One‐Step Synthesis of Iodinated Polypyrrole Nanoparticles for CT Imaging Guided Photothermal Therapy of Tumors

Abstract

Theranostic materials are of great significance to a personalized precise medicine. However, conventional theranostic agents are mainly fabricated by combining presynthesized independent imaging probes and therapeutic agents, suffering from multiple synthesis procedures, poor morphological control, and time/reagent‐consuming process. Herein, iodinated polypyrrole (I‐PPy) nanoparticles are fabricated via a one‐step synthesis strategy combining chemical oxidation and iodination for computed tomography (CT) imaging‐guided photothermal therapy. Iodic acid with a high standard electrode potential enables the chemical oxidation polymerization of pyrrole monomers. Meanwhile, the iodination of PPy induced by the corresponding reduction product I2 takes place during the polymerization process to generate I‐PPy nanoparticles. The prepared I‐PPy nanoparticles possess a uniform size, excellent colloidal stability, intense near‐infrared absorption, strong X‐ray attenuation ability, and favorable biocompatibility. The as‐synthesized I‐PPy nanoparticles not only guarantee remarkable contrast‐enhanced CT imaging of blood pool and tumors, but also realize effective tumor suppression in vitro and in vivo by I‐PPy nanoparticles‐mediated CT imaging‐guided photothermal therapy. To the best of the authors' knowledge, it is the first time that multifunctional PPy nanoparticles are fabricated through a one‐step synthesis process. The proposed strategy opens up a new way for the fabrication of high‐performance theranostic agents via a one‐step strategy under mild conditions.

Research Progress of Thermosensitive Hydrogel in Tumor Therapeutic

“…Various photothermal materials have been widely exploited as drug delivery carriers or coupling reagents for cancer therapy, including metal-organic frameworks and carbon dots [24][25][26][27]. Among these materials, conjugated polymer dots (Pdots) are biocompatible, degradable, and nontoxic biomaterial with easy functionalization.…”

“…Iohexol is an efficient and safe contrast agent approved by U.S. Food and Drug Administration for body computed tomography (CT) imaging [ 35 ]. However, the time of Iohexol for CT imaging is very short, and this inevitable shortcoming limits Iohexol widely used in the clinic [ 26 ]. Grating iohexol into Pdots-DOX-based thermosensitive hydrogel can successfully overcome this disadvantage of iohexol for enhanced CT imaging ability.…”

Recent progress in imaging technology combined with nanomaterials for medical applications

“…The commonly used contrast agent for CT is iodine‐containing organic molecules. Zou et al [11] prepared iodinated polypyrrole (I‐PPy) by chemical oxidation combined and iodination. CT imaging of I‐PPy revealed that CT value presented a linearly increasing trend with the concentration of I‐PPy solution.…”

Multifunctional microcapsules: A theranostic agent for US/MR/PAT multi-modality imaging and synergistic chemo-photothermal osteosarcoma therapy

“…[ 19 , 20 ] and organic materials (polydopamine nanoparticle, polypyrrole nanoparticle, etc.) [ 21 , 22 ], the scattered light interference, nonuniform heat distribution of the edges and low energy penetration into the deep tissue make them insufficient effect to completely eradicate tumor tissue, resulting in the incomplete tumor ablation and tumor recurrence [ 23 ].…”