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.

Controlling Transplanted Stem Cells from the Inside Out


Scientists have worked very hard to understand how to control stem cell differentiation.  However, despite how well you direct stem cell behavior in culture, once those stem cells have been transplanted, they will often do as they wish.  Sometimes, transplanted stem cells surprise people.

Several publications describe stem cells that, once transplanted undergo “heterotropic differentiation.” Heterotropic differentiation refers to tissues that form in the wrong place. For example, one lab found that transplantation of mesenchymal stem cells into mouse hearts after a heart attack produced bone (don’t believe me – see Martin Breitbach and others, “Potential risks of bone marrow cell transplantation into infarcted hearts.” Blood 2007 110:1362-1369).  Bone in the heart – that can’t be good. Therefore, new ways to control the differentiation of cells once they have been transplanted are a desirable goal for stem cell research.

From this motivation comes a weird but wonderful paper from Jeffrey Karp and James Ankrum of Brigham and Women’s Hospital and MIT, respectively, that loads stem cells with microparticles that give the transplanted stem cell continuous cues that tell them how to behave over the course of days or weeks as the particles degrade.

“Regardless of where the cell in the body, it’s going to be receiving its cues from the inside,” said Karp. “This is a completely different strategy than the current method of placing cells onto drug-doped microcarriers or scaffolds, which is limiting because the cells need to remain in close proximity to those materials in order to function. Also these types of materials are too large to be infused into the bloodstream.”

Controlling cells in culture is relatively easy. If cells take up the right molecules, they will change their behavior. This level of control, however, is lost after the cell is transplanted. Sometimes implanted cells readily respond to the environment within the body,. but other times, their behavior is erratic and unpredictable. Karp’s strategy, which her called “particle engineering,” corrects this problem by turning cells into pre-programmable units. The internalized particles stably remain inside the transplanted cell and instruct it precisely how to act. It can direct cells to release anti-inflammatory factors, or regenerate lost tissue and heal lesions or wounds.

“Once those particles are internalized into the cells, which can take on the order of 6-24 hours, we can deliver the transplant immediately or even cryopreserve the cells,” said Karp. “When the cells are thawed at the patient’s bedside, they can be administrated and the agents will start to be released inside the cells to control differentiation, immune modulation or matrix production, for example.”

It could take more than a decade for this type of cell therapy to be a common medical practice, but to speed up the pace of this research, Karp published the study to encourage others in the scientific community to apply the technique to their various fields. Karp’s paper also illustrates the range of different cell types that can be controlled by particle engineering, including stem cells, cells of the immune system, and pancreatic cells.

“With this versatile platform, which leveraged Harvard and MIT experts in drug delivery, cell engineering, and biology, we’ve demonstrated the ability to track cells in the body, control stem cell differentiation, and even change the way cells interact with immune cells, said Ankrum, who is a former graduate student in Karp’s laboratory. “We’re excited to see what applications other researchers will imagine using this platform.”

Skin-Based Stem Cells Repair Peripheral Nerves


Italian scientists from Milan have used skin-derived stem cells in combination with a previously developed collagen tube to successfully bridge the gaps in injured nerves in a rat model, On the strength of that animal model system, the Italian group successfully used this procedure to heal the damaged peripheral nerves in the upper arms of a patient whose only other option was limb amputation.

“Peripheral nerve repair with satisfactory functional remains a great surgical challenge, especially for severe nerve injuries resulting in extended nerve defects,” said the corresponding author of this study Dr, Yvan Torrente of the Department of Pathophysiology and Transplantation at the University of Milan. “However, we hypothesized that the combination of autologous (self donated) stem cells placed in collagen tubes to bridge gaps in the damaged nerves would restore the continuity of injured nerves and save from amputation the upper arms of a patient with poly-injury to motor and sensory nerves.”

Although autologous nerve grafting has been the “gold standard” for reconstructive surgeries, these researchers recognized the disadvantages of such a procedure. Graft availability is the first drawback of autologous nerve grafting. Secondly, the condition of the donor site or “donor site morbidity.” If the donor site is in bad shape, taking a nerve from that site will probably make the donor site worse and provide a nerve that does not work as well. Finally, neuropathic pain is also an issue.

Autologous skin-derived stem cells have several advantages over autologous nerve grafts. First, the skin provides an accessible source of stem cells that are rapidly expandable in culture. Secondly, these skin-derived cells are capable of survival and integration within host tissues.

