DWI e.V. and Institute of Technical and Macromolecular Chemistry, RWTH Aachen, D-52056 Aachen, Germany.
Biomacromolecules. 2010 Dec 13;11(12):3375-83. doi: 10.1021/bm100881y. Epub 2010 Oct 29.
Biomaterials that prevent nonspecific protein adsorption and cell adhesion are of high relevance for diverse applications in tissue engineering and diagnostics. One of the most widely applied materials for this purpose is Poly(ethylene glycol) (PEG). We have investigated how micrometer line topography and substrate elasticity act upon the antiadhesive properties of PEG-based hydrogels. In our studies we apply bulk hydrogel cross-linked from star-shaped poly(ethylene oxide-stat-propylene oxide) macromonomers. Substrate surfaces were topographically patterned via replica molding. Additionally, the mechanical properties were altered by variations in the cross-linking density. Surface patterns with dimensions in the range of the cells' own size, namely 10 μm wide grooves, induced significant cell adhesion and spreading on the Acr-sP(EO-stat-PO) hydrogels. In contrast, there was only little adhesion to smaller and larger pattern sizes and no adhesion at all on the smooth substrates, regardless the rigidity of the gel. The effect of varied substrate stiffness on cell behavior was only manifest in combination with topography. Softer substrates with line patterns lead to significantly higher cell adhesion and spreading than stiff substrates. We conclude that the physical and mechanical surface characteristics can eliminate the nonadhesive properties of PEG-based hydrogels to a large extent. This has to be taken into account when designing surfaces for biomedical application such as scaffolds for tissue engineering which rely on the inertness of PEG.
用于组织工程和诊断等多种应用的生物材料，需要能防止非特异性蛋白质吸附和细胞黏附，聚乙二醇（PEG）是最常被用于此目的的材料之一。我们研究了微米级线形貌和基底弹性如何影响基于 PEG 的水凝胶的抗黏附特性。在研究中，我们应用了由星形聚氧化乙烯-聚氧化丙烯大分子单体交联而成的块状水凝胶。通过复制模塑对基底表面进行形貌图案化处理。此外，还通过改变交联密度来改变机械性能。细胞自身大小范围内的尺寸（即 10 μm 宽的沟槽）的表面图案，会显著诱导 Acr-sP（EO-stat-PO）水凝胶上的细胞黏附和铺展。相比之下，对于更小和更大的图案尺寸，只有很少的黏附，而在光滑的基底上则完全没有黏附，无论凝胶的刚性如何。基底刚度变化对细胞行为的影响仅在与形貌结合时才表现出来。具有线图案的较软基底会导致细胞黏附和铺展显著增加，而较硬基底则不会。我们得出结论，物理和机械表面特性可以在很大程度上消除基于 PEG 的水凝胶的非黏附特性。在设计用于生物医学应用的表面（例如组织工程支架）时，必须考虑到这一点，因为这些应用依赖于 PEG 的惰性。
