NASA Tech Briefs: What is the study of microgravity science? Dr. Rafat Ansari: Microgravity science involves the study of several different disciplines of science. The idea is to use the absence of gravity to help study some fundamental phenomena, which is very difficult to study under one G or gravity conditions. The basic idea is that under microgravity or zero gravity conditions sedimentation rates are very low, which means that particles suspended in a solution do not sediment and convection currents are absent. This is essential especially to study, for example, the growth of protein crystals in space or novel phenomena such as growing colloidal crystals or colloidal materials. All of these applications require some fundamental physics problems to see if you can avoid problems due to sedimentation and convection. This is what microgravity offers. NTB: What is the Biofluid Sensor System/"Built-for-Space" fiber-optic probe? Dr. Ansari: The Biofluid Sensor System is a noninvasive system, which means it does not touch any portion of the sample. The sensors that I am particularly involved in developing are all noninvasive sensors, so we are essentially looking into the eye by saying that the eye is a window to the body. On a very basic level, it's a response to certain input. The tissues and fluids in a human eye from the cornea to the retina represent virtually every fluid and tissue type in the human body. By shining light into the eye and collecting the scattered light back, we can evaluate the different structures, morphology, and composition of these components as the light-scattering characteristics change because of normal aging and disease. So, by looking for these changes, detection can occur much earlier than when the clinical symptoms appear. NTB: Why is NASA interested in this technology? Dr. Ansari: NASA is interested in this technology not only for NASA use, but also for use right here on Earth, because noninvasive is really very attractive. For example, I am working with seven different technologies, the first of them being dynamic light scattering (DLS), which we are using to look at the development of cataracts at very, very early stages - about three to four orders of magnitude earlier than any other system in practice right now. Therefore, that early, noninvasive detection can perhaps lead to treatment. NASA's original interest in this technology was for microgravity fluid physics experiments in space; that's how I started. We used it on space station/shuttle-type applications growing colloidal crystals, protein crystals, and the nucleation and growth of microporous materials called zeolites. This led to the application to the eye, especially because of my own personal interest - my father developed cataracts about ten years ago. The DLS technique is also being used to look at the effects of diabetes on the eye. That work I am doing in collaboration with the Food and Drug Administration (FDA) and the cataract work is going on in collaboration with the National Eye Institute in Washington. We have
also shown that the same technology can be applied in the eye to look
for the onset of Alzheimer's disease. Alzheimer's
is a disease
of the brain. There are certain proteins called amyloids that form
plaques on the brain of Alzheimer patients, which can only be detected
at autopsy
by putting the brain tissue under a microscope and looking for these
types of plaques. Some researchers have shown that these same amyloids
can be expressed in the eye and can be detected using this technology. With all of these techniques, if we send someone into deep space exploration - say to Mars, which would take about three years from start to finish - there are really no medical personnel on board to evaluate everything going on in the bodies of the astronauts. By detecting changes very, very early, before the clinical symptoms appear, we can intervene to make sure the astronauts return to Earth safe and sound. So we are looking at diabetes, we are looking at Alzheimer's, we are looking at cataracts and diabetic retinopathy, and a whole bunch of things. NTB: Is the sensor currently being used in the medical field? Dr. Ansari: The DLS technique is currently in clinical trials at the NEI and they just finished the first phase of the study on cataracts in humans and are moving on into the second phase. We have also done studies looking for countermeasures: how to help avoid or perhaps reverse cataracts. That work I recently presented was in collaboration with John Clark of the University of Washington in Seattle, and he has come up with a drug called Pantethine, which we used in animal models (mice) to see if it could show any effect in the early inhibition of cataracts. We have seen good results in which the cataract does not progress. I am also working with some other people right now including the folks at the NEI and Johns Hopkins starting trials in monkeys. The monkeys are given soy-based products to see if we can avoid the development of cataracts. So, the clinical work at the NEI, the work being done at the FDA, and the work being done in collaboration with the aforementioned people, are all beginning to work not only in the diagnosis part of the trials, but in the treatment part as well. NTB: What is the ultimate goal of your research? Dr. Ansari: The ultimate goal for NASA is that if we are successful in putting all seven different technologies together for measuring all of these vital signs or vital parameters for evaluating health indices in humans, then we certainly would like to use it for astronauts in deep space exploration, and to use it here on Earth to essentially help everybody. For example, 1.4 million cataract surgeries are performed each year in the United States, and this number is going to double. Right now there are 34 million Americans over the age of 65 who have cataracts, and that number is going to become 70 million in the next 20 years. So it is a pretty significant to help this group and to also help those people with age-related macular degeneration. About 16 million Americans are diagnosed with diabetes every year, and the compliance rate is very low because people don't like to have blood samples drawn for testing. If we could perform these tests noninvasively and control the compliance rate, it would result in a significant development for people here on Earth. If we are successful in integrating all of these technologies - and it looks like we will be, because we are already using some of these in the clinical applications right now - it would help monitor the health of humans noninvasively all over the world, whether it be in developed or underdeveloped countries. Hopefully, someday we can say that NASA helped to achieve this goal. Resources:
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