A Scaffolding Approach to Anterior Cruciate Ligament Repair
The use of scaffolding in regenerative medicine is becoming more sophisticated, with researchers developing a wider range of approaches that offer a variety of different structural characteristics. This allows for attempts to repair load bearing or supporting tissues such as ligaments and tendons:
Not only is the anterior cruciate ligament (ACL) inelastic and prone to popping, it is incapable of healing itself, causing surgeons to rely on autografts for reconstruction. Most common is the bone-patellar tendon-bone (BPTB) graft, in which the surgeon removes part of the patellar tendon to replace the damaged ACL. "BPTB autografts have a high incidence of knee pain and discomfort that does not go away. By saving the patient's patellar tendon and using an off-the-shelf product, one may have a better chance of preserving the natural biomechanics of the knee."[Researchers] are working to engineer such a product by combining three components: polyester fibers that are braided to increase strength and toughness, an inherently antioxidant and porous biomaterial, and calcium nanocrystals, a mineral naturally found in human teeth and bones. During ACL reconstruction surgeries, tunnels are drilled into the femur and tibia bones to hold the new ligament in a fixed position. [The researchers] created a bone-like material by combining antioxidant biomaterials with the calcium nanocrystals and then embedded braided polyester fibers into it. The artificial ligament's bone-like ends healed to the native bone in the drilled tunnels, anchoring the ligament into place.
By studying an animal model, the team noticed that the animal's natural bone and tissue cells migrated into the pores of the artificial ligament, populating it throughout and integrating with the bone tunnels. "The engineered ligament is biocompatible and can stabilize the knee, allowing the animal to function. Most importantly, we may have found a way to integrate an artificial ligament with native bone."
Link: http://www.eurekalert.org/pub_releases/2014-12/nu-run123014.php