PHOTOPATTERNING OF MULTI-DOMAIN DNA HYDROGELS
We used the Mightex Polygon to photopattern multi-domain DNA hydrogels. We designed a DNA program within these hydrogels that executes a multi-stage sequential release process of different DNA molecules in precisely specified locations and times. The locations of release are determined by photopatterning DNA hydrogels using the Polygon at resolutions of tens of microns. The time of release is controlled by a toehold-mediated DNA strand displacement reaction cascade (a DNA “program”) that releases target DNA sequentially. The release of DNA from the hydrogel enables a fluorescent DNA molecule within the gel to light up, which provides a quantitative readout for local target DNA concentration. Our platform for programmable release of DNA at prescribed times and locations could be used in DNA/RNA drug delivery, reaction-diffusion systems, and chemical computing.
Figure 1. Photopatterning over 40 hours. Left hand column depicts the pattern being used for each row.
Fluorescent signals caused by the release of DNA from three 3-domain hydrogels that have unique embedded DNA within each domain. Each row depicts the time-lapse for each multi-domain hydrogel, while each column represents the time of each photo. The blue domain activates first, followed by the red and then the green domain. The digital masks uploaded to the DMD are shown in the left-most panel – each mask (row 1, 2, and 3) is used for the patterning of a hydrogel section with unique DNA molecules embedded within: Mask 1 contains red stage-1 DNA (released first), mask 2 contains blue stage-2 DNA (released second), and mask 3 contains green stage-3 DNA (released third). Scale bar is 200 µm.
Author: Misha Rubanov
Bio: Misha is a PhD student in the DNA Nanotechnology and Intelligent Materials Group at Johns Hopkins University. He is supervised by Dr. Rebecca Schulman.