LHRH-Targeted Redox-Responsive Crosslinked Micelles Impart Selective Drug Delivery and Effective Chemotherapy in Triple-Negative Breast Cancer.

Systemic chemotherapy is efficacious against triple-negative breast cancer (TNBC), but it is often associated with serious side effects. Here, a luteinizing hormone-releasing hormone (LHRH) receptor-targeted and tumor microenvironment-responsive nanoparticle system to selectively deliver chemotherapeutic drugs to TNBC cells, is reported. This delivery system (termed "LHRH-DCMs") contains poly(ethylene glycol) and dendritic cholic acid as a micellar carrier, reversible intra-micellar disulfide bond as a redox-responsive crosslink, and synthetic high-affinity (D-Lys)-LHRH peptide as a targeting moiety. LHRH-DCMs exhibit high drug loading efficiency, optimal particle size, good colloidal stability, and glutathione-responsive drug release. As expected, LHRH-DCMs are more efficiently internalized into human TNBC cells through receptor-mediated endocytosis, resulting in stronger cytotoxicity against these cancer cells than the non-targeted counterpart when encapsulated with paclitaxel (PTX). Furthermore, near-infrared fluorescence and magnetic resonance imaging demonstrate that LHRH-DCMs facilitate the tumor distribution and penetration of payloads in three different animal models of breast cancer, including cell line-derived xenograft (CDX), patient-derived xenograft (PDX), and transgenic mammary carcinoma. Finally, in vivo therapeutic studies show that PTX-LHRH-DCMs outperform both the corresponding nontargeted PTX-DCMs and the current clinical formulation (Taxol) in an orthotopic TNBC model. These results provide new insights into approaches for precise drug delivery of TNBC.