NIR-II Fluorescence Imaging-Guided Photothermal Therapy with Amphiphilic Polypeptide Nanoparticles Encapsulating Organic NIR-II Dye

NIR-II fluorescence imaging-guided photothermal therapy is a potential tumor therapeutic that has exhibited accurate diagnosis and noninvasive therapy of tumors. Here, we developed an organic macromolecular nanoparticle (PFD) by encapsulating a fluorophore with an amphiphilic polypeptide. The PFD nanoparticle presented a uniform size of 70 nm with a slightly negative charge and exhibited superior photothermal conversion efficiency (40.69%), thermal imaging ability, and considerable photothermal stability. The PFD nanoparticle could accumulate at the tumor site by an enhanced penetration and retention effect and exhibited satisfactory fluorescence imaging and prominent photothermal inhibition effect. In vivo experiments demonstrated that PFD nanoparticles exhibited a prominent photothermal inhibition effect against the tumor. Meanwhile, the therapeutic procedure was monitored by both NIR-II fluorescence and infrared thermal imaging, which demonstrated that the PFD nanoparticles have a potential application in imaging-guided photothermal therapy of tumors.