Curcumin Releasing Eggshell Derived Carbonated Apatite Nanocarriers for Combined Anti-Cancer, Anti-Inflammatory and Bone Regenerative Therapy.

Bone cancer or osteosarcoma is an aggressive cancer affecting the long bones and is treated by a combination of surgery and chemotherapy. Local drug delivery directly to the site of bone cancer and the use of plant-based drugs has been explored towards improving the efficacy and decreasing the toxicity of the anti-cancer drugs. Curcumin, derived from turmeric is highly effective against cancer cells and shows very low toxicity against normal cells. Bone repair is facilitated by use of bone substitutes such as bioceramics, amongst which the carbonated apatite (CA) nanocarriers closely mimic the natural bone mineral. In the current work, we have developed CA nanocarriers based local delivery of curcumin as an adjunct treatment for bone cancer. CA nanocarriers with 6 wt.% carbonate were prepared by wet chemical synthesis using synthetic derived (6SWCA) and eggshell derived (6EWCA) precursors along with hydroxyapatite (WHA) as a control. The X-ray diffraction (XRD) patterns showed the CAs to be phase pure with a mean crystallite size of 17 nm. The Fouriertransform infrared spectroscopy (FTIR) analysis of both CAs indicated the carbonate substitution as B-Type. The amount of carbonate substitution was observed to be around 6 wt.% using FTIR and CHNO elemental analyzer. The 6EWCA showed a greater loading (36%) and release (66%) of curcumin than 6SWCA and WHA nanocarriers. The bovine serum albumin (BSA) protein denaturation assay showed the curcumin loaded CAs to be highly anti-inflammatory while their anti-cancer activity was confirmed by the high cytotoxic activity against MG-63 human osteosarcoma cells. Conclusively, an eggshell derived apatite drug delivery system was found to be very suitable to cure osteosarcoma, prevent post-cancer inflammation and modulate bone repair and regeneration.