This study described a valuable drug delivery system for poorly water-soluble anticancer naturalproduct, licochalcone A, isolated from Glycyrrhiza inflata , loaded on hollow gold nanoparticles by green method to improve solubility and dissolution and maintain its natural pharmacological property. Briefly, the formation of hollow gold nanoparticles involves three steps: preparing of silica nanospheres by Stober method, forming of a thick gold shell around the silica templates and etching of silica particles by HF solution. Hollow gold nanoparticles (HGNPs) and drug loaded hollow gold nanoparticles (L-HGNPs) displayed spherical structure and approximately 200nm in size observed by SEM, XRD, EDS and DSC analysis showed that HGNPs were gold hollow structure and crystalline form. The solubility in aqueous solution of licochalcone A was increased obviously to 488.9 μg/ml, compared with free drugs of 136.1 μg/ml. Another interesting finding is that near-infrared (NIR) irradiation increased the speed of solubility of licochalcone A in aqueous solutions, rather than quantity. In short, the method of nano-delivery system combined with poorly water-soluble drug to improve its solubility and dissolution is worth applying to other natural products in order to increase their opportunities in clinical applications.
This study aimed to investigate the antibiofilm activity and mechanism of licochalcone A (Lico A), a natural flavonoid compound, against biofilms of L. monocytogenes , S. aureus , and their dual-species, and evaluate the potential application of Lico A in beef. The minimum inhibitory concentration (MIC) of Lico A against both L. monocytogenes and S. aureus was 7.5 μg/mL. Crystal violet staining and confocal laser scanning microscopic analysis showed that Sub-MICs of Lico A remarkably inhibited the biofilm formation of mono- and dual-species of L. monocytogenes and S. aureus . Meanwhile, Lico A significantly reduced the extracellular polymeric substances (EPS) production and the metabolic activity of biofilms, causing decreases in surface hydrophobicity, auto-aggregation, and motility. Furthermore, Lico A inhibited autoinducer-2 signaling activity by binding to LuxS and suppressing luxS expression, which disturbed the interspecies communication and thereby impeded biofilm formation. Biofilm-related genes such as sigB , flaA , icaA , and SarA were also regulated by Lico A. Importantly, Lico A effectively inhibited the dual-species biofilms of S. aureus and L. monocytogenes on beef, decreasing by 1.1 and 1.0 log CFU/g, respectively, on day 7 of storage at 4 °C. These findings highlight the potential of Lico A as a natural antibiofilm agent, especially against mixed-species biofilms, in food industry applications.
危险品化学品经营许可证（带存储）