Melanin-like Nanoparticles Loaded with Angiotensin Antagonist for Improved Photothermal Cancer Therapy
The abnormal tumor growth induces solid stress in tumors, thus reducing blood perfusion. As a result, the impaired blood perfusion plus with dense interstitial matrix in tumors significantly reduce the penetration and efficacy of nanotherapeutics. In this study, we developed a losartan-loaded polydopamine nanoparticle (PLST) for enhanced delivery of nanoparticles to tumors and improved photothermal cancer therapy. Losartan, an angiotensin inhibitor, is also able to alleviate the solid stress in tumors. It was laden on polydopamine nanoparticle via π-π stacking and was released upon tumor extracellular acidity. PLST reduced collagen production in vitro along with lowered expression of profibrotic factors of TGF-β1, CCN2, and TIMP-1. The in vivo studies revealed that PLST reduced solid stress in tumors, and the amount of PLST accumulated in tumors was enhanced. The efficiency of photothermal ablation of tumors was significantly enhanced by using PLST.