Treatment of Maxillofacial Cancers by Zein Nanoparticles Loaded with Anticancer Peptide Pistacia Zardin1: Enhanced Cytotoxicity and Apoptosis Induction in Head and Neck Squamous Cell Carcinoma (HNSCC).

Head and neck squamous cell carcinomas (HNSCCs) are considered the most common histological type of head and neck cancer. This study aims to develop a drug delivery system based on zein protein nanoparticles (Zein NPs) to enhance the therapeutic effect of the anticancer peptide, Pistacia zardin1 (PZ1), for the treatment of maxillofacial cancers. PZ1-Zein NPs were synthesized by the desolvation method. These spherical nanoparticles (size: 162.8 nm, PDI: 0.27) showed high encapsulation efficiency (89%) and pH-responsive release (with higher drug release in the acidic tumor microenvironment). In vitro cytotoxicity assays showed that PZ1-Zein NPs significantly reduced IC50 values in HNSCC cell lines (e.g., SCC-25: 7.5 µM vs. 19.3 µM for free peptide, p < 0.001) while exhibiting improved selectivity for cancer cells over normal HaCaT cells. Mechanistic investigations confirmed that PZ1-Zein NPs significantly increased apoptosis, as shown by increased caspase-3/7 activity (5.8-fold vs. 2.6-fold). These findings highlight PZ1-Zein NPs as a promising nanomedicine strategy and a candidate functional component for future dual-functional scaffolds aimed at targeted hard tissue engineering and surgery in HNSCC management.