UNC-TV Science Week in Review: July 18, 2013
Whether they are mind-controlled drones or advanced medicines that course through our bloodstreams, many of the most popular research discoveries move. It’s easy for us to get excited when planes fly overhead, cheetahs cross the savannah at full tilt and subatomic particles crash into each other at a few hundred million miles per hour.
But some of the greatest scientific challenges involve getting molecules, cells and structures to just sit still for a while. This week, North Carolina scientists focused on the stationary and long lasting.
Back pain keeps many Americans from moving the way they want to. Soft compressible cushions, called discs, separate our vertebrae. These discs are filled with a jelly-like substance called nucleus pulposus (NP), and as we age, the NP can degrade. This can lead to back pain and herniated (torn) discs.
Researchers from Duke’s Pratt School of Engineering have found a way to inject new NP cells into the spine and keep them in place to rebuild the discs. Their method involves injecting NP cells along with a protein called laminin and polyethylene.
The mixture enters the disc as a liquid, but within 20 minutes, the laminin and polyethylene react to form a gel that holds the fresh NP cells in place, like a Jell-O mold. Previously, NP cell injections did not gel, and the NP cells flowed out of the discs in 3 to 4 days. The NP Jell-O stayed in place for 14 days when injected into rat tails.
The NP Jell-O is in its infancy as a possible treatment, but the research shows it is possible to hold cells in place in the spinal column.
Using Suspended Cells to Identify Cancer
Even within the broad cancer types (lung, skin, etc.) there are many different variations of cancer. Determining which variation a patient has allows doctors to prescribe specific treatments to fight each specific variation. Researchers from the UNC and University of Utah Schools of Medicine have developed a system to more easily identify these variations.
Cancer develops through genetic mutations, so the best way to identify each variation is by looking at the genes. When doctors examine cancer tissues, they routinely preserve those tissues by drying them out and sealing them in paraffin wax, essentially mummifying the cancer tissue. The trouble is, cancer mummies don’t express their genes, so genetic testing has, until recently required fresh cancer cells which are difficult to come by.
The researchers, led by Dr. Neil Hayes, developed a system that can use cancer mummies to predict which variation of cancer a patient has. Their system is 84% accurate, which is on par with pathologists.
We reported in this blog that scientists from NC State University developed an injectable matrix that releases insulin into the blood only when needed. The same group, led by professor Zhen Gu, developed another way to delay insulin delivery.
The whole mechanism operates like an automatic thermostat. If the thermostat’s thermometer reads that the temperature is too hot, a switch is flipped and the air conditioner turns on. Then when the temperature drops, the thermometer realizes it and the switch is flipped back.
In this case, the thermostat is insulin trapped in a network of chitosan, a protein found in shrimp and crab shells. The thermometers are glucose oxidase and catalase enzymes. When glucose is present, the enzymes metabolize it and release hydrogen ions. The ions bind to chitosan and their charges repel, forcing the chitosan to spread out. When chitosan spreads, insulin escapes.
As the insulin helps remove glucose from the blood, the hydrogen ions float away and the chitosan closes back down. The system controls blood sugar for 48 hours, but the group’s other mechanism worked for 10 days.
- Daniel Lane
Daniel Lane covers science, medicine and the environment as a reporter/writer. He is currently pursuing a master's degree in medical and science journalism at UNC - Chapel Hill.