Nanosubmarine

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Nanosubmarines, or nanosubs, are synthetic microscopic devices that can navigate and perform specific tasks within the human body. Most of the self-propelled devices will be used to detect substances, decontaminate the environment, perform targeted drug delivery, conduct microsurgery and destroy malicious cells. Nanosubmarines use a variety of methods to navigate through the body; currently the preferred method uses the electrochemical properties of molecules. There have been multiple successful tests using this technology to heal mice with inflammatory bowel diseases. The general goal of nanosubmarines is to be able to produce a machine which can sense and respond autonomously, all while being fueled by its environment. [1]

Targeted drug delivery, sometimes called smart drug delivery, is a method of delivering medication to a patient in a manner that increases the concentration of the medication in some parts of the body relative to others. This means of delivery is largely founded on nanomedicine, which plans to employ nanoparticle-mediated drug delivery in order to combat the downfalls of conventional drug delivery. These nanoparticles would be loaded with drugs and targeted to specific parts of the body where there is solely diseased tissue, thereby avoiding interaction with healthy tissue. The goal of a targeted drug delivery system is to prolong, localize, target and have a protected drug interaction with the diseased tissue. The conventional drug delivery system is the absorption of the drug across a biological membrane, whereas the targeted release system releases the drug in a dosage form. The advantages to the targeted release system is the reduction in the frequency of the dosages taken by the patient, having a more uniform effect of the drug, reduction of drug side-effects, and reduced fluctuation in circulating drug levels. The disadvantage of the system is high cost, which makes productivity more difficult and the reduced ability to adjust the dosages.

Microsurgery surgery requiring a microscope

Microsurgery is a general term for surgery requiring an operating microscope. The most obvious developments have been procedures developed to allow anastomosis of successively smaller blood vessels and nerves which have allowed transfer of tissue from one part of the body to another and re-attachment of severed parts. Microsurgical techniques are utilized by several specialties today, such as: general surgery, ophthalmology, orthopedic surgery, gynecological surgery, otolaryngology, neurosurgery, oral and maxillofacial surgery, plastic surgery, podiatric surgery and pediatric surgery.

Inflammatory bowel disease intestinal disease characterized by inflammation located in all parts of digestive tract

Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the colon and small intestine. Crohn's disease and ulcerative colitis are the principal types of inflammatory bowel disease. Crohn's disease affects the small intestine and large intestine, as well as the mouth, esophagus, stomach and the anus, whereas ulcerative colitis primarily affects the colon and the rectum.

Contents

Uses

The main purpose of a nanosubmarine is to navigate the body and perform a specific task. The most speculated task is the treatment and diagnosis of diseases from within the body. [2] This is supported by the task of detecting substances, as most diseases cause a specific type of protein or other molecule to be made in abundance within the bloodstream. Another speculated task is microsurgery. With this technology, doctors will be able to perform surgery on specific locations from within the body. [1] One example of this could be a treatment for cancer. A nanosubmarine could be built to detect specific cancer cells within the body; after locating the cells, the nanosub would be able to kill only the mutated cells and ignore healthy cells. [3]

Medical diagnosis process to determine or identify a disease or disorder

Medical diagnosis is the process of determining which disease or condition explains a person's symptoms and signs. It is most often referred to as diagnosis with the medical context being implicit. The information required for diagnosis is typically collected from a history and physical examination of the person seeking medical care. Often, one or more diagnostic procedures, such as diagnostic tests, are also done during the process. Sometimes posthumous diagnosis is considered a kind of medical diagnosis.

Cancer disease of uncontrolled, unregulated and abnormal cell growth

Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss and a change in bowel movements. While these symptoms may indicate cancer, they can also have other causes. Over 100 types of cancers affect humans.

Cancer cell tumor cell

Cancer cells are cells that divide relentlessly, forming solid tumors or flooding the blood with abnormal cells. Cell division is a normal process used by the body for growth and repair. A parent cell divides to form two daughter cells, and these daughter cells are used to build new tissue, or to replace cells that have died because of aging or damage. Healthy cells stop dividing when there is no longer a need for more daughter cells, but cancer cells continue to produce copies. They are also able to spread from one part of the body to another in a process known as metastasis.

Navigation is one of the most difficult aspects to develop in nanosubmarines. The goal is to be able to travel throughout the bloodstream without getting stuck in even the smallest of capillaries. However, this is difficult because the smallest capillaries are 2 μm across (2.0 x 10−6m); blood cells are about 7μm but they are easily pliable and can squeeze through the capillaries. Another challenge with navigation is the fact that physics restricts the amount of propulsion such a small device can output. The blood flow is simply too strong for any device even compete with the flow, therefore the nanosubmarine would have to be carried by the blood. [4]

Micrometre one millionth of a metre

The micrometre or micrometer, also commonly known by the previous name micron, is an SI derived unit of length equalling 1×10−6 metre ; that is, one millionth of a metre.

