Scientists use magnetic nanoparticles to place stem cells to treat TBI

Using stem cells to treat traumatic brain injury is thought to be promising, but delivering those cells via an injection into the central nervous system is fraught with risk including intracranial hemorrhage and the simple failure of the cells to reach the correct area of the brain.

Now, researchers at the University of Maryland, Baltimore and the Veterans Affairs Maryland Healthcare System have developed a means to label human neural progenitor cells with magnetic iron-oxide nanoparticles. These are then guided via a magnetic field to the injured area of the brain.

The next step for this research is to determine what happens to the transplanted stem cells after the magnetic field isn't present any longer. In addition, scientists still need to determine an optimal length for the density of cells, the length of time the magnetic field should be in use, the viability and the differentiation of the cells after magnetic retention and if the technique actually enhances TBI functional recovery.

Dr. Paul Yarowsky

"Magnetic cell targeting is ideally suited to augmenting cell therapies," study lead author Dr. Paul Yarowsky, of the University of Maryland School of Medicine and the VA Maryland Healthcare System, said in a statement.

"The external magnetic field and field gradient can guide cells to sites of injury and, using MRI, the iron-oxide superparamagnetic nanoparticles can be visualized as they travel to the site of injury. The goal when employing this method is not only guiding the particles to the site of injury, but also enhancing entry into the brain and the subsequent retention of transplanted cells," he added.

The researchers found that in vitro the intensity of the magnetic field did not affect the viability, proliferation or differentiation of the nanoparticle-loaded cells.

"The significance of this study lies in the fact the method used circumvented the need for invasive transplantation procedures, such as intracerebroventricular injection," Dr. John Sladek, a professor in the Department of Neurology at the University of Colorado School of Medicine who is an editor at the journal Cell Transplantation that published the study, said in a statement .

"Furthermore, use of a magnetic field to increase homing of cells, which can be problematic, to the target tissue proved efficacious. Future studies should explore whether this method would be safe and effective for humans, as it would necessitate a more intense magnetic field in order to increase migration of cells to deeper regions of the brain parenchyma," he concluded.

- here is the announcement
- and here is the study

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