基于仿生粘合和无铜“点击化学”的表面修饰及其抗污染性能研究

Biofouling arising from the protein adsorption and the microbial adhesion is of great concern in numerous biomedical and biotechnological applications, as the unwanted biofouling may reduce the sensitivity and service life of the medical devices and also result in the infections of medical implants. The development in coating technology has provided a library of surface chemistry treatments that can be utilized to combat biofouling. A commonly employed method in surface modification relies strictly on the careful selection of anchoring groups and post-functionalization strategies. In this study, the biomimetic catechol-containing anchors will be utilized to immobilize electron-deficient alkynyl groups on the stainless steel (SS) surfaces, while the subsequent copper-free alkyne-azide cycloaddition (AAC) will be used to introduce antifouling coatings onto the SS surfaces. The biomimetic catechol-containing anchors are a good alternative to the traditional chemical coupling agents, such as silanes and thiol compounds. They can be simply and versatilely prepared from the starting materials, and they exhibit strong adhesion to a variety of metal, metal oxide, and inorganic oxide substrates. The copper-free AAC is employed by eliminating a cytotoxic copper catalyst, allowing reaction to proceed environmentally-friendlily. It can be developed as a feasible and nontoxic strategy for the surface grafting of desired molecules or macromolecules. In details, we will firstly synthesize four catechol derivates with different alkynyl electronic environments, and immobilize them on the hydroxyl-riched SS surfaces. By comparing their surface reactivities with azido-containing fluorophore and poly(ethylene glycol) under the same condition, the most effective and easiest alkynyl-containing catechol derivate and its optimized reaction condition will be obtained. Secondly, we will prepare a series of azido-functionalized hydrophilic polymers and graft them onto the electron-deficient alkynyl-immobilized SS surfaces. The protein adsorption, and the bacteria and blood platelet adhesion on these polymer brushes-grafted SS surfaces will be studied. Finally, we will synthesize alkynyl-functionalized hyperbranched polyglycerol and azido-functionalized quaternized chitosan, and deposit these gel precursors onto the electron-deficient alkynyl-immobilized SS surfaces to form the hydrogel coatings. The stability as well as the antifouling properties of the hydrogel coatings will be evaluated.

表面蛋白质非特异性吸附和微生物粘附会降低医学设备的灵敏度和使用寿命，也会直接影响到医学植入材料的生物相容性。构建功能化的抗污染涂层是解决生物医学基材诸多问题的一种有效手段。成功的基材表面改性主要依赖于优异的且能够引入活性官能团的表面粘合剂以及高效的表面后修饰方法。含有儿茶酚官能团的分子在基材表面具有较强的粘附行为，所以本研究中我们利用含有缺电子炔烃的儿茶酚衍生物在基材表面引入“可点击”的炔基官能团，并通过高效的无铜催化叠氮-缺电子炔烃环加成（AAC）反应在表面接枝聚合物刷和凝胶抗污染涂层。我们还比较不同炔电子环境对表面无铜AAC的影响，以获取最易发生无铜AAC的炔基儿茶酚衍生物。相对于传统的硫醇化、硅烷化等表面粘合作用，基于儿茶酚衍生物的粘合剂为表面改性提供了一种简便且广式的固定活性官能团的方式。无铜AAC消除了铜催化“点击化学”中使用铜离子的潜在风险，为表面改性提供一种环境友好的选择。

表面蛋白质非特异性吸附和微生物粘附会降低医学设备的灵敏度和使用寿命，也会直接影响到医学植入材料的生物相容性。构建功能化的抗污染涂层是解决生物医学基材诸多问题的一种有效手段。成功的基材表面改性主要依赖于优异的且能够引入活性官能团的表面粘合剂以及高效的表面后修饰方法。含有儿茶酚官能团的分子在基材表面具有较强的粘附行为，所以本研究中我们通过儿茶酚表面仿生粘合作用：1)合成含有金刚烷以及偶氮苯的儿茶酚衍生物，利用主客体作用，将亲水性环糊精聚合物和两性离子修饰的环糊精接枝到医用钛片表面，构筑的两性离子环糊精以及环糊精聚合物修饰的钛片表面具有较强的抗污能力，能够抑制蛋白吸附以及细菌粘附;2)合成含儿茶酚基团的水溶性壳聚糖，通过儿茶酚基团的表面附着将其沉积到医用钛片表面，利用儿茶酚基团的氧化活性在表面进一步沉积纳米银颗粒，壳聚糖和纳米银颗粒共沉积的钛片表面具有较强的杀菌性能，几乎完全抑制细菌在表面的附着和生长，且具有较低的细胞毒性。.