Chlorogenic Acid-Embedded Hydrogel for Visual pH Monitoring and Enhanced Antibacterial Performance

Bacteria-infected wounds remain a major global biomedical challenge, with persistent inflammation and the lack of real-time monitoring significantly impairing wound healing. To address the limitations of conventional dressings, which often provide single-function and static treatment, we developed a multifunctional HP@CGA hydrogel based on methacrylated hyaluronic acid (HA-MA) and polyvinyl alcohol (PVA), incorporating chlorogenic acid (CGA) and bromothymol blue (BTB). In the presence of a photoinitiator, the methacryloyl groups of HA-MA undergo UV-induced free-radical polymerization to form a covalently crosslinked network, while PVA chains interact with the HA-MA backbone through hydrogen bonding and physical entanglement, resulting in a stable interpenetrating double-network structure. This integrated "treatment + monitoring" design offers a low-cost and convenient alternative to conventional wound dressings and separate sensing systems. Material characterization and preliminary experiments demonstrated that the hydrogel enabled visual pH detection within the range of 6.0-8.0 through distinct color changes. In addition, it exhibited excellent antibacterial activity, achieving antibacterial rates of 99.9% ± 0.08% against both S. aureus and E. coli. These results demonstrate the multifunctional performance of the HP@CGA hydrogel, including bacterial inhibition, inflammation alleviation, and real-time wound pH feedback, thereby providing a favorable microenvironment for infected wound healing. This work highlights the potential of HP@CGA hydrogel for precise and intelligent wound care.