Receptor selection in targeted small extracellular vesicles: comparative evaluation of EGFR- and NTSR1-mediated drug delivery in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains a leading cause of cancer-related mortality. Moreover, the clinical utility of conventional chemotherapies is limited by systemic toxicity and poor tumor selectivity. Receptor-targeted small extracellular vesicles (sEVs) represent a promising nanotechnology-based strategy for precision drug delivery; however, rational receptor selection remains insufficiently explored. We performed a comparative evaluation of epidermal growth factor receptor (EGFR)-targeted (GE11-sEVs) and NTSR1-targeted (RKPDIL-sEVs) sEVs for doxorubicin delivery in HCC models. GE11-sEVs exhibited efficient uptake in EGFR-overexpressing SK-Hep1 cells, triggered apoptosis through activation of p53 and cleaved PARP1, and significantly suppressed tumor growth in xenograft models. In contrast, RKPDIL-sEVs exhibited higher cellular uptake than control EVs (Ct-sEVs) in cells with high NTSR1 expression; however, it did not result in a significant increase in apoptotic responses. Furthermore, in vivo biodistribution analyses revealed that sustained tumor accumulation and therapeutic efficacy were achieved only with GE11-sEVs. Importantly, both formulations exhibited minimal systemic toxicity. Receptor expression alone is insufficient for effective sEV-mediated drug delivery. Instead, receptor-specific uptake efficiency and in vivo retention critically are critical determinants of therapeutic outcomes. This study highlights the importance of rational receptor selection and comparative validation—including informative negative results—in the design of targeted sEV-based nanomedicines for HCC.