by admin | Oct 30, 2018 | Studies, Stem Cell Research, Stem Cell Therapy
Spinal cord injury is the second leading cause of paralysis in the United States. When the spinal cord is severely injured, nerve cells in the spinal cord are damaged or destroyed. Also, a sort of scar forms in the affected area, which prevents nerve signals from traveling between the brain and the extremities. Consequently, people who sustain spinal cord injuries suffer from paralysis. The degree of paralysis depends on the location of the spinal cord injury; injuries higher on the spinal cord such as the neck or upper back area can lead to paralysis of all four limbs, for example. In almost all cases, the paralysis is permanent once it occurs, because nerve cells in the spinal cord do not regenerate.
Because spinal cord injuries are common and the consequences are usually permanent, researchers have been aggressively and tirelessly researching ways to treat this condition. One approach is to try to form new nerve cells in the spinal cord using stem cells. Mesenchymal stem cells can become new nerve cells given the right set of circumstances. Unfortunately, simply injecting mesenchymal stem cells into patients with severe spinal cord injuries cannot reverse paralysis. On the other hand, using exosomes from mesenchymal stem cells may be the push that stem cells need to become nerve cells in the spinal cord.
Exosomes are tiny packets of cellular material released by stem cells. They contain a variety of potentially beneficial substances; perhaps the most important in cell regeneration is micro RNA (miRNA). miRNA can cause complex changes in cells that simple drugs, proteins, or even regular RNA cannot. Researchers cannot easily deliver miRNA to where it is needed in the body, but exosomes taken from stem cells can deliver miRNA right where it needs to be.
Researchers collected human mesenchymal stem cells and placed them in an environment that would cause them to become nerve cells. But instead of simply using the stem cells directly, they instead collected the exosomes from those stem cells. Those exosomes could then be used to prompt mesenchymal stem cells to become nerve cells. Simply put, the exosomes drove the process more efficiently than the stem cells alone.
What does this all mean? Exosomes taken from the mesenchymal stem cells could eventually be used to treat spinal cord injury. Those special exosomes would magnify the nerve cell-creating effect, perhaps restoring nerve cell function to a damaged spinal cord. Considerable research needs to be done before this possibility becomes a clinical reality, but this knowledge helps researchers design targeted experiments in the future.
by admin | Oct 18, 2018 | Stem Cell Research, Stem Cell Therapy, Studies
A couple of weeks ago, scientists published findings showing that implanting human stem cells that are embedded within the engineered tissue can lead to the recovery of sensory perception in rats. The recovery of sensory perception is also accompanied by healing within the spinal cord and the ability to walk independently. The stem cells used in this experiment were collected from the membrane lining the mouth.
These results help demonstrate the potential for stem cells to help with spinal cord injuries but also point to the utility of combining stem cells with other factors to enhance their therapeutic effects. In this case, the researchers used a 3-dimensional scaffold to enable stem cells to attach and to stabilize them in the spinal cord. By adding growth factors, such as human thrombin and fibrinogen to the engineered tissue scaffolding, the researchers also increased the chances that attached stem cells would grow and differentiate.
The researchers compared the effects of their stem cell implants in paraplegic rats with the effects of adding no stem cells. Whereas the control rats who did not receive stem cells did not experience any improvement in mobility or sensation, 42% of the rats that did receive stem cells became better at supporting their weight on their hind limbs and at walking.
While these results are pre-clinical and do not apply directly to humans, the researchers conclude that further research is warranted. Given the positive impact of stem cells on the spinal cord in animals, it is reasonable to assume that stem cells may also benefit the human spinal cord. Further research will help clarify whether these stem cells can be adequately used to help treat patients with paraplegia.
by admin | Oct 11, 2018 | Stem Cell Research
Myocardial infarction, also known as heart attack, can be a devastating or even deadly event. It occurs when blood flow in one or more coronary arteries is blocked. Since coronary arteries supply blood to the heart muscle, a blockage in a coronary artery prevents oxygen and nutrients from reaching heart tissue.
While the heart can sustain short periods of time without oxygen or nutrients, heart cells become dysfunctional and die if blood flow is not restored within several hours. While clot-busting drugs, percutaneous intervention (PCI), and balloon angioplasty have provided a way to restore blood flow to the heart during a heart attack, once heart cells die there is no way to bring them back. Since most heart tissue is cardiac muscle, dead heart tissue cannot participate in the contraction or squeezing of the heart during a heartbeat. Thus, people who have survived a heart attack are often left with poor heart function (e.g. congestive heart failure).
Stem cell researchers have begun to question whether heart tissue destroyed during a heart attack is necessarily gone forever. Research is beginning to show that stem cells given after myocardial infarction are able to improve the squeezing power of the heart. By extension, stem cell treatment is able to improve the abilities heart to pump blood throughout the body.
Researchers initially assumed that it was the stem cells themselves that became new heart cells, replacing dead and dysfunctional heart tissue. While there is evidence that this occurs, it seems that stem cells play an even bigger role in heart tissue repair than simply becoming new heart cells. Stem cells release small packets of a material called exosomes and microvesicles. Exosomes and microvesicles hold proteins, cytokines, chemokines, growth factors, DNA, messenger RNA, and micro RNA. Researchers now believe that these materials hold the true power of stem cells in cardiac repair and regeneration.
Various types of stem cells produce exosomes that could potentially help repair a damaged heart. While cardiac stem cells may seem like an obvious source for these exosomes, induced pluripotent stem cells and mesenchymal stem cells are also capable of releasing exosomes that are potentially beneficial in cardiac repair.
Stem cells—or more accurately the exosomes contained within the stem cells—help repair damaged heart tissue in several ways. Stem cell-derived exosomes contain factors that promote the survival of vulnerable heart cells and cells that are dysfunctional after a heart attack (but not dead). Exosomes also help new blood vessels to form in and around the damaged heart muscle in a process called angiogenesis. These new blood vessels deliver oxygen, nutrients, and molecules that help support the growth and function of heart tissue. Exosomes also appear to promote a healthy immune system response after a heart attack, rather than a destructive inflammatory reaction. In other words, the materials found in exosomes guide the immune system to clear away damaged tissue without creating extensive fibrotic (i.e., tough, nonfunctional) tissue.
While most clinical trials thus far have studied the effects of stem cells directly infused into humans after myocardial infarction, exosomes are rapidly becoming the focus of future clinical trials in this area.
by admin | Sep 24, 2018 | Stem Cell Research, Stem Cell Therapy
The application of stem cells to treat health disorders, diseases, and injuries has been rapidly expanding in recent years. The breadth of their application comes from the fact that stem cells are undifferentiated and can, therefore, differentiate into all sorts of cells with different specialized functions and therefore have an enormous number of potential ways that they can improve health. A review published in Frontiers in Physiology covers the way stem cells can be used for therapy of oral diseases.
According to the authors of the article, adult stem cells and induced pluripotent stem cells are the best types of stem cells to use to treat oral and maxillofacial defects. There are pros and cons associated with adult stem cells, including both autologous and allogeneic stem cells, as well as with induced pluripotent stem cells. For instance, whereas autologous stem cells can modulate the immune system, allogeneic stem cells appear helpful for malignant diseases, and induced pluripotent stem cells are unlimited in terms of their source and do not involve any ethical issues.
There are a number of potential sources for treating oral disease, including tooth germ progenitor cells, dental follicle stem cells, salivary gland stem cells, stem cells of the apical papilla, dental pulp stem cells, inflamed periapical progenitor cells, among others. While adults stem cells can differentiate directly into specialized cells or can be turned into induced pluripotent stem cells, induced pluripotent stem cells can be driven to differentiate into specialized cells.
Clinical trials have been undertaken to study the ways in which stem cells can address a number of oral diseases, including bone diseases, dental pulp diseases, eye diseases, facial diseases, and periodontal diseases, as well as tooth extraction. The strategies for treating oral disease with stem cells involve sorting and expanding the stem cells outside of the body, mixing them with materials and factors that help them grow, and implanting them into the impaired region.
Future research will help to delineate the different ways in which certain types of stem cells can best be used to address individual oral diseases. Studies will also help to uncover the specific types of stem cells that are best for specific diseases and the protocols that should be used to reap the greatest benefits for patients.
by admin | Sep 13, 2018 | Stem Cell Research, Stem Cell Therapy, Studies
Patients usually recover from bone fractures with the right treatment, but sometimes the bone fails to heal because new tissue does not form and connect the broken pieces properly. Delayed union refers to cases where the bone takes longer than usual to heal, and nonunion refers to cases where the bone does not heal. In approximately 5 to 10 percent of cases of a fractured bone, delayed union or nonunion occurs. These conditions are associated with long-term pain and discomfort, and though can be addressed through surgical treatments, these interventions do not always lead to long-term healing.
In recent years, researchers have begun exploring the potential for mesenchymal stem cells to help address these important challenges of delayed union and nonunion. A review of the potential for these stem cells to help in these cases where fractures do not properly heal was recently published in the Journal of Biomedical Materials Research.
Mesenchymal stem cells are helpful in bone healing because they differentiate well and can differentiate into different cell lineages that are all important for bone formation, growth, and maintenance. These cell types include chondrocytes, osteoblasts, myoblasts, and adipocytes.
According to the authors of the review, mesenchymal stem cells can be used in conjunction with extracellular matrix scaffolds and biological adjuvants that promote growth, differentiation, and blood vessel formation, to help in the bone healing process when the delayed union or nonunion occurs. Future research will help to determine the best ways that mesenchymal stem cells can be used in combination with bioengineering strategies to help patients whose bone fractures do not heal or do not heal properly.
by admin | Sep 5, 2018 | Hyperbaric Oxygen Therapy, Stem Cell Research, Stem Cell Therapy, Studies, Traumatic Brain Injury
Traumatic brain injury (TBI) is one of the most common causes of disability in the United States, affecting over 13 million citizens. Traumatic brain injury is responsible for over 2 million emergency department visits, over a quarter of 1 million hospitalizations, and nearly 60,000 deaths each year.
Traumatic brain injury harms brain tissue in two phases. The first phase of injury occurs at the time of the traumatic incident. This initial injury may cause small or large areas of the brain to bleed. It may also shear (stretch/tear) nerve cells, making them dysfunctional. The second phase occurs hours or days after the initial injury. The brain is subjected to ongoing damage because of inflammation, cell death, and injury to blood vessels. Many people with TBI are left with lifelong problems with thinking, memory, and behavior.
In both of these phases of injury, one major way to help prevent long-term brain damage is by maintaining adequate blood flow to brain tissue. Unfortunately, once the damage has occurred, it can be a challenge to reverse the damage. Patients usually must endure months or years of physical and occupational therapy to regain what was lost. Moreover, patients often need substantial amounts of psychiatric and psychological support to treat mental health problems.
Fortunately, researchers are using hyperbaric oxygen therapy (HBOT) to improve blood flow to the brain in patients with traumatic brain injury. Hyperbaric oxygen therapy provides patients with pure oxygen (100%) at slightly higher pressures than they would experience normally. It is been used for hundreds of years to treat scuba divers who suffered “the bends” or decompression sickness; however, researchers are finding that hyperbaric oxygen therapy is a “coveted neurotherapeutic method for brain repair.”
To study the effects of hyperbaric oxygen therapy, researchers selected 10 people who had suffered mild traumatic brain injury in the previous 7 to 13 years. Patients all had brain damage that interfered with attention, memory, and thinking abilities.
Even though patients had sustained traumatic brain injury and brain damage a decade earlier, hyperbaric oxygen therapy was able to improve blood flow in the brain. Likewise, the amount of blood detected within the brain significantly increased, suggesting that hyperbaric oxygen therapy actually caused blood vessels in the brain to grow and multiply. Just as impressively, patients with chronic brain damage performed better on tests of cognition (i.e. thinking). They were able to process information more quickly, they had better motor function, and they were able to take in and process information about the world around them more efficiently.
Because people with traumatic brain damage have limited treatment options to improve their situations, these results are incredibly exciting. This was a study on 10 patients and more studies on larger numbers are still needed to build on these findings. Nonetheless, these results are quite encouraging for people with traumatic brain injury and their loved ones.
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