DEPARTMENT OF DEFENSE - CONGRESSIONALLY DIRECTED MEDICAL RESEARCH PROGRAMS

Enhanced Soft Tissue Attachment and Fixation Using a Mechanically Stimulated Cytoselective Tissue-Specific ECM Coating

Principal Investigator: HAGGARD, WARREN O
Institution Receiving Award: MEMPHIS, UNIVERSITY OF
Program: PRORP
Proposal Number: OR090447
Award Number: W81XWH-10-1-0768
Funding Mechanism: Hypothesis Development Award
Partnering Awards:
Award Amount: $133,731.03


PUBLIC ABSTRACT

Recently, in military conflicts and other high-impact non-battle injuries, there has been an interest in increasing the integration of soft tissues, such as tendon and ligaments, to bone in order to enhance the performance of musculoskeletal repairs after injury to wounded warriors. Commonly, these injuries are repaired with autograft, allograft, or xenograft tissues which may invoke an adverse immunological response and have delayed tissue healing, thereby hindering musculoskeletal function and return to duty. An evolving therapeutic strategy involves the use of tissue-engineered soft tissue replacements to treat these injuries. These engineered implants can bypass the adverse immunological response; however, these implants have also been associated with low initial tissue-loading strength, which lengthens the time required for the patient to rehabilitate after a traumatic injury and return to duty. This lack of strength may be due to the engineered tendon/ligaments' inability to induce tissue ingrowth quickly at the implant/bone interface. Recently, therapeutic attempts have been made to either promote new tissue into an implant at the surgical site by augmenting a scaffold's characteristics or coating, or to implant a mechanically robust scaffolding material (i.e. woven degradable polymer) that can assist in loading until the tendon is able to re-assume function. This aim of this project is a bridge of three concepts where (1) co-cultures of osteoblasts and fibroblasts can produce tissue-specific regions on the scaffold for bone and soft tissue, (2) a biomechanically robust scaffold can aid in initial tendon strength after surgery, and 3) cyclic mechanical loading of pre-implant scaffolds enhances cell selective coating and the ultimate tensile strength of the scaffold implant. Therefore, a cell-selective tissue-specific tendon/ligament coating exposed to cyclic in vitro mechanical loading will enhance tissue repair and functional loading in a tendon/ligament repair scaffold. This technology will be pursued with standard tissue engineering techniques for a novel approach to creating a translational therapy for traumatic soft tissue military wounds and injuries.