LAUSR

This study investigates the molecular mechanisms by which superparamagnetic iron oxide nanoparticles (SPIONs) loaded with the WSGC peptide (WSGC@FA@PEG/PEI‐SPIONs)—a 40‐amino acid polypeptide derived from apoC‐III—modulate chemotherapy resistance in gastric adenocarcinoma (GA). Emphasis is placed on their role in regulating mitophagy and mitochondrial homeostasis via the Notch signaling pathway. The physicochemical properties of WSGC@FA@PEG/PEI‐SPIONs are thoroughly characterized, demonstrating favorable biocompatibility, stable size distribution, and efficient peptide loading. In vitro experiments show that these nanoparticles significantly inhibit GA cell proliferation, migration, and invasion by downregulating mitophagy‐associated proteins (LC3, PINK1, and Parkin), primarily through modulation of the Notch pathway. In vivo studies, using a GA nude mouse model, confirm the therapeutic potential of WSGC@FA@PEG/PEI‐SPIONs, revealing marked tumor growth inhibition and increased apoptotic activity. Collectively, the findings highlight the WSGC peptide as a promising therapeutic agent for overcoming chemotherapy resistance in GA by targeting the Notch signaling pathway and suppressing mitophagy, thereby presenting a novel strategy for polypeptide‐based cancer therapy.