Navigation Links
Crustacean shell with polyester creates mixed-fiber material for nerve repair

In the clothing industry it's common to mix natural and synthetic fibers. Take cotton and add polyester to make clothing that's soft, breathable and wrinkle free.

Now researchers at the University of Washington are using the same principle for biomedical applications. Mixing chitosan, found in the shells of crabs and shrimp, with an industrial polyester creates a promising new material for the tiny tubes that support repair of a severed nerve, and could serve other medical uses. The hybrid fiber combines the biologically favorable qualities of the natural material with the mechanical strength of the synthetic polymer.

"A nerve guide requires very strict conditions. It needs to be biocompatible, stable in solution, resistant to collapse and also pliable, so that surgeons can suture it to the nerve," said Miqin Zhang, a UW professor of material science and engineering and lead author of a paper now available online in the journal Advanced Materials. "This turns out to be very difficult."

After an injury that severs a peripheral nerve, such as one in a finger, nerve endings continue to grow. But to regain control of the nerve surgeons must join the two fragments. For large gaps surgeons used to attempt a more difficult nerve graft. Current surgical practice is to attach tiny tubes, called nerve guides, that channel the two fragments toward each other.

Today's commercial nerve guides are made from collagen, a structural protein derived from animal cells. But collagen is expensive, the protein tends to trigger an immune response and the material is weak in wet environments, such as those inside the body.

The strength of the nerve guide is important for budding nerve cells.

"This conduit serves as a guide to protect the neuron from injury," Zhang said. "If the tube is made of collagen, it's difficult to keep the conduit open because any stress and it's going to collapse."

Zhang and colleagues developed an alternative. The first component of their material, polycaprolactone, is a strong, flexible, biodegradable polyester commonly used in sutures. It is not suitable on its own for use as a nerve guide because water-based cells don't like to grow on the polyester's water-repelling surface.

The second component, chitosan, is found in the shells of crustaceans. It's cheap, readily available, biodegradable and biocompatible, meaning that it won't trigger an immune response. Chitosan has a rough surface similar to the surfaces found inside the body that cells can attach to. The problem is chitosan swells in water, making it weak in wet environments.

Researchers combined the fibers at the nanometer scale by first using a technique called electrospinning to draw the materials into nanometer-scale fibers, and then weaving the fibers together. The resulting material has a texture similar to that of the nanosized fibers of the connective tissue that surrrounds human cells.

The two materials are different and are difficult to blend, but proper mixing is crucial because imperfectly blended fibers have weak points.

Zhang and colleagues built prototype nerve guides measuring 1.5 millimeters (0.06 inches) in diameter, and between five and 15 centimeters (two to six inches) long. They tested a guide made from the chitosan-polyester blend against another biomaterial under study, polylacticcoglycolic acid, and a commercially available collagen guide.

Of the three materials, the chitosan-polyester weave showed the most consistent performance for strength, flexibility and resistance to compression under both dry and wet conditions. Under wet conditions, which the researchers say best mimics those in the body, the chitosan-polyester blend required twice as much force to push the tube halfway shut as the other biomaterial, and eight times as much force as the collagen tube.

The new material showed promise for nerve guides but would also work well for wound dressings, heart grafts, tendons, ligament, cartilage, muscle repair and other biomedical applications, Zhang said.


Contact: Hannah Hickey
University of Washington

Related biology news :

1. Clue to mystery crustacean in parasite form
2. Heavy metal link to mutations, low growth and fertility among crustaceans in Sydney Harbor tributary
3. Resilin springs simplify the control of crustacean limb movements
4. Engineered eggshells to help make hydrogen fuel
5. Shell Provides Consumers Gasoline Industrys First Pay By Touch Technology at the Pump
6. GestureTek/Imagination Launch AirPoint, Worlds First Hand-Tracking Unit, for Shell Group.
7. Underwater microscope helps prevent shellfish poisoning along Gulf Coast of Texas
8. Shell-breaking crabs lived 20 million years earlier than thought
9. Prof. David Kisailus studies engineering and invention on the half-shell
10. Saltwater sleuths: Seeking clues to help determine the ages of fish and shellfish populations
11. Fruit fly helps identify protein critical to eggshell formation that may be pesticide target
Post Your Comments:
Related Image:
Crustacean shell with polyester creates mixed-fiber material for nerve repair
(Date:9/28/2015)... , September 28, 2015 According ... (Hardware & Software), Product (Scanner & Others), Application (Access ... Defense, & Others) & Geography Global - Forecast to ... to reach USD 3627.90 Million by 2020, at a ... Browse 65 market data T ables and ...
(Date:9/24/2015)... , Sept. 24, 2015  EyeLock LLC, a market ... its award winning and latest technology in Booth #602 ... California . EyeLock,s iris authentication technology ... unmatched biometric accuracy, making it the most proven way ... uses video technology to deliver a fast and friendly ...
(Date:9/10/2015)... Report Details Emerging Biological ... and Revenue Prospects to Help You Stay Ahead ... new drug classes? Get the latest technological and ... market data and industry knowledge, benefitting your influence. ... and sales predictions. Visiongain,s new study reveals ...
Breaking Biology News(10 mins):
(Date:10/12/2015)... , Oct. 12, 2015 This report covers ... include cell type, products, applications, end-user markets and geographic ... HIGHLIGHTS The global cell expansion market generated revenue ... to reach revenues of $9.7 billion in 2015 and ... rate (CAGR) of 17.8% from 2015 to 2020. ...
(Date:10/12/2015)... 2015 /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ:  AEZS) (TSX: ... developing and commercializing novel treatments in oncology, endocrinology and ... Turpin , the Company,s former Senior Vice President, Chief ... Quebec City office.  ... Officer of the Company commented, "After a comprehensive review, ...
(Date:10/12/2015)... NAMUR , Belgium , Oct. 12, ... today announced that full results from a completed clinical study ... pancreatic cancers have been published in the online issue of ... Epigenetics Society. The peer-reviewed study was conducted in collaboration with ... , and led by Roland Andersson , MD, PhD, ...
(Date:10/11/2015)... , ... October 11, 2015 , ... ... Spinal System has been officially launched and multiple surgeries have been completed with ... William Hunter of the Neuroscience & Spine Center of the Carolinas. The ...
Breaking Biology Technology: