In-Vitro Bioactivity Investigation of Sol-Gel Derived Alumina-Bovine Hydroxyapatite (BHA) Composite Powders

Abstract

Alumina (α-Al2O3) and hydroxyapatite (HA, Ca10(PO4)6(OH)2) are well-known for beingclinically successful bioceramic materials. In this work, in-vitro biological characterization of thesol-gel alumina-bovine hydroxyapatite composite powders was realized. Alumina powders weresynthesized through the sol-gel process. First, boehmite (AlOOH) sol was prepared utilizingaluminium isopropoxide (Al(OC3H7)3, AIP) as the starting precursor. Bovine hydroxyapatite(BHA) powders, which can be defined as naturally derived calcium phosphate powders wereadded as 10, 20, 30, and 50% wt. of AIP to each AlOOH sol. Homogeneous dispersion of theBHA powders in the AlOOH sol was managed due to employing Na-alginate as a kind ofthickener. Gelation of the AlOOH-BHA mixtures was carried out at 110 ºC for 3h. After drying,AlOOH-BHA mixtures were heat-treated at 1300 ºC for 2h. Chemical, microstructural, thermal,and physical properties of the precursors/process products were characterized with X-RayDiffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray FluorescenceSpectroscopy (XRF), Differential Thermal Analysis (DTA), and Scanning Electron Microscopy- Energy Dispersive Spectroscopy (SEM-EDS) analyses. Indirect MTT assay was done toevaluate the biocompatibility of the Al2O3-BHA based biocomposite extracts using the L929 cellline. It is found that all Al2O3-BHA composite extracts with varying doses of 25% and 50% hadno negative effect on the cell viability. In addition, % cell viability decreased with the increasingof the extract concentration. It can be concluded that the prepared Al2O3-BHA composites can be a good candidate for biomedical applications.