Surface analysis of erodible multilayered polyelectrolyte films: Nanometer-scale structure and erosion profiles
Surface analysis of erodible multilayered polyelectrolyte films: Nanometer-scale structure and erosion profiles
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DOI：
10.1021/la050596
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发表时间：
2005-06-21
期刊：
影响因子：
3.9
通讯作者：
Lynn, DM
中科院分区：
文献类型：
--
作者：
Fredin, NJ;Zhang, JT;Lynn, DM
利用原子力显微镜（AFM）和扫描电镜（SEM）结合椭偏光技术，研究了由可降解多胺1和聚苯乙烯磺酸钠（SPS）或质粒DNA制备的可降解多层膜的微尺度和纳米尺度结构。在37摄氏度的PBS缓冲液中孵育后，这两种材料在地形、结构和侵蚀剖面上发现了显著的差异。对于由SPS制成的薄膜，AFM数据与侵蚀过程一致，在大的微米尺度区域均匀发生，没有产生孔或坑。相比之下，由质粒DNA制成的薄膜经过结构重排，呈现出尺寸从50到400纳米的表面结合颗粒。通过扫描电镜对这些颗粒结构的进一步表征表明，它们与硅表面的聚电解质层相互渗透或融合，这为操纵这些颗粒与表面结合的附着力提供了一种潜在的机制。观察到的聚合物1/SPS薄膜的侵蚀剖面表明，有可能设计出具有明确释放动力学的释放两种膜组分的组件。在基因传递的背景下，在这些表面上以纳米粒子的形式呈现浓缩DNA可能有利于刺激细胞对DNA的内化和加工。定量了解影响这些材料的制造、结构和侵蚀剖面的因素，将有助于设计用于特定应用的多层组件，其中需要控制薄膜侵蚀或释放治疗材料。
Atomic force microscopy (AFM) and scanning electron microscopy (SEM) coupled with ellipsometry have been used to characterize the microscale and nanoscale structures of erodible multilayered films fabricated from degradable polyamine 1 and either sodium poly(styrene sulfonate) (SPS) or plasmid DNA. Striking differences were found in the topography, structures, and erosion profiles of these two materials upon incubation in PBS buffer at 37 degrees C. For films fabricated from SPS, AFM data are consistent with an erosion process that occurs uniformly without the generation of holes or pits over large, micrometer-scale areas. By contrast, films fabricated from plasmid DNA undergo structural rearrangements to present surface-bound particles ranging in size from 50 to 400 nm. Additional characterization of these particulate structures by SEM suggested that they are interpenetrated with or fused to underlying polyelectrolyte layers on the silicon surface, providing a potential mechanism to manipulate the adhesive forces with which these particles are bound to the surface. The erosion profile observed for polymer 1/SPS films suggests that it may be possible to design assemblies that release two film components with well-defined release kinetics. In the context of gene delivery, the presentation of condensed DNA as nanoparticles at these surfaces may be advantageous with respect to stimulating the internalization and processing of DNA by cells. A quantitative understanding of the factors influencing the fabrication, structure, and erosion profiles of these materials will be useful for the design of multilayered assemblies for specific applications in which controlled film erosion or the release of therapeutic materials is desired.