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.

Frozen Stem Cells Taken from a Cadaver Five Years Ago Vigorously Grow


It is incumbent upon regenerative medicine researchers to discover non-controversial sources of stem cells that are safe and abundant. To that end, harvesting stem cells from deceased donors might represent an innovative and potentially unlimited reservoir of different stem cells.

In this present study, tissues from the blood vessels of cadavers were used as a source of human cadaver mesenchymal stromal/stem cells (hC-MSCs). The scientists in this paper successfully isolated cells from arteries after the death of the patient and subjected them to cryogenic storage in a tissue-banking facility for at least 5 years.

After thawing, the hC-MSCs were re-isolated with high-efficiency (12 × 10[6]) and showed all the usual characteristics of mesenchymal stromal cells. They expressed all the proper markers, were able to differentiate into the right cell types, and showed the same immunosuppressive activity as mesenchymal stromal cells from living persons.

Thus the efficient procurement of stem cells from cadavers demonstrates that such cells can survive harsh conditions, low oxygen tensions, and freezing and dehydration. This paves the way for a scientific revolution where cadaver stromal/stem cells could effectively treat patients who need cell therapies.

See Sabrina Valente, and others, Human cadaver multipotent stromal/stem cells isolated from arteries stored in liquid nitrogen for 5 years.  Stem Cell Research & Therapy 2014, 5:8.

The Therapeutic Potential of Fat-Based Stem Cells Decreases With Age


Fat is a rich source of stem cells for regenerative medicine.  Treating someone with their own stem cells from their own fat certainly sounds like an attractive option.  However, a new study shows that demonstrates that the therapeutic value of fat-based stem cells declines when those cells come from older patients.

“This could restrict the effectiveness of autologous cell therapy using fat, or adipose-derived mesenchymal stromal cells (ADSCs), and require that we test cell material before use and develop ways to pretreat ADSCs from aged patients to enhance their therapeutic potential,” said Anastasia Efimenko, M.D., Ph.D.  Dr Efimenko and Nina Dzhoyashvili, M.D., were first authors of the study, which was led by Yelena Parfyonova, M.D., D.Sc., at Lomonosov Moscow State University, Moscow.

Heart disease remains the most common cause of death in most countries.  Mesenchymal stromal cells (MSCs) collected from either bone marrow or fat are considered one of the most promising therapeutic agents for regenerating damaged tissue because of their ability to proliferate in culture and differentiate into different cell types.  Even more importantly they also have the ability to stimulate the growth of new blood vessels (angiogenesis).

In particular, fat is considered an ideal source for MSCs because it is largely dispensable and the stem cells are easily accessible in large amounts with a minimally invasive procedure.  ADSCs have been used in several clinical trials looking at cell therapy for heart conditions, but most of the studies used stem cells from relatively healthy young donors rather than sick, older ones, which are the typical patients who suffer from heart disease.

“We knew that aging and disease itself may negatively affect MSC activities,” Dr. Dzhoyashvili said. “So the aim of our study was to investigate how patient age affects the properties of ADSCs, with special emphasis on their ability to stimulate angiogenesis.”

The Russian team analyzed age-associated changes in ADSCs collected from patients of different age groups, including some patients who suffered from coronary artery disease and some without.  The results showed that ADSCs from the older patients in both groups showed some of the characteristics of aging, including shorter telomeres (the caps on the ends of chromosomes that protect them from deterioration), which confirms that ADSCs do age.

“We showed that ADSCs from older patients both with and without coronary artery disease produced significantly less amounts of angiogenesis-stimulating factors compared with the younger patients in the study and their angiogenic capabilities lessened,” Dr. Efimenko concluded. “The results provide new insight into molecular mechanisms underlying the age-related decline of stem cells’ therapeutic potential.”

“These findings are significant because the successful development of cell therapies depends on a thorough understanding of how age may affect the regenerative potential of autologous cells,” said Anthony Atala, M.D., director of the Wake Forest Institute for Regenerative Medicine, and editor of STEM CELLS Translational Medicine, where this research was published.