Our group has developed DNA hydrogels that are made entirely from DNA. Biological components can be easily encapsulated in these gels during the enzymatic gelation process which is performed under physiological conditions. The DNA hydrogels can be easily tuned by adjusting initial concentrations and using different types of branched DNA monomers, allowing them to be tailored for specific applications such as controlled drug delivery, tissue engineering, 3D cell culture, cell transplant therapy and other biomedical applications.
Our DNA hydrogels provided the foundation for our newly developed cell free expression system which we call the P-gel system. In this system, a linear expression plasmid is incorporated into a DNA hydrogel by using branched DNA monomers as croslinkers. The resulting P-gel is molded into micropads which are used in place of plasmid DNA during coupled transcription/translation cell free expression. The P-gel system can produce up to 5 mg/ml of protein in a single expression, a vast improvement over commercially available solution phase systems.
Our current projects include developing methods to use DNA hydrogels as a scaffold for 3D cell culture and siRNA delivery by using microfluidic techniques to generate spherical structures. In addition, we are aiming to develop DNA hydrogels that can deliver proteins that prevent autoimmune responses from transplanted tissues in vivo. We are also working to scale-up protein production in our P-gel system with the goal of synthesizing proteins on the gram scale.
Bottom left: various DNA hydrogels created using branched DNA structures. DNA hydrogels can be molded and made into various shapes as seen, different colors are the result of different nucleic acid stains used.
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