Multifunctional antibacterial intelligent hydrogel for infection detection and inflammation regulation to promote...

Infection remains a major barrier to diabetic wound repair and can lead to severe complications. Therefore, timely infection detection, effective antibacterial therapy, and sustained inflammation regulation are critical for successful wound healing. Here, we developed an intelligent hydrogel dressing that enables fluorescence-based infection indication while simultaneously providing coordinated antibacterial and anti-inflammatory therapy. The injectable hydrogel was constructed via dynamic boronate ester crosslinking between polyvinyl alcohol and phenylboronic acid-modified chitosan, and functionalized with BODIPY-loaded mesoporous polydopamine nanoparticles (mPDA@BP) and the fluorogenic substrate 4-Methylumbelliferyl-β-D-glucuronide (MUG). Upon cleavage of MUG by bacteria-secreted β-glucuronidase, the released 4-methylumbelliferone emits a blue fluorescence signal, enabling rapid visualization of infection progression. Meanwhile, mPDA@BP generates reactive oxygen species under light exposure for photodynamic antibacterial therapy, while maintaining sustained anti-inflammatory immunomodulation in the dark condition. Benefiting from its dynamic network, the hydrogel exhibits excellent injectability and conformal adaptability to irregular wound geometries. In an infected diabetic mouse wound model, this hydrogel significantly reduced bacterial burden and inflammatory responses, accelerated wound closure, and enhanced epidermal regeneration, collagen deposition, and angiogenesis. Collectively, this work presents a cost-effective theranostic hydrogel platform for integrated infection monitoring and coordinated diabetic wound therapy.