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

Abstract

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.