Progress in Interface Tissue Engineering
10/23/2008
Helen H. Lu, associate professor of biomedical engineering, has received $2 million in funding, including $1.93 million from the National Institutes of Health, to pursue three specific projects in the Biomaterials and Interface Tissue Engineering Laboratory, of which she is director. "All three projects focus on problem areas in the interface between hard tissue (e.g., bone) and soft tissue (e.g., ligaments or tendons)," says Lu. "Each year, there are hundreds of thousands of new injuries to soft tissue, such as the anterior cruciate ligament (ACL) in the knee or the rotator cuff in the shoulder. Our research aims to mimic the body's original soft tissue-to-bone interface and to promote integration by harnessing cellular interactions using a novel stratified scaffold system."
These engineered ligament-to-bone and tendon-to-bone grafts grown on the scaffold system can lead to the formation of complex tissue systems through graft integration with each other as well as with the host environment, Lu says, so that significantly improved reconstructive surgery might be achieved. One of the most common sports injuries is the rupture of the anterior cruciate ligament. The ACL, located in the center of the knee joint, connects two bones that control rotation and prevent hyperextension of the knee. Currently, when the ACL is injured, it is surgically reconstructed, generally by using tendons from another part of the body that are grafted into each of the bone tunnels.
One NIH grant for more than $1.5 million will focus on developing and improving a stratified scaffold design for the regeneration of the ACL-to-bone interface. With collaborators from the Hospital for Special Surgery, Stephen Doty and Scott Rodeo, an orthopaedic surgeon who routinely performs ACL surgeries, Lu will design and optimize a novel biomimetic scaffold that will promote functional integration of biological and synthetic grafts for ACL reconstruction. A second grant from the Wallace H. Coulter Foundation focuses on the design of an integrative interference screw for ACL reconstruction. The interference screw, used to fix the soft tissue reconstruction graft in place, has traditionally been made of stainless steel or titanium alloys, but a tissue engineered screw would have none of the drawbacks of a metal insert and would promote integrative ACL repair.
Professor Lu's group has extended the interface tissue engineering approach for ACL repair to the repair of another critical soft tissue-to-bone transition found in the shoulder. The third grant, also from the National Institutes of Health, funds a project to develop nanofiber-based scaffolds for integrative rotator cuff repair. Rotator cuff tears are one of the most debilitating and common injuries of the shoulder and there is significant demand for grafting systems that can facilitate integrative and functional cuff repair. "The nanofiber scaffold investigated here mimics the native tissue in organization as well as functionality," says Lu, "and we will investigate its potential in both in vitro and in vivo studies." This work is in collaboration with Dr. William Levine, who specializes in shoulder surgery at the Department of Orthopaedic Surgery at Columbia.
Read more about Professor Lu's Lab.