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

Abstract

Jing Wang,1,* Weijian Chen,1,2,* Wenxiang Du,2 Hongjie Zhang,2 Matthias Ilmer,3 Lei Song,2 Yuan Hu,2 Xiaopeng Ma1 1Department of General Surgery, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, People’s Republic of China; 2State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui, 230026, People’s Republic of China; 3Department of General, Visceral, and Transplantation Surgery, Ludwig-Maximilians-University (LMU), Campus Grosshadern, Munich, 81377, Germany*These authors contributed equally to this workCorrespondence: Yuan Hu; Xiaopeng Ma, Email [email protected]; [email protected]: 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 (1O2) were as expected generated under ultrasound stimulation. TAM@BP-FA nanoplatform showed excellent internalization in both TAM-sensitive MCF7 and TAM-resistant (TMR) cells. Using TMR cells, TAM@BP-FA displayed significantly enhanced antitumor ability in comparison with TAM (7.7% vs 69.6% viability at 5μg/mL), the additional SDT further caused 15% more cell death. RNA-seq unraveled the TAM@BP-FA antitumor mechanisms including effects on cell cycle, apoptosis and cell proliferation. Further analysis showed additional SDT successfully triggering reactive oxygen species (ROS) generation and mitochondrial membrane potential (MMP) reduction. Moreover, PBMCs exposed to TAM@BP-FA induced an antitumor immune response by natural killer (NK) cell upregulation and immunosuppression macrophage reduction.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.Keywords: black phosphorus, breast cancer, sonodynamic therapy, tamoxifen, PBMC, combination therapy

Keywords

• black phosphorus
• breast cancer
• sonodynamic therapy
• tamoxifen
• pbmc
• combination therapy