Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran.
Department of Systems and Synthetic Biology, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research Education and Extension Organization (AREEO), Karaj, Iran.
Sci Rep. 2022 Feb 8;12(1):2072. doi: 10.1038/s41598-022-06013-0.
Herein, four novel and bio-based hydrogel samples using sodium alginate (SA) and chitosan (CH) grafted with acrylamide (AAm) and glycidyl methacrylate (GMA) and their reinforced nanocomposites with graphene oxide (GO) were synthesized and coded as SA-g-(AAm-co-GMA), CH-g-(AAm-co-GMA), GO/SA-g-(AAm-co-GMA), and GO/CH-g-(AAm-co-GMA), respectively. The morphology, net charge, and water absorption capacity of samples were entirely changed by switching the biopolymer from SA to CH and adding a nano-filler. The proficiencies of hydrogels were compared in the immobilization of a model metagenomic-derived xylanase (PersiXyn9). The best performance was observed for GO/SA-g-poly(AAm-co-GMA) sample indicating better stabilizing electrostatic attractions between PersiXyn9 and reinforced SA-based hydrogel. Compared to the free enzyme, the immobilized PersiXyn9 on reinforced SA-based hydrogel showed a 110.1% increase in the released reducing sugar and almost double relative activity after 180 min storage. While immobilized enzyme on SA-based hydrogel displayed 58.7% activity after twelve reuse cycles, the enzyme on CH-based carrier just retained 8.5% activity after similar runs.
在此，使用丙烯酰胺（AAm）和甲基丙烯酸缩水甘油酯（GMA）接枝的海藻酸钠（SA）和壳聚糖（CH）合成了四个新型生物基水凝胶样品，并将其与氧化石墨烯（GO）进行了增强纳米复合材料，分别编码为 SA-g-（AAm-co-GMA）、CH-g-（AAm-co-GMA）、GO/SA-g-（AAm-co-GMA）和 GO/CH-g-（AAm-co-GMA）。通过将生物聚合物从 SA 切换到 CH 并添加纳米填料，完全改变了样品的形态、净电荷和吸水性。通过固定模型宏基因组衍生的木聚糖酶（PersiXyn9）来比较水凝胶的性能。GO/SA-g-聚（AAm-co-GMA）样品表现出最佳性能，表明 PersiXyn9 与增强的基于 SA 的水凝胶之间存在更好的稳定静电吸引力。与游离酶相比，固定在基于 SA 的增强水凝胶上的 PersiXyn9 释放的还原糖增加了 110.1%，在 180 分钟储存后相对活性几乎增加了一倍。虽然基于 SA 的水凝胶上固定的酶在 12 次重复使用循环后仍保持 58.7%的活性，但基于 CH 的载体上的酶在类似运行后仅保留 8.5%的活性。
