Synergistic anticancer and antimicrobial efficacy of betanin and IR806 co-encapsulated liposomes against triple-negative breast cancer

Breast cancer is the most often diagnosed malignancy in women, exceeding lung cancer with almost 2.3 million new cases per year. Triple-negative breast cancer (TNBC), comprising 10%-15% of cases, is distinguished by its aggressive development, high invasiveness, and restricted treatment alternatives. Patients with malignancies often exhibit impaired immune function, predisposing them to opportunistic infections, particularly those caused by<i>S. aureus (S. aureus)</i>. In this study, the development and characterization of a multifunctional liposomal nanosystem co-delivering betanin and IR806 dye (Bet-IR806-LPs) for the dual management of TNBC and bacterial infections was reported. The liposomes were formulated using soybean phosphatidylcholine (Soya PC), which enhanced drug encapsulation, stability, and biocompatibility. Bet-IR806-LPs exhibited strong photothermal (PTT) conversion efficiency under near-infrared (NIR) irradiation, enabling effective PTT and photodynamic therapy (PDT). Antibacterial assessment against<i>S. aureus</i>revealed potent inhibitory activity, with an IC₅₀of 5 μg ml^-1. Biocompatibility was confirmed in fibroblast cell models, while zebrafish assays provided further insights into nanomaterial safety through analyses of reactive oxygen species and apoptosis. Cytotoxicity studies in 4T1 TNBC cells demonstrated significant anti-proliferative and anti-migratory effects, with enhanced tumor cell ablation upon NIR irradiation mediated by combined PTT-PDT mechanisms. Collectively, Bet-IR806-LPs demonstrate promising dual functionality, integrating antibacterial and anticancer activities within a single nanosystem. These findings suggest their potential as a versatile therapeutic platform with clinical relevance for improving treatment outcomes in TNBC while simultaneously addressing bacterial co-infections.