Injectable immunomodulatory hydrogel with photothermal antibacterial activity for enhanced type H vessels formation and post-craniotomy scalp infection management

Post-craniotomy scalp infection with antibiotic-resistant bacteria remains a great challenge in neurosurgery clinical practice, which hinders the healing process and increases the risk of intracranial infection, thereby endangering life. In this study, a versatile injectable hydrogel dressing with antibacterial and angiogenic activity composed of Pluronic F-127, silk fibroin (SF), and graphene oxide quantum dots (GOQDs) is fabricated (F-127/SF/GOQDs). The hydrogel is rapidly formed through thermosensitive gelation at body temperature and has controllable degradation and good biocompatibility. In vitro studies show that the F-127/SF/GOQDs hydrogel demonstrates excellent antibacterial performance (including drug-resistant strains) through photothermal treatment (PTT) via disruption of cellular energy metabolism and membrane function. In the meantime, the F-127/SF/GOQDs hydrogel promotes endothelial cell migration and differentiation toward CD31 hi Emcn hi type H vessels. In vivo results using post-craniotomy scalp infection models show that the hydrogel significantly enhances bacterial clearance to accelerate wound closure, and promotes angiogenesis and the immune modulation, which are related to enhanced collagen deposition, re-epithelialization and, ultimately accelerates wound healing of post-craniotomy scalp infections. Collectively, this multifunctional F-127/SF/GOQDs hydrogel, with dual action of photothermal antibacterial efficacy and type H vessels-related angiogenesis promotion, emerges as an innovative injectable dressing with potential for advancing post-craniotomy scalp infection management.