Scientists had previously been unable to study the mechanical properties of individual fibrin fibers because of their small size.
Guthold and his research team at Wake Forest created a device by combining two microscopes that could not only see the fibrin fibers but also stretch the fibers. The fibers were suspended across a channel and anchored to the ridges of the channel at right angles. The fibers were stretched using the tip of an atomic force microscope. Movies showing the stretching are available at http://www.wfu.edu/%7Egutholdm/research.html.
Results showed that on average fibrin fibers can be stretched to 4.3 times their length before breaking. In addition, the fibers can be stretched to more than 2.8 times their length and still recover without permanent damage.
Roy Hantgan, associate professor of biochemistry at Wake Forest University School of Medicine and a member of the research team, said the study findings have significant implications for human health.
"Knowing that the fibrin strands that make up a human blood clot are more stretchable than a spider's web helps us to understand how clots can seal wounds tightly and withstand the pressure in our blood vessels," Hantgan said. "This new information also helps us to understand how tough it is to remove a clot that is preventing blood flow to a person's heart or brain, causing a heart attack or stroke."
Guthold said he has already been contacted by a company that uses an ultrasonic device to break up blood clots. He said the company has an interest in knowing the properties of the fibers comprising a blood clot to determine how much force should be applied to break up clots.
Researchers from Guthold's lab who worked on the project include Wenhua Liu, a physics graduate student at Wake Forest; and Eric Sparks
Contact: Jacob McConnico
Wake Forest University