Application of multilayer drug-loaded hydrogels in protection of open abdomen wounds.

Abstract

Open abdomen (OA) therapy is crucial for managing severe abdominal infections, intra-abdominal hypertension, and trauma but often faces complications like infections and enteric fistulas. To address this, a novel multilayer drug-loaded hydrogel dressing was designed to promote wound healing. The dressing comprises a bottom layer of a carboxymethyl chitosan/aldehyde-modified hyaluronic acid (CC/HA-CHO) hydrogel loaded with Ag nanoparticles (AgNPs) for rapid gelation and broad-spectrum antibacterial action; a middle polyacrylamide (PAAm) gel layer loaded with interleukin-4 (IL-4) to polarize macrophages toward the M2 phenotype for tissue repair; and a top polydimethylsiloxane (PDMS) antifouling layer treated with oxygen plasma for enhanced adhesion and hydrophilicity. Characterization <i>via</i> FTIR, SEM, swelling tests, and drug release assays confirmed the hydrogel's structure, stability, and sequential release of AgNPs and IL-4. <i>In vivo</i> experimental results show that the percentage of wound closure in the drug-loaded hydrogel group reached approximately 30% on day 7, while that in the control group was only about 10%. Thus, the drug-loaded hydrogel can significantly accelerate wound healing of open abdominal wounds. This multifunctional hydrogel combines antibacterial, anti-inflammatory, and tissue-regenerative properties, offering a promising strategy for OA wound management.