Monodisperse Polypyrrole Nanoparticles Prepared via γ-Ray Radiolysis of Water: An Efficient Near-Infrared Photothermal Agent for Cancer Therapy

Abstract

Biosafe nanoparticles with strong near‐infrared (NIR) light photothermal conversion effect can bring effective hyperthermia as one of the promising approaches in cancer therapy. In this work, a new facile and green preparation method of polypyrrole (PPy) nanoparticles based on 60Co γ‐ray radiation on a simple air‐saturated strong acidic aqueous solution of pyrrole (pH ≤ 1) is studied. According to the MCAP‐FACSIMILE simulation on the concentrations of the radiolysis products of water at the presence of H+ and O2, the main strong oxidative radiolysis products ·OH and H2O2 rapidly induce the polymerization of pyrrole. The size of the prepared PPy nanoparticles is about several tens of nanometers and can be controlled by the pH, the concentration of the stabilizer poly(vinyl alcohol), and the absorbed dose rate (the amount of energy absorbed per unit mass of the irradiated material within per unit of time). The PPy nanoparticles show rapid and remarkable NIR (808 nm) photothermal conversion efficiency up to 40.1% in water. Furthermore, the in vitro and in vivo experiments confirm that the prepared PPy nanoparticles exhibit enough strong NIR photothermal effect in tumor cells (4T1 and HeLa) and show a promising prospect as the NIR photothermal agent for the future cancer therapy.

Thermosensitive Lipid Bilayer-Coated Mesoporous Carbon Nanoparticles for Synergistic Thermochemotherapy of Tumor

“…The calipers and the following equation were applied to measure and compute the size of the tumor, respectively. The formula is that tumor volume = width 2 × length/2 . The major organs (heart, liver, spleen, lung, and kidney) and tumor were collected for hematoxylin and eosin (H&E) staining and terminal-deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay to determine the systemic toxicity of DOX and intratumoral late apoptosis respectively on the 15th day.…”

TLR-7/8 Agonist-Loaded Polypyrrole-Based Theranostic Nanovaccine for Second Near-Infrared Photothermal Immunotherapy of Cancer

“…However, minimal dosages of PPy NPs (<200 μg/mL) induced negligible long-term cytotoxicity in animals . PPy-based NPs have been studied in several morphologies in recent years, although they have been mostly explored for NIR-I PTT. − However, the strong NIR-II absorbance rate of PPy and photothermal immunotherapy (PIT) have been mostly unexplored and rarely addressed. Moreover, pure PPy NPs have weak aqueous solubility, which limits their use in tumor PTT.…”

NIR‐Responsive Fe3O4@MSN@PPy‐PVP Nanoparticles as the Nano‐Enzyme for Potential Tumor Therapy

“…Mesoporous nanomaterials have been widely used in the biomedical industry for their low toxicity, adjustable pore size, large specific surface area, and easy surface modification [10] . Among many organic photothermal conversion materials, polypyrrole (PPy) nanoparticles have attracted much attention because they have a good biocompatibility and can convert the near‐infrared (NIR) light into thermal energy [5a,6d,11] . Nevertheless, the polymerization ability of pyrrole at α and β sites makes it difficult to form ordered structures like spheres or nanotubes, which limits the biological application [12] .…”