Facile exfoliation of MoS2 nanosheets by protein as a photothermal-triggered drug delivery system for synergistic tumor therapy

We report here a facile method to prepare molybdenum disulfide (MoS2) nanosheets using protein, with high near-infrared (NIR) absorbance and high-efficiency drug loading ratio, as a photothermal-triggered drug delivery system for synergistic tumor therapy. MoS2 nanosheets were prepared by physical ultrasonic exfoliation in the presence of bovine serum albumin (BSA), which not only acted as an auxiliary agent of ultrasonic exfoliation, but also functioned as a surfactant for MoS2 nanosheets. The resulting MoS2 nanosheets exhibited great stability and a high surface-area-to-mass that had a loading ratio of about 180% (w/w) of the anti-cancer drug, resveratrol (RV). Exposing MoS2 nanosheets in Raji cells for 3 h resulted in a 58.2% cellular uptake ratio and low cytotoxicity for an extra 21 h incubation. After loading RV onto MoS2 nanosheets (MoS2-RV), RV molecules could be released from the MoS2 surface, triggered by NIR laser irradiation (1 W cm(-2)), thus enhancing the cell viability inhibition effect. MoS2-RV at 24 h post-injection into tumor-bearing mice could passively target and accumulate to the tumor region and, along with NIR laser irradiation for 5 min, the tumor was efficiently ablated and exhibited no relapse. These results, including in vitro and in vivo tumor therapy studies, demonstrated an excellent synergistic tumor therapeutic effect of the NIR-controlled RV delivery and release system of MoS2-RV, in comparison with chemotherapy and photothermal therapy (PTT) alone.