Multifunctional chitosan/gelatin@tannic acid cryogels decorated within situreduced silver nanoparticles for wound healing

Abstract

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 in situ 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 Staphylococcus aureus (S. aureus) and gram-negative bacterium Escherichia coli (E. coli) were cultured with the cryogels for 12 h. Meanwhile, S. aureus was introduced to cause bacterial infection in vivo. 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 S. aureus and E. coli. 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, in vivo 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.

In Vitro Release Kinetics of Nystatin and Tannic Acid in Artificial Body Fluids from Hydrogels Prepared by Using Polyvinylpyrrolidone Crosslinked with Tannic Acid

“…In previous research, NYS has shown broad‐spectrum fungicidal activity and effectiveness against some fungal infections resistant to Amphotericin B, making it a desirable compound in topical patches [40] . NYS release in addition to TA would greatly benefit in wound healing which is why TA was not washed from the hydrogel [41–44] …”

Mussel-inspired adhesive hydrogels for local immunomodulation

“…87,88 It has been reported that the reduction of nuclear p65 may promote the conversion of heterodimer p65/ p50 into homodimer p50/p50, and the increased p50/p50 could assist in the transcriptional upregulation of IL-10, which promotes M2c macrophage polarization through the IL-10R/STAT3 signaling pathway. 89,90 He et al reported that a TA/Mg 2+ coating manipulated the adhesion and morphology of macrophages, inhibited M1 polarization, exerted an anti-inflammatory effect, and promoted M2 polarization. 91 Dong et al utilized TA to assemble red blood cells (RBCs) onto a Ti surface, conferring anti-biological contamination and immunomodulatory properties to the implants.…”

Hydrogel-Based Strategies for the Management of Osteomyelitis

“…Xu et al fabricated a AgNP-embedded chitosan-gelatin hydrogel (CS/Gel@TA/Ag) for both anti-infection and wound-healing purposes. 104 Tannic acid was introduced as a reducing agent for in situ AgNP preparation, as well as a protecting agent that delays the release of Ag + and prevents direct AgNP/cell contact. CS/Gel@TA/Ag hydrogels were found to be bactericidal against both S. aureus and E. coli by reducing TNF-α and scavenging excessive ROS.…”

“…The AgNP-alginate-dopamine hydrogel also exhibited significant inhibition zones against S. aureus and E. coli , while no inhibition zone was observed for the alginate-dopamine group. Xu et al fabricated a AgNP-embedded chitosan-gelatin hydrogel (CS/Gel@TA/Ag) for both anti-infection and wound-healing purposes . Tannic acid was introduced as a reducing agent for in situ AgNP preparation, as well as a protecting agent that delays the release of Ag + and prevents direct AgNP/cell contact.…”