Multifunctional chitosan/gelatin@tannic acid cryogels decorated with reduced silver nanoparticles for wound healing.

BACKGROUND

Most traditional wound dressings only partially meet the needs of wound healing because of their single function. Patients usually suffer from the increasing cost of treatment and pain resulting from the frequent changing of wound dressings. Herein, we have developed a mutifunctional cryogel to promote bacterial infected wound healing based on a biocompatible polysaccharide.

METHODS

The multifunctional cryogel is made up of a compositive scaffold of chitosan (CS), gelatin (Gel) and tannic acid (TA) and formed silver nanoparticles (Ag NPs). A liver bleeding rat model was used to evaluate the dynamic hemostasis performance of the various cryogels. In order to evaluate the antibacterial properties of the prepared cryogels, gram-positive bacterium () and gram-negative bacterium () were cultured with the cryogels for 12 h. Meanwhile, was introduced to cause bacterial infection . After treatment for 2 days, the exudates from wound sites were dipped for bacterial colony culture. Subsequently, the anti-inflammatory effect of the various cryogels was evaluated by western blotting and enzyme-linked immunosorbent assay. Finally, full-thickness skin defect models on the back of SD rats were established to assess the wound healing performances of the cryogels.

RESULTS

Due to its porous structure, the multifunctional cryogel showed fast liver hemostasis. The introduced Ag NPs endowed the cryogel with an antibacterial efficiency of >99.9% against both and . Benefited from the polyphenol groups of TA, the cryogel could inhibit nuclear factor-κB nuclear translocation and down-regulate inflammatory cytokines for an anti-inflammatory effect. Meanwhile, excessive reactive oxygen species could also be scavenged effectively. Despite the presence of Ag NPs, the cryogel did not show cytotoxicity and hemolysis. Moreover, experiments demonstrated that the biocompatible cryogel displayed effective bacterial disinfection and accelerated wound healing.

CONCLUSIONS

The multifunctional cryogel, with fast hemostasis, antibacterial and anti-inflammation properties and the ability to promote cell proliferation could be widely applied as a wound dressing for bacterial infected wound healing.