The use of artificial cell membranes are ubiquitous in bio-science but many of their aspects remain poorly understood. Now, University of Southern Denmark researchers have uncovered one of the mysteries of these membranes – that they contain beautiful flower formations.
"To understand complex systems such as real biological cells it is absolutely crucial that we understand the simpler systems that make up the cell, for example the cell membrane, through studies of model membranes," Jonas Jeppesen, who participated in the research, said in a press release.
Jeppesen and his team decided to investigate the structures within artificial cell membranes in order to determine if they remained static or changed over time during their lifespan.
"We knew that freezing membranes containing two different types of lipids (fat molecules) cause domains of curious flower shapes to form. It is kind of like freezing a 'mixture' of oil and water. When the water freezes at 0 degrees C it forms ice crystals, or domains, in the still liquid oil. We knew these flower shaped domains form, but we did not know if they were stable static structures, or if they would change shape given time," Jeppesen said.
The team ended up taking time-lapse photos of the process, uncovering how fat molecules take the shape of flowers just a few minutes after the temperature drops below the freezing point. However, they do no keep these shapes indefinitely – Jeppesen and his team found that their shapes altered after a few days time and after weeks they because rounded.
The scientists believe that like all other elements in nature, the fat molecules in artificial membranes seek to find a state of equilibrium, which is round for their membrane domains.
"Everything in nature is round. Find a square tree trunk or a square oil droplet on your frying pan and you would be suspicious," Jeppesen said. "But it was important to find out how long they remain flower shaped. Researchers have assumed the flower shapes to be static, at least for several hours. We have now shown that it is reasonable to assume the flowers are static for hours, but not for days."
The findings were published in the Oct. 26 issue of Langmuir.
Take a look at the footage below:
