纳米酶:对抗细菌的新策略

由细菌引发的相关疾病和环境污染等问题引起了人们的高度重视,同时随着抗生素的使用,细菌的耐药性逐渐增强,人们急需开发新型抗菌剂。诸如溶菌酶、髓过氧化物酶等天然酶具有显著的抗菌能力,但其作为抗菌剂存在保质期短、生产成本高等缺点,很难大规模生产。因此,人们正探索寻求天然酶的替代品。纳米酶是新一代人工模拟酶,兼具纳米材料独特的理化性质和类酶催化活性,因其结构稳定、生产成本低等优点受到广泛关注。本文综述了纳米酶的抗菌机制和近期抗菌纳米酶的主要研究进展,并对未来该领域的研究进行展望。     

Functional Enzyme Mimics for Oxidative Halogenation Reactions that Combat Biofilm Formation

Transition‐metal oxide nanoparticles and molecular coordination compounds are highlighted as functional mimics of halogenating enzymes. These enzymes are involved in halometabolite biosynthesis. Their activity is based upon the formation of hypohalous acids from halides and hydrogen peroxide or oxygen, which form bioactive secondary metabolites of microbial origin with strong antibacterial and antifungal activities in follow‐up reactions. Therefore, enzyme mimics and halogenating enzymes may be valuable tools to combat biofilm formation. Here, halogenating enzyme models are briefly described, enzyme mimics are classified according to their catalytic functions, and current knowledge about the settlement chemistry and adhesion of fouling organisms is summarized. Enzyme mimics with the highest potential are showcased. They may find application in antifouling coatings, indoor and outdoor paints, polymer membranes for water desalination, or in aquacultures, but also on surfaces for food packaging, door handles, hand rails, push buttons, keyboards, and other elements made of plastic where biofilms are present. The use of natural compounds, formed in situ with nontoxic and abundant metal oxide enzyme mimics, represents a novel and efficient “green” strategy to emulate and utilize a natural defense system for preventing bacterial colonization and biofilm growth.     

基于超疏水和卤代过氧化物酶活性协同防污的氧化铈纳米涂层研究

目的 将特定防污功能的纳米粒子引入到环氧复合涂料中,制备具有超疏水和卤代过氧化物酶活性协同防污的氧化铈纳米涂层。方法 以环氧树脂和羟基封端的聚二甲基硅氧烷为基质,球形氧化铈（CeO₂）纳米颗粒为填料,采用溶液共混的制备方式,通过空气喷涂法构建氧化铈超疏水纳米涂层。借助X射线衍射仪、扫描电子显微镜、接触角测试仪等设备对涂层进行表征,并以典型海洋污损生物芽孢杆菌和三角褐指藻为研究对象分析涂层的防污性能。结果 当涂层中纳米氧化铈的质量分数为55%时,氧化铈纳米涂层具有超疏水特性,接触角达到153°,接触角滞后低至3°。在防污性能方面,相比于环氧复合涂层,超疏水氧化铈纳米涂层对三角褐指藻和芽孢杆菌的防污率分别为97.5%和97.3%。在存在过氧化氢和溴化铵的条件下,失去疏水性能的氧化铈涂层通过卤代过氧化物酶的活性减少了96.2%的三角褐指藻和96.8%的芽孢杆菌贴附。结论 该体系所构建的纳米涂层在初期可以利用其超疏水性能防污,后期利用其卤代过氧化物酶的活性防污,实现防污的长效性。