Application of Nano robots in Medicine

Introduction:

What is medicine.

Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness. Contemporary medicine applies health science, biomedical research, and medical technology to diagnose and treat injury and disease, typically through medication, surgery, or some other form of therapy.

Limitations of current medicine.

When the body’s working, building, and battling goes awry, we turn to medicine for diagnosis and treatment. Today’s methods, though, have obvious shortcomings.

1.     Crude Methods: Diagnostic procedures vary widely, from asking a patient question, through looking at X-ray shadows, through exploratory surgery and the microscopic and chemical analysis of materials from the body. Doctors can diagnose many ills, but others remain mysteries. Even a diagnosis does not imply understanding: doctors could diagnose infections before they knew about germs, and today can diagnose many syndromes with unknown causes. After years of experimentation and untold loss of life, they can even treat what they don’t understand a drug may help, though no one knows why.

2.     Limited Abilities: Current medicine is limited both by its understanding and by its tools. In many ways, it is still more an art than a science. Mark Pearson of Du Pont points out, “In some areas, medicine has become much more scientific, and in others not much at all. We’re still short of what I would consider a reasonable scientific level. Many people don’t realize that we just don’t know fundamentally how things work. It’s like having an automobile, and hoping that by taking things apart, we’ll understand something of how they operate. We know there’s an engine in the front and we know it’s under the hood, we have an idea that it’s big and heavy, but we don’t really see the rings that allow pistons to slide in the block. We don’t even understand that controlled explosions are responsible for providing the energy that drives the machine.

What is nanotechnology

Nanotechnology (sometimes shortened to "nanotech"/”nano science”) is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with structures sized ranging from 1 to 100 nanometers in at least one dimension, and involve developing materials or devices possessing at least one dimension within that size.

What are Nanorobots.

Nanorobots are nanodevices that will be used for the purpose of maintaining and protecting the human body against pathogens.

Nanomedicine:

Nanomedicine is the medical application of nanotechnology. Nanomedicine ranges from the medical applications of nanomaterial, to nanoelectronic biosensors, and even possible future applications of molecular nanotechnology. Current problems for Nanomedicine involve understanding the issues related to toxicity and environmental impact of nanoscale materials.

Nanorobots will be basically used for the treatment in the field of nanomedicine. They will have a diameter of about 0.5 to 3 microns and will be constructed out of parts with dimensions in the range of 1 to 100 nanometers. The main element used will be carbon in the form of diamond because of the strength and chemical inertness of these forms.

Types of nanorobots:

Various forms of nanorobots are used in different field, but in medical field only three main types of nanorobots are used:

1.     Respirocytes: Respirocytes are hypothetical, artificial red blood cells that can supplement or replace the function of much of the human body's normal respiratory system.

2.     Microbivores: The microbivore is an oblate spheroidal nanomedical device consisting of 610 billion precisely arranged structural atoms plus another ~150 billion mostly gas or water molecules when fully loaded. Microbivores when given intravenously (I.V) would achieve complete clearance of even the most severe septicemic infections in hours or less.

3.     Chromallocyte: A chromallocyte is a lozenge-shaped mobile nanorobot, consisting of about four trillion atoms. Its purpose is to be a gene delivery vector superior to viruses (typically used today), offering a much greater degree of precision and control for the experimenter. Although the chromallocyte, designed by Robert Freitas, a pioneer in nanotechnology, has not yet been fabricated, it does seem feasible in the next few decades.

Different components inside nanorobots:

1.     Medicine cavity -- A hollow section inside the nanorobot might hold small doses of medicine or chemicals.

2.     Probes, knives and chisels -- To remove blockages and plaque, a nanorobot will need something to grab and break down material.

3.     Microwave emitters and ultrasonic signal generators -- To destroy cancerous cells, doctors need methods that will kill a cell without rupturing it.

4.     Electrodes -- Two electrodes protruding from the nanorobot could kill cancer cells by generating an electric current, heating the cell up until it dies.

5.     Lasers -- Tiny, powerful lasers could burn away harmful material like arterial plaque, cancerous cells or blood clots. The lasers would literally vaporize the tissue.

The two biggest challenges and concerns scientists have regarding these small tools are making them effective and making them safe. For instance, creating a small laser powerful enough to vaporize cancerous cells is a big challenge, but designing it so that the nanorobot doesn't harm surrounding healthy tissue makes the task even more difficult. While many scientific teams have developed nanorobots small enough to enter the bloodstream, that's only the first step to making nanorobots.

Mechanism of action of nanorobots:

The target has surface chemicals allowing the nanorobots to detect and recognize it. Manufacturing better sensors and actuators with nanoscale sizes makes them find the source of release of the chemical. NCD simulator was developed, which is software for nanorobots in environments with fluids dominated by Brownian motion and viscous rather than inertial forces. First, as a point of comparison, the scientists used the nanorobots’ small Brownian motions to find the target by random search. In a second method, the nanorobots monitor for chemical concentration significantly above the background level. After detecting the signal, a nanorobot estimates the concentration gradient and moves toward higher concentrations until it reaches the target. In the third approach, nanorobots at the target release another chemical, which others use as an additional guiding signal to the target. With these signal concentrations, only nanorobots passing within a few microns of the target are likely to detect the signal.

Applications of nanorobots in medicine:

The artificial respirocyte is a simple Nano technological device whose primary applications include transfusable blood substitution; treatment for anemia, perinatal and neonatal disorders, and a variety of lung diseases and conditions; contribution to the success of certain aggressive cardiovascular and neurovascular procedures, tumor therapies and diagnostics; prevention of asphyxia; maintenance of artificial breathing in adverse environments; and a variety of sports, veterinary, battlefield and other applications. Some possible applications using Nanorobots (Respirocytes) are as follows:

1.     To cure skin diseases, a cream containing nanorobots may be used. It could remove the right amount of dead skin, remove excess oils, add missing oils, apply the right amounts of natural moisturizing compounds, and even achieve the elusive goal of 'deep pore cleaning' by actually reaching down into pores and cleaning them out. The cream could be a smart material with smooth-on, peel-off convenience.

2.     A mouthwash full of smart nanomachines could identify and destroy pathogenic bacteria while allowing the harmless flora of the mouth to flourish in a healthy ecosystem. Further, the devices would identify particles of food, plaque, or tartar, and lift them from teeth to be rinsed away. Being suspended in liquid and able to swim about, devices would be able to reach surfaces beyond reach of toothbrush bristles or the fibers of floss. As short-lifetime medical nanodevices, they could be built to last only a few minutes in the body before falling apart into materials of the sort found in foods (such as fiber).

3.     Medical nanodevices could augment the immune system by finding and disabling unwanted bacteria and viruses. When an invader is identified, it can be punctured, letting its contents spill out and ending its effectiveness. If the contents were known to be hazardous by themselves, then the immune machine could hold on to it long enough to dismantle it more completely.

4.     Devices working in the bloodstream could nibble away at arteriosclerotic deposits, widening the affected blood vessels. Cell herding devices could restore artery walls and artery linings to health, by ensuring that the right cells and supporting structures are in the right places. This would prevent most heart attacks.

5.     Drug delivery: Nanotechnology provides a wide range of new technologies for developing customized solutions that optimize the delivery of pharmaceutical products.

To be therapeutically effective, drugs need to be protected during their transit to the target action site in the body while maintaining their biological and chemicals properties. Some drugs are highly toxic and can cause harsh side effects and reduced therapeutic effect if they decompose during their delivery. Depending on where the drugs will be absorbed (i.e. colon, small intestine, etc.), and whether certain natural defense mechanisms need to