- 13/04/2013
- Posted by: essay
- Category: Free essays
In the current essay we will review current literature of the Blood Brain Barrier and the use of Nanotechnology. According to Getting into the brain: approaches to enhance brain drug delivery, “The developmental process for new drugs for the treatment of CNS disorders has not kept pace with progress in molecular neurosciences because most of the new drugs discovered are unable to cross the BBB. The current challenge is to develop drug delivery strategies that will allow the passage of drug molecules through the BBB in a safe and effective manner.”
According to the official definition, “Nanotechnology – is the interdisciplinary field of basic and applied science and technology, dealing with a set of theoretical study and practical research methods, analysis and synthesis, as well as methods of production and use of products with a given atomic structure by controlled manipulation of individual atoms and molecules.”
A Review of Current Literature Of the Blood Brain Barrier and the use of Nanotechnology
The blood brain barrier is a barrier between the blood vessels and the central nervous system. The barrier prevents many toxic substances to pass through, while allowing the passage of nutrients and oxygen. In the absence of this barrier many harmful substances reach the brain affecting his performance and the body becoming unviable. Barrier cells have specific proteins that actively transport substances such as glucose through the barrier.
Its existence was supposed and was tested in 1885 by Paul Ehrlich, who injected aniline in the blood of a rat, which stained blue throughout the body except the brain, which remained unstained. That brought the evidence that the body provided some kind of protection mechanism of the central nervous system. In 1967 he was able to see the blood brain barrier through the electron microscope, thanks to Thomas Reese and Morris Karnovsky of Harvard University. They could also check the extent to which endothelial cells were linked together.
This could show the blood vessels reach the cells that form a firm layer in this area, while the rest of the body formed a flexible barrier. Outside the walls of brain capillaries consist of endothelial cells that have small gaps between them, but inside the brain these cells are closely intertwined without those gaps between them, making components selectively pass through the cells. This first barrier blocks the passage of molecules except those that cross the cell membrane to be soluble. A second layer of cells with high fat content does not allow the passage of soluble substances. Thus, only the smallest molecules (oxygen, carbon dioxide, ethanol and sugars) can pass through the barrier. Drugs and other toxins are usually too large to pass, and the barrier also protects the brain from infection, and therefore infection of the brain is very rare.
There are some viruses and bacteria capable of crossing it, as those responsible for rabies, meningitis, Lyme disease and cholera. Later, in 2002, the German Rolf Dermietzel showed that the BBB has other components as well as endothelial cells, pericytes and astrocytes. Although many are toxic insurmountable barrier for others it is not, well, alcohol, nicotine, heroin or ecstasy they can get through, taking immediate effect on receptors in the nervous system, according to Blood Brain Barrier (2010).
Some neurological studies carried out in April 2008 suggest that a dose of 3 mg of caffeine daily can help prevent Alzheimer’s disease and dementia caused by the harmful effects of excess dietary cholesterol such preventive effect could be explained by the protection exercise caffeine, precisely because of vasoconstriction on the blood-brain barrier.
It is also essential to mention the studies of the Nanotechnology. Nanotechnology is the study of manipulation of matter on atomic and molecular scale. It usually deals with structures measuring between 100 to 100 nanometers in at least one dimension, and include the development of materials and components and is associated with several areas (such as medicine, electronics, computer science, physics, chemistry, biology and engineering materials) production and research in nano- scale (atomic scale).The basic tenet of nanotechnology is the construction of structures and new materials from atoms (building blocks of nature). It is a promising area, but whose who give only first steps, show amazing results (in the production of semiconductors, nano composites, Biomaterials, Chips, etc.). Built in Japan, nanotechnology inventions seeks to innovate, improving them and providing a better life to man. One of the tools used for exploration of materials on this scale is a scanning electron microscope, the SEM. The main goal is not to arrive at a precise control of individual atoms, but creating stable structures with them.
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