Mechanochemical synthesis of nanocrystalline hydroxyapatite from <i>Mercenaria</i> clam shells and phosphoric acid

Abstract

The aim of the present study is to synthesize hydroxyapatite from seashell and to explore its biocompatibility in vitro. Nano-crystalline hydroxyapatite (HAp) ceramics were successfully fabricated by a mechanochemical method using clam seashells and phosphoric acid. The CaO and H3PO4 acid at different w.t% ratios i.e. 1:0.75, 1:1.25, 1:1.5 and 1:1.75, were ball milled and then heat treated at 1000 °C for 3 h to complete reactions. The synthesized powders were characterized using x-ray diffraction (XRD), FTIR spectroscopy, scanning electron microscope and high resolution transmission electron microscopy. XRD results showed that the average crystallite size of the powder varies from 53 to 67 nm and crystallinity of powder found to be in the range of 88% and 96%. In vitro biocompatibility studies were carried out using osteoblast (MG63) and fibroblast cells (NIH3T3), demonstrated non-toxic nature of the seashell derived HAp powder.