Vapor deposition synthesis of polypyrrole nanoparticles with a tunable photothermal conversion capacity.

• The synthesis of PPy nanoparticles (PPy-PVP NPs) using a vapor deposition method. • This method allows the formation of uniform PPy-PVP NPs at room temperature. • PVP 40kDa can ensure a better performance of the synthesized PPy-PVP NPs. In recent years, nanomaterials have aroused people's interest in the field of biomedicine. Polypyrrole (PPy) has become a research hotspot because of its simple synthesis, excellent photothermal conversion performance, and high biocompatibility. Here, we report the synthesis of PPy nanoparticles (PPy-PVP NPs) using a vapor deposition method, for tumor photothermal therapy. In this method, the slowly produced volatile pyrrole vapor was absorbed by the PVP (polyvinylpyrrolidone)/FeCl 3 aqueous solution. This slow vapor production and absorption allows the formation of uniform PPy-PVP NPs at room temperature. Then, the effects of the molecular weight of PVP on the photothermal property and anti-tumor efficiency of PPy-PVP NPs were compared. It was found that the selection of PVP 40kDa as the template and surface linker can ensure a better application performance of the synthesized nanomaterials. This work provides a theoretical basis for the rational design of nano-therapy carriers and biomedical applications. [ABSTRACT FROM AUTHOR]