I am an Orthopaedic Sports Medicine specialist pursuing a career as a clinician-scientist focusing on the biology of soft tissue healing to bone. The comprehensive training plan described in this proposal will uniquely position me as a surgeon-scientist to i) investigate the biology of soft-tissue-to-bone healing, ii) characterize novel approaches for growth factor delivery and scaffold design, iii) perform preclinical assessments of potential therapies and, ultimately, iv) design and operate appropriately powered clinical trials aimed at improving the treatment of soft tissue musculoskeletal injuries. There are 32 million musculoskeletal injuries in the United States annually of which 45% involve tendons or ligaments. Complete tendon and ligament separation injuries do not heal back to their bony attachments without surgical intervention and, thus, are often treated with surgical procedures including rotator cuff tendon repairs and anterior cruciate ligament reconstructions. There are more than 5.7 million people with a rotator cuff tendon tear in the US alone and this number is increasing as our population ages. In addition, there are more than 200,000 ACL injuries in the US each year; the incidence of these injuries in the military population is ten times higher than that of the civilian population. Normal tendon and ligament insertions to bone are comprised of a complex tissue structure that effectively transmits the interactions between dynamic muscle tissues and the rigid skeleton. Unfortunately, surgically repaired tendon tears and ligament reconstruction procedures characteristically “heal” with an abnormal tissue architecture that results in inferior biomechanical properties resulting in high failure rates. In this proposal we aim to stimulate local progenitor cells to repair the enthesis via a novel approach by delivering bisphosphonate-targeted growth factors to the bony site of the ruptured enthesis coupled with the insertion of a uniquely-designed biomimetic scaffold embedded with those factors. The CDA award would provide me the opportunity to turn potential into results. In order to accomplish the aims of this proposal we have assembled an internationally-recognized mentoring team to provide me with the technical training required for this research. In parallel with my mentored technical training, instruction in career development, drug discovery, data analysis and translational aspects relevant to my research goals will be provided via the UCLA CTSA-sponsored Training Program in Translational Science modules and supplemental graduate school course work. With guaranteed protected time, institutional financial support from my Department and 500 square feet of independent laboratory space and with transdisciplinary, cross-specialty guidance provided by my mentorship committee, my scientific advisory panel and my team of collaborators to assist in my development into an independent translational scientist, The ultimate goal is to allow me to successfully i) compete for additional VA, NIH and DoD grant funding, ii) manage a laboratory and iii) concurrently navigate a career that flourishes at both the benchtop and the bedside.

Despite the hundreds of thousands of tendon repairs and ligament reconstructions performed each year in the United States, clinically there is still no effective strategy to regenerate the complex tissue organization of native tendon and ligament attachments to bone (the enthesis). The goal of this proposal is to; 1) compare the efficacy of targeted delivery of biologically relevant growth factors BMP-2 and NELL-1 to promote enthesis regeneration; and 2) develop novel biomimetic scaffolds that facilitate local delivery of these factors in an environment that has favorable micro-mechanical enthesis-like properties. It is anticipated that these innovative approaches to the fundamental problem of enthesis generation will shift the current paradigm of treating musculoskeletal soft tissue injuries.