Co-delivery of platelet-derived growth factor (PDGF-BB) and bone morphogenic protein (BMP-2) coated onto heparinized titanium for improving osteoblast function and osteointegration

The aim of this study was to improve osteoblast function by delivering two growth factors, PDGF-BB and BMP-2, incorporated onto heparinized titanium (Hep-Ti) substrate. To achieve co-delivery of PDGF-BB and BMP-2, the surface of anodized Ti was immobilized with heparin, and then the two growth factors were coated onto the Hep-Ti surface. Incorporation of the two growth factors onto Hep-Ti was evaluated by SEM and XPS. Incorporated PDGF-BB and BMP-2 were released from the Hep-Ti substrate in a sustained manner. In vitro studies revealed that osteoblasts grown on PDGF-BB- and BMP-2-immobilized Hep-Ti increased ALP activity, calcium deposition, osteocalcin and osteopontin levels as compared to those grown on PDGF-BB alone- or BMP-2 alone-immobilized Hep-Ti. These results suggested that co-delivery of PDGF-BB and BMP-2 using Hep-Ti substrate will be a promising material for the enhancement of osteoblast function and osteointegration.