 due to the influence of heparin. Therefore, BMP-2 immobilized heparin-coated chitosan scaffolds are promising materials for improving osteoblast functions through sustained release of BMP-2.