Tristán Ferdinando, Palestino Gabriela, Menchaca J-Luis, Pérez Elías, Atmani Hassan, Cuisinier Frédéric, Ladam Guy
Advanced Materials Department, IPICYT, 78216 San Luis Potosi, Mexico.
Biomacromolecules. 2009 Aug 10;10(8):2275-83. doi: 10.1021/bm900453s.
The prevention of nonspecific protein adsorption is a crucial prerequisite for many biomedical and biotechnological applications. Therefore, the design of robust and versatile methods conferring optimal protein-resistance properties to surfaces has become a challenging issue. Here we report the unexpected case of polycation-ending polyelectrolyte multilayers (PEM) that efficiently prevented the adsorption of a negatively charged model protein, glucose oxidase (GOX). PEM films were based on two typical weak poyelectrolytes: poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA). No chemical modification of the polyelectrolytes was required and tunable GOX adsorption was possible by simply changing the buildup pH conditions. Protein-resistance properties are attributed to high film hydration becoming the predominant factor over electrostatic interactions. We explain this effect by oscillations of the internal PAA ionization state throughout the buildup, which results in an excess of carboxylic acid groups within the film. This excess acts as a reservoir of potential carboxylate groups compensating the outer PAH positive charges. Partial results indicated that the system was also resistant to the adsorption of a positively charged protein, lysozyme. Control of the internal ionization of weak polyelectrolyte multilayers might open a route toward simple tuning of protein adsorption. These results should help to rationalize the design of biomaterials, biosensors, or protein separation devices.
防止非特异性蛋白质吸附是许多生物医学和生物技术应用的关键前提。因此，设计出能赋予表面最佳抗蛋白质性能的强大且通用的方法已成为一个具有挑战性的问题。在此，我们报道了一种意外情况，即带有聚阳离子末端的聚电解质多层膜（PEM）能有效防止带负电荷的模型蛋白葡萄糖氧化酶（GOX）的吸附。PEM膜基于两种典型的弱聚电解质：聚（烯丙胺盐酸盐）（PAH）和聚（丙烯酸）（PAA）。无需对聚电解质进行化学修饰，通过简单改变组装pH条件就可以实现对GOX吸附的调控。抗蛋白质性能归因于高膜水合作用成为比静电相互作用更主要的因素。我们通过组装过程中内部PAA电离状态的振荡来解释这种效应，这导致膜内存在过量的羧酸基团。这种过量充当了潜在羧酸盐基团的储备，可补偿外部PAH的正电荷。部分结果表明该系统对带正电荷的蛋白质溶菌酶的吸附也具有抗性。控制弱聚电解质多层膜的内部电离可能为简单调节蛋白质吸附开辟一条途径。这些结果应有助于合理设计生物材料、生物传感器或蛋白质分离装置。
