The Vivian L Smith Department of Neurosurgery, McGovern Medical School at University of Texas Health Science Center at Houston, Houston, Texas, 77030.
Center for Stem Cell and Regenerative Medicine, Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, Texas, 77030.
J Biomed Mater Res A. 2017 Nov;105(11):3059-3068. doi: 10.1002/jbm.a.36160. Epub 2017 Aug 21.
Many studies have utilized Irgacure 2959 photopolymerized poly(ethylene glycol) (PEG) hydrogels for tissue engineering application development. Due to the limited penetration of ultraviolet light through tissue, Irgacure 2959 polymerized hydrogels are not suitable for use in tissues where material injection is desirable, such as the spinal cord. To address this, several free radical initiators (thermal initiator VA044, ammonium persulfate (APS)/TEMED reduction-oxidation reaction, and Fenton chemistry) are evaluated for their effects on the material and mechanical properties of PEG hydrogels compared with Irgacure 2959. To emulate the effects of endogenous thiols on in vivo polymerization, the effects of chain transfer agent (CTA) dithiothreitol on gelation rates, material properties, Young's and shear modulus, are examined. Mouse embryonic stem cells and human induced pluripotent stem cell derived neural stem cells were used to investigate the cytocompatibility of each polymerization. VA044 and Fenton chemistry polymerization of PEG hydrogels both had gelation rates and mechanical properties that were highly susceptible to changes in CTA concentration and showed poor cytocompatibility. APS/TEMED polymerized hydrogels maintained consistent gelation rates and mechanical properties at high CTA concentration and had a similar cytocompatibility as Irgacure 2959 when cells were encapsulated within the PEG hydrogels. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3059-3068, 2017.
许多研究都利用 Irgacure 2959 光聚合聚乙二醇（PEG）水凝胶来开发组织工程应用。由于紫外线在组织中的穿透有限，因此 Irgacure 2959 聚合水凝胶不适合在需要材料注射的组织中使用，例如脊髓。为了解决这个问题，评估了几种自由基引发剂（热引发剂 VA044、过硫酸铵（APS）/TEMED 氧化还原反应和 Fenton 化学）对 PEG 水凝胶的材料和机械性能的影响，与 Irgacure 2959 相比。为了模拟内源性巯基对体内聚合的影响，考察了链转移剂（CTA）二硫苏糖醇对凝胶速率、材料性能、杨氏模量和剪切模量的影响。使用小鼠胚胎干细胞和人诱导多能干细胞衍生的神经干细胞来研究每种聚合的细胞相容性。VA044 和 Fenton 化学聚合的 PEG 水凝胶的凝胶速率和机械性能都非常容易受到 CTA 浓度变化的影响，并且表现出较差的细胞相容性。APS/TEMED 聚合的水凝胶在高 CTA 浓度下保持一致的凝胶速率和机械性能，并且当细胞被包封在 PEG 水凝胶中时，其细胞相容性与 Irgacure 2959 相似。© 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3059-3068, 2017.
