A Modular and Practical Synthesis of Zwitterionic Hydrogels through Sequential Amine-Epoxy “Click” Chemistry and N-Alkylation Reaction

In this work, the amine-epoxy “click” reaction is shown to be a valuable general tool in the synthesis of reactive hydrogels. The practicality of this reaction arises due to its catalyst-free nature, its operation in water, and commercial availability of a large variety of amine and epoxide molecules that can serve as hydrophilic network precursors. Therefore, hydrogels can be prepared in a modular fashion through a simple mixing of the precursors in water and used as produced (without requiring any post-synthesis purification step). The gelation behavior and final hydrogel properties depend upon the molecular weight of the precursors and can be changed as per the requirement. A post-synthesis modification through alkylation at the nitrogen atom of the newly formed β-hydroxyl amine linkages allows for functionalizing the hydrogels. For example, ring-opening reaction of cyclic sulfonic ester gives rise to surfaces with a zwitterionic character. Finally, the established gelation chemistry can be combined with soft lithography techniques such as micromolding in capillaries (MIMIC) to obtain hydrogel microstructures.

A Novel Single Cell Culture Chip Based on One-Step Method

More and more basic biology research focus on the single cell level. However, the way to fabricate a chemically patterned surface exist some questions such as complex fabrication process, graphic quality puzzle and so on. In this paper, we present a One-Step method based on Poly 2-hydroxyethyl methacrylate (PolyHEMA) and micromolding in capillaries (MIMIC) technology to fabricate single cell culture chip. Experimental evidence indicates that the integrity and stability of the PolyHEMA pattern can perfectly satisfy the need of long-term cell culture.