Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, 80523-1370, USA.
Colloids Surf B Biointerfaces. 2010 May 1;77(1):60-8. doi: 10.1016/j.colsurfb.2010.01.006. Epub 2010 Jan 20.
Nanoscale chemical and topographical features have been demonstrated to influence a variety of significant responses of mammalian cells to biomaterials surfaces. Thus, an important goal for biomaterials scientists is the ability to engineer the nanoscale surface features of biologically active materials. The goal of the current work is to demonstrate that polyelectrolyte complex nanoparticles (PCNs) in polyelectrolyte multilayers (PEMs) can be combined to create surfaces with controlled nanoscale surface topography and nanoscale presentation of surface chemistry. The polysaccharides used in this work are the biomedically relevant chitosan, heparin, and hyaluronan. Nanostructured surface coatings were characterized on both modified gold substrates and tissue-culture polystyrene surfaces. PCNs were adsorbed to oppositely charged PEMs, and were also embedded within PEMs. The construction of the surface coatings was characterized by quartz crystal microbalance with dissipation (QCM-D). The surface morphology was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The chemistry of the coatings was confirmed by both X-ray photoelectron spectroscopy (XPS) and polarization modulation infra-red reflection absorption spectroscopy (PM-IRRAS). Morphologically, we found that PCNs were colloidally stable and homogeneously distributed when adsorbed on or in the PEMs. Chemical analysis confirms that the PCNs adsorbed to PEMs significantly altered the surface chemistry, indicating significant surface coverage. Furthermore, the position of the PCNs normal to the surface can be adjusted by adding PEMs on top of adsorbed PCNs. Thus, PCNs can be used to introduce discrete nanoscale surface topographical features and varying surface chemistry into PEM surface coatings in a controlled way.
纳米级化学和形貌特征已被证明会影响哺乳动物细胞对生物材料表面的多种重要反应。因此，生物材料科学家的一个重要目标是能够对具有生物活性的材料的纳米级表面特征进行工程设计。目前这项工作的目的是证明聚电解质复合物纳米颗粒（PCN）在聚电解质多层膜（PEM）中可以结合在一起，从而创造具有受控纳米级表面形貌和纳米级表面化学呈现的表面。在这项工作中使用的多糖是生物医学相关的壳聚糖、肝素和透明质酸。在经过修饰的金基底和组织培养聚苯乙烯表面上对纳米结构表面涂层进行了表征。PCN 被吸附到带相反电荷的 PEM 上，并且也嵌入在 PEM 中。通过石英晶体微天平（QCM-D）对表面涂层的构建进行了表征。通过扫描电子显微镜（SEM）和原子力显微镜（AFM）对表面形貌进行了表征。通过 X 射线光电子能谱（XPS）和偏振调制红外反射吸收光谱（PM-IRRAS）确认了涂层的化学性质。形态学上，我们发现 PCN 在吸附到 PEM 上或在 PEM 中时是胶体稳定且均匀分布的。化学分析证实，吸附到 PEM 上的 PCN 显著改变了表面化学性质，表明表面覆盖率很高。此外，通过在吸附的 PCN 上添加 PEM，可以调整 PCN 垂直于表面的位置。因此，可以以可控的方式将离散的纳米级表面形貌特征和不同的表面化学引入 PEM 表面涂层中。
