Department of Chemical and Biological Engineering, ECCH 111 CB 424, University of Colorado, Boulder, Colorado 80309, USA.
Biomacromolecules. 2009 Nov 9;10(11):3114-21. doi: 10.1021/bm900846m.
A rapid, water-soluble enzyme-mediated radical chain initiation system involving glucose oxidase and Fe(2+) generated hydrogels within minutes at 25 degrees C and in ambient oxygen. The initiation components were evaluated for their effect on polymerization rates of hydroxyethyl acrylate-poly(ethylene glycol)(575) diacrylate comonomer solutions using near-infrared spectroscopy. Increasing glucose concentration increased polymerization rates until reaching a rate plateau above 1 x 10(-3) M of glucose. A square root dependence of the initial polymerization rate on Fe(2+) concentration was observed between 1.0 x 10(-4) M and 5.0 x 10(-4) M of Fe(2+), whereupon excess Fe(2+) reduced final acrylate conversions. The glucose oxidase-mediated initiation system was employed for encapsulation of fibroblasts (NIH3T3s) into a poly(ethylene glycol) tetra-acrylate (M(n) approximately 20000) hydrogel scaffold demonstrating 96% (+/-3%) viability at 24 h postencapsulation. This first use of enzyme-mediated redox radical chain initiation for cellular encapsulation demonstrates polymerization of hydrogels in situ with kinetic control, minimal oxygen inhibition issues, and utilization of low initiator concentrations.
一种快速、水溶性的酶促自由基链引发体系，涉及葡萄糖氧化酶和 Fe(2+)，可在 25°C 和环境氧下在数分钟内生成水凝胶。使用近红外光谱法评估引发组分对羟乙基丙烯酰胺-聚(乙二醇)(575)二丙烯酸酯共聚单体溶液聚合速率的影响。增加葡萄糖浓度会增加聚合速率，直到达到 1 x 10(-3) M 以上的葡萄糖的速率平台。在 1.0 x 10(-4) M 和 5.0 x 10(-4) M 的 Fe(2+)之间，观察到初始聚合速率与 Fe(2+)浓度的平方根依赖性，此后过量的 Fe(2+)会降低最终丙烯酸盐转化率。将葡萄糖氧化酶介导的引发体系用于将成纤维细胞（NIH3T3）封装到聚(乙二醇)四丙烯酸酯（M(n)约 20000）水凝胶支架中，在封装后 24 小时内，细胞活力达到 96%（+/-3%）。这是首次将酶促氧化还原自由基链引发用于细胞封装，证明了水凝胶的原位聚合具有动力学控制、最小的氧气抑制问题以及低引发剂浓度的利用。