The NeuraGen nerve guide is a tiny collagen tube that connects the two damaged ends of a nerve together to mediate and expedite nerve healing.  NeuraGen tubes guide the transplanted stem cells to the gaps in the damaged nerves.  Torrente and his co-workers developed and tested the NeuraGen tubes in rats, and the US Food and Drug Administration (FDA) has approved NeuraGen for use in human patients.  See this figure from the NeuraGen web site:

NeuraGen_Open

 

Torrente and others successfully used skin-derived stem cells and NeuraGen tubes to heal the severed sciatic nerves in rats.  Therefore, once the FDA approved NeuraGen tubes, Torrente tried NeuraGen tubes in human patients with severe peripheral nerve damage.

A three-year follow-up on one particular patient showed that injured median and ulnar nerves showed extensive healing as ascertained by magnetic resonance imaging.  Functional tests, such as pinch gauge tests, static two-point discrimination and monofilament touch tests established the functional recovery of these peripheral nerves in the patient.

“Our three-year follow-up has witnesses nerve regeneration with suitable functional recovery in the patient and the salvage of upper arms from amputation,” said researchers from Torrente’s group.  “This finding opens an alternative avenue for patients who are at-risk of amputation after the injury to important nerves.”

Pluristem stem cell trial to treat muscle injury meets main goal | Reuters


Pluristem’s placental PLX-PAD cells produced show statistically significant improvement over placebo in the change of the maximal contraction force of the gluteal muscle

Pluristem Therapeutics Inc., a leading developer of placenta-based cell therapies, has announced results from its Phase I/II clinical trial that examines the safety and efficacy of PLacental eXpanded (PLX-PAD) cells in the treatment of muscle injury.  This trial showed patients treated with PLX-PAD had a greater improved change of maximal voluntary muscle contraction force than the placebo group.  These results show that PLX cells may have the ability to improve muscle and tendon healing after orthopedic injuries.

This Phase I/II trial was a randomized, placebo-controlled, double-blinded study conducted at the Orthopedic Clinic of the Charité University Medical School under the oversight of the Paul-Ehrlich-Institute (PEI), Germany’s health authority.  The injured muscle studied was the gluteus medius muscle in the buttock. Total hip replacement surgery via the standard transgluteal approach necessitates injury of the gluteus medius muscle, and post-operative healing is crucial for joint stability and function.

The 20 patients in the study were randomized into three treatment groups. Each patient received an injection in the traumatized gluteal muscle that had been injured during hip replacement surgery.  One group was treated with 150 million PLX-PAD cells per dose (n=7), the second was administered 300 million PLX-PAD cells per dose (n=6), and the third received placebo (n=7).

The primary safety endpoint was clearly met, since patients showed no serious adverse events reported at either dose level.  In this study, PLX-PAD cells were safe and well tolerated.

The primary efficacy endpoint of the study was the change in maximal voluntary isometric contraction force of the gluteal muscle at six months after the surgery.  Efficacy was shown in both PLX-PAD treated patient groups, but the patients in the group who had received the 150 million cell dose displayed a statistically significant 500% improvement over the placebo group in the change of the maximal contraction force of the gluteal muscle (p=0.0067).   Patients treated at the 300 million cell dose showed a 300% improvement over the placebo (p=0.18).

The structure of the gluteal muscle was also evaluated by means of magnetic resonance imaging (MRI).  MRI analysis revealed an increase in muscle volume in those patients treated with PLX-PAD cells versus the placebo group.  This efficacy endpoint was demonstrated in both PLX-PAD treated patient groups, with the group receiving the 150 million cell dose displaying a statistically significant superiority over the placebo group.  Patients treated at the 150 million cell dose showed an approximate 300% improvement over the placebo in the analysis of muscle volume (p=0.004).  Patients treated at the 300 million cell dose showed an approximate 150% improvement over the placebo in the change of muscle volume (p=0.19).  The complete dataset that includes biopsy results and functional assessments and will be presented at a medical conferences in the future.

The study’s Senior Scientist, Dr. Tobias Winkler of the Center for Musculoskeletal Surgery, Julius Wolff Institute Berlin, Charité – Universitaetsmedizin Berlin, Germany, commented, “I am very impressed with the magnitude of the efficacy results seen in this trial. PLX cells demonstrated safety and suggested that the increase in muscle volume could be a mechanism for the improvement of contraction force.”

Zami Aberman Chairman and CEO stated, “This was a very important study not only for Pluristem but for the cell therapy industry in general. The study confirms our pre-clinical findings that PLX-PAD cell therapy can be effective in treating muscle injury. Having a statistically significant result for our primary efficacy endpoint is very encouraging and consistent with our understanding of the mechanism of action associated with cell therapy. Based on these results, we intend to move forward with implementing our strategy towards using PLX cells in orthopedic indications and muscle trauma.”

