壳聚糖基抑菌抗氧化活性复合膜的制备及其性能研究

为获得具有良好功能特性的壳聚糖(CS)基复合膜材料,采用混合溶液浇筑法制备含有纳米细菌纤维素(nBC)、曲酸(KA)和姜黄素(CUR)的CS基抑菌抗氧化活性复合膜(CS/nBC/KA/CUR),考查不同组分复合膜的水分阻隔性能、机械性能、光学性能、抑菌活性和抗氧化活性。结果表明,CS/nBC/KA/CUR复合膜中各组分之间主要是通过氢键与范德华力相互作用,膜内部结晶度明显增强。相较于CS/nBC、CS/nBC/CUR和CS/nBC/KA复合膜,CS/nBC/KA/CUR复合膜的水溶性显著下降,水蒸气透过率比CS/nBC复合膜提升近24%,拉伸强度比CS/nBC/KA复合膜提高近3倍,断裂伸长率比CS/nBC/KA复合膜提高约1.8%,对E.coli的抑菌效果比其余复合膜平均提升约12.2%,ABTS自由基清除率比CS/nBC复合膜最高提升约35.2%。CS/nBC/KA/CUR复合膜结合了各组分的优势,在食品抑菌抗氧化活性包装材料的开发领域具有一定潜在价值。

Differential Antibacterial Effects of Chiral Co_(3)O_(4)

With the global spread of antimicrobial resistance,it is imperative to satisfy the need to develop novel antibacterial agents.Here,we synthesized chiral Co_(3)O_(4) nanoparticles (NPs) with obvious bactericidal effects.It was found that the circular dichroism (CD) spectra of L-Co_(3)O_(4) NPs and D-Co_(3)O_(4) NPs exhibited perfect mirror image inversion.Specifically,the survival rate of primary uterine fibroblast (PCS) cells reached above 90% by co-culturing with chiral Co_(3)O_(4) NPs.Besides,the chiral Co_(3)O_(4) NPs showed obvious killing ability on Gram-positive (Staphylococcus aureus);Gram-negative (Escherichia coli O157:H7) bacteria both in vitro and in vivo.Particularly,D-Co_(3)O_(4) NPs showed better antibacterial activity.Mechanistic studies confirmed that the level of reactive oxygen species level generated by D-Co_(3)O_(4) NPs was higher than that of L-Co_(3)O_(4) NPs.Overall,the synthesized D-Co_(3)O_(4) NPs have the potential to become a kind of novel antibacterial nanomaterials.