Stem Cell Clinic

Encouraging Results with Stem Cell Transplant for Brain Injury

Imaging Technology Tracks Stem Cells to Brain after Carotid Artery Injection in Animals

Newswise — Philadelphia, Pa. (February 1, 2012) – Experiments in brain-injured rats show that stem cells injected via the carotid artery travel directly to the brain, where they greatly enhance functional recovery, reports a study in the February issue of Neurosurgery, official journal of the Congress of Neurological Surgeons. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

The carotid artery injection technique—along with some form of in vivo optical imaging to track the stem cells after transplantation—may be part of emerging approaches to stem cell transplantation for traumatic brain injury (TBI) in humans, according to the new research, led by Dr Toshiya Osanai of Hokkaido University Graduate School of Medicine, Sapporo, Japan.

Advanced Imaging Technology Lets Researchers Track Stem Cells
The researchers evaluated a new "intra-arterial" technique of stem cell transplantation in rats. Within seven days after induced TBI, stem cells created from the rats' bone marrow were injected into the carotid artery. The goal was to deliver the stem cells directly to the brain, without having them travel through the general circulation.

Before injection, the stem cells were labeled with "quantum dots"—a biocompatible, fluorescent semiconductor created using nanotechnology. The quantum dots emit near-infrared light, with much longer wavelengths that penetrate bone and skin. This allowed the researchers to noninvasively monitor the stem cells for four weeks after transplantation.

Using this in vivo optical imaging technique, Dr Osanai and colleagues were able to see that the injected stem cells entered the brain on the "first pass," without entering the general circulation. Within three hours, the stem cells began to migrate from the smallest brain blood vessels (capillaries) into the area of brain injury.

After four weeks, rats treated with stem cells had significant recovery of motor function (movement), while untreated rats had no recovery. Examination of the treated brains confirmed that the stem cells had transformed into different types of brain cells and participated in healing of the injured brain area.

Further Progress toward Stem Cell Therapy for Brain Injury in Humans
Stem cells are likely to become an important new treatment for patients with brain injuries, including TBI and stroke. Bone marrow stem cells, like the ones used in the new study, are a promising source of donor cells. However, many questions remain about the optimal timing, dose, and route of stem cell delivery.

In the new animal experiments, stem cell transplantation was performed one week after TBI—a "clinically relevant" time, as it takes at least that long to develop stem cells from bone marrow. Injecting stem cells into the carotid artery is a relatively simple procedure that delivers the cells directly to the brain.

The experiments also add to the evidence that stem cell treatment can promote healing after TBI, with significant recovery of function. With the use of in vivo optical imaging, "The present study was the first to successfully track donor cells that were intra-arterially transplanted into the brain of living animals over four weeks," Dr Osanai and colleagues write.

Some similar form of imaging technology might be useful in monitoring the effects of stem cell transplantation in humans. However, tracking stem cells in human patients will pose challenges, as the skull and scalp are much thicker in humans than in rats. "Further studies are warranted to apply in vivo optical imaging clinically," the researchers add.

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About Neurosurgery
Neurosurgery, the Official Journal of the Congress of Neurological Surgeons, is your most complete window to the contemporary field of neurosurgery. Members of the Congress and non-member subscribers receive 3,000 pages per year packed with the very latest science, technology, and medicine, not to mention full-text online access to the world's most complete, up-to-the-minute neurosurgery resource. For professionals aware of the rapid pace of developments in the field, Neurosurgery is nothing short of indispensable.

About Lippincott Williams & Wilkins
Lippincott Williams & Wilkins (LWW) is a leading international publisher for healthcare professionals and students with nearly 300 periodicals and 1,500 books in more than 100 disciplines publishing under the LWW brand, as well as content-based sites and online corporate and customer services.

LWW is part of Wolters Kluwer Health, a leading global provider of information, business intelligence and point-of-care solutions for the healthcare industry. Wolters Kluwer Health is part of Wolters Kluwer, a market-leading global information services company with 2010 annual revenues of €3.6 billion ($4.7 billion).

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Encouraging Results with Stem Cell Transplant for Brain Injury

Stem Cell Stage Bypassed in Skin Cell to Brain Cell Transformation

The stem cell stage was always thought to be a necessary step in the transformation of one type of cell into another, but new research from the Stanford University School of Medicine suggests that may not be the case. According to Medical News Today, scientists at the California school were able to successfully convert mouse skin cells directly into neural precursor cells, which then form the three main types of brain and nervous system cells.

“We’ve shown the cells can integrate into a mouse brain and produce a missing protein important for the conduction of electrical signal by the neurons,” said senior author Marius Wernig. “This is important because the mouse model we used mimics that of a human genetic brain disease.”

The same team had previously transformed mouse and human skin cells directly into functional neurons, but the new study is particularly exciting because of the possibilities neural precursor cells offer. While the cells can go on to become neurons, they can also differentiate into atrocytes and andoligodendrocytes, which maintain neurons and connect them to one another in order to transmit signals. Neural precursor cells are also easily stored in large numbers and better for lab work, the researchers noted.

If the implications of the research are correct and the stem cell stage is no longer necessary, controversial embryonic stem cell research may be needless. And not only would eliminating embryonic stem cell research avoid ethical questions, it would negate the need for stem cell patients to take drugs that stop their immune system from rejecting the foreign tissue. Wernig cautioned that further work is needed before these conclusions can be drawn, however. Researchers must still show that a similar cell conversion in humans is possible.

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Stem Cell Stage Bypassed in Skin Cell to Brain Cell Transformation