Mikhail A S, Jones K S, Sheardown H
Dept. of Chemical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7.
Biotechnol Prog. 2008 Jul-Aug;24(4):938-44. doi: 10.1002/btpr.5.
Surface concentration of cell adhesion peptides is thought to play a role in the interactions between biomaterials and cells. The high density of functional groups at the periphery of dendrimers has been exploited in various applications, but their full potential for generating surfaces with high functional group concentrations has not yet been realized. Poly(dimethylsiloxane) elastomers were surface modified with both polyethylene oxide (PEO) and generation 3 diaminobutane dendrimers. PEO and the dendrimers were subsequently used as linker molecules for surface grafting of cell adhesion peptides. ATR-FTIR, X-ray photoelectron spectroscopy, and water contact angle results confirmed the successful attachment of the polymer linkers and peptides. Peptide grafting density was quantified by means of (125)I radiolabeling. Maximum surface peptide grafting density on dendrimer-modified surfaces was twofold greater than the maximum peptide grafting density achieved via the PEO linker. However, vascular endothelial cell adhesion was significantly greater on surfaces modified with the PEO linker, presumably due to the highly flexible PEO spacer making the peptide more accessible for binding with the cell surface receptors. These results suggest that, although peptide surface density may be important, optimizing surface density may not be sufficient for improving biological interactions.
细胞黏附肽的表面浓度被认为在生物材料与细胞之间的相互作用中发挥作用。树枝状大分子外围的高密度官能团已在各种应用中得到利用，但其产生具有高官能团浓度表面的全部潜力尚未实现。聚二甲基硅氧烷弹性体用聚环氧乙烷（PEO）和第3代二氨基丁烷树枝状大分子进行表面改性。随后，PEO和树枝状大分子用作细胞黏附肽表面接枝的连接分子。衰减全反射傅里叶变换红外光谱（ATR-FTIR）、X射线光电子能谱和水接触角结果证实了聚合物连接分子和肽的成功附着。通过（125）I放射性标记对肽接枝密度进行定量。树枝状大分子改性表面上的最大表面肽接枝密度比通过PEO连接分子实现的最大肽接枝密度高两倍。然而，血管内皮细胞在PEO连接分子改性表面上的黏附明显更强，推测是由于高度柔性的PEO间隔基团使肽更易于与细胞表面受体结合。这些结果表明，尽管肽表面密度可能很重要，但优化表面密度可能不足以改善生物相互作用。
