A biomolecule-assisted one-pot synthesis of zinc oxide nanoparticles and its bioconjugate with curcumin for potential multifaceted therapeutic applications

Here, milk protein casein was used as a reducing and capping agent for the biogenic synthesis of zinc oxide nanoparticles (ZnONPCS) with a mean size of similar to 9.2 nm. Further, its nanoconjugate with curcumin (ZnONPCS-Cur) with a mean size of 13.7 nm was prepared. ZnONPCS demonstrated excellent loading of curcumin, a popularly known anticancer phytochemical, with a loading capacity of 302.2 mg g(-1) and pH driven drug release up to 90% at pH 5.0. When applied in cancer cells, ZnONPCS-Cur demonstrated higher cytotoxicity to multiple cancer cell lines (breast, cervical, osteosarcoma and myeloma) than ZnONPCS or curcumin alone. We further observed that ZnONPCS could induce intracellular reactive oxygen species, thus causing cytotoxicity in cancer cells. We also observed that this cytotoxicity induced by ZnONPCS-Cur can be enhanced similar to 10% further using folate receptor-based targeting. Moreover, ZnONPCS-Cur demonstrated an enhanced anti-inflammatory activity of curcumin in RAW 246.7 cells. Both formulations exhibited excellent cytocompatibility to human keratinocyte and erythrocyte cells. Overall, we conclude that the ZnONPCS and curcumin nanoconjugate can demonstrate high anticancer and anti-inflammatory activity in vitro, and thus can be considered as a possible therapeutic nanoconjugate for future treatment of cancer.