Design, biomimetic synthesis, and tumor photothermal therapy of peptide-based two-dimensional photothermal conversion nanomaterials

Biomimetic synthesis and molecular self-assembly are typical ways for creating functional artificial nanomaterials. Here we demonstrate a facile strategy for the fabrication of two-dimensional (2D) photothermal conversion materials (PTCMs) using peptide-mediated molecular self-assembly and biomimetic synthesis of silver sulfide (Ag₂S) nanoparticles on graphene oxide (GO) nanosheets. A bifunctional peptide, KIIIIKYWYAF, is designed for the formation of self-assembled peptide nanofibers (PNFs), which provides high affinity towards GO nanosheets and exhibits good ability to promote the biomimetic synthesis of Ag₂S nanoparticles with photothermal conversion (PTC) property. The toxicity and cancer therapeutic efficacy of the prepared 2D GO/PNF/Ag₂S PTCM are systematically evaluated in vitro and in vivo. The experimental results in vitro indicate that as-created PTCMs have good PTC efficiency and stability under 808 nm laser irradiation. In addition, the in vivo experimental results further prove that the as-designed 2D GO/PNF/Ag₂S PTCM shows better photothermal properties, high biocompatibility, and low cytotoxicity compared to other PTCMs. We believe that GO- and PNF-based green synthesis provides a flexible and reliable strategy for the construction of functional PTCMs for non-invasive tumor photothermal therapy, and the synthesized GO/PNF/Ag₂S nanocomposite could be used as a novel PTCM agent for NIR-induced tumor therapy.