One of the most interesting and exciting sessions at the WSCS discussed projects managed and funded by the Armed Forces Institute for Regenerative Medicine (AFIRM), a multi-institutional endeavor focused on developing treatment options for our wounded military men and women. Researchers from across the nation are collaborating together to solve these difficult medical situations, with numerous clinical trials in progress using fat grafts and engineered tissues for various regenerative purposes. Mayo Clinic neurologist and Center for Regenerative Medicine physician, Dr. Anthony Windebank, spoke with Drs. J. Peter Rubin (U Pitt) and John Jackson (Wake Forest) on the status of current AFIRM projects, and the prospect of clinical trials for our military personnel.
AFIRM has five major research programs, including extremity injury treatment, skin injury treatment, tissue transplantation, craniomaxillofacial reconstruction and genitourinary/lower abdominal injury treatment. Most of the session focused on the latter two areas, with Dr. Windebank explaining the greatest challenge of innervation to restore functionality of these engineered tissues.
Innervation is a challenge faced by researchers in tissue engineering due to the delicate nature of nerve fibers, and the difficulty nerve cells and neural tissues have regenerating on their own after neural damage. Dr. Windebank gives hope, however, noting that peripheral nerve regeneration is possible, provided the nerve cell body remains intact. One can transplant a nerve cell body and see regeneration to restore nerve function, a principle that is particularly important when dealing with limb loss and organ damage.
Similarly, a second obstacle faced in tissue engineering and regenerative medicine is vascularization of these biomaterials. Without adequate vascularization, both in the laboratory setting and in vivo, tissue necrosis occurs. While in the body there are endothelial cells to create these vascular networks, in the laboratory setting such factors are absent. Moreover, with the transplantation of large, bioengineered tissues in to a human, these vascular networks are too vast for endothelial cells to make the needed connections. Unfortunately, recurrent tissue necrosis inhibits research activities in tissue engineering in the laboratory, and increases one's risk for future complications upon transplant. Researchers have yet to solve this complicated issue, and until they do, tissue implantation faces a significant obstacle.
One method of tissue engineering involves using scaffolds and fat tissue. Dr. Rubin discussed using adipose tissue with scaffolding materials to restore function and appearance after the severe craniofacial injuries seen on the battlefield. While the bony structures of the face can be reconstructed, it is difficult to return the soft tissue back to its original form. Fat grafting is a powerful tool to correct these injuries and deformities, and aids in restoration of the soft tissue.
Dr. Jackson provided a comprehensive overview of research projects underway at Wake Forest Institute for Regenerative Medicine. Focusing on genitourinary injuries, research is being conducted on engineering bladder and urethral tissue, as well as regaining fertility in engineered scrotal tissues. Clinical trials in humans are anticipated soon given the success he has seen in rabbit models.
To learn more about the military's response to our increasing wounded warrior population using regenerative medicine technology, explore the Armed Forces Institute of Regenerative Medicine website.
For more information on Dr. Jackson and his team's AFIRM projects, see video below.