The Stem Cell Blog

  • cells were safe and well tolerated
  • one group receiving a 150 million cell dose displaying a 500 percent improvement over the placebo group.
  • Patients treated with a 300 million cell dose showed a 300 percent improvement over the placebo.
  • An analysis of the gluteal muscle indicated an increase in muscle volume in those patients treated…versus the placebo group.

Pluristem stem cell trial to treat muscle injury meets main goal

TEL AVIV Tue Jan 21, 2014 3:07am EST

(Reuters) – Pluristem Therapeutics Inc said results from its early/mid-stage clinical trial indicated its placenta-derived stem cells for the treatment of muscle injury were safe and provided evidence the cells might be effective in treating orthopedic injuries.

\”Patients treated with PLX-PAD had a greater improved change of maximal voluntary muscle contraction force than the placebo group,\” Israel-based Pluristem said in a statement on Tuesday.

The trial was conducted at the Orthopedic Clinic of…

View original post 219 more words

Treating Age-Related Blindness with a Stem Cell Replacement Method


A collaboration between German and American scientists in New York City has resulted in the invention of a new method for transplanting stem cells into the eyes of patients who suffer from age-related macular degeneration, which is the most frequent cause of blindness. In an animal test, the implanted stem cells survived in the eyes of rabbits for several weeks.

Approximately 4.5 millino people in Germany suffer from age-related macular degeneration (AMD), which causes gradual loss of visual acuity and affects the ability to read, drive a car or do fine work. The center of the vision field becomes blurry as though covered by a veil. This vision loss is a consequence of the death of cells in the retinal pigment epithelium or RPE, which lies are the back of the eye, underneath the neural retina.

Inflammation within the RPE causes AMD. Increased inflammation prevents efficient recycling of metabolic waste products, and the build-up of toxic wastes causes RPE die off. Without the RPE, the photoreceptors in front of the RPE cells that also depend on the RPE to repair the damage suffered from continuous light exposure, begin to die off too.

RPE

Retinal Pigmented Epithelium

Presently no cure exists for AMD, but scientists at Bonn University, in the Department of Ophthalmology and New York City have tested a new procedure that replaces damaged RPE cells.

In the present experiment, RPE cells made from human stem cells were successfully implanted into the retinas of rabbits.

Boris V. Stanzel, the lead author of this work, said, “These cells have now been used for the first time in research for transplantation purposes.”

The adult RPE stem cells were characterized by Timothy Blenkinsop and his colleagues at the Neural Stem Cell Institute in New York City. Blenkinsop designed methods to isolate and grow these cells. He also flew to Germany to assist Dr. Stanzel with the transplantation experiments.  Blenkinsop obtained his RPE cells from human cadavers, and he grew them on polyester matrices.

These experiments demonstrate that RPE cells obtained from adult stem cells can replace cells destroyed by AMD. This newly developed transplantation method makes it possible to test which stem cells lines are most suitable for transplantation into the eye.

Stem Cell-Based Gene Therapy Restores Normal Skin Function


Michele De Luca from the University of Modena, Italy and his collaborator Reggio Emilia have used a stem cell-based gene therapy to treat an inherited skin disorder.

Epidermolysis bullosa is a painful skin disorder that causes the skin to be very fragile and blister easily. These blisters can lead to life-threatening infections. Unfortunately, no cure exists for this condition and most treatments try to alleviate the symptoms and infections.

Stem cell-based therapy seems to be one of the best ways to treat this disease, there are no clinical studies that have examined the long-term outcomes of such a treatment.

However, De Luca and his colleagues have examined a particular patients with epidermolysis bullosa who was treated with a stem cell-based gene therapy nearly seven years ago as part of a clinical trial.

The treatment of this patient has established that transplantation of a small quantity of stem cells into the skin on this patient’s legs restored normal skin function without causing any adverse side effects.

“These findings pave the way for the future safe use of epidermal stem cells for combined cell and gene therapy of epidermolysis bullosa and other genetic skin diseases,” said Michele De Luca.

De Luca and his research team found that their treatment of their patient, named Claudio, caused the skin covering his upper legs to looker normal and show no signs of blisters. To treat Claudio, De Luca and his colleague extracted skin cells from Claudio’s palm, used genetic engineering techniques to correct the genetic defect in the cells, and then transplanted these cells back into the skin of his upper legs. This was part of a clinical trial conducted at the University of Modena.

Claudio’s legs also showed no signs of tumors and the small number of transplanted cells sufficiently repaired Claudio’s skin long-term. Keep in mind that Claudio’s skin cells had undergone approximately 80 cycles of cell division and still had many of the features of palm skin cells, they show proper elasticity and strength and did not blister.

“This finding suggests that adult stem cell primarily regenerate the tissue in which they normally reside, with little plasticity to regenerate other tissues,” De Luca said. “This calls into question the supposed plasticity of adult stem cells and highlights the need to carefully chose the right type of stem cell for therapeutic tissue regeneration.”

I think De Luca slightly overstates his case here. Certainly choosing the right stem cells is crucial for successful stem cell treatments, but to take stem cells from skin, which are dedicated to making skin and expect them to form other tissues is unreasonable. However, several experiments have shown that stem cells from hair follicles and form neural tissues and several other cell types as well (see Jaks V, Kasper M, Toftgård R. The hair follicle-a stem cell zoo. Exp Cell Res. 2010 May 1;316(8):1422-8).

Adult stem cells have limited plasticity to be sure, but their plasticity is far greater than originally thought and a wealth of experiments have established that.

Despite these quibbles, this is a remarkable experiment that illustrates the feasibility and safety of such a treatment.  A larger problem is that large quantities of cells will be required to treat a person.  It is doubtful that small skin biopsies around the body can provide enough cells to treat the whole person.  Therefore, this might a case for induced pluripotent skin cells, which seriously complicates this treatment strategy.

Stem Cell Therapy Following Meniscus Knee Surgery Reduces Pain and Regenerates Meniscus


According to a new study published in the January issue of the Journal of Bone and Joint Surgery (JBJS), a single stem cell injection after meniscus knee surgery can provide pain relief and aid in meniscus regrowth.

In the US alone, over one million knee arthroscopy procedures are performed each year. These surgeries are usually prescribed to treat tears to the wedge-shaped piece of cartilage on either side of the knee called the “meniscus.” The meniscus acts as an important shock absorber between the thighbone (femur) and the shinbone (tibia) at the knee-joint.

Knee-Ligament-Pain-and-Strains-Meniscus-Tear-and-Pain

This novel study, “Adult Human Mesenchymal Stem Cells (MSC) Delivered via Intra-Articular Injection to the Knee, Following Partial Medial Meniscectomy,” examined 55 patients who had undergone a surgical removal or all or part of a torn meniscus (known as a partial medial meniscectomy). Each patient was randomly assigned to one of three treatment groups: Groups A, B and C. The 18 patients in group A received a “low-dose” injection of 50 million stem cells within seven to 10 days after their meniscus surgery. Another 18 patients in group B received a higher dose of 150 million stem cells seven to ten days after their knee surgery. The controls group consisted of 19 patients who received injections of sodium hyaluronate only (no stem cells). All patients were evaluated to determine the safety of the procedure, the degree of meniscus regeneration (i.e. with MRI and X-ray images), the overall condition of the knee-joint, and the clinical outcomes through two years. Most of the patients enrolled in this study had some arthritis, but patients with severe (level three or four) arthritis, were excluded from the study.

Most of the patients who had received stem cell treatments reported a significant reduction in pain. 24 percent of the patients in one MSC group and 6 percent of the other showed at least a 15 percent increase in meniscal volume at one year. Unfortunately, there was no additional increase in meniscal volume at year two.

“The results demonstrated that high doses of mesenchymal stem cells can be safely delivered in a concentrated manner to a knee-joint without abnormal tissue formation,” said lead study author C. Thomas Vangsness, Jr., MD. “No one has ever done that before.” In addition, “the patients with arthritis got strong improvement in pain” and some experienced meniscal regrowth.

The key findings of this study are that there no abnormal (ectopic) tissue formation or “clinically important” safety issues identified. Also, 24 percent of the patients in the low-dose injection group (A) and six percent of the high-dose injection group (B) at one year showed “significantly increased meniscal volume,” as determined by an MRI, and this increase did not continue into the second year, but remained stable (should future studies try a second injection of MSCs?). Third, none of the patients in the control group (non-MSC group) showed significant meniscus regrowth. Finally, patients with osteoarthritis experienced a reduction in pain in the stem cell treatment groups, but there was no reduction in pain in the control (non-MSC group).

“The results of this study suggest that mesenchymal stem cells have the potential to improve the overall condition of the knee joint,” said Dr. Vangsness. “I am very excited and encouraged” by the results. With the success of a single injection, “it begs the question: What if we give a series of injections?”