Nano Scale Hydroxyapatite from Crassostreao virginica (Oyster Seashells) and its Modification with Azadirachta Indica (Neem) Extract

Abstract

Hydroxyapatite (HAp) is a widely explored biomaterial for bone and tooth replacements. Most of the research studies are being carried out in terms of novel routes of synthesis and fabrication in the nano scale to suit its applications. The present research study is unique in two aspects one being the use of seawaste namely Crassostreao virginica (Oyster) seashells as the source of calcium carbonate along with phosphoric acid and in the alkaline pH to synthesize nano sized HAp and secondly to check the enhanced activity of HAp if any, upon the addition of Azadirachta indica Extract (neem leaf and neem stem) by wet precipitation method. The structural activity relationship of assynthesised HAp sample was compared with that of the modified HAp using Azadirachta indica extract as medium. The presence of Hexagonal phase (JCPDS no-09-0432) was identified in all HAp samples. The crystallite size of 38nm was observed in the HAP prepared from the seashell in comparison with the crystallite of 49 nm (neem leaf) and 52mm (neem stem) modified HAp. The presence of spherical morphology and elemental composition of Ca,P in HAp and modified HAps were identified from Scanning Electron Microscopic images. The toxicity studies of assynthesised HAp and modified HAp with Azadirachta indica against Candida albicans and Streptococcus mutans were compared and the results were encouraging. This study ultimately provided a simple, cost effective green method of converting seawaste into high value biomedical product of nanoscale hydroxyapatite with enhanced antimicrobial activity.