Accelerated bone growth in vitro by the conjugation of BMP2 peptide with hydroxyapatite on titanium alloy.

•Osteoconductive hydroxyapatite acts as a carrier of osteoinductive BMP2 peptide on titanium alloy for accelerated bone growth.•Hydroxyapatite formation is induced by polydopamine film that is a universal route to functionalize all kinds of materials.•The controlled release of BMP2 peptide is achieved by the slow dissolution of HA coating.•Synthesized BMP2 peptide is an appropriate alternative of much more expensive BMP2 for enhanced cell differentiation.