The Polymer Society of Korea

Abstract

ROS-responsive drug delivery systems have emerged as a promising strategy for targeting the tumor microenvironment. In this study, we developed an injectable, ROS-responsive thermogel by conjugating doxorubicin (DOX) to octanoyl glycol chitosan (OGC) via a thioketal (TK) linker. The degree of substitution of OGC and conversion efficiency of TK-DOX were calculated using ¹H-NMR and FT-IR, while the drug content of the OGC-TKDOX conjugate was determined via UV-Vis spectroscopy. Screening results indicated that OGC10-based conjugates failed to undergo phase transition, while OGC14 conjugates with a feed ratio ≥ 0.06 exhibited gelation even at 4°C. Consequently, OGC14-TKDOX with a 0.04 feed ratio was identified as the optimal candidate, demonstrating a reversible sol-gel transition around 30°C at 3.0–3.5 wt%. This optimized thermogel is expected to provide sustained, ROS-specific drug release, offering a potent platform for localized cancer therapy.