Preparation and analysis of pure and surface modified nanohydroxyapatite derived from eggshells and its in-vitro studies for bone graft applications

Abstract

The need and significance for quality bone graft substitute increases due to the worldwide increment in the health problems such as osteoporosis, accidental loss and teeth decay etc. Nowadays, nanohydroxyapatite and its polymeric composites are effectively used as bone grafts and dentin. In this work, nanohydroxyapatite (nHAp) and surface-modified nanohydroxyapatite were synthesized through the precipitation method using bio-wastes (eggshells) as a Calcium precursor. The polymers Polyethylene glycol (PEG) and polyvinyl acrylate (PVA) were used as surface modifiers to control the particle size. The prepared samples were analyzed through X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Differential Thermal Analysis (TG-DTA), Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HR-TEM) and X-ray Photoelectronic Spectroscopy (XPS). Also, the samples were subjected to simulated body fluid analysis, antimicrobial and hemolytic assay to analyze the apatite forming ability and hemolytic nature. The XRD, SEM and HR-TEM results show the crystallite and particle sizes are about 41 nm, 57 nm and 66.6 nm (rod-shaped) respectively. While the EDAX spectra show the presence of Calcium, Phosphate, Oxygen and Sodium in the prepared sample. However, the FT-IR spectra confirm the presence of OH, PO43−, and CO32− functional groups in the sample. The thermogram depicts the stability of nHAp/PVA composite is better than nHAp without polymer. This study reports that reprocessing of eggshells to nHAp and its composites paves the way to recover the ecosphere and the obtained value-added product, which may use in making a promising material for bone implants, dental fillers and coatings at low cost.