Preparation and Characterization of Chitosan/Hydroxyapatite Nanowire Composite Scaffolds for Bone Regeneration

In this study, chitosan/hydroxyapatite nanowire composite scaffolds were prepared by the cryogenic 3D printing method. Their properties were investigated for bone regeneration. Synthesized hydroxyapatite nanowire and strontium doped hydroxyapatite nanowire were studied by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetry. The synthesized nanowires have good biocompatibility. Then, chitosan/hydroxyapatite nanowire composite scaffolds were prepared by cryogenic 3D printing. The morphologies, composition, biocompatibility, and osseogenesis in vivo of scaffolds were observed. Results indicated that scaffolds prepared by cryogenic 3D printing exhibited desirable 3D interconnected macro/microporous structures and good biocompatibility. Meanwhile, in vivo cranial defect implantation results confirmed that chitosan and strontium-doped hydroxyapatite nanowire composite scaffolds have the best ability of in vivo bone regeneration. The present composite scaffold has promising characteristics for bone regeneration.