Curcumin-loaded zein nanoparticles: A quality by design approach for enhanced drug delivery and cytotoxicity against cancer cells.

Zein, a maize protein, has been explored for constructing potential biomaterial due to its hydrophobic nature, self-assembly capability, and biocompatibility. In its nanoparticulate form, zein is a promising material for drug delivery applications, particularly in cancer treatment. Despite the importance of colloidal stability for effective drug delivery, systematic studies investigating the effect of various surface modifying agents (MAs) on the zein nanoparticles (ZNPs)-based formulations are limited. This study employs quality-by-design (QbD) approach to optimize curcumin-loaded ZNPs, enhancing colloidal stability, size, and drug-encapsulation efficiency using different MAs for potential cancer therapy. Gum arabic (GA) emerged as the optimal stabilizer, with GA-stabilized curcumin-loaded ZNPs (GA-Cur-ZNPs) achieving a particle size of 184.8 ± 2.85 nm, zeta potential of -23.4 ± 0.56 mV and 87.1 ±1.55 % drug encapsulation efficiency, along with excellent colloidal stability over two months. The optimal formulation also demonstrated sustained release of Cur over 72 h. GA-Cur-ZNPs demonstrated lower IC values and higher anti-proliferative effects on three different cancer cell lines compared to the free drug, while also exhibiting superior intracellular uptake. With negligible toxicity to human dermal fibroblast cells, the optimized Cur-GA-ZNPs show promise for safe and effective killing of cancer cells.