Biggs Caroline I, Walker Marc, Gibson Matthew I
Department of Chemistry, ‡Warwick Medical School, and §Department of Physics, University of Warwick , Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom.
Biomacromolecules. 2016 Aug 8;17(8):2626-33. doi: 10.1021/acs.biomac.6b00662. Epub 2016 Jul 28.
Surface-grafted polymers have been widely applied to modulate biological interfaces and introduce additional functionality. Polymers derived from reversible addition-fragmentation transfer (RAFT) polymerization have a masked thiol at the ω-chain end providing an anchor point for conjugation and in particular displays high affinity for gold surfaces (both flat and particulate). In this work, we report the direct grafting of RAFTed polymers by a "thiol-ene click" (Michael addition) onto glass substrates rather than gold, which provides a more versatile surface for subsequent array-based applications but retains the simplicity. The immobilization of two thermoresponsive polymers are studied here, poly[oligo(ethylene glycol) methyl ether methacrylate] (pOEGMA) and poly(N-isopropylacrylamide) (pNIPAM). Using a range of surface analysis techniques the grafting efficiency was compared to thiol-gold and was quantitatively compared to the gold alternative using quartz crystal microbalance. It is shown that this method gives easy access to grafted polymer surfaces with pNIPAM resulting in significantly increased surface coverage compared to pOEGMA. The nonfouling (protein resistance) character of these surfaces is also demonstrated.
表面接枝聚合物已被广泛应用于调控生物界面并引入额外功能。由可逆加成-断裂链转移（RAFT）聚合反应衍生的聚合物在ω链端具有一个被掩蔽的硫醇，为共轭提供了一个锚定点，并且对金表面（包括平面和颗粒状）表现出高亲和力。在这项工作中，我们报道了通过“硫醇-烯点击”（迈克尔加成）将RAFT聚合物直接接枝到玻璃基板而非金表面上，这为后续基于阵列的应用提供了一个更通用的表面，同时保持了操作的简便性。本文研究了两种热响应性聚合物的固定化，即聚[聚（乙二醇）甲基醚甲基丙烯酸酯]（pOEGMA）和聚（N-异丙基丙烯酰胺）（pNIPAM）。使用一系列表面分析技术，将接枝效率与硫醇-金体系进行了比较，并使用石英晶体微天平与金替代体系进行了定量比较。结果表明，该方法能够轻松获得接枝聚合物表面，与pOEGMA相比，pNIPAM导致表面覆盖率显著提高。这些表面的抗污（抗蛋白质）特性也得到了证明。