One form of propulsion nanosubmarines could use is electrochemical. One example of a motor is a nanorod which is platinum on one side and gold on the other. When submerged in hydrogen peroxide the platinum oxidizes the H2O2 into 2H+ and O2. This process occurs because platinum takes two electrons from the molecule. On the other side of the rod, the gold reduces hydrogen peroxide into water, in doing so an electron is pulled from the gold. This causes a steady electron flow from the platinum side of the rod towards the gold side. Since the rod is so small, Newton's third law of physics applies. For any action there is a reaction, when the electrons are pulled across the surface of the rod, so too is the rod pulled in the opposite direction. [1]

In nanotechnology, nanorods are one morphology of nanoscale objects. Each of their dimensions range from 1–100 nm. They may be synthesized from metals or semiconducting materials. Standard aspect ratios are 3-5. Nanorods are produced by direct chemical synthesis. A combination of ligands act as shape control agents and bond to different facets of the nanorod with different strengths. This allows different faces of the nanorod to grow at different rates, producing an elongated object.

Hydrogen peroxide is a chemical compound with the formula H
2O
2. In its pure form, it is a pale blue, clear liquid, slightly more viscous than water. Hydrogen peroxide is the simplest peroxide. It is used as an oxidizer, bleaching agent and antiseptic. Concentrated hydrogen peroxide, or "high-test peroxide", is a reactive oxygen species and has been used as a propellant in rocketry. Its chemistry is dominated by the nature of its unstable peroxide bond.

Scientific achievements

The first recorded success of a nanosubmarine was performed by a team of students led by Dan Peer from Tel Aviv University in Israel. This was a continuation to Peer's work at Harvard on nanosubmarines and targeted drug delivery. Tests have proven successful in delivering drugs to heal mice with ulcerative colitis. Tests will continue and the team plans to experiment on the human body soon. [5]

Tel Aviv University public university located in Ramat Aviv, Tel Aviv, Israel

Tel Aviv University (TAU) is a public research university in Tel Aviv, Israel. With over 30,000 students, the University is the largest in the country. Located in northwest Tel Aviv, the University is the center of teaching and research of the city, comprising 9 faculties, 17 teaching hospitals, 18 performing arts centers, 27 schools, 106 departments, 340 research centers, and 400 laboratories.

Ulcerative colitis inflammatory bowel disease that causes ulcers in the colon

Ulcerative colitis (UC) is a long-term condition that results in inflammation and ulcers of the colon and rectum. The primary symptoms of active disease are abdominal pain and diarrhea mixed with blood. Weight loss, fever, and anemia may also occur. Often, symptoms come on slowly and can range from mild to severe. Symptoms typically occur intermittently with periods of no symptoms between flares. Complications may include megacolon, inflammation of the eye, joints, or liver, and colon cancer.

See also

<i>Fantastic Voyage</i> 1966 film directed by Richard Fleischer

Fantastic Voyage is a 1966 American science fiction film directed by Richard Fleischer and written by Harry Kleiner, based on a story by Otto Klement and Jerome Bixby. The film is about a submarine crew who are shrunk to microscopic size and venture into the body of an injured scientist to repair damage to his brain. The original story took place in the 19th century and was meant to be a Jules Verne-style adventure with a sense of wonder. Kleiner abandoned all but the concept of miniaturization and added a Cold War element. The film starred Stephen Boyd, Raquel Welch, Edmond O'Brien, Donald Pleasence, and Arthur Kennedy.

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Redox Chemical reaction

Redox is a chemical reaction in which the oxidation states of atoms are changed. Any such reaction involves both a reduction process and a complementary oxidation process, two key concepts involved with electron transfer processes. Redox reactions include all chemical reactions in which atoms have their oxidation state changed; in general, redox reactions involve the transfer of electrons between chemical species. The chemical species from which the electron is stripped is said to have been oxidized, while the chemical species to which the electron is added is said to have been reduced. It can be explained in simple terms:

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Microcirculation circulation of the blood in the smallest blood vessels

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Microvasculature is defined as the microvessels – venules and capillaries of the microcirculation, with a maximum average diameter of 0.3 millimeters. As the vessels decrease in size, they increase their surface-area-to-volume ratio. This allows surface properties to play a significant role in the function of the vessel.

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Electrochemical aptamer-based biosensors


Electrochemical aptamer-based (E-AB) biosensors have the ability to generate electrochemical signal in response to specific target binding in vivo. The signal is measured by a change in Faradaic current passed through an electrode. E-AB sensors are advantageous over previously reported aptamer-based sensors, such as fluorescence generating aptamers, due to their ability to detect target binding in vivo with real-time measurements. An E-AB sensor is composed of a three-electrode cell: an interrogating electrode, a reference electrode, and a counter electrode. A signal is generated within the electrochemical cell then measured and analyzed by a potentiostat. There are several biochemical and electrochemical parameters to optimize signal gain for E-AB biosensors. The density packing of DNA or RNA aptamers, the ACV frequency administered by the potentiostat, and the chemistry of the SAM are all factors that determine signal gain as well as the signal to noise ratio of target binding. E-AB biosensors provide a promising mechanism for in-situ sensing and feedback-controlled drug administration.

References

  1. 1 2 3 Pumera, Martin (August 2, 2010). "Electrochemically Powered Self-propelled Electrophoretic Nanosubmarines". Nanoscale. RSC Publishing.
  2. ↑ Moore, Andrew (May 2001). "Of Silicon and Submarines". New York: European Molecular Biology Organization. Retrieved 13 February 2013.
  3. ↑ Jones, Richard (August 2004). The Future of Nanotechnology. Physics World.
  4. ↑ "The nanosubmarine". October 2003. Retrieved 29 January 2013.
  5. ↑ "A Fantastic Voyage Brought To Life". American Friends of Tel Aviv University. 12 January 2009. Retrieved 29 January 2009.
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