A pH-Triggered, Fast-Responding DNA Hydrogel
A pH-Triggered, Fast-Responding DNA Hydrogel
复制标题
pH 触发、快速响应的 DNA 水凝胶
DOI：
10.1002/anie.200902538
复制
发表时间：
2009-01-01
影响因子：
16.6
通讯作者：
Liu, Dongsheng
中科院分区：
文献类型：
--
作者：
Cheng, Enjun;Xing, Yongzheng;Liu, Dongsheng
在过去的二十年里，DNA已被证明是纳米技术的优秀建筑材料，特别是在制造新型功能DNA纳米结构[1-3]和纳米电机方面。[4]除了平面二维网格[2]和孤立的三维纳米结构外，[3]DNA组装的概念最近已扩展到实现无约束的三维DNA结构，如“DNA树状大分子”[5]和“DNA水凝胶”。[6]已报道的凝胶过程基于双螺旋形成，随后酶催化连接，相当缓慢，需要在室温下连夜连接。包埋的物质和药物从凝胶中释放非常缓慢；例如，释放包裹的胰岛素需要10天以上。[6A]如果需要快速捕获和释放过程，这可能会限制这些凝胶的潜在应用。在这项研究中，我们报道了一种快速、pH响应的DNA水凝胶的制备，其中三臂DNA纳米结构(Y单元)通过形成分子间I基序结构组装在一起。这种DNA水凝胶可以在一分钟内切换到非凝胶状态。我们的策略如图1所示。Y形DNA纳米结构(Y单位)由三个单链DNA组成，每个37聚体单链DNA包含两个功能结构域：一个11聚体互锁的imotif结构域，包含两个富含胞嘧啶的延伸部分(图1中黑色标记)和一个26聚体结构域，用于形成
Over the past two decades, DNA has been demonstrated as an excellent building material for nanotechnology, especially in the fabrication of novel functional DNA nanostructures [1–3] and nanomotors.[4] In addition to planar two-dimensional grids [2] and isolated three-dimensional nanostructures,[3] the concept of DNA assembly has recently been expanded to realize unconstrained three-dimensional DNA structures, such as “DNA dendrimers”[5] and “DNA hydrogels”.[6] The reported gelling processes, which are based on double-helix formation followed by enzyme-catalyzed ligation, are rather slow and require overnight ligation at room temperature.[6a] Furthermore, the release of the entrapped materials and drugs from the gel is very slow; for example, it takes over 10 days to release entrapped insulin.[6a] This may limit the potential applications of these gels if fast trapping and releasing processes are required. In this study, we report the preparation of a fast, pH-responsive DNA hydrogel with three-armed DNA nanostructures (Y units) assembled together through the formation of intermolecular i-motif structures. This DNA hydrogel can be switched to the non-gel state in one minute by simply using environmental pH changes.Our strategy is illustrated in Figure 1. A Y-shaped DNA nanostructure (the Y unit) is formed from three singlestranded DNAs (ssDNAs), with each 37-mer ssDNA containing two functional domains: an 11-mer interlocking imotif domain containing two cytosine-rich stretches (marked in black in Figure 1) and a 26-mer domain for formation of the