Researchers from the University of Illinois with Urbana-Champaign have invented a novel live-cell imaging technique that could someday help biologists better understand how stem cellular material transform into specialized cells and how diseases like malignancy spread. The Photonic Crystal Enhanced Microscope (PCEM) is definitely capable of monitoring and quantitatively measuring cell adhesion, a crucial process involved cell migration, cell differentiation, cell department, and cell death.
“Our approach is important because there are not currently label-free and high resolution imaging tools that allow cell-surface interactions to be quantified and imaged dynamically, although these processes are essential to things like wound healing, tissue development, tumor intrusion, and cancer metastasis, ” said Brian Cunningham, the professor electrical and computer engineering and of bioengineering in Illinois.
Most conventional imaging methods depend on fluorescent dyes, which attach to and illuminate the cellular components so they are visible under a microscope. However , neon tagging has its limitations — namely that it is intrusive, difficult for quantitative measurement, and only provides a short-term home window of time for cell examination and measurement due to picture bleaching.
By using the PCEM, the researchers possess successfully measured the effective mass density of cellular membranes during stem cell differentiation, and cancer cellular response to drugs in an extended period. Their results, “Quantitative imaging of cell membrane-associated effective mass density making use of Photonic Crystal Enhanced Microscopy, ” were reported within the journal Progress in Quantum Electronics , (November 2016, Volume 50).
According to PCEM lead researcher Yue Zhuo, a post-doctoral Beckman Start Fellow, fluorescent tagging doesn’t allow scientists to see what sort of protein or cell changes over time.
“You can see the cell for maybe a few hours optimum before the fluorescent light dies out, but it takes various days to conduct a stem cell experiment, inch said Zhuo. “Scientists commonly use fluorescent tagging mainly because there’s no better way to monitor live cells due to their lower imaging contrast among cellular organelles. That urges all of us to develop a label-free and high-resolution imaging method for reside cell study. ”
The Illinois team’s microscope functions with an LED light source and a photonic amazingly biosensor made from inexpensive materials like titanium dioxide plus plastic using a fabrication method like nanoreplica molding.
“Our sensor can be massively fabricated easily, plus our cost to make the sensor is less than $1 every. ” noted Zhuo.
In Zhuo’s equipment, the photonic crystal biosensor is an optical sensor which can affect any attachable cells. The sensor surface is covered with extracellular matrix materials to facilitate cellular connections, which are then viewed through a normal objective lens plus recorded with a CCD camera.
“The benefit of our PCEM system is you can see as the [live] cell is beginning to attach to our sensor, and we may quantitatively and dynamically measure what happened at that time, ” Zhuo said. “We’re able to actually measure a very thin level on the bottom of the cell that’s about 100 nanometers, which is beyond the diffraction limit for visible gentle. ”
In the future, Zhuo plans to clothing the microscope with higher imaging resolution and at some point hopes to be able to build a library of cell adhesion information for scientists.
“Different types of cells may have different dynamic attachment profiles. ” she explained. “We can use this library to screen different types of cells designed for tissue regeneration, disease diagnostic, or drug treatment, for example , observe how diseased cells spread, or see how the cancer tissues respond to different drug treatment. ”