Synthesis of luminescent Mg-incorporated hydroxyapatite by reflux condensation method: Photoluminescence, in-vitro drug release and kinetic studies

Abstract

The role of biomaterials in the field of medicine has immense applications because they are engineered to be in close proximity to the biological organ or tissue and thereby healing or replacing the damaged tissues or organs. These biomaterials are of natural and synthetic made of different components to interact with the biological system. They can be tailored in such a way either for therapeutic or diagnostic purposes. The focus of the present study is to prepare nanosized magnesium doped hydroxyapatite (Mg-HAp) using magnesium nitrate as the source of magnesium (Mg). The reflux condensation method was used to synthesize pure HAp and Mg-HAp samples that were subjected to microwave irradiation. XRD studies verify that the integration of Mg into HAp did not bring about any phase changes in HAp. Further, the changes in the lattice parameters of Mg-HAp show that Mg is well incorporated into the HAp lattice. FTIR and Raman spectroscopic investigations show the absence of the hydroxyl group, which adds to the confirmation of Mg substitution in the HAp lattice. Crystallinity and size of the Mg-HAp decreased for microwave irradiated samples compared to as-synthesized samples because of the uniform heating of the sample. The morphology of Mg-HAp samples further indicates that particle size reduces with increasing Mg concentration which was proven by SEM results. Photoluminescence spectra of microwave irradiated Mg-HAp samples exhibit increased intensity for increased Mg concentration because of the blocking of recombination of charge carriers. The self-luminescent property of Mg-HAp particles, which is because of their surface plasmon, can be used in imaging and drug delivery applications.