Injectable and self-healable hydrogel based on pullulan polysaccharide loading platelet-rich plasma and metal-phenol network nanoparticles for infectious wound healing.

Due to elevated glucose levels, oxidative stress, weakened immune function, and delayed angiogenesis, diabetic wounds are difficult to heal. However, current dressings often do not successfully achieve the desired therapeutic outcome for diabetic wounds. Platelet rich plasma (PRP) is widely used in the treatment of diabetic wounds. Even so, the sudden release of growth factors or proteins in PRP frequently hampers the therapeutic efficacy. Therefore, it is of considerable clinical value to achieve long-term release of active molecules in PRP and to create more effective diabetic wound dressings. Here, PRP was combined with pullulan polysaccharide derivatives (OPD) and polylysine derivatives (EPL-BA) to form a multifunctional hydrogel backbone. Tea polyphenols (TP), gallic acid (GA), and metal ions (Cu) were utilized to prepare metal-phenol network nanoparticles (TGMPN) which were encapsulated in the hydrogel system. The EPL-BA/OPD/PRP/TGMPN (EOPM) composite hydrogel showed injectable and self-healing properties. The hydrogel system could effectively remove reactive oxygen species (ROS) and showed excellent antibacterial properties against different bacteria. The results showed that EOPM hydrogel was effective in reducing the inflammatory response and promoting the regeneration of blood vessels and neoplastic tissues, thus greatly accelerating the repair of infected wounds.