Preparation and characterization of bioceramic composites based on anorthite and β-TCP from dolomitic phosphate and kaolin rocks

Abstract

The current study demonstrates the possibility of producing novel economic biomaterials with biocompatible and acceptable mechanical properties for bone tissue engineering applications from dolomitic phosphate and kaolin rocks. The solid-state reaction was adapted to produce various batch compositions, through the substitution of kaolin with dolomitic phosphate rocks in which 20–30 wt% dolomitic phosphate rock was combined with kaolin material (20 PK, 25 PK and 30 PK). The fabricated ceramics composites were sintered at different temperatures ranging from 1175 to 1325 ᴼC. The phase composition, bulk density and bending strength of the sintered bioceramics were evaluated through X-ray diffraction (XRD), applying the Archimedes method, and 3-point bending test, respectively. Moreover, the in-vitro tests were estimated by immersing the samples in stimulated body fluid solution (SBF). The results showed that anorthite, β-tricalcium phosphate, and calcium magnesium phosphate were produced as primary phases during the sintering process and that their content increased with the increase in the phosphate rock content. Notably, the sample containing 20 wt% dolomitic phosphates exhibited good densification of 1.99 g/cm3 and achieved a bending strength of 45.66 MPa at 1250 °C. After immersing in the SBF for four weeks, changes in the surfaces of all the studied materials were observed, owing to the deposition of apatite particles. The pH values were in a nearby region of the natural pH levels. Such behaviour may be related to the sample's high stability, which originated from its chemical composition and dense structure. Moreover, a cytotoxicity test was carried out using osteosarcoma cells (HOS). The results demonstrated that all the studied bioceramics composites are safe for use as potential biomaterials.