Pannier Angela K, Wieland Julie A, Shea Lonnie D
Department of Interdepartmental Biological Sciences, Northwestern University, 2145 Sheridan Road E156, Evanston, IL 60208-3120, USA.
Acta Biomater. 2008 Jan;4(1):26-39. doi: 10.1016/j.actbio.2007.08.008. Epub 2007 Sep 1.
Substrate-mediated gene delivery describes the immobilization of gene therapy vectors to a biomaterial, which enhances gene transfer by exposing adhered cells to elevated DNA concentrations within the local microenvironment. Surface chemistry has been shown to affect transfection by nonspecifically immobilized complexes using self-assembled monolayers (SAMs) of alkanethiols on gold. In this report, SAMs were again used to provide a controlled surface to investigate whether the presence of oligo(ethylene glycol) (EG) groups in a SAM could affect complex morphology and enhance transfection. EG groups were included at percentages that did not affect cell adhesion. Nonspecific complex immobilization to SAMs containing combinations of EG- and carboxylic acid-terminated alkanethiols resulted in substantially greater transfection than surfaces containing no EG groups or SAMs composed of EG groups combined with other functional groups. Enhancement in transfection levels could not be attributed to complex binding densities or release profiles. Atomic force microscopy imaging of immobilized complexes revealed that EG groups within SAMs affected complex size and appearance and could indicate the ability of these surfaces to preserve complex morphology upon binding. The ability to control the morphology of the immobilized complexes and influence transfection levels through surface chemistry could be translated to scaffolds for gene delivery in tissue engineering and diagnostic applications.
底物介导的基因传递描述了将基因治疗载体固定到生物材料上的过程，通过使黏附细胞暴露于局部微环境中升高的DNA浓度来增强基因转移。表面化学已被证明会影响使用金上的烷硫醇自组装单分子层（SAMs）非特异性固定的复合物的转染。在本报告中，再次使用SAMs来提供一个可控表面，以研究SAM中聚乙二醇（EG）基团的存在是否会影响复合物形态并增强转染。EG基团的含量设定在不影响细胞黏附的百分比。非特异性地将复合物固定到含有EG端基和羧酸端基烷硫醇组合的SAMs上，比不含EG基团的表面或由EG基团与其他官能团组合而成的SAMs表面产生的转染效果要显著得多。转染水平的提高不能归因于复合物的结合密度或释放曲线。固定复合物的原子力显微镜成像显示，SAMs中的EG基团会影响复合物的大小和外观，并能表明这些表面在结合时保持复合物形态的能力。通过表面化学控制固定复合物形态并影响转染水平的能力可转化应用于组织工程和诊断应用中的基因传递支架。
