Bacterial cellulose is an extracellular polysaccharide produced by microorganisms, offering advantages such as high water-holding capacity, flexibility, and biocompatibility. However, its lack of bactericidal activity hampers its wide application. Usnic acid, a secondary metabolite derived from lichens of the Usnea genus, is recognized for its antibacterial and anti-biofilm efficiency, coupled with anti-inflammatory properties. Its water insolubility presents challenges for wide utilization and stable release. Sanxan gel, a novel polysaccharide, exhibits exceptional freeze-thaw stability, suspension properties, and high elasticity, rendering it effective as a suspending agent to improve the bioavailability of water-insoluble drugs. In this study, a hydrogel membrane is designed by combining bacterial cellulose and usnic acid suspended in sanxan gel through a simple in situ microorganism fermentation. The obtained membranes demonstrate excellent ability for sustained drug release, strong eradication capability against tested bacteria in both in vitro and in vivo experiments, effective inhibition of biofilm formation, and excellent hemocompatibility and cytocompatibility. Additionally, the composite membranes promote wound healing with reduced inflammation and bacterial infection in a full-thickness wound infection model in mice. This study provides innovative insights and strategies for the development of functional dressings for infected wounds in future clinical applications.
Zhong Shi,Zhuangzhuang Shi,Mengmeng Wu,Yaqi Shen,Guoqiang Li,Ting Ma
Food-grade emulsion gels have attracted increasing attention in food and drug manufacturing, owing to their potential as novel delivery systems for lipophilic bioactive ingredients. Emulsion gels are structurally either a polymeric gel matrix with incorporated emulsion droplets (emulsion-filled gels), or a network of aggregated emulsion droplets (emulsion particulate gels). In this study, a novel emulsion gel was prepared by formulating an oil-in-water (O/W) emulsion stabilized by sanxan alone, followed by heating and cooling treatment, resulting in a structured solid system. Stable O/W type sanxan emulsion gels (SEGs) were obtained at sanxan concentration >0.5% ( w /w). Fluorescence microscopy results confirmed the adsorption of sanxan on oil droplet surfaces. The effect of temperature and sanxan/oil concentrations on the rheological and textural properties of the SEGs was evaluated: the SEG containing 1% (w/w) sanxan and 20% (w/w) sunflower oil exhibited excellent rheological and textural properties. Further, the addition of 10 mM Na + or 5 mM Ca 2+ greatly enhanced the thermostability of the SEG. The potential of SEGs as sustained-release delivery systems for β-carotene was also explored. The findings are of great interest for the development of novel delivery systems based on emulsion gels stabilized by sanxan for the sustained release of lipophilic components.
危险品化学品经营许可证（带存储）