Anti-EGFR Aptamer-Conjugated Erythrocyte Membrane-Derived Nanoparticles for Targeted Doxorubicin Delivery

Conventional nanomedicines frequently suffer from rapid systemic clearance via the mononuclear phagocytic system (MPS) and off-targeting, which severely limits their therapeutic index. Recently, new attempts using cell membrane-derived nanoparticles (CDNs) have been proposed as a novel platform of drug carriers. To address these challenges, we report a biomimetic drug delivery platform utilizing erythrocyte-derived nanoparticles (EDNs) that leverage the actual "self" signaling of erythrocyte cell membranes. But many ligand functionalizations often rely on monoclonal antibodies, which are frequently hampered by antidrug antibody (ADA) response and limited tumor penetration due to their bulky size. In this study, we engineered a next-generation biomimetic nanocarrier by conjugating anti-EGFR targeting aptamers onto EDNs. And we successfully encapsulated doxorubicin (DOX) into EDNs using an optimized phosphate gradient method, achieving a high loading efficiency of 38% while preserving the structural integrity of membrane proteins. The size of Apt-EDNs-DOX was measured by the dynamic light scattering (DLS) method, 215 nm in diameter. Furthermore, <i>in vitro</i> assays confirmed that the aptamer-mediated targeting significantly enhanced intracellular drug delivery and selective cytotoxicity in MDA-MB-231 (EGFR+) compared to MDA-MB-453 (EGFR-). <i>In vivo</i> therapeutic evaluation in a tumor xenograft mouse model demonstrated significant tumor growth inhibition and a favorable safety profile compared with the free drug. These findings suggest that substituting antibodies with aptamers represents a crucial advancement in developing more stable, less immunogenic, and highly efficient targeted nanomedicines for clinical translation in cancer therapy.