Biomimetic synthesis and biocompatibility of nano-hydroxyapatite/chitosan scaffold for bone tissue engineering

Abstract

Objective To evaluate the physicochemical properties and biocompatibility of nano-hydroxyapatite/chitosan (n-HA/CS) scaffolds. Methods n-HA/CS scaffolds were generated by in situ hybridization and freeze-drying technology. The microscopic morphology and components of the composite were analyzed by scanning electron microscopy (SEM), morphology, X-ray diffraction (XRD) examination and Fourier transformed infrared spectroscopy (FTIR) . The effects of u-HA/CS scaffolds on adherence and proliferation of human bone marrow stromal cells (hBMSCs) were evaluated by leaching liquor and scaffolds surface seeding methods. After being implanted into back muscle pockets of New Zealand rabbits, the histo-compatibility of n-HA/CS was observed by histological staining. Results n-HA/CS composite showed abundant homogeneous pores with (112.63 ± 20.47) μm diameter and (88.65 ± 2.34)% porosity. HA particles were distributed on the pore walls homogeneously with (200 ～ 700 nm) nanoscale. XRD and FTIR results showed that the HA crystals were carbonate-substituded and not well-crystallized. Cytocompatibility teat showed that the seeded hBMSCs could adhere to the scaffolds, and their proliferation ability was not affected by n-HA/CS composite and its leaching liquor. In addition, histocompatibility test found that tissue inflammatory reactions of n-HA/CS composite implanted decreased significantly at 4 w, and the composite was degraded mostly and was substituted by new tissue at 12 w. Conclusion The n-HA/CS scaffolds could be successfully used in the bone tissue engineering, as it has good physicochemical properties and fine biocompatibility. Key words: Hydroxyapatites; Chitosan; Tissue engineering; Scaffold; Nanocomposites