ROS Generative Black Phosphorus-Tamoxifen Nanosheets for Targeted Endocrine-Sonodynamic Synergistic Breast Cancer Therapy.

Introduction: Tamoxifen (TAM) has proven to be a therapeutic breakthrough to reduce mortality and recurrence in estrogen receptor-positive (ER+) breast cancer patients. However, the application of TAM exhibits low bioavailability, off-target toxicity, instinct and acquired TAM resistance. Methods: We utilized black phosphorus (BP) as a drug carrier and sonosensitizer, integrated with TAM and tumor-targeting ligand folic acid (FA) to construct TAM@BP-FA for synergistic endocrine and sonodynamic therapy (SDT) of breast cancer. The exfoliated BP nanosheets were modified through in situ polymerization of dopamine, followed by electrostatic adsorption of TAM and FA. The anticancer effect of TAM@BP-FA was evaluated through in vitro cytotoxicity and in vivo antitumor model. RNA-sequencing (RNA-seq), quantitative real-time PCR, Western blot analysis, flow cytometry analysis and peripheral blood mononuclear cells (PBMCs) analysis were performed for mechanism investigation. Results: TAM@BP-FA had satisfactory drug loading capacity, the TAM release behavior can be controlled through pH microenvironment and ultrasonic stimulation. An amount of hydroxyl radical (∙OH) and singlet oxygen ( Conclusion: The novel BP-based strategy not only delivers TAM specifically to tumor cells but also exhibits satisfactory antitumor effects through targeted therapy, SDT, and immune cell modulation. The nanoplatform may provide a superior synergistic strategy for breast cancer therapy.