New process could usher in the evolution of polymers.
Researchers at Cornell University, US, have developed a process whereby DNA from biomass can be converted into degradable materials. The resulting material, researchers say, can be used for everyday objects, unusually strong adhesive and more effective methods of drug delivery, without negatively impacting the environment. Their work is published in the Journal of the American Chemical Society.
Biomass has been a feedstock for biodegradable materials for many years. However the process, in which polysaccharides such as cellulose are broken down and converted to polymers, is very energy intensive. The research team has bypassed the breakdown-synthesis process by developing a one-step cross-linking method that maintains DNA’s function as a polymer without breaking its chemical bonds. The process, described as ‘surprisingly simple’, involves the extraction of DNA from any organic source, which is then dissolved in water. After the pH of the solution is adjusted with alkali, polyethylene glycol diacrylate is added, this links with the DNA polymer forming a hydrogel. This material can be dehydrated to produce a range of denser materials such as plastic and glue.
The research team also found that cross-linking allowed them to alter the material giving rise to unusual properties. For example, glue was created that stuck to Teflon at -20oC, a temperature that would freeze traditional water-based adhesives.
‘The product’s applications depend on the properties we afford it. You can make it luminescent, make it conducting or non-conducting, make it stronger. Anything you can think of,’ said Dan Luo Professor of biological and environmental engineering at the College of Agriculture and Life Sciences at Cornell University. The hydrogel has wide application, but is said to be particularly well suited for controlled release of drugs.
In a lab setting the cost of conversion is put at $1 per gram of material, 90% of that expense covering the ethanol required to extract DNA from the biomass. It is estimated that on an industrial scale the costs could be reduced 100 or even 1000 fold.
At present the researchers see a potential challenge in obtaining large enough volumes of biomass, there is also work to be done to control the lifespan of the materials and the time it takes for them to degrade.