Study on Dual-Targeted Liposomes Containing Curcumin-Copper Chelate in the Treatment of Triple-Negative Breast Cancer

Background: Triple-negative breast cancer (TNBC) remains primarily treated with chemotherapy due to the lack of effective therapeutic targets, but this approach carries significant systemic toxicity and a high risk of drug resistance. Curcumin (Cur), despite its multifaceted antitumor activity, faces limitations in clinical application due to poor water solubility and weak targeting properties. This study aims to develop a folate/mitochondria dual-targeted curcumin-copper chelate liposome (Cu-Cur DTLPs) formulation that enables copper accumulation within tumor cells and induces copper-mediated cell death, thereby providing an effective and relatively low-toxicity therapeutic strategy for triple-negative breast cancer. Methods: Curcumin-copper chelates (Cu-Cur) were first synthesized and characterized using mass spectrometry, NMR, and infrared spectroscopy. Subsequently, dual-targeted liposomes (Cu-Cur DTLPs) were prepared via the thin-film dispersion method, with systematic evaluation of particle size, zeta potential, encapsulation efficiency, and in vitro release profiles. In vitro cytotoxicity was assessed against 4T-1 and MDA-MB-231 cells using the MTT assay. In a 4T-1 tumor-bearing BALB/c mouse model, comprehensive evaluation of targeting efficiency, antitumor efficacy, and mechanisms of action was conducted via in vivo imaging, tumor volume monitoring, immunohistochemistry (detecting FDX1 and DLAT proteins), and TUNEL staining. Results: Cu-Cur DTLPs with a uniform particle size of approximately 104.4 nm were successfully synthesized. In vitro and in vivo studies demonstrated that compared to free curcumin and conventional liposomes, Cu-Cur DTLPs significantly enhanced drug accumulation in tumor tissues and exhibited effective tumor growth inhibition. Mechanistic studies confirmed that this formulation specifically accumulates copper ions within tumor cells, upregulates FDX1, promotes DLAT oligomerization, and induces mitochondrial dysfunction, thereby driving copper death. TUNEL staining ruled out apoptosis as the primary mechanism. Safety evaluation revealed no significant toxicity in major organs. Conclusions: The Cu-Cur DTLPs developed in this study effectively induce copper-mediated death in TNBC through a dual-targeted delivery system, significantly enhancing antitumor activity with favorable safety profiles. This establishes a highly promising novel nanotherapeutic strategy for TNBC treatment.