Department of Chemistry and Biochemistry and the California NanoSystems Institute, University of California, Los Angeles, 607 Charles E. Young Drive South, Los Angeles, California 90095, USA.
J Am Chem Soc. 2012 Jan 11;134(1):247-55. doi: 10.1021/ja205524x. Epub 2011 Dec 22.
Understanding and controlling cell adhesion on engineered scaffolds is important in biomaterials and tissue engineering. In this report we used an electron-beam (e-beam) lithography technique to fabricate patterns of a cell adhesive integrin ligand combined with a growth factor. Specifically, micron-sized poly(ethylene glycol) (PEG) hydrogels with aminooxy- and styrene sulfonate-functional groups were fabricated. Cell adhesion moieties were introduced using a ketone-functionalized arginine-glycine-aspartic acid (RGD) peptide to modify the O-hydroxylamines by oxime bond formation. Basic fibroblast growth factor (bFGF) was immobilized by electrostatic interaction with the sulfonate groups. Human umbilical vein endothelial cells (HUVECs) formed focal adhesion complexes on RGD- and RGD and bFGF-immobilized patterns as shown by immunostaining of vinculin and actin. In the presence of both bFGF and RGD, cell areas were larger. The data demonstrate confinement of cellular focal adhesions to chemically and physically well-controlled microenvironments created by a combination of e-beam lithography and "click" chemistry techniques. The results also suggest positive implications for addition of growth factors into adhesive patterns for cell-material interactions.
理解和控制工程支架上的细胞黏附对于生物材料和组织工程非常重要。在本报告中，我们使用电子束（e-beam）光刻技术来制造细胞黏附整合素配体与生长因子的组合图案。具体来说，我们制造了具有氨氧基和苯乙烯磺酸盐官能团的微米级聚乙二醇（PEG）水凝胶。使用酮功能化的精氨酸-甘氨酸-天冬氨酸（RGD）肽来修饰 O-羟胺，通过肟键形成引入细胞黏附部分。碱性成纤维细胞生长因子（bFGF）通过静电相互作用与磺酸盐基团结合固定。如通过对 vinculin 和肌动蛋白的免疫染色所示，人脐静脉内皮细胞（HUVEC）在 RGD 和 RGD 和 bFGF 固定图案上形成了焦点黏附复合物。在存在 bFGF 和 RGD 的情况下，细胞面积更大。这些数据表明，细胞焦点黏附被限制在由电子束光刻和“点击”化学技术组合形成的化学和物理上得到很好控制的微环境中。结果还表明，在黏附图案中添加生长因子对于细胞-材料相互作用具有积极意义。
