Department of Chemical Engineering, University of Massachusetts Lowell, One University Ave, Lowell, MA, 01854, United States.
Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, MA, 02155, United States.
Colloids Surf B Biointerfaces. 2019 Jun 1;178:276-284. doi: 10.1016/j.colsurfb.2019.02.055. Epub 2019 Feb 28.
Polyelectrolyte multilayers (PEMs) are a category of materials commonly used as coatings on surfaces that interact with cells. The properties of PEMs have been established to be controlled by not only polyelectrolyte choice, but by the identity of the initially applied (bottom) layer. In this work, 5-bilayer PEMs consisting of poly(diallyldimethylammonium chloride) (PDADMAC) and poly(sodium 4-styrenesulfonate) (PSS) were coated on gold-sputtered quartz substrates with different first layer materials. A final poly-l-lysine (PLL) layer was added to all PEMs to provide identical top layers conducive to cell growth. As in previous work, initial layer selection affected PEM roughness. All coated surfaces, including the PLL-only control, showed increased dispersive surface energy but decreased polar surface energy, as compared to uncoated surfaces. When human mesenchymal stem cells (hMSCs) were cultured on these surfaces, analysis through lateral cell imaging for the first 90 min and fluorescent staining after 1 day showed improved attachment on surfaces with a PDADMAC bottom layer. However, after 4 days, a higher cell density was observed on the PLL-only and uncoated control surfaces, indicating that the PEMs negatively affected hMSC proliferation. Both the long and short time period results did not correlate to any of the roughness and surface energy trends, indicating more complex interactions between the cells and the surface relating to charge distribution and functional group density.
聚电解质多层（PEMs）是一类常用于与细胞相互作用的表面涂层材料。已经确定 PEM 的性质不仅可以通过聚电解质的选择来控制，还可以通过最初应用的（底层）层的身份来控制。在这项工作中，由聚二烯丙基二甲基氯化铵（PDADMAC）和聚（对苯乙烯磺酸钠）（PSS）组成的 5 层 PEM 被涂覆在具有不同第一层材料的镀金石英衬底上。所有 PEM 都添加了最后一层聚-l-赖氨酸（PLL），以提供有利于细胞生长的相同顶层。与之前的工作一样，初始层选择会影响 PEM 的粗糙度。与未涂覆的表面相比，所有涂覆的表面（包括仅涂覆 PLL 的对照）显示出增加的分散表面能但降低的极性表面能。当人骨髓间充质干细胞（hMSCs）在这些表面上培养时，通过侧向细胞成像在前 90 分钟进行分析，以及在 1 天后进行荧光染色，显示出在具有 PDADMAC 底层的表面上附着性得到改善。然而，在 4 天后，在仅涂覆 PLL 和未涂覆的对照表面上观察到更高的细胞密度，表明 PEMs 对 hMSC 增殖产生负面影响。长和短时间周期的结果都与任何粗糙度和表面能趋势都没有相关性，这表明细胞与表面之间存在更复杂的相互作用，涉及电荷分布和官能团密度。
