紫花地丁提取环肽改性的抗菌表面制备及防污机制研究

Biofouling is an important factor affecting the efficient operation of ships, which seriously restricts the development of ships and ocean engineering. The use of traditional coatings will bring serious harm to the marine environment. Chinese herbal extracts are a source of green antifouling agents, which are environmentally friendly and meet the development needs of green ships. However, the preparation and antifouling mechanism of marine antifouling materials modified by antibacterial cyclotides is still unclear.The application is based on the biofouling of marine metal materials surface, and the antibacterial cyclotides separated and purified from Chinese medicine Viola philippica are selected. The extracted antibacterial cyclotides are bound to the surfaces of the marine metal using dopamine as a coupling agent to obtain the metal surfaces modified by antibacterial cyclotides. The mechanism of the antibacterial cyclotides with the surface of the substrate will be analyzed, and the effect of antibacterial cyclotides modification on the physical and chemical properties of metal surface will also be investigated. Biochemical examinations and structural characterizations will be effective in investigating antifouling mechanisms at molecular level by exploring the mechanisms of adhesion of marine fouling organisms and biofilm inhibition on cyclotides modified surfaces. Stability and timeliness of cyclotides modified surfaces were also studied, which provided a theoretical basis for design and practical application of antifouling and drag reduction surfaces of ship, and contributed to the ship's green antifouling and drag reduction.

生物污损是影响船舶高效运行的重要因素，制约了船舶与海洋工程的发展。传统船用涂料的使用会给海洋环境带来严重危害，而中药提取抗菌环肽是一种绿色的防污剂，符合绿色船舶发展的需要，但抗菌环肽修饰的船舶绿色防污材料的制备及防污机理尚不清楚。申请项目基于船用金属材料表面的污损问题，结合前期研究结果，拟从中药紫花地丁中分离、纯化抗菌环肽，利用多巴胺作为偶联剂将提取的抗菌环肽结合在船用金属表面，获得中药抗菌环肽修饰的金属表面；分析抗菌环肽与基底表面的作用机制，明确抗菌环肽改性对金属表面理化性能的影响规律；选择典型海洋污损生物，采用多种生化分析和结构表征手段，研究抗菌环肽修饰后的船用金属表面对海洋污损生物贴附和生物膜抑制等行为的影响规律，从分子层面揭示抗菌环肽修饰表面的防污机理，并研究抗菌环肽修饰表面防污性能的稳定性、时效性，为船舶防污减阻表面设计和实际应用提供理论依据，对船舶的绿色防污减阻做出贡献。

船体浸入海水中后，表面很快就会被生物附着，发生污损现象。污损生物在船体表面大量附着会增加船体的重量和表面航行摩擦力，增大船舶油耗，降低船舶运行效率，降低船舶的使用寿命。而目前常用的涂料多是含有铜离子的有机物，它的使用仍会给环境带来危害，因此，研发绿色的防污材料是目前船体防污减阻的研究方向。本研究从中药紫花地丁中分离、提取了抗菌肽，并将其结合在不锈钢基底表面，结果显示抗菌肽修饰的表面具有明显的抗菌防污性能；采用多重修饰的手段，将抗菌肽结合在不锈钢基底表面，获得具有抗菌防污性能的防污涂层，为提高抗菌肽在基底表面的结合量，本项目利用单分子多巴胺在弱酸性条件下与抗菌肽结合获得的衍生抗菌肽修饰不锈钢表面，并比较了其与传统多巴胺作为偶联剂结合抗菌肽的方法，结果显示衍生肽修饰法防污能力更强；利用反应离子刻蚀技术制备了防污微结构表面，利用抗菌肽修饰表面微结构获得了具有绿色协同防污性能的船体表面。针对上述抗菌肽及其衍生物修饰的防污表面，通过分析表面的物理化学性能，明确了抗菌肽及其衍生物改性对船体材料表面理化性能的影响规律，采集并分析材料表面的形貌参数及其对抗菌肽衍生物结合强度的影响，明确了表面参数与抗菌肽及其衍生物结合量、结合强度的关系，揭示表面结构参数对抗菌肽结合量的影响机制；对获得的抗菌肽及其衍生物修饰的防污表面开展实验室防污性能测试，根据防污表面对污损生物及其代谢产物的影响规律分析其防污性能，并探索了抗菌肽修饰后表面对海洋污损生物贴附和生物膜抑制等行为的影响规律，揭示了抗菌肽修饰表面的抗菌防污机理，研究了抗菌肽修饰表面防污性能的稳定性、时效性，结果为获得具有绿色防污性能的船体表面提供新的方法和理论依据。