C60-Decorated Melanin Nanoparticles Conjugated with Hyaluronic Acid for Synergistic Theranostic and Immunotherapy of Tumors under near-Infrared Excitation

Photodynamic therapy (PDT), a promising noninvasive tumor treatment strategy, is limited by poor biocompatibility, high cost, and complicated synthesis procedures of rare-earth up-conversion materials. Herein, natural melanin particles (MNPs), excellent photothermal therapy (PTT) materials, were found to significantly promote production of reactive oxygen species (ROS) under 808 nm irradiation when cross-linked with C60, whereas synthetic polydopamine had no such property. On the basis of this special character of MNP, MNP-C60-hyaluronic acid (MC60H) nanoparticles, independent of rare-earth up-conversion materials, were prepared for multimodal attack toward a tumor under 808 nm irradiation. After targeting recognition by hyaluronic acid (HA), MC60H could not only efficiently promote temperature rise and the production ROS in tumor but also activate the prominent immunotherapy and help tumor immunosuppressed M2-type macrophages transformed into antitumor M1-type. Under the premise of high biosecurity and simple preparing strategy, the versatile nanoparticle material, MC60H, is utilized for collaborative PTT, PDT, and immunotherapy under NIR excitation without participation of any rare-earth elements. The character of promoting ROS production of C60 by MNP, which is a natural biomaterial, is first reported in this paper, which provides a good demonstration of MC60H in application of a synergistic antitumor strategy without the dependence of traditional up-conversion material.