Junjie Cai,Bo Liu,Wei Liu,Lina Liu,Zhe Fan,Song Lin
Biomimetic materials are of great significance in wide applications. As a bioactive polysaccharide , chitosan (CS) has attracted much attention in multiple fields. Inspired by the natural shark skin interface, herein, we proposed a methodology to obtain serial biomimetic CS/glycerol membranes via a facile mold casting and solvent evaporation process under mild aqueous conditions. The surface morphology , chemical structures , and physical characteristics of the developed membranes were determined by scanning electron microscopy, Fourier transformed infrared spectroscopy , tensile measurement, water vapor transmission rate, liquid uptake behavior, solubility, and dynamic water contact angle tests. Furthermore, in vitro and in vivo biological assays were performed, including antibacterial ability, hemostatic performance, hemolytic reaction, cytotoxicity evaluation, and contaminated wound healing assessment. Compared with the flat membranes, the micro-patterned CS/glycerol membranes show the higher water-absorbing ability (up to ca . [email protected] min), moderate tensile strength (8.5–14.7 MPa), superior bacteriostasis (84.9% to 98.6% against S. aureus , 84.3% to 99.6% against E. coli ), decent hemostat efficacy (within 75.7 s), low hemolysis rates (less than 0.5%), and benign cytotoxicity (84.2% to 98.4% of viability), which favor promoting contaminated wound healing. Thus, the biomimetic micro-patterned membranes improve bioactive performance and show the merits of simple operation, low cost, and easy scale-up. All these properties indicate that the hybrid micro-patterned membrane could be used as a suitable candidate for dermal wound dressings and open up the insights for developing other bionic interfaces in future potential applications.
Haibo Lou,Jian Wang,Yaping Wang,Yongdong Gao,Wei Wang
In this study, the probiotic characteristics of Enterococcus faecalis SN21-3 were explored by genotype and phenotype, and the safety of this strain was evaluated in vitro and vivo . The complete genome sequence of E. faecalis SN21-3 revealed basic genetic information and corresponding genes underlying its probiotic characteristics. In vitro experiments were performed with E. faecalis SN21-3, which showed prominent antimicrobial activity and excellent abilities of resistance to simulated gastrointestinal fluid, cholesterol assimilation, adhesion, and antioxidant. In addition, E. faecalis SN21-3 was susceptible to the most common antimicrobial agents, did not contain transferable resistance gene and pathogenic gene, and did not perform haemolysis reactions and gelatinase activity in vitro . Furthermore, in vivo experiments demonstrated that feeding E. faecalis SN21-3 to broilers for 28 days did not significantly affect their normal growth or blood biochemistry parameters. Moreover, H&E staining showed no evidence of lesions in the heart, liver, spleen, or kidney of the broilers. No migration of E. faecalis SN21-3 was observed in the heart, liver, spleen, kidney, or blood samples during the feeding trial, indicating that the bacteria did not cause infections. In summary, E. faecalis SN21-3 exhibits numerous probiotic characteristics and is sufficiently safe for use as a novel animal probiotic.
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