A tumor-targeting black phosphorus-based nanoplatform for controlled chemo-photothermal therapy of breast cancer

Combination therapy with high efficacy and precision shows great potential in breast cancer treatment. Herein, we developed a multifunctional nanocarrier (NBP@mSiO₂-PEG-cRGD) for tumor-targeting chemo-photothermal therapy of breast cancer in a controlled manner. The nanocarrier was constructed by enveloping nano-sized black phosphorus (NBP) within a mesoporous silica shell (mSiO₂) modified with the tumor-targeting peptide c(Arg-Gly-Asp-dPhe-Cys) (cRGD). Due to the existence of pore channels within mSiO₂, NBP@mSiO₂-PEG-cRGD achieved high loading efficiency of indole-3-carbinol (I3C) molecules (NBP@mSiO₂-PEG-cRGD/I3C), an anti-tumor agent derived from food. Mediated by cRGD/integrin αvβ3 interaction, NBP@mSiO₂-PEG-cRGD/I3C reached breast tumors in a targeted manner. Once irradiated by the near-infrared laser, our nanocarrier exhibited superior photothermal conversion, which not only induced photothermal therapy but also facilitated the release of I3C from NBP@mSiO₂-PEG-cRGD/I3C within tumor cells to inhibit the activation of proto-oncogenic phosphoinositide 3-kinase (PI3K)-AKT signaling pathway and drive chemotherapy. All these attributes contributed to a satisfactory therapeutic effect toward breast tumors, manifesting in significant inhibition of cell proliferation, promotion of cell apoptosis, and reduction of tumor micro-vessel formation, which led to the efficient inhibition of tumor growth. Collectively, the nanocarrier developed here provided useful insights into the development of multifunctional platforms to effectively combat cancer.