One-pot green reduction and surface decoration of graphene oxide nanosheets with PEGylated chitosan for application in cancer photothermal therapy

Background: The practical applications of reduced graphene oxide (rGO) nanosheets in cancer photothermal therapy (PTT) are still largely limited by their poor dispersion in serum-containing environment, irreversible aggregation and potential cytotoxicity.Methods: To conquer the above challenges, in this work, the PEGylated chitosan20k (PCS20k)-decorated rGO (PCS-rGO) nanosheets were developed by one-pot green reduction and PEGylation of GO nanosheets using PCS as a novel reducing and stabilizing agent.Significant findings: In addition to the decreased particle size, the reduction degree of GO nanosheets was significantly increased by raising the mass ratio of PCS20k and GO from 4/1 to 16/1. Notably, in the high salt and serum-containing milieu, distinct from GO nanosheets with massive aggregation, the PCS20k-rGO nano sheets exhibited virtually unchanged particle size (ca. 170 >> 200 nm), indicating their prominent dispersion due to the nearly neutral and PEG-rich surfaces. Importantly, under 808 nm near-infrared (NIR) irradiation, the PCS20k-rGO nanosheets exhibited photothermal conversion efficiency (77 = 67.7%) superior to GO nano sheets (77 = 55.0%). The in vitro cellular uptake and cytotoxicity studies revealed that the internalized PCS20k-rGO nanosheets effectively ablated cancer cells upon NIR-elicited hyperthermia (over 49 degrees C), suggesting their great potential in applications of cancer PTT.(c) 2022 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

This study successfully developed PCS20k-decorated rGO nanosheets, which exhibited excellent dispersion in high salt and serum-containing environment. These nanosheets had higher photothermal conversion efficiency under near-infrared irradiation and effectively suppressed the growth of cancer cells.