扩散核磁法测定DNA水凝胶的分子通透性上限

DNA hydrogels have unique small molecules permission property, which lead to a wide application in 3D cell cultivation and tissue engineering. By changing the length of building blocks in DNA hydrogel, we can systematically control the network structure of DNA hydrogel. In addition, biotin molecules modified with trimethylsilyl or trifluoromethyl are used as probe molecules in the system while the size of probe molecules can be controlled by the specific bonding between biotin and streptavidin or marker protein molecules tagged with SA. We will use DOSY to monitor the diffusion of different sizes of probe molecules in DNA hydrogel and try to construct the model for probe molecules diffusion in confined space, thus achieving the in-situ characterization of the limitation size of molecules which could self-diffuse in DNA hydrogel, and offering experimental confirmation and interpretation about the special molecules permission property of DNA hydrogel.

本课题拟在DNA超分子水凝胶研究的基础上，利用DNA序列的高度特异性识别和可设计性，通过改变DNA组件的长度来调控DNA水凝胶的网络结构；同时，以修饰有硅甲基或者氟甲基的生物素分子为探针分子，基于生物素分子-链霉亲和素（Biotin-SA）之间的特异性结合实现探针分子尺寸的增长，通过SA标记不同尺寸的蛋白分子，进一步实现分子尺寸的调控。利用扩散核磁法来深入研究不同尺寸的探针分子在DNA水凝胶内部的扩散行为，建立探针分子在受限空间下的扩散模型，实现对DNA水凝胶分子通透性上限的原位表征。