A Locally Injectable, pH/ROS-Responsive Hydrogel Platform for Combination Therapy of Cervical Cancer with Anti-Fibrotic and Chemotherapeutic Agents

Background: The fibrous tumor extracellular matrix (ECM), driven by cancer-associated fibroblasts (CAFs), forms a physical barrier against drugs and immune cells, yet direct CAF elimination risks promoting metastasis. Methods: In this study, we developed a locally injectable hydrogel based on synergistic dynamic covalent crosslinking (imine and boronate ester bonds), enabling instant gelation, shear thinning, and dual-pH/ROS-responsive degradation. Two types of drug-loaded nanoparticles (NPs), coated with homotypic cell membranes, were incorporated into this hydrogel. In the acidic, reactive oxygen species (ROS)-rich tumor microenvironment (TME), the system responsively releases the antifibrotic drug SIS3 to reprogram CAFs while simultaneously delivering doxorubicin (DOX) specifically to tumor cells. Biological effects were evaluated in vitro using cell cultures and in vivo in mouse models. Results: This dynamic hydrogel-based co-delivery system effectively reprograms CAFs, reduces tumor mechanical stress, breaks the fibrotic barrier, and promotes the deep infiltration of chemotherapeutics and immune cells, thereby enhancing the efficacy of chemotherapy. Conclusions: This injectable pH/ROS-responsive dynamic covalent hydrogel, loaded with CAF- and cancer cell-targeting NPs, remodels the TME, enhances drug and immune cell penetration, and offers a promising biomaterial-based strategy for cervical cancer treatment.