Characteristics and cytotoxicity of hydroxyapatite from Padalarang–cirebon limestone as bone grafting candidate

Limestone, as a natural source has the main component of calcium carbonate (CaCO3) and is abundantly existed in Indonesia. Calcium carbonate is one of the compounds that could be a precursor in the fabrication of hydroxyapatite (HA) that has been commonly used in clinical application. The center of ceramics in Indonesia (BBK: Balai Besar Keramik) has synthesize HA from limestone’s calcium carbonate derived from mountains in Padalang and Cirebon, West Java, Indonesia. This study aims to evaluate the characteristics and cytotoxity of hydroxyapatite made from Padalarang-Cirebon limestone by BBK as a bone graft candidate. Characterizations of HA were Fourier Transform Infra-Red (FTIR), X–Ray Diffraction (XRD) and Energy Dispersive X-ray (EDX). Cytotoxicity of the samples were evaluated with MTT assay on umbilical cord mesenchymal stem cells (UC-MSCs) with the concentrations of 50μg/ml, 25μg/ml, 12.5μg/ml, 6.25μg/ml, 3.12μg/ml, 1.56μg/ml, 0.78μg/ml, 0.39μg/ml, and 0.19μg/ml. HA from limestone has hydroxyl (OH-) dan phosphate (PO4 2-) functional groups, the particle was in the crystal form and has the composition of O, Ca, and P with the Ca/P ratio was 1.64. Toxicity was not found in all concentrations (p > 5). HA from Padalarang-Cirebon limestone by BBK has hydroxyl and phosphate groups, crystal particles, the composition of O, Ca, and P, Ca/P ratio of 1.64 and no toxicity, which satisfied the requirements of a bone graft candidate