Fabrication and in-vitro biocompatibility of freeze-dried CTS-nHA and CTS-nBG scaffolds for bone regeneration applications

The thought of biodegradable organic-inorganic composites composed of natural polymer chitosan and ceramic nanoparticles (hydroxyapatite and bioglass) can be considered as a solution for hard tissue engineering. In this paper, we described a comparative assessment of chitosan-nanohydroxyapatite (CTS-nHA) and chitosan-nano-bioglass (CTS-nBG) scaffolds. The dispersion of nanoscaled hydroxyapatite (nHA) and bioglass (nBG) in chitosan remained satisfactory. The freeze-dried composite based CTS-nHA and CTS-nBG scaffolds shown porous structure. The physiochemical and morphological analysis of all samples has been performed through X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The SEM image confirmed the presence of spherically shaped nHA particles of 4.20 μm and irregularly shaped nBG particles of 6.89 μm. The TEM analysis revealed the existence of 165.52 to 255.17 nm sized nHA particles and 167.35 to 334.69 nm sized nBG particles. TEM analysis also showed the interconnected structure of CTS-nHA and CTS-nBG nanocomposites. After seven days' incubation period, the CTS-nHA and CTS-nBG scaffolds shown good mineralization behavior in simulated body fluid (SBF). The CTS-nHA scaffolds exhibited enhanced compressive strength and elastic modulus compared with the CTS-nBG sample. The cell culture experiment revealed that fabricated scaffolds had good compatibility with fibroblast cells (L929, ATCC) and MG-63 which are able to adhere, proliferate, and migrate through the porous structure. All the obtained results clearly recommend that pre-loaded hydroxyapatite and bioglass nanoparticles can enhance the apatite formation. The scaffolds with chitosan, bioglass, and hydroxyapatite have better biomechanical characteristics and allow cell growth. Therefore, these scaffolds can be perfect candidates for various hard tissue engineering applications such as bone regeneration.