One-Pot Synthesis of MoS 2 Nanoflakes with Desirable Degradability for Photothermal Cancer Therapy.

Developing biodegradable photothermal agent holds great significance for potential clinical translation of photothermal therapy. In the current study, one-pot hydrothermal synthesis of MoS ₂ nanoflakes with desirable degradation capability was presented. The participation of poly(acrylic acid) (PAA) in hydrothermal process could not only facilitate the modification of polyethylene glycol (PEG), but also bestow degradability to the prepared MoS ₂ nanoflakes. Moreover, the PEGylated hybrid nanoflakes (MoS ₂ -PPEG) also exhibited excellent stability in various medium and outstanding photothermal properties. Interestingly, MoS ₂ -PPEG behaved distinctly different degradation rate in diverse condition. The rapid degradation of MoS ₂ -PPEG was observed in neutral pH solution, whereas much slower degradation occurred in an acidic tumor microenvironment. Furthermore, data indicated that the major degradation product of MoS ₂ -PPEG was water-soluble Mo-based ion. Meanwhile, the good in vitro biocompatibility of MoS ₂ -PPEG was also confirmed in terms of cytotoxicity and hemolysis. With favorable photothermal performance, MoS ₂ -PPEG can efficiently killing cancer cells in vitro and suppress the tumor growth in vivo. More importantly, the gradual decreasing content of MoS ₂ -PPEG in organs and detectable Mo element in urine of mice suggested that the degradability of MoS ₂ -PPEG might facilitate its excretion to some degree. Hence, the degradable MoS ₂ nanoflakes prepared by one-pot hydrothermal routine may provide insight for further biomedical applications of inorganic photothermal agent.