Fabrication and Characterization of silk fibroin scaffold containing ascorbic acid-loaded chitosan nanoparticles for bone regeneration applications

Abstract

The aim of this study was to fabricate and characterize silk fibroin scaffold containing ascorbic acid-loaded chitosan nanoparticles. Therefore, ascorbic acid-loaded chitosan nanoparticles were first fabricated using the ionic gelation method. Scanning electron microscope (SEM) images and dynamic light scattering (DLS) results showed the spherical nanoparticles with an average particle size of 200 nm. Then, different amounts of nanoparticles were placed in the silk fibroin solution, and finally, the scaffolds were prepared by the freeze-drying method. The effect of nanoparticle concentrations on various properties such as morphology, structural changes, water absorption, drug release, toxicity, adhesion, and alkaline phosphatase activity of MG63 cells were studied. Morphological examinations of the cross-section of the scaffold showed that all scaffolds have a porous structure with interconnected pores. The results of infrared fourier transform spectroscopy(FTIR) confirmed the presence of nanoparticles in the scaffold. The mean size of the pores and porosity percentages reduced as the nanoparticle content rose. The release of ascorbic acid in all samples started with the burst release in the first 24 hours and then continued with a controlled release for up to 14 days. Higher amounts of ascorbic acid were released from the scaffold containing more nanoparticles. Cellular studies showed that the scaffold was non-toxic and that MG63 cells adhered well onto the surface of the scaffold and the pore wall. Also, the proliferation and alkaline phosphatase activity of MG63 cells increased with increasing ascorbic acid amounts.