Accelerated Bone Regeneration by Chitosan/Nanometer Hydroxyapatite/Collagen Composite Incorporating BMP-7 Mimetic Peptide

The purpose of the present study was to examine whether the chitosan/ nanometer hydroxyapatite / collagen composite (chitosan/nHAC) incorporating BMP-7 mimetic peptide could accelerate bone regeneration. The chitosan/nHAC composite was prepared and the BMP-7 mimetic peptide introduced into the composite by vacuum adsorption. The released peptide content from the composite was detected using high performance liquid chromatography at different set times. 5 mm diameter cranial bone defects were created on both sides of the parietal bone in 24 adult Sprague-Dawley rats, which were randomized into two treatment groups; one receiving the chitosan/nHAC composite loaded with 1 mg BMP-7 mimetic peptide and the other one receiving the unload composite. Bone healing was evaluated with radiographic and histological analysis. The results showed that significantly improved and effective bone regeneration was achieved with the composite loaded with 1 mg BMP-7 mimetic peptide compared to the unloaded composite. In conclusion, the BMP-7 mimetic peptide in combination with the chitosan/nHAC composite could successfully accelerate the healing of rat's cranial bone defects. The chitosan/nHAC/BMP-7 mimetic peptide composite is an ideal bone substitute material.