A novel synthesis and characterization of bio-based hydroxyapatite obtained from a residue of eggshells

Abstract

Eggshell is a waste generated in high quantities worldwide and can be exploited since it is a rich source of Ca. It is estimated that it contains about 94 to 96% of CaCO3 and through a thermal process can be transformed into CaO, and this is an efficient precursor for the synthesis of hydroxyapatite (Ha), which is a biomaterial and due to its biological properties has been the subject of multiple studies of great importance in different branches of biomedicine. The purpose of this paper was to synthesize bio-based Ha from eggshells, using the precipitation method, eliminating the addition of NH4OH, used in the traditional synthesis, and making the washes with citric acid. The eggshells, CaO obtained, and bio-based Ha were characterized by FTIR-(ATR), XRD, and TGA, thus demonstrating the functional groups, crystalline structure, and thermal stability of each material. MTT assay on NIH-3T3 fibroblast cell line indicated that viability in each of the materials is not affected at different
concentrations (50, 100, and 200 μg/mL), as well as with modification in Ha synthesis. The biobased Ha presented cell viability of 110.7 % at a concentration of 200 μg/mL. Hence, the synthesized Ha shows potential for use in wound healing.