摘要： Functionalized nanomaterials with near-infrared (NIR) responsive capacity are quite promising for theranostic treatment of tumors, but formation of NIR responsive nanomaterials with enhanced theranostic ability and excellent biocompatibility is still very challenging. Herein, PEGylated indocyanine green (ICG)-loaded polypyrrole nanoparticles (PPI NPs) were designed and successfully formed through selecting polydopamine as the linkage between each component, demonstrating enhanced NIR responsive theranostic ability against tumor. Combining in vitro cell study with in vivo assay, the formed PPI NPs were proved being fantastic biocompatible while effectively internalizing in HeLa cells and retaining in HeLa tumor demonstrated by in vitro flow cytometry/confocal measurement and in vivo photoacoustic imaging assay. With the guidance of photoacoustic imaging, successful photothermal ablation of tumor was achieved when treating with PPI NPs plus laser, which was much more effective than the group treated with NPs free of ICG. The greatly combined enhanced photoacoustic and photothermal effect is mainly ascribed to the functionalized polypyrrole nanoparticles, which could accumulate in tumor site more effectively with a relative longer retention time taking advantage of the nanomaterial-induced endothelial leakiness phenomenon. All these results demonstrate the designed PPI NPs possess enhanced NIR responsive property are to hold a great promise for tumor NIR theranostic applications.