U.S. Army scientists, working with medical technology companies, have successfully tested and used products and techniques that have enabled Army surgeons to replace the severely burned skin of soldiers as well as transplant new hands and even faces.
At Duke University, researchers are studying zebra fish to learn how science and medicine might someday be able to regenerate severed human spinal cords.
These examples — one already in practice and the other in the early research stages — illustrate the potential that regenerative medicine offers for the future of medical care.
This research aims to go beyond easing the pain of life-threatening illnesses by changing the way diseases affect the body and then eradicating them.
“The vast majority of currently available treatments for chronic and/or life-threatening diseases are palliative,” Morrie Ruffin, managing director of the Alliance for Regenerative Medicine (ARM), told Healthline.
ARM, based in Washington, D.C., is considered the preeminent global advocate for regenerative and advanced therapies.
“Other treatments delay disease progression and the onset of complications associated with the underlying illness,” he said. “Very few therapies in use today are capable of curing or significantly changing the course of disease.
“Regenerative medicine has the unique ability to alter the fundamental mechanisms of disease, and thereby offer treatment options to patients where there is significant unmet medical need.”
And it has the potential to address the underlying causes of disease, Ruffin said, representing “a new and growing paradigm” in human health.
The field encompasses a number of different technologies, including cell, gene, and tissue-based therapies.
Helping with the wounds of war
With the Army breakthroughs, government investment was key.
The U.S. Department of Defense (DOD) has invested more than $250 million in regenerative medicine research over the past decade in an effort to make promising technologies available to wounded service members.
Dr. Wendy Dean is medical officer for the Tissue Injury and Regenerative Medicine Project Management Office at the U.S. Army Medical Materiel Development Activity at Fort Detrick, Md., home to the Army’s Medical Research and Materiel Command.
“Those investments have yielded a stress-shielding surgical bandage, Embrace, to reduce scarring after surgery,” Dean told Healthline. “The research has also enabled tremendous progress in burn care, allowing surgeons to improve recovery from severe burns with the use of novel skin replacement strategies, such as ReCell ‘spray-on’ skin, or skin substitutes such as StrataGraft. These skin replacement methods reduce or eliminate the need for donor sites, a frequent request of burn patients.”
These revolutionary products were not developed by the Army, Dean said, but were supported with research funding, initially through the Armed Forces Institute of Regenerative Medicine.
“The DOD also has invested in hand and face transplantation efforts for service members and civilians whose injuries are so severe that conventional reconstruction is insufficient,” she said.
Dean noted that DOD funding has supported 13 hand transplants to date, including a transplant for retired Sgt. Brendan Marrocco in 2012. He was the first service member to survive quadrilateral amputations sustained in combat. The funding also supported eight face transplants.
The Army’s goal is to heal those injured in battle.
“Regenerative medicine is still young, but it has shown tremendous progress over the last decade,” Dean said. “Our mission is to make wounded warriors whole by restoring form, function, and appearance. This field offers the best hope to someday fully restore lost tissue with tissue that is structurally, functionally, and aesthetically a perfect match. It may be years before the vision is a widespread reality, but the field is well on its way.”
Helping with spinal injuries
At Duke University, Kenneth Poss, professor of cell biology, and director of the Regeneration Next initiative, was the senior investigator for a study of spinal cord regeneration in zebra fish.
Those findings were published in November in the journal ScienceDaily.
“In my lab, we are researching genetic factors that enable regeneration of tissues such as heart and spinal in nonmammalian animals like zebra fish,” Poss told Healthline. “A scientist in my lab, Mayssa Mokalled, led a study finding that a gene called connective tissue growth factor [CTGF] is important for spinal cord regeneration in zebra fish after an injury that completely severs the cord.”
CTGF is necessary to stimulate cells called glia to form a tissue bridge across the severed parts of the spinal cord — an early step in spinal cord regeneration.
Within eight weeks, the scientists found that zebra fish regenerate a severed spinal cord, including nerve cells, and fully reverse their paralysis.
Developing techniques to treat and reverse spinal cord damage, a paralyzing and often fatal injury, is a pressing need in regenerative medicine, Poss said.
“Our findings present a step toward understanding which glial cells can be encouraged to help heal the spinal cord, and how to stimulate this activity,” he said. “This is just the first step in many before the findings could be applied to humans.”
Poss is already planning trials with mice that he hopes to start in the next few months. Mice represent an important stage in applying his latest findings, he said.
Why this field is needed
So, why is regenerative medicine important?
“Regenerative medicine seeks ways to re-grow or engineer healthy tissue without the need for transplants,” Poss said. “On a global scale, there’s a tremendous organ shortage, and transplantation is an expensive and nonpermanent solution.
“Imagine the number of lives that could be improved if, for example, we could find ways to use the body’s innate healing mechanisms to regenerate heart muscle in patients that are spiraling toward heart failure after a heart attack.”
“Imagine how many lives could be improved if we could find interventions that restore functional spinal cord tissue and reverse paralysis.”
Ruffin of ARM sees a promising future for regenerative medicine.
“We will continue to see the development of additional regenerative medicine therapies for a broad number of acute and chronic, inherited and acquired diseases and disorders,” he said. “Therapies in this area will continue to advance along the regulatory pathway, many of which are entering phase III clinical trials this year.”
“In fact, in the next two years, we are anticipating a number of U.S. and E.U. approvals in the cell and gene therapy sector, including therapies that address certain types of cancers, debilitating retinal disorders, rare genetic diseases, and autoimmune conditions. We also expect to see sustained investment, which will help fuel growth and product development within this sector.”
A number of cell and gene therapies and technology platforms are demonstrating real potential to address areas of significant unmet medical need, Ruffin said.
These include cell therapies for blood cancers and solid tumors; gene therapies for rare genetic diseases as well as chronic conditions; and gene editing for the precise targeting and modification of genetic material of a patient’s cells to cure a broad range of diseases with a single treatment.
Poss at Duke talked about the ultimate quest.
Regenerative medicine has been most successful in restoring or replacing the hematopoietic tissue that creates blood, he said.
“We still lack successful regenerative therapies for most tissues,” Poss said. “The future of regenerative medicine — the holy grail — will be stimulating the regeneration of healthy tissue in patients without adding cells or manufactured tissue.”
Working out the details of innate mechanisms of regeneration in animals like salamanders, zebra fish, and mice, can inform this approach, he said. So can improvement in factor delivery and genome editing applications to encourage the regeneration of healthy tissue.
“Ultimately,” Poss said, “regenerative medicine will change the toolbox of physicians and surgeons, with major impact on outcomes of diabetes, spinal cord injuries, neurodegenerative disease, and heart failure.”
ARM says the public does not realize how far the field has progressed in recent years.
“Currently, there are more than 20 regenerative medicine products on the market,” Ruffin said, primarily in the therapeutic areas of oncology, musculoskeletal and cardiovascular repair, and wound healing.
More than 800 clinical trials are now underway to evaluate regenerative advanced therapies in a vast array of therapeutic categories, he said.
“We’re seeing a significant focus on oncology, cardiovascular disease, and neurodegenerative diseases, with more than 60 percent of trials falling into one of these three categories,” he added. “Even though the majority of people perceive regenerative medicine as something of the future, it’s actually here and now.”
By Patrick Keeffe