In-vitro and thermal stability study of bioglass synthesized from biogenic sources

Abstract

In this work, the bioactive glasses are derived from biowaste resources such as corn husk ash, sugarcane leaves ashes, and eggshell powder via the melt quench method. The raw materials were melted in a platinum rhodium crucible at 1550 °C, followed by rapid cooling to obtain a glassy phase. In order to assess the in-vitro bioactivity, glasses were soaked in simulated body fluid at 37 °C for different time durations, i.e., 7,14, 21, and 28 days. Biocompatibility of these glasses was also tested on MG-63 cell lines using a 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl tetrazolium bromide (MTT) assay test. X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) were used to analyze the hydroxyapatite (HAp) layer formation and the thermal stability of soaked samples. SEM micrographs showed the cauliflower and flakes type morphology of hydroxyapatite (HAp) on the glass surfaces after 7 days of soaking in SBF. The EDS analysis also confirmed the formation of a hydroxyapatite layer with a Ca/P ratio that varies from 1.6 to 3.9. MTT assay revealed the biocompatibility for different dosages (1, 2, 5, and 10 mg/ml) of the as-prepared glasses with MG-63 cell lines. The heat treatment of soaked glasses converts the amorphous HAp layer into a crystalline HAp layer, followed by its conversion in stable diopside as main and Ca2.589Mg0.41(PO4)2 as minor phase. The tested glasses exhibited good bioactivity and biocompatibility particularly higher CaO content glass, suggesting for use in bone regeneration applications.