Led by University of Illinois electrical and computer engineering professor Gabriel Popescu, the team developed a model that could lead to breakthroughs in screening and treatment of blood-cell-morphology diseases, such as malaria and sickle-cell disease. The group published its findings in the Proceedings of the National Academy of Sciences.
Red blood cells (RBCs) are unique in structure – a doughnut-shaped disc full of the oxygen-carrying molecule hemoglobin but none of the intracellular structures of other cells, not even DNA. In circulation, RBCs must contort to squeeze through capillaries half their diameter. Their flexibility and resilience come from their membrane structure, which couples a typical lipid bilayer with an underlying matrix of protein. However, knowledge of the membrane’s mechanics is very limited.
“The deformability of red blood cells is their most important property,” said Popescu, also affiliated with the Beckman Institute for Advanced Science and Technology at U. of I. “What we wanted to find is, how does deformability relate to morphology?”
The research team used a novel measurement technique called diffraction phase microscopy, which uses two beams of light while other microscopes only use one.
“One beam goes through the specimen and one beam is used as a reference,” Popescu said. “It is very, very sensitive to minute displacements in the membrane, down to the nanoscale.”
RBC membrane movement can be observed through typical light microscopes, a phenomenon known as “flickering,” but Popescu’s team was able not only to see nanoscale membrane fluctuations in live cells, but also to measure them quantitatively – a first.
In addition to normal cells, the team also measured two other morphologies: bumpy RBCs called echinocytes and round ones called spherocytes. They discovered that these deformed cells display less flexibility in their membranes, a finding that could provide insight into mechanics and treatment of diseases that affect RBC shape, such as malaria, sickle-cell disease and spherocytosis.
With collaborators from UCLA, the group used its data to construct a new model of the RBC membrane that accounts for fluctuations and curvature, a more complete and accurate rendering than previous models that treated the membrane as a flat sheet.
“Our measurements showed that a flat model could not explain the data. With this curvature model, we understand much better what is happening in the RBC,” said Popescu, adding, “It’s really a combination of a new optical method and new theoretical model, and that is what allowed us to find some new results where the shape and deformability are coupled.”
The team’s technique eventually could be used to screen for blood diseases such as malaria or to screen banked blood for membrane flexibility before transfusion, since stored blood often undergoes cellular shape changes.
In addition, this novel microscopy technique has important implications for researchers interested in membrane biology and dynamics, according to Catherine Best, co-author of the paper and instructor in the U. of I. College of Medicine. “An advantage to studying red blood cells in this way is that we can now look at the effects of chemical agents on membranes, specifically. It is very exciting. For instance, we can look at the membrane effects of alcohol, and we may learn something about tolerance to alcohol,” Best said.
Because diffraction phase microscopy measures live cells without physically manipulating or damaging them, it also could be used to evaluate medications being developed to treat blood cell morphology diseases, according to Popescu. “We can study the mechanics of a single cell under different pharmacological conditions, and I think that would be ideal for testing drugs,” he said.
The National Institutes of Health and the National Science Foundation funded this research, which included collaborators from MIT, Harvard Medical School, the University of Colorado, Harvard University and UCLA.
Liz Ahlberg | EurekAlert!
UTSA study describes new minimally invasive device to treat cancer and other illnesses
02.12.2016 | University of Texas at San Antonio
Earlier Alzheimer's diagnosis may be possible with new imaging compound
02.11.2016 | Washington University School of Medicine
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy