APPLICATIONS
AP7
THE ENVIRONMENT
Microbubbles have the potential to aid in the issue of global warming. The rate of increasing temperatures have caused scientists to propose for new solutions. Russell Seitz, a physics Harvard professor has suggested to pump the ocean full of microbubbles to increase its reflectivity. As a result, oceans that cover 71% of Earth would decrease in temperature. Natural bubbles are responsible for only 1% of the Earth's reflectiveity, however, if this mechanism of pumping microbubbles into the ocean, Earth's reflectivity could double.
By doubling Earth's reflectivity, the planet would experience a 3 degrees Celsius decline. Seitz describes microbubbles as a "mirrors made of air" that have the ability to scatter sunlight. However, making bubbles small and stable enough to not dissolve proves to be a problem. One option would be separating larger microbubbles to form smaller bubbles, mixed by vortex mixers. The distribution of these bubbles is also another problem, as to make this proposal successful ten thousand ships would have to inject 11,000 m3 of air a day. However, with these obstacles, microbubbles have the valuable ability to counteract the relevant topic of global warming.
THE BRAIN
Microbubbles are able to disrupt the blood brain barrier (BBB), the barrier that is responsible for keeping out potential medications to treat diseases like Parkinson's and Alzheimer's. The BBB acts as a shield to block viruses, fungi, and 98% of beneficial medications. Microbubbles create a temporary barrier by contracting and expanding when they interact with sound waves. As these bubbles reach eight microns, the BBB opens and allows for a variety of medications such as antibodies, genes, and chemotherapy agents to enter. The BBB can be open for up to four hours by using this noninvasive technique.
Depression, Parkinson's, and Alzheimer's are some obstacles that microbubbles could overcome. Alzheimer's specifically can be aided with the reduction of amyloid plaque in the brain. Scientists have attempted to reduce this plaque by inserting microbubbles in and sweeping an ultrasound beam across mice's brains. After repeating this routine frequently, mice completed tasks that emphasized memory to find that they had a "full restoration of memory in all three tasks" (Medgadget.com).
CANCER
Microbubbles have the ability to assist in a procedure known as embolotherapy to obstruct blood vessels that support tissue growth. During gas embolotherapy, acoustic droplet vaporization is used and involves microbubbles to deliver drugs to the diseased area. In acoustic droplet vaporization (ADV), heated dodecafluoropentane droplets are first injected where intensive ultrasounds are used to form microbubbles around the infected location. Once these bubbles grow in size, the vessels that feed the tumor are cut off, "starving" the tumor from nutrients and blood supply. Due to the blocked blood supply, drug dosage can decrease while the effectiveness remains the same. The side effects from chemotherapy could also be decreased by the use of microbubbles. Microbubbles release the encapsulated drug at a targeted site to minimize uncessary contact with healthy tissue.
Ovarian has been tested using this method, as both the drug delivery properties and the constriction of blood vessels were tested. Paclitaxel was loaded in microbubbles lined with the Luteinizing hormone to maxamize the properties of the drug in ovarian cancer. This non invasive technique can revolutionize the way these illnesses are treated.
