Oregon Health & Science University, Department of Orthopaedics & Rehabilitation, 3181 Sam Jackson Park Road, Portland OR 97239, USA.
Eur Cell Mater. 2011 Jul 15;22:43-55; discussion 55. doi: 10.22203/ecm.v022a04.
Biological activity can be added to synthetic scaffolds by incorporating functional peptide sequences that provide enzyme-mediated degradation sites, facilitate cellular adhesion or stimulate signaling pathways. Poly(ethylene glycol) diacrylate is a popular synthetic base for tissue engineering scaffolds because it creates a hydrophilic environment that can be chemically manipulated to add this biological functionality. Furthermore, the acrylate groups allow for encapsulation of cells using photopolymerization under physiological conditions. One complication with the addition of these peptides is that aromatic amino acids absorb light at 285 nm and compete with the ultraviolet (UV)-sensitive photoinitiators such as IrgacureTM 2959 (I2959), the most commonly used initiator for cytocompatible photoencapsulation of cells into synthetic scaffolds. In this study we define non-toxic conditions for photoencapsulation of human mesenchymal stem cells (hMSC) in PEGDA scaffolds using a visible light photoinitiator system composed of eosin Y, triethanolamine and 1-vinyl-2-pyrrolidinone. This visible light photoinitiator produced hydrogel scaffolds with an increased viability of encapsulated hMSCs and a more tightly crosslinked network in one-third the time of UV polymerization with I2959.
生物活性可以通过将提供酶介导的降解位点、促进细胞黏附和刺激信号通路的功能肽序列整合到合成支架中得到增强。聚（乙二醇）二丙烯酸酯是组织工程支架的一种常用合成基质，因为它可以创造出亲水性环境，通过化学手段来添加这种生物功能。此外，丙烯酸酯基团允许在生理条件下使用光聚合来封装细胞。添加这些肽的一个复杂问题是，芳香族氨基酸在 285nm 处吸收光，并与紫外线（UV）敏感的光引发剂（如 IrgacureTM 2959（I2959））竞争，I2959 是最常用于将细胞包封到合成支架中的细胞相容性光聚合的引发剂。在这项研究中，我们使用由曙红 Y、三乙醇胺和 1-乙烯基-2-吡咯烷酮组成的可见光引发剂系统，确定了在 PEGDA 支架中光封装人骨髓间充质干细胞（hMSC）的无毒条件。该可见光引发剂在三分之一的时间内产生了具有更高封装 hMSC 活力的水凝胶支架，并且交联网络更紧密，而使用 I2959 进行 UV 聚合则需要相同的时间。
