Breast Cancer–Targeted Doxorubicin Therapy via Folate-Conjugated Nanoliposomal Carriers

Abstract

Introduction: Targeted drug delivery systems have emerged as a promising strategy to enhance therapeutic efficacy and minimize off-target toxicity in cancer therapy. In this study, folic acid–conjugated nanoliposomes (FA-NLs) were developed as a selective delivery vehicle for doxorubicin (DOX) to folate receptor–overexpressing breast cancer cells (MCF-7).

Materials and Methods: FA-NLs were synthesized using the thin-film hydration method and loaded with DOX. The nanocarriers were characterized by SEM, TEM, and DLS to determine morphology, size distribution, and zeta potential. Drug encapsulation efficiency (EE%) and in vitro release profiles at physiological and acidic pH were assessed. Cytotoxicity was evaluated via MTT assay in MCF-7 cells. Cellular uptake was analyzed using fluorescence microscopy. Apoptosis induction was quantified through Annexin V/ PI flow cytometry.

Results: FA-NLs exhibited uniform spherical morphology with a mean particle size of 182 nm (PDI: 0.24) and a negative surface charge (−34 mV). The formulation achieved high DOX encapsulation (EE%: 92%) with drug loading of 2 %, and demonstrated pH-responsive sustained release over 50 h (~90% at pH 5.2 vs ~62% at pH 7.4). In MCF-7 cells, FA-NLs enhanced anticancer activity relative to non-targeted liposomes and free DOX, with the IC₅₀ decreasing from ~20 μM (free DOX; F5) to ~7 μM (FA/FL-DOX; folate-depleted; F1) (≈2.9-fold reduction). Flow cytometry confirmed stronger apoptosis induction, including higher late apoptosis compared with conventional DOX.

Conclusion: These results demonstrate the strong potential of FA-NLs as a smart nanocarrier system to enhance intracellular uptake and apoptosis-mediated anticancer efficacy of DOX in folate receptor–positive breast cancer cells, supporting further translational evaluation for precision oncology.