Source: Wolters Kluwer Health: Lippincott Williams & Wilkins
Date: February 1, 2012
Summary:
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.
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.
