Université de Strasbourg, CNRS, Institut Charles Sadron UPR 22, 67034 Strasbourg, France.
J Mater Chem B. 2020 May 28;8(20):4419-4427. doi: 10.1039/d0tb00456a. Epub 2020 Mar 18.
Peptide supramolecular self-assemblies are recognized as important components in responsive hydrogel based materials with applications in tissue engineering and regenerative medicine. Studying the influence of hydrogel matrices on the self-assembly behavior of peptides and interaction with cells is essential to guide the future development of engineered biomaterials. In this contribution, we present a PEG based host hydrogel material generated by oxime click chemistry that shows cellular adhesion behavior in response to enzyme assisted peptide self-assembly (EASA) within the host gel. This hydrogel prepared from poly(dimethylacrylamide-co-diacetoneacrylamide), poly(DMA-DAAM) with high molar fractions (49%) of DAAM and dialkoxyamine PEG cross-linker, was studied in the presence of embedded enzyme alkaline phosphatase (AP) and a non-adhesive cell behavior towards NIH 3T3 fibroblasts was observed. When brought into contact with a Fmoc-FFpY peptide solution (pY: phosphorylated tyrosine), the gel forms intercalated Fmoc-FFY peptide self-assemblies upon diffusion of Fmoc-FFpY into the cross-linked hydrogel network as was confirmed by circular dichroism, fluorescence emission spectroscopy and confocal microscopy. Nevertheless, the mechanical properties do not change significantly after the peptide self-assembly in the host gel. This enzyme assisted peptide self-assembly promotes fibroblast cell adhesion that can be enhanced if Fmoc-F-RGD peptides are added to the pre-gelator Fmoc-FFpY peptide solution. Cell adhesion results mainly from interactions of cells with the non-covalent peptide self-assemblies present in the gel despite the fact that the mechanical properties are very close to those of the native host gel. This result is in contrast to numerous studies which showed that the mechanical properties of a substrate are key parameters of cell adhesion. It opens up the possibility to develop a diverse set of hybrid materials to control cell fate in culture due to tailored self-assemblies of peptides responding to the environment provided by the host guest gel.
肽超分子自组装被认为是基于响应性水凝胶的重要组成部分，在组织工程和再生医学中有广泛的应用。研究水凝胶基质对肽自组装行为的影响以及与细胞的相互作用，对于指导工程生物材料的未来发展至关重要。在本研究中，我们展示了一种通过肟点击化学制备的基于 PEG 的主体水凝胶材料，该材料在主体凝胶中表现出对酶辅助肽自组装（EASA）的细胞黏附行为。这种水凝胶由聚（二甲基丙烯酰胺-co-二乙酰丙酮丙烯酰胺）（poly(DMA-DAAM)）和二烷氧基胺 PEG 交联剂组成，具有较高的 DAAM 摩尔分数（49%），在嵌入酶碱性磷酸酶（AP）存在的情况下进行了研究，同时观察到对 NIH 3T3 成纤维细胞的非黏附行为。当与 Fmoc-FFpY 肽溶液（pY：磷酸化酪氨酸）接触时，凝胶在 Fmoc-FFpY 扩散到交联水凝胶网络中时形成插入的 Fmoc-FFY 肽自组装，这一点通过圆二色性、荧光发射光谱和共聚焦显微镜得到了证实。然而，在主体凝胶中进行肽自组装后，其机械性能并没有显著变化。这种酶辅助的肽自组装促进了成纤维细胞的黏附，如果在预凝胶 Fmoc-FFpY 肽溶液中添加 Fmoc-F-RGD 肽，则可以增强细胞黏附。细胞黏附主要源于细胞与凝胶中存在的非共价肽自组装的相互作用，尽管其机械性能与天然主体凝胶非常接近。这一结果与许多研究结果形成了对比，这些研究表明，底物的机械性能是细胞黏附的关键参数。由于主体-客体凝胶提供的环境中肽的自组装可以响应，这为控制培养中的细胞命运提供了开发各种混合材料的可能性。
