Sensitivity of Protein Adsorption to Architectural Variations in a Protein-Resistant Polymer Brush Containing Engineered Nanoscale Adhesive Sites
Sensitivity of Protein Adsorption to Architectural Variations in a Protein-Resistant Polymer Brush Containing Engineered Nanoscale Adhesive Sites
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DOI：
10.1021/la203293k
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发表时间：
2011-12-20
期刊：
影响因子：
3.9
通讯作者：
Santore, Maria M.
中科院分区：
文献类型：
--
作者：
Gon, Saugata;Santore, Maria M.
片状聚合物刷含有纳米级（5-15 nm）粘合剂元件，例如聚合物线圈或纳米颗粒，其在表面上的随机位置处嵌入其基部。刷的空间（蛋白质抗性）排斥和来自离散粘合剂元件的吸引之间的竞争提供了控制生物粘附的精确手段。这与经典方法不同，经典方法将功能放在画笔的外围。目前的研究表明，聚（乙二醇）（PEG）刷结构和离子强度对纤维蛋白原吸附在含有嵌入式聚-L-赖氨酸（PLL，20 K MW）线圈或“补丁”刷的影响。纤维蛋白原吸附阈值的一致外观，在表面上的最小负载的补丁，低于蛋白质吸附不会发生，表明多价蛋白质捕获：吸附蛋白质同时从事几个补丁。阈值处的表面组成（贴片负载）对刷高度和离子强度极其敏感，PLL贴片的表面负载变化高达5倍（类似于可能表面范围的50%）。离子强度的变化也有类似的效果，最小的阈值出现在最大的德拜长度。虽然刷高度的趋势是最明显和最主要的，考虑到PEG负载内的刷或其持久性长度没有显示一个关键的刷参数的吸附开始。刷子物理学上缺乏直接相关性可能是多价结合的结果（产生对贴片负载的额外依赖性），并且可能在单价吸附到更强结合贴片上时得到解决。虽然将类似的刷子均匀放置在表面上的研究表明，刷子内的PEG负载是蛋白质抗性的最佳指标，但目前的结果表明，刷子高度对斑块状刷子更重要。产生与界面垂直的细胞刷延伸的相互作用可能类似地驱动侧向系绳延伸以阻塞贴片。
Patchy polymer brushes contain nanoscale (5-15 nm) adhesive elements, such as polymer coils or nanoparticles, embedded at their base at random positions on the surface. The competition between the brush's steric (protein resistant) repulsions and the attractions from the discrete adhesive elements provides a precise means to control bioadhesion. This differs from the classical approach, where functionality is placed on the brush's periphery. The current study demonstrates the impact of poly(etheylene glycol) (PEG) brush architecture and ionic strength on fibrinogen adsorption on brushes containing embedded poly-L-lysine (PLL, 20K MW) coils or "patches". The consistent appearance of a fibrinogen adsorption threshold, a minimum loading of patches on the surface, below which protein adsorption does not occur, suggests multivalent protein capture: Adsorbing proteins simultaneously engage several patches. The surface composition (patch loading) at the threshold is extremely sensitive to the brush height and ionic strength, varying up to a factor of 5 in the surface loading of the PLL patches (similar to 50% of the range of possible surfaces). Variations in ionic strength have a similar effect, with the smallest thresholds seen for the largest Debye lengths. While trends with brush height were the clearest and most dominant, consideration of the PEG loading within the brush or its persistence length did not reveal a critical brush parameter for the onset of adsorption. The lack of straightforward correlation on brush physics was likely a result of multivalent binding, (producing an additional dependence on patch loading), and might be resolved for univalent adsorption onto more strongly binding patches. While studies with similar brushes placed uniformly on a surface revealed that the PEG loading within the brush is the best indicator of protein resistance, the current results suggest that brush height is more important for patchy brushes. Likely the interactions producing brush extension normal to the interface act similarly to drive lateral tether extension to obstruct patches.