| Bacterial infection and antibiotic interference are the main obstacles to wound healing after skin damage.Bacterial colonization,prolonged inflammatory phase,angiogenesis difficulties,insufficient collagen deposition,and other metabolic syndromes,such as diabetes mellitus,can impede the wound repair process,therefore,the development of new multifunctional skin repair dressings without relying on antibiotics and accelerated infected wound healing is imminent.Electrical stimulation(ES)is an attractive emerging therapy.However,ES has limited healing effect as a stand-alone therapy because the electrodes are difficult to cover the wound surface completely and the wound remains in a state of impaired signaling,and it cannot provide the antimicrobial and anti-inflammatory microenvironment required for wound repair.Based on this,this study constructed a non-releasable antimicrobial conductive hydrogel(Polyvinyl alcohol/Borax/0.3 M 1-Vinyl-3-butylimidazolium bromide/Polyethylene glycol dimethacryl-ate,PBVP2)combined with exogenous ES and explored its physicochemical properties and biological efficacy.The main findings are as follows:Using free radical polymerization and dynamic cross-linking methods to construct PBVP2hydrogels,the optimal preparation process conditions were obtained by single-factor and orthogonal experiments:1-Vinyl-3-butylimidazolium bromide([VBIM]Br)was 0.3 mol/L,polyvinyl alcohol(PVA)was 10 wt%,borax was 0.3 wt%,polyethylene glycol dimethacrylate(PEGDA)was 0.1 wt%and freeze-thawing 2 times.The lyophilized hydrogels had a cross-linked porous structure by scanning electron microscopy.The results of physical and chemical properties indicated that the tensile stress of the hydrogels was 401.01 kPa,the water content and equilibrium swelling ratio were 81.03±0.02%and 210±9.31%,respectively,the protein adsorption was 124.68±8.97 mg/g,the water vapor transmission was 814.06±14.92 g/m~2/d,the optical transmittance was 90.25%,and the electrical conductivity was 0.095±0.013 S/m,which is suitable for the application of ES.Antibacterial experiments showed that the survival rate of Escherichia coli,Staphylococcus aureus,and Candida albicans under co-culture with PBVP2 hydrogel was less than 1%,indicating that the hydrogel exhibited a still showed good antibacterial performance after three times of repeated use.The anti-inflammatory results showed that the nitric oxide concentration of 0.22±0.07μM in the PBVP2 group was beneficial to stimulate cell division and promote wound healing.The biocompatibility results found that the cell survival rate could reach 95.10±3.10%and the relative hemolysis rate was 1.988±0.17%within 3 d.In addition,ES optimization results showed that cell activity was highest at a pulsed current of 0.25 m A,frequency of 2 Hz,and 30 min of treatment,and this condition promoted cell migration and secretion of basic fibroblast growth factor(b FGF).The PBVP2 hydrogel-treated wounds basically healed after 11 d in the rat model with acute infected wounds.It was found that PBVP2 hydrogel combined with ES therapy had faster wound healing rate and better wound recovery ability than PBVP2 hydrogel or ES alone,and had no toxicity to the heart,liver,spleen,lung,and kidney in bacteria-infected diabetic rats. |
