Background
Cell arrangement irregularity causes diseases to living things.
Adhesion of different types of cells can cause diseases. Dry eye syndrome is caused by adhesion of T cell and old macrophage[1]. To treat these diseases, chemical compounds or drugs can be used. They work as molecular-scale or nanometer-scale. However, molecular-scale approaches can bring unfavorable side-effect related with chemical reaction. If we were able to move the cells as we wanted, we could also control the interaction among cells without less side effect by chemical reaction.
Therefore, it is crucial to cause dynamic movement with micrometer, millimeter level. Some studies have been reported that focus on moving cells, such as manipulating cells by using razor[2], [3].
However, there is little studies which focus on moving cells using DNA hydrogel. DNA hydrogel can form micrometer, millimeter-scale structure[4]. In addition, DNA can be injected into organisms, so DNA hydrogel could be an approach to move cells in vivo.
In this project, we aim to open the door of micrometer, millimeter-scale approach for one of the cell controlling method with swelling and shrinking DNA hydrogel.
Project Idea
Here we designed a DNA hydrogel, which can move huge structures such as cells in millimeter-scale and synthesize in human body.
Hydrogels form three-dimensional network structures by cross-linking hydrophilic polymers. There are some advantages for DNA as gel materials.
First, the bases of DNA has only four kinds --- adenine, thymine, guanine and cytosine, and DNA bonds sequence specifically by only bonding complemental bases. Therefore, DNA is highly designable.
Moreover, there is plenty of DNA in human bodies. Therefore, DNA is highly biocompatible and gives little harm in human bodies. Because of these advantages, DNA hydrogels have attracted much attention recently as one of structural DNA nanotechnologies.
There are two big advantages of our DNA hydrogels.
First, our DNA hydrogels can change in volume dynamically. In theory, the gels change in range from 55% to 185% in size.
Another advantages is that the shape of DNA hydrogel can be controlled by microdevices easily. Shape designed gel represents interaction with surrounding cells in many ways by swelling and shrinking.
To proof the above two advantages, the potential of dynamical structure change and the flexibility of DNA hydrogel shape, our goal is to make a spider-web DNA hydrogel swell or shrink.
Reference
[1]http://kompas.hosp.keio.ac.jp/sp/contents/medical_info/science/201409.html(viewed at 21st October)
[2]Neuman, K. C., Chadd, E. H., Liou, G. F., Bergman, K. & Block, S. M. Characterization of photodamage to Escherichia coli in optical traps. Biophys. J.77,2856–2863 (1999).
[3]Norregaard, K., Metzler, R., Ritter, C. M., Berg-Sørensen, K. & Oddershede, L. B. Manipulation and Motion of Organelles and Single Molecules in Living Cells. Chem. Rev. 117, 4342–4375 (2017).
[4]Um, S. H., Lee, J. B., Park, N., Kwon, S. Y., Umbach, C. C., & Luo, D. (2006). Enzyme-catalysed assembly of DNA hydrogel. Nature Materials, 5(10), 797–801. https://doi.org/10.1038/nmat1741