NIR-Controlled HSP90 Inhibitor Release from Hollow Mesoporous Nanocarbon for Synergistic Tumor Photothermal Therapy Guided by Photoacoustic Imaging
Photothermal therapy (PTT) has been widely studied for tumor therapy. However, the clinical transformation of PTT has encountered great challenge for the tumor recurrence, because the uneven hyperthermia in tumor tissue can result in the survival of the cancer cells in the lower temperature region nearing blood vessels (due to the blood flow can dissipate the local heat), then it is significant for clinic to retain excellent therapeutic efficiency of PTT at relative lower temperature. In this article, innocuous hollow mesoporous carbon spheres (HMCS) with high photothermal conversion efficiency were obtained by a one-pot synthesis method. After modification with DSPE-PEG, the HMCS-PEG exhibited superior stability in biomedium, which is benefit to further biological applications. Interestingly, combined with hydrophobic gambogic acid (GA) which can downregulate heat shock protein 90 (HSP90), HMCS-PEG-GA system showed great NIR-enhanced tumor therapeutic effect in vitro and in vivo under mild temperature (~43oC), the combination index (CI) value of HMCS-PEG-GA is 0.72. Meanwhile, this nano-system possessed good photothermal imaging and photoacoustic imaging ability. Guided by photoacoustic imaging signal, HMCS-PEG-GA showed enormous perspectives in accurate tumor diagnosis and mild-temperature PPT treatment applications, which is very important for clinical transformation of this nano-system.