Reactive oxygen specie-induced photodynamic therapy activation by supramolecular strategy

Photodynamic therapy(PDT)agents may accumulate in skin and cause severe skin cytotoxicity.We report a pro-guest-based supramolecular strategy to selectively activate PDT in the reactive oxygen specie(ROS)overexpressed microenvironment,which is often existing in tumor and inflammatory tissues.PDT agents methylene blue(MB)and basic blue 17(BB17)are used as model drugs.When encapsulated by acyclic cucurbit[n]uril(CB[n]),the efficacy of PDT agents is significantly inhibited.By contrast,in the presence of ROS(H_(2)O_(2))and pro-guest,PDT agents are displaced and reactivated to show a dramatically enhanced PDT efficacy in cells.