Tumor-Targeting W18O49 Nanoparticles for Dual-Modality Imaging and Guided Heat-Shock-Response-Inhibited Photothermal Therapy in Gastric Cancer

Photothermal therapy (PTT) is an emerging noninvasive and precise localized therapeutic modality; however, it is deeply limited by its poor tumor accumulation, inadequate photothermal conversion efficiency, and the thermoresistance of cancer cells. Aimed at these shortcomings, tumor-targeting nanoparticles (iRGD-W18O49-17AAG) comprising carboxyl-group-functionalized W18O49 nanoparticles, integrin-targeting peptide iRGD, and HSP90-inhibitor 17AAG are developed. The W18O49 nanoparticles act as excellent PTT carriers and computed tomography (CT) imaging contrast agents. The ring type polypeptide iRGD promotes the accumulation of nanoparticles in the tumour and further penetration into cancer cells. The introduction of 17AAG can inhibit the heat-shock response and overcome the thermoresistance, thus increasing the curative effect of PTT and reducing the chance of tumor recurrence. The W18O49 nanoparticles can also be used to monitor and guide the phototherapeutic through CT and near-infrared fluorescence imaging after modification with Cy5.5. In addition, superior biosafety is also indicated in both preliminary in vitro and in vivo assessments. The potential of iRGD-W18O49-17AAG in tumor targeting, dual modality imaging-guided and remarkable enhanced PTT of gastric cancer with ignorable side effect both in vitro and in vivo, which may be further applied in clinic, is highlighted.