Polyvinyl Alcohol–Lecithin Functionalized Biogenic Silver Nanocarriers as a Smart pH/Ros‐Responsive Delivery System for Curcumin‐Mediated Cancer Therapy

Elevated intracellular reactive oxygen species (ROS) levels are a characteristic feature of cancer cells and can be strategically exploited for drug delivery. In this work, ROS‐responsive nanocarriers were developed through the biogenic synthesis of silver nanoparticles (AgNPs) using Catharanthus roseus flower extract. The resulting AgNPs were subsequently functionalized with lecithin (LEC) and polyvinyl alcohol (PVA) to yield Ag@LEC‐PVA nanoparticles, which were then loaded with curcumin (CUR) to form Ag@LEC‐PVA‐CUR‐NPs. Comprehensive characterization using UV–vis spectroscopy, FTIR, SEM‐EDX, TEM‐DLS, XRD, and TGA confirmed successful synthesis, functionalization, and drug encapsulation. In vitro drug release studies demonstrated that CUR release was markedly enhanced in the presence of hydrogen peroxide (H 2 O 2 ), validating the ROS‐responsive behavior of the system. The Ag@LEC‐PVA‐CUR‐NPs exhibited potent cytotoxicity against MCF‐7 breast cancer cells (IC 50 = 10.8 ± 0.35 µg/mL) and notable anti‐inflammatory activity (IC 50 = 30.24 µg/mL). These findings highlight Ag@LEC‐PVA‐CUR‐NPs as a promising biogenic‐engineered nanoplatform for ROS‐mediated drug delivery in breast cancer therapy, offering improved therapeutic efficacy and reduced systemic toxicity compared to conventional chemotherapy.