Hong Kong (Scicasts) — Neurodegenerative diseases, such as Parkinson’s and Alzheimer’s diseases, are devastating. Sufferers could lose control of their bodies from disabilities in movements, difficulties in talking, eating and even seeing. Some sufferers will eventually lose their personalities, memories and lives. These diseases are very poorly understood and at present there is NO CURE.
Dying of neurons in the brain causes most neurodegenerative diseases. There are various reasons why the neurons are dying, including genetic reasons such as gene mutations, infectious diseases or metabolic reasons such as strokes. But the disease onset in many patients with neurodegeneration is sporadic and with unknown reasons.
Many neurodegenerative diseases are now known to be more complicated than originally thought. These diseases could be caused by multi-factors and multi-origins. Different neurons in the brain are affected differently and thus worsen the disease symptoms. The degeneration process can be unpredictable and uncontrollable. At this moment, neither stopping the neurons dying or rescuing the neurons by one single miracle drug or chemical is possible. Patients need a real cure for these complicated diseases.
Cell replacement using stem cells in our bodies is one of the new hopes to combat the diseases. Stem cells are the “origins” or “mothers” of all cells in our body. Recent discoveries of stem cells especially the discoveries of stem cells in adult bodies have opened up a great opportunity to apply the stem cells on diseases treatments. The concept is very simple: whenever cells in one part of our body are damaged or are dying, we replace the cells in that part of our body using our own stem cells.
However, despite the hopes, using stem cells in treating diseases in the brain is considered to be very difficult. First, adult stem cells in the brain, called neural stem cells, exist, but they are low in number. They can be found primarily in only two places in the brain. The largest pool of neural stem cells lays within the internal hollow region of the brain namely the lateral ventricles. Secondly, since they lay deep inside the brain, there is no way to reach unless patients undergo an invasive brain surgery. And thirdly, even though we know they are there, there is no way to recognize them during the brain surgery.
How about using other stem cells? The answer could be “Yes and No”.
There are different stem cells that might be potential candidates for the cell replacement. Induced pluripotent stem cells or IPSCs in short, are possible candidates. The technology for producing IPSCs is a Nobel Prize-winning technology and it is considered to be a breakthrough in stem cell research. Adult cells from our body, for instance skin cells, can be used to produce stem cells using genetic modifications. The name “induced pluripotent” came from the induction of changes in adult cells by genetic modifications and returns to their ancestral states, which can be molded into different kinds of cells, i.e., “pluripotent” in nature. However, one major difficulty for applying IPSCs on patients is genetic modifications. Genetic modifications of IPSCs are often achieved by using viruses. There are a number of virus-related therapies undergoing testing and a small number of viruses are approved for human use. However, there are always risks associated with using viruses in treatment procedures. There are even more risks in the genetic modification procedures.
In order to address the genetic instabilities and tumorigenicity of stem cells (for example IPSCs) for research and clinical applications, our team found out that harvesting autologous neural stem cells, the stem cells naturally present in our brain, can be the solution for it. The idea is similar to the treatment of burn injury. Our healthy skin will be removed as skin graft and transplanted to the burn area. The concern of immune rejection will be greatly minimized as the skin graft is 100 % compatible to the patients. For our technology, we injected our strategically designed magnetic nanoparticles with the conjugation of antibodies into the lateral ventricles of the animal subjects. Our nanoparticles can specifically tag on the neural stem cell lining on the ventricles. After the magnetic agitation, the nanoparticles tagged neural stem cells can be safely and effortlessly detached. Further culture for cell replacement can be made. It is not only a technological breakthrough in the advancement of precision and regenerative medicine, but also a new hope for the patients with neurodegenerative diseases.