Electrospun triazole-based chitosan nanofibers as a novel scaffolds for bone tissue repair and regeneration

For the first time, the novel type of guided bone regeneration composite nanofibers were prepared by grafting polycaprolactone (PCL) to chitosan (CS) using the copper (I) - catalyzed azide-alkyne cycloaddition (CuAAC) reaction. For improve the bioactivity of scaffolds the magnesium-doped hydroxyapatite (Mg-HA) was used. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and proton nuclear magnetic resonance (H-1 NMR) were applied to characterize the prepared scaffolds. The SEM observations show defect-free uniform composite nanofibers with about 419-495 nm diameter. The in vitro cell viability test (MTT assay) show that fabricated scaffolds don't have any significant cytotoxicity. Also, osteoblast-like MG63 cells cultured on the nanofibers which prepared through CuAAC reaction (CS-g-PCL/Mg-HA) show higher antibacterial activity, mechanical properties, and cell attachment compared to CS/PCL/Mg-HA blend scaffolds. Moreover, the Alkaline phosphatase (ALP) activity and Alizarin red S (ARS) staining showed that the introduction of the triazole ring into the chemical structure of the copolymer enhanced bone mineralization ability of the scaffolds. These results suggested that this novel scaffold provides an interesting option for bone repair and regeneration.