Development of Egg Shell Derived Carbonated Apatite Nanocarrier System for Drug Delivery.

Carbonated apatite has a chemical composition quite similar to biological apatite found in native bone. The incorporation of carbonate (CO2-3) ions groups into the apatitic crystal structure can tailor its crystallinity, solubility and biological activity that benefit the bone repair and regeneration. In this study, we report a simple and elegant method of synthesizing carbonated calcium deficient hydroxyapatite (ECCDHA) nanoparticles from egg shell wastes and its efficacy has been compared with synthetic calcium deficient hydroxyapatite (SCDHA) nanoparticles. Egg shell contains about 94% of calcium carbonate. Fourier transform infrared (FT-IR) spectroscopy results confirmed the carbonate substitution in the apatite as B-type and CHNS/O elemental analysis showed 6 wt.% of carbonate content in ECCDHA. Energy dispersive spectroscopy (EDS) analysis confirmed the presence of biologically relevant elements such as magnesium, strontium, fluoride, potassium etc., in ECCDHA inherited from the egg shell. In vitro cell culture studies confirmed that the ECCDHA is cellular compatible and it has enhanced cell adhesion and proliferation of L6 myoblast cells as compared to SCDHA. The potential of ECCDHA suitable for bone drug applications was tested with an antibiotic drug, doxycycline. The results showed higher drug loading and releasing for ECCDHA as compared to SCDHA during the period of study. Based on these results, the ECCDHA may be considered as a potential bone substitute and drug carrier system.