Enhanced Biomineralization in Osteoblasts on a Novel Electrospun Biocomposite Nanofibrous Substrate of Hydroxyapatite/Collagen/Chitosan

Electrospun chitosan (CTS)-based hydroxyapatite (HAp)/CTS biocomposite nanofibers for bone tissue engineering could afford a close biomimicry to the fibrous nanostructure and constituents of the hierarchically organized natural bone, but their biological performance is somewhat deficient compared with the HAp/collagen (Col) biocomposite system. This necessitates doping the electrospun HAp/CTS hybrid with the bioactive component of Col. We show herein that Col-doped HAp/CTS biocomposite (i.e., HAp/Col/CTS) containing 27.8 wt% HAp nanoparticles, 7.2 wt% Col, and 57.8 wt% CTS can be successfully electrospun into nanofibrous form through using small amount (7.2 wt%) of ultrahigh-molecular-weight poly(ethylene oxide) as the fiber-forming additive. Morphology, structure, composition, and mechanical properties of the electrospun HAp/Col/CTS scaffolds were examined by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy, and tensile tests, respectively. Human fetal osteoblasts on the nanofibrous HAp/Col/CTS scaffolds were cultured for up to 15 days to assess the cell-scaffold interaction and biomineralization effect. In comparison with different controls, significant increments in osteoblast proliferation, alkaline phosphatase expression, and mineral deposition were observed. Results obtained thus highlight that introduction of Col can significantly enhance the biological performance of osteoblasts on the CTS-based nanofibrous substrates and suggest that current electrospun HAp/Col/CTS biocomposite, as a highly biomimetic and bioactive nanofibrous structure, may be one of the most attractive candidates for various osteoregeneration-related applications.