Nano-co-delivery Systems Combining Chemical and Photodynamic Therapy against Breast Cancer

Introduction Objective: Combination therapy is considered an effective strategy to improve cancer treatment outcomes. This study aimed to develop a Pluronic F127-based nano-codelivery system (FDC) encapsulating docetaxel (DTX) and chlorin e6 (Ce6) to enhance the efficacy of PDT using Ce6 and the chemotherapy effect of docetaxel (DTX).

FDC was prepared by the thin film hydration method. Particle size, polydispersity index (PDI), zeta potential, drug loading efficiency, and 7‑day colloidal stability were characterized. Cellular uptake, reactive oxygen species (ROS) generation (using DCFH‑DA and SOSG probes), cytotoxicity (MTT assay), apoptosis (flow cytometry), and live/dead staining were evaluated in 4T1 breast cancer cells under light irradiation (630 nm, 29.8 mW/cm², 5 min). Statistical comparisons used Student's t‑test or one‑way ANOVA, with p < 0.05 considered significant.

FDC exhibited a uniform hydrodynamic diameter of 200.33 ± 7.71 nm, a PDI of 0.392 ± 0.03, high drug loading efficiency, and good stability over 7 days. Compared with free Ce6, FDC significantly enhanced cellular uptake of Ce6 and markedly increased ROS generation upon light irradiation (p < 0.01). Cytotoxicity assays, apoptosis analysis, and live/dead staining also showed that FDC plus light induced the strongest anti-tumor effect, showing better antitumor effect than free Ce6, free DTX, and the physical mixture of Ce6+DTX Discussion: The improved anti-tumor effect of FDC may be related to enhanced cellular uptake of Ce6 and the co-delivery of DTX and Ce6.

The FDC nano-co-delivery system represents a promising strategy for chemotherapy combined with photodynamic therapy against breast cancer.