New material to patch injured knee ligaments

March 27, 2002

GOOD news for injured athletes. Damaged knee ligaments heal better if patched with a scaffold made from pig's intestine. Tearing the medial collateral ligament, or MCL, is one of the most common sporting injuries. The ligament tends to heal by itself, so doctors don't usually resort to surgery. But afterwards it can be weaker and prone to further injury.

So Volker Musahl and his postdoc Savio L-Y Woo at the University of Pittsburgh in Pennsylvania tried patching up MCL injuries in rabbits with the material derived from pig gut. The patched ligaments were stronger than those left to heal by themselves, Musahl told the Engineering Tissue Growth International Conference last week in Pittsburgh. "We have clearly shown that the quality of the tissue is better after treatment," he says.

Musahl and Woo used material developed by Stephen Badylak of Purdue University in Indiana. To make his patches, Badylak takes the middle layer of pig intestine, removes all the cellular material and sterilises what is left. The result is a thin and strong biological mesh.

Intestinal tissue contains an abundance of healing factors that promote cell growth, and the mesh retains many of these. When implanted into an injury, the scaffold attracts cells such as fibroblasts and blood vessels into the area, inducing an impressive healing response.

And it's not just knees that can be treated. The scaffolds help the body grow new skin, cartilage and bones with little scarring. "We get site-specific remodelling of injuries and defects," says Badylak. "Many of the patients successfully treated have had life-threatening problems."

Already, these treatments have moved out of the lab and into hospitals. The US Food and Drug Administration has approved the material and it has been used to treat 70,000 patients in the US for a variety of injuries, including knees and shoulders, as well as skin wounds.

Badylak has also developed alternative scaffolds derived from different tissues. And Arnold Caplan of Case Western Reserve University in Cleveland, Ohio, works with a common biological material called hyaluronic acid, which is normally found in the spaces between cells. He seeds the sponge-like material with stem cells from bone marrow, before implanting it in deep holes drilled in rabbit knees. "It regenerates cartilage at the surface of the joint, and then brings in blood vessels at the bottom to regenerate bone," says Caplan.

Although these results are exciting, much needs to be done to truly understand whether function, not just structure, is properly restored. At the conference, David Butler of the University of Cincinnati in Ohio talked about the need to design implants that can withstand the unique loads different joints encounter. "It's important to meet the functional demands of the tissue," he says.
Author: Sylvia Pagan Westphal, Boston

New Scientist issue: 30 March 2002


"These articles are posted on this site to give advance access to other authorised media who may wish to quote extracts as part of fair dealing with this copyrighted material. Full attribution is required, and if publishing online a link to is also required. Advance permission is required before any and every reproduction of each article in full - please contact Please note that all material is copyright of Reed Business Information Limited and we reserve the right to take such action as we consider appropriate to protect such copyright."

UK CONTACT - Claire Bowles, New Scientist Press Office, London:
Tel: +44(0)20 7331 2751 or email

New Scientist

Related Blood Vessels Articles from Brightsurf:

Biofriendly protocells pump up blood vessels
In a new study published today in Nature Chemistry, Professor Stephen Mann and Dr Mei Li from Bristol's School of Chemistry, together with Associate Professor Jianbo Liu and colleagues at Hunan University and Central South University in China, prepared synthetic protocells coated in red blood cell fragments for use as nitric oxide generating bio-bots within blood vessels.

Specific and rapid expansion of blood vessels
Upon a heart infarct or stroke, rapid restoration of blood flow, and oxygen delivery to the hypo perfused regions is of eminent importance to prevent further damage to heart or brain.

Flexible and biodegradable electronic blood vessels
Researchers in China and Switzerland have developed electronic blood vessels that can be actively tuned to address subtle changes in the body after implantation.

Lumpy proteins stiffen blood vessels of the brain
Deposits of a protein called ''Medin'', which manifest in virtually all older adults, reduce the elasticity of blood vessels during aging and hence may be a risk factor for vascular dementia.

Cancer cells take over blood vessels to spread
In laboratory studies, Johns Hopkins Kimmel Cancer Center and Johns Hopkins University researchers observed a key step in how cancer cells may spread from a primary tumor to a distant site within the body, a process known as metastasis.

Novel function of platelets in tumor blood vessels found
Scientists at Uppsala University have discovered a hitherto unknown function of blood platelets in cancer.

Blood vessels can make you fat, and yet fit
IBS scientists have reported Angiopoietin-2 (Angpt2) as a key driver that inhibits the accumulation of potbellies by enabling the proper transport of fatty acid into general circulation in blood vessels, thus preventing insulin resistance.

Brothers in arms: The brain and its blood vessels
The brain and its surrounding blood vessels exist in a close relationship.

Feeling the pressure: How blood vessels sense their environment
Researchers from the University of Tsukuba discovered that Thbs1 is a key extracellular mediator of mechanotransduction upon mechanical stress.

Human textiles to repair blood vessels
As the leading cause of mortality worldwide, cardiovascular diseases claim over 17 million lives each year, according to World Health Organization estimates.

Read More: Blood Vessels News and Blood Vessels Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to