AsianScientist (Aug. 1, 2017) – A research group in Japan has used DNA nanotechnology to create a structural frame that strengthens lipid-based droplets and prevents them from collapsing. Their findings are published in Proceedings of the National Academy of Sciences.
Lipid-based droplets known as liposomes have been used as a material in many common products such as capsules for drug delivery and cosmetics. However, the surface of these liposomes is fragile and prone to collapsing under only slight pressure, causing their contents to leak.
Living cells are also encapsulated in a layer of lipid, but unlike liposomes, they do not deform or collapse easily under pressure. This is because living cells have a structural scaffold known as the cytoskeleton which provides internal support.
Inspired by the cytoskeleton, a team of researchers led by Associate Professor Miho Yanagisawa at the Tokyo University of Agriculture and Technology, together with collaborators from Tokyo Institute of Technology, Keio University and Tohoku University, have used DNA technology to toughen liposomes and control their strength.
In their study, the scientists used DNA strands to reinforce the insides of liposomes. At higher temperatures, the DNA remained single-stranded. But by decreasing the temperature, the researchers were able to induce the DNA to form a mesh-like structure that is resistant to deformation.
Since DNA has a negative electric charge while the inner layer of the liposome is positively charged, the attractive forces between them produced a cytoskeleton-like structure that strengthened the liposome membrane. With this newly developed DNA cytoskeleton, the liposomes became tolerant of osmotic pressures comparable to that applied by the human body.
Importantly, the properties of this DNA cytoskeleton were tunable. By altering the base sequences of the DNA, the liposomes could be made stronger. In the future, the researchers expect to incorporate various functions into these DNA-enhanced liposomes, such as using DNA chemical reactions to induce membrane collapse. Such modifications will allow the controlled release of encapsulated compounds such as drugs.
The article can be found at: Kurokawa et al. (2017) DNA Cytoskeleton for Stabilizing Artificial Cells.
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Source: Tohoku University; Photo: Shutterstock.
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