Experimental study on advanced bone regeneration by BMP-7 derived-peptide chitosan nanometer hydroxyapatite collagen biomimetic composite

Abstract

Objective: To investigate the effect of BMP-7 derived-peptide chitosan nanometer hydroxyapatite biomimetic collagen composite on repairing rat critical-sized cranial defects.

Methods: The chitosan nanometer hydroxyapatite collagen composite was prepared and the microcosmic appearance of the composite was observed by scanning electron microscope. The BMP-7 derived-peptide was introduced into the composite by vacuum adsorption. The released peptide content from the scaffold was detected using high performance liquid chromatography at different set times. Critical-sized cranial defects were created on both sides of the parietal bone in 24 adult Sprague-Dawley rats. The BMP-7 derived-peptide chitosan nanometer hydroxyapatite biomimetic collagen composites were implanted on the right side as experimental group and the left side was implanted with chitosan nanometer hydroxyapatite biomimetic collagen composites alone as control group. The rats of both groups were killed in batch respectively after 6 and 12 weeks. Macroscopic observation, three-dimensional reconstruction of computed tomography (CT) and histological observation were performed on these samples.

Results: The results of scanning electron microscope showed that the surface of the scaffold was porous. The releasing character of BMP-7 derived-peptide belonged to slow release. The result of animal experiment showed that the BMP-7 derived-peptide chitosan nanometer hydroxyapatite biomimetic collagen composite could more effectively promote the repair of cranial bone defects comparing with the chitosan nanometer hydroxyapatite biomimetic collagen composite alone. The difference was statistically significant (p < .05).

Conclusions: The BMP-7 derived-peptide chitosan nanometer hydroxyapatite collagen biomimetic composite can effectively promote bone regeneration of bone defects. The composite is a kind of ideal scaffold material for bone tissue engineering.