Preparation scheme of demonstrated injectable thermosensitive composite hydrogel. PECE hydrogel solutions were prepared by dissolving PECE copolymers in deionized water at a designated temperature then cooled to 4°C. Then, pluronic F127 were dissolved in icy cold deionized water to a transparent solution. Subsequently, the obtained two solutions were mixed together under mild agitation to obtain homogeneous liquid solution, and then drug were added into the composite hydrogel. The prepared hydrogel containing drug was inhaled into injector and injected into or around the focus of infection in animal. Thus, composite sol turned into gel state and acted as depots for sustained release of drug in situ when the cold sol is warmed to body temperature (37°C)in vivo. At last, for the degradation of the composite hydrogel, the introduced drug delivery system was gradually emanated from body.