Waters Dale J, Engberg Kristin, Parke-Houben Rachel, Hartmann Laura, Ta Christopher N, Toney Michael F, Frank Curtis W
Department of Chemical Engineering, Stanford University, 381 North-South Mall, Stauffer III, Stanford, CA 94305-5025, United States.
Macromolecules. 2010 Aug 24;43(16):6861-6870. doi: 10.1021/ma101070s.
Due to the biocompatibility of poly(ethylene glycol) (PEG), PEG-based hydrogels have attracted considerable interest for use as biomaterials in tissue engineering applications. In this work, we show that PEG-based hydrogels prepared by photopolymerization of PEG macromonomers functionalized with either acrylate or acrylamide end-groups generate networks with crosslink junctions of high functionality. Although the crosslink functionality is not well controlled, the resultant networks are sufficiently well ordered to generate a distinct correlation peak in the small angle x-ray scattering (SAXS) related to the distance between crosslink junctions within the PEG network. The crosslink spacing is a useful probe of the PEG chain conformation within the hydrogel and ranges from approximately 6 to 16 nm, dependent upon both the volume fraction of polymer and the molecular weight of the PEG macromonomers. The presence of a peak in the scattering of photopolymerized PEG networks is also correlated with an enhanced compressive modulus in comparison to PEG networks reported in the literature with much lower crosslink functionality that exhibit no scattering peak. This comparison demonstrates that the method used to link together PEG macromonomers has a critical impact on both the nanoscale structure and the macroscopic properties of the resultant hydrogel network.
由于聚乙二醇（PEG）具有生物相容性，基于PEG的水凝胶作为组织工程应用中的生物材料引起了广泛关注。在这项工作中，我们表明，通过光聚合用丙烯酸酯或丙烯酰胺端基官能化的PEG大分子单体制备的基于PEG的水凝胶会生成具有高官能度交联节点的网络。尽管交联官能度控制不佳，但所得网络的有序程度足以在小角X射线散射（SAXS）中产生与PEG网络内交联节点之间距离相关的明显相关峰。交联间距是水凝胶中PEG链构象的有用探针，范围约为6至16nm，这取决于聚合物的体积分数和PEG大分子单体的分子量。与文献中报道的交联官能度低得多且无散射峰的PEG网络相比，光聚合PEG网络散射中峰的出现还与压缩模量的提高相关。这种比较表明，用于连接PEG大分子单体的方法对所得水凝胶网络的纳米级结构和宏观性质都有至关重要的影响。
