Promising Colloidal Rhenium Disulfide Nanosheets: Preparation and Applications for In Vivo Breast Cancer Therapy

Photothermal therapy (PTT) has become an important therapeutic strategy in the treatment of cancer. However, exploring novel photothermal nanomaterials with satisfactory biocompatibility, high photothermal conversion efficiency, and efficient theranostic outcomes, remains a major challenge for satisfying clinical application. In this study, poly-ethylene glycol modified rhenium disulfide (PEG-ReS(2)) nanosheets are constructed by a simple-liquid phase exfoliation method. The PEG-ReS(2) nanosheets were demonstrated to have good solubility, good biocompatibility, low toxicity, and strong capability of accumulating near-infrared (NIR) photons. Under 808 nm laser irradiation, the PEG-ReS(2) nanosheets were found to have an excellent photothermal conversion efficiency (PTCE) of 42%. Moreover, the PEG-ReS(2) nanosheets were demonstrated to be ideal photothermal transduction agents (PTAs), which promoted rapid cancer cell death in vitro and efficiently ablated tumors in vivo. Interestingly, the potential utility of up-regulation or down-regulation of miRNAs was proposed to evaluate the therapeutic outcomes of PEG-ReS(2) nanosheets. The expression levels of a set of miRNAs in tumor-bearing mice were restored to normal levels after PTT therapy with PEG-ReS(2) nanosheets. Both down-regulation miRNAs (miR-125a-5p, miR-34a-5p, miR-132-3p, and miR-148b-3p) and up-regulation miRNAs (miR-133a-3p, miR-200c-5p, miR-9-3p, and miR-150-3p) were suggested to be important clinical biomarkers for evaluating therapeutic outcomes of breast cancer-related PTT. This work highlights the great significance of PEG-ReS(2) nanosheets as therapeutic nanoagents for cancer therapy.