Duke University Tissue Engineering Team Grows Self-Healing Muscle in Laboratory


Scientists have grown living muscle in the lab. While this is nothing new, this new advance has succeeded in making muscle that not only looks and works like genuine skeletal muscle, but also heals by itself, which is a significant advance in the field of tissue engineering.

This ultimate goal of this research is to use lab-grown muscle repair muscle damage in human patients. To date, preclinical trials have shown that lab-grown muscle properly regenerated damaged muscle in laboratory mice.

This research comes from Duke University, and the research team responsible for this work thinks that their success was due to the culture environment that they have created to grow muscle in the laboratory. Their well-developed contractile muscle fibers also contained a pool of satellite cells, which are an immature stem cell population in skeletal muscle that are activated when the muscle is damaged. Satellite cells can divide and differentiate into normal muscle tissue in order to heal muscle damage.

Cultured Muscle

Laboratory tests showed that the lab-grown muscle was as strong and good at contracting as muscle isolated from living organism. Also, the laboratory-grown muscle was able to use its satellite cell population to repair itself when the muscle was damaged with toxic chemicals.

Muscle satellite cells

When it was grafted into laboratory mice, the muscle properly integrate into the rest of the surrounding tissue and functioned beautifully when called upon to do so.

The Duke team, however, stresses that more tests must be conducted before this work can be translated into human patients.

The lead researcher for this work, Nenad Bursac, Associate Professor of Biomedical Engineering at Duke University, said: “The muscle we have made represents an important advance for the field. It’s the first time engineered muscle has been created that contracts as strongly as native neonatal [newborn] skeletal muscle.”

UK expert in skeletal muscle tissue engineering Prof Mark Lewis, from Loughborough University, said: “A number of researchers have ‘grown’ muscles in the laboratory and shown that they can behave in similar ways to that seen in the human body. However, transplantation of these grown muscles into a living creature, which continue to function as if they were native muscle has been taken to the next level by the current work.”

Tissue engineering seeks to use stem cells to fashion new organs and tissues from cultured stem cells. Tissue engineering and stem cell biology will certainly transform regenerative medicine, and in many ways it is already doing so. Scientists have already made mini-livers and kidneys in the lab using stem cells, and others are using stem cells to heal damaged heart muscles. Even though some cures and treatments are still some years away, advances continue to pile up. The future of medicine is upon us.

Umbilical Cord Blood Cells Combined with Growth Factors Improves Traumatic Brain Injury Outcomes


Approximately 2 million Americans experience a traumatic brain injury every year. Most of these are individuals who employed in high-risk jobs such as the military, firefighting, police work and others types of essential but highly dangerous jobs. No matter how small the injury, individuals who have suffered a traumatic brain injury (TBI) can suffer from a whole host of motor, behavioral, intellectual and cognitive disabilities over the short or long-term. Unfortunately, there are few clinical treatments for TBI, and the few we have are rather ineffective.

In order to design better, more effective treatments for TBI, neuroscientists at the Center of Excellence for Aging and Brain Repair, Department of Neurosurgery in the USF Health Morsani College of Medicine, University of South Florida, have used umbilical cord stem cells in combination with growth factors to treat TBIs in mice.

This study investigated the ability of several strategies, both by themselves and in combination with other therapies, to treat rats with a laboratory form of TBI. In particular, the USF team discovered that a combination of human umbilical cord blood cells (hUBCs) and granulocyte colony stimulating factor (G-CSF), a growth factor, was more therapeutic than either administered alone, or each with saline, or saline alone.

“Chronic TBI is typically associated with major secondary molecular injuries, including chronic neuroinflammation, which not only contribute to the death of neuronal cells in the central nervous system, but also impede any natural repair mechanism,” said study lead author Cesar V. Borlongan, PhD, professor of neurosurgery and director of USF’s Center of Excellence for Aging and Brain Repair. “In our study, we used hUBCs and G-CSF alone and in combination. In previous studies, hUBCs have been shown to suppress inflammation, and G-CSF is currently being investigated as a potential therapeutic agent for patients with stroke or Alzheimer’s disease.”

In previous studies, Borlongan and his team showed that G-CSF can mobilize stem cells from bone marrow and induce them to home to and infiltrate injured tissues. While there, the cells promote neural cell self-repair. Cells from human umbilical cord blood also have the ability to suppress inflammation and promote cell growth.

“Our results showed that the combined therapy of hUBCs and G-CSF significantly reduced the TBI-induced loss of neuronal cells in the hippocampus,” said Borlongan. “Therapy with hUBCs and G-CSF alone or in combination produced beneficial results in animals with experimental TBI. G-CSF alone produced only short-lived benefits, while hUBCs alone afforded more robust and stable improvements. However, their combination offered the best motor improvement in the laboratory animals.”

“This outcome may indicate that the stem cells had more widespread biological action than the drug therapy,” said Paul R. Sanberg, distinguished professor at USF and principal investigator of the Department of Defense funded project. “Regardless, their combination had an apparent synergistic effect and resulted in the most effective amelioration of TBI-induced behavioral deficits.”

This particular study examined motor improvements or improvements in movement, but the USF group suggested that future combination therapy research should also include analysis of cognitive improvement in the laboratory animals with TBI.

In short, umbilical cord cell and growth factor treatments tested in animal models could offer hope for millions, including U.S. war veterans with traumatic brain injuries.

Post-script:  On Twitter, Alexey Bersenev made some very helpful observations about this paper.  In this paper, the authors used whole human umbilical cord blood.  They did not attempt to separate any of the different cell types from the cord blood.  Now when such whole blood is used, it is easy to assume that the stem cells in the blood that are doing the regenerative work.  However, as Alexey graciously pointed out, you cannot assume that the stem cells are responsible for the therapeutic effects for at least two main reasons:  1)  the number of stem cells in the cord blood is quite small relative to the other cells; 2) some of the non-stem cells in the blood turn out to have therapeutic effects.  See here and here.  I have seen some of these papers before, but I did not think much of them.  Therefore, until the cell populations in the umbilical cord blood are dissected out and studied, all we can say with any confidence is SOMETHING in the cord blood is conveying a therapeutic effect, but the identity of the therapeutic culprit remains unclear at this time.

Placenta-Based Stem Cells Increasing Healing of Damaged Tendons in Laboratory Animals


Pluristem Therapuetics, a regenerative therapy company based in Haifa, Israel, has used placenta-based stem cells to treat animal with tendon damage, and the results of this preclinical study were announced at a poster presentation at the American Academy of Orthopedic Surgeons’ (AAOS) annual meeting in New Orleans.

Dr. Scott Rodeo of New York’s Hospital for Special Surgery (HSS) is the principal investigator for this preclinical trial. His poster session showed placental-based stem cells that were grown in culture and applied to damaged tendons seemed to have an early beneficial effect on tendon healing. In this experiment, animal tendons were injured by treatments with the enzyme collagenase. This enzyme degrades tendon-specific molecules and generates tendon damage, which provides an excellent model for tendon damage in laboratory animals. These placenta-based cells are not rejected by the immune system and can also be efficiently expanded in culture. The potential for “off-the-shelf” use of these cells is attractive but additional preclinical studies are necessary to understand how these cells actually help heal damaged tendons and affect tendon repair.

“Although our findings should be considered preliminary, adherent stromal cells derived from human placenta appear promising as a readily available cell source to aid tendon healing and regeneration,” stated Dr. Rodeo.

“These detailed preclinical results, as well as the favorable top-line results we announced from our Phase I/II muscle injury study in January, both validate our strategy to pursue advanced clinical studies of our PLX cells for the sports and orthopedic market,” stated Pluristem CEO Zami Aberman.

Dr. Rodeo and his orthopedic research team at HSS studied the effects of PLX-PAD cells, which stands for PLacental eXpanded cells in a preclinical model of tendons around the knee that had sustained collagenase-induced injuries. Favorable results from the study were announced by Pluristem on August 14, 2013. Interestingly, Dr. Rodeo, the Principal Investigator for this study is Professor of Orthopedic Surgery at Weill Cornell Medical College; Co-Chief of the Sports Medicine and Shoulder Service at HSS; Associate Team Physician for the New York Giants Football Team; and Physician for the U.S.A. Olympic Swim Team.