Preparation and characterization of mesoporous hydroxyapatite with non-cytotoxicity and heavy metal adsorption capacity

Abstract

Mesoporous hydroxyapatite (MPHA) particles have recently gained a great deal of interest in a broad range of fields including biomedical fields, wastewater treatment and catalysis. In this paper, we describe a novel and convenient route to synthesise MPHA particles using calcium carbonate nanoparticle templates for the formation of mesopores in HA. In this method, both nano-CaCO₃ templates and HA are prepared simultaneously using calcium sucrate as a precursor by allowing the nano-CaCO₃ to embed in HA. Mesopores in HA are obtained by removing the template. The porosity of HA is confirmed by Brunauer–Emmett–Teller (BET) analysis and the average pore size (below 50 nm) is determined from Transmission Electron Microscopy (TEM) images. The synthesized material is noncytotoxic as confirmed by cytotoxicity studies, which makes it a potential candidate as a biomaterial for biomedical applications. Furthermore, the MPHA shows a superior adsorption ability towards Pb²⁺ Ni²⁺ and Cd²⁺ in aqueous solutions, and could also be used as an environmental-friendly material for wastewater treatment and water purification. Therefore, we believe that this simple and novel synthesis route for the fabrication of porous HA could be useful in fulfilling the current demand for HA in biomedical and water purification applications.