Lilienthal Sivan, Shpilt Zohar, Wang Fuan, Orbach Ron, Willner Itamar
Institute of Chemistry, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
ACS Appl Mater Interfaces. 2015 Apr 29;7(16):8923-31. doi: 10.1021/acsami.5b02156. Epub 2015 Apr 16.
Acrylamide/acrylamide-modified nucleic acid copolymer chains provide building units for the construction of acrylamide-DNA hydrogels. Three different hydrogels are prepared by the cross-linking of the acrylamide-DNA chains with metal ion-dependent DNAzyme sequences and their substrates. The metal ion-dependent DNAzyme sequences used in the study include the Cu(2+)-, Mg(2+)-, and Zn(2+)-dependent DNAzymes. In the presence of the respective metal ions, the substrates of the respective DNAzymes are cleaved, leading to the separation of the cross-linking units and to the dissolution of the hydrogel. The different hydrogels were loaded with a fluorophore-modified dextran or with a fluorophore-functionalized glucose oxidase. Treatment of the different hydrogels with the respective ions led to the release of the loaded dextran or the enzyme, and the rates of releasing of the loaded macromolecules followed the order of Cu(2+) > Mg(2+) > Zn(2+). Also, the different hydrogels were loaded with the enzymes β-galactosidase (β-Gal), glucose oxidase (GOx), or horseradish peroxidase (HRP). In the presence of the appropriate metal ions, the respective hydrogels were dissolved, resulting in the activation of the β-Gal/GOx or GOx/HRP bienzyme cascades and of the β-Gal/GOx/HRP trienzyme cascade.
丙烯酰胺/丙烯酰胺修饰的核酸共聚物链为构建丙烯酰胺 - DNA水凝胶提供了构建单元。通过将丙烯酰胺 - DNA链与金属离子依赖性DNAzyme序列及其底物交联，制备了三种不同的水凝胶。该研究中使用的金属离子依赖性DNAzyme序列包括Cu(2 +) - 、Mg(2 +) - 和Zn(2 +) - 依赖性DNAzyme。在各自金属离子存在的情况下，各自DNAzyme的底物被切割，导致交联单元分离，水凝胶溶解。不同的水凝胶负载有荧光团修饰的葡聚糖或荧光团功能化的葡萄糖氧化酶。用各自的离子处理不同的水凝胶导致负载的葡聚糖或酶释放，负载大分子的释放速率遵循Cu(2 +)>Mg(2 +)>Zn(2 +)的顺序。此外，不同的水凝胶负载有β - 半乳糖苷酶(β - Gal)、葡萄糖氧化酶(GOx)或辣根过氧化物酶(HRP)。在适当金属离子存在的情况下，各自的水凝胶溶解，导致β - Gal/GOx或GOx/HRP双酶级联以及β - Gal/GOx/HRP三酶级联的激活。
