Synthesis and characterization of a novel freeze-dried silanated chitosan bone tissue engineering scaffold reinforced with electrospun hydroxyapatite nanofiber

Novel chitosan scaffolds containing different weight ratios of electrospun hydroxyapatite nanofibers (n-HAs) were fabricated. The fibers possessed diameters in the range 110-170 nm. A fixed concentration of glycidyloxypropyl-trimethoxysilane (GPTMS) as a crosslinking agent was added to the chitosan solution (CG). The porosity percentage was increased when GPTMS and n-HAs were added to the chitosan structure. The presence of GPTMS in the chitosan structure caused a decrease in the average pore size. The pores were more irregular in shape than pure chitosan and CG scaffolds when n-HAs were added. A uniform distribution of n-HAs was seen for a chitosan-GPTMS hybrid scaffold containing 25 wt% n-HAs (CGH25) using energy dispersive X-ray spectroscopy and mapping. The best values of compressive strength and elastic modulus were achieved for CGH25. The swelling ratio was decreased on adding GPTMS to the chitosan scaffold. Different morphologies of hydroxyapatite deposits on the surface of CG and CGH25 (string-like versus needle-like precipitates) were observed after 14 days of soaking in simulated body fluid. For CGH25, the viability of MG-63 osteoblastic cells improved with respect to CG for up to 72 h of cell culture. These results reveal the potential of the chitosan-CGH25 scaffold for use in bone tissue engineering. (c) 2019 Society of Chemical Industry