Thursday, 6 December 2012

Crazy DNA Remembers its Shape

Just add water and this DNA hydrogel forms into the letters DNA.  The texture reminds me a little bit of those little toy dinosaurs that you put into the water and they grow into bigger dinosaurs.  But hydrogel is not so much different than the superabsorbant polymer in that both are polymers and a hydrogel can contain up to 99.9% water (much less for the larger dinosaur).  
People are doing a lot of different research on hydrogels and have found many applications including: biosensors, environmentally sensitive smart gels, tissue engineering, contact lenses, drug delivery (put some drugs in a hydrogel that slowly releases them over time), water gel explosives and rectal drug delivery.  Some other less common uses are breast implants and adhesives.  Scientists are trying to get the right physicochemical characteristics like rheology, viscoscity, and surface tension to help make new applications.  
What makes this hydrogel different?  Firstly, it is made using DNA.  DNA  make different shapes during replication and branching.  Understanding  branched DNA has led to making new shapes with  DNA, termed DNA origami.  This new molecular scale engineering have also helped scientists make new drug delivery vehicles e.g. putting drugs in a box constructed by DNA.  This hydrogel is not so different than the DNA origami except that it reacts to make the shapes with water.
This was reported in Nature Nanotechnology.  We'll see if these scientists can take it to the next level to produce better drug delivery vehicles and perhaps better wound treatments with water absorbing hydrogels.  Possibly the art community might also contribute to make interesting shape shifting hydrogels but hopefully not by making DNA dinosaurs.