Enhancing curcumin's efficacy with zinc oxide nanoparticles: A dynamic duo in combatting disease

The combination of Zinc Oxide Nanoparticles (ZnO NPs) and Curcumin (Cur) has garnered significant attention due to its therapeutic potential (e. g., cancer treatment, wound healing, and antioxidant applications). CUR has been highly regarded as a natural compound with pharmacological properties such as anticancer, antimicrobial, and antioxidant effects; however, its clinical applications are limited due to its low solubility and bioavailability. In this review, the potentials of CUR and ZnO NPs in the case of biomedical applications were taken into consideration. There have been many attempts to integrate ZnO NPs and CUR for enhancing the mentioned drawbacks of CUR. The effectiveness of ZnO-Cur (CUR/ZnO NPs) nanocomposites, particularly in cancer therapies has been very promising. These nanocomposites exhibit selective toxicity towards cancer cells, with their pH-sensitive release mechanism proving advantageous in targeting the acidic tumor microenvironment. In addition to these effects, CUR/ZnO NPs have antioxidant activity, induce apoptosis in cancer cells, and promote wound healing. The use of ZnO and ZnO-Cur composites led to notable improvements across various applications such as osteoblast viability increased by approximately 60%, Cur release improved by 150%, and osteosarcoma inhibition enhanced by 300%. In agricultural use, ZnO NPs increased silybin content and plant yield while sperm cryopreservation studies showed improved post-thaw quality with ZnO-Cur by measurable margins, significantly. The role of ZnO in boosting Cur bioavailability, therapeutic efficacy, and targeted delivery potential have been confirmed in several studies. However, there are many unsolved challenges such as scalability, cytotoxicity data, and toxicity at higher concentrations that need to be addressed.