PLG-g-mPEG Mediated Multifunctional Nanoparticles for Photoacoustic Imaging Guided Combined Chemo/Photothermal Antitumor Therapy

Under laser irradiation, photothermal therapy (PTT) effectively ablates tumors above 50 degrees C. However, hyperthermia can cause additional damage due to the inevitable heat spread to surrounding healthy tissue. Herein, nanoparticles named as GI@P NPs were designed for enhanced PTT with heat shock protein 90 (HSP90) inhibition at temperatures below 50 degrees C to achieve optimal cancer therapy and avoid surrounding damage. GI@P NPs were done by co-loading Garcinia cambogia acid (GA) and photosensitizer IR783 in polymer PLG-g-mPEG to form a nanomedicine, where IR783 with excellent photoacoustic (PA) signal acted as an excellent photothermal therapeutic agent that converted the laser energy into heat to kill tumor cells, GA was used as antitumor drug for chemotherapy and an inhibitor of HSP90 to overcome the heat resistance of tumors for efficient cryo-photothermal therapy, and PLG-g-mPEG can encapsulate IR783 and GA to increase biocompatibility and accumulate effectively in the tumor. After GI@P NPs were injected into the mice, we could observe that the PA signals gradually increased in the tumor region and showed the strongest PA signals at 12 h. Under laser irradiation, the tumor temperature of the mice could raise to about 43.5 degrees C, and the tumor was significantly inhibited after long-term monitoring by PA imaging. As a result, gentle PTT produced by GI@P NPs exhibited good antitumor effects at relatively low temperature and minimized nonspecific thermal damage to normal tissues. The GI@P NPs as nanomedicine enriched our understanding of various applications of polymeric carriers, especially in the biomedical field.