Rice husk derived bioactive glass-ceramic as a functional bioceramic: synthesis, characterization and biological testing

Abstract

Bioactive glasses represent a class of attractive materials in bone reconstruction. This study describes the detailed preparation and characterization of a silicate-based bioactive glass-ceramic (R-SBgC). Synthesis of bioactive glasses using the sol-gel method has advantages compared to the melting method. However, expensive raw materials are required and pose a major issue. To overcome this, R-SBgC was synthesized via the sol-gel method using Rice Husk (RH) as a natural silica precursor. The RH was heat treated and used as an alternative to tetraethyl orthosilicate (TEOS), which is a common synthetic silica precursor. X-ray diffraction (XRD), X-ray Fluorescence (XRF) and Scanning Electron Microscopy (SEM) were used to characterize the rice husk ash (RHA). The findings reveal that the extracted silica has a high purity (~ 99%). The synthesized R-SBgC powder was characterized using SEM, Energy Dispersive X-ray Analysis (EDX), XRD, XRF and Fourier-Transform Infrared Spectroscopy (FTIR) to complete the morphological and elemental analysis. Moreover, in vitro bioactivity via an immersion assessment was conducted for up to 14 days. The HA layer formation, which is an indicator of the bioactivity on the surface of the R-SBgC, was confirmed using SEM, EDX and further by FTIR. Biocompatibility of the R-SBgC was evaluated in vitro. After 3 days of human bone marrow stromal cell (hBMSC) seeding, SEM analysis revealed cell attachment on the surface of the R-SBgC. Alamar blue and XTT cytotoxic assays demonstrated cell proliferation abilities and the non-cytotoxic effect of the R-SBgC. Altogether, the results demonstrate that prepared rice husk-derived bioactive glass ceramic may be a promising carrier for tissue engineering applications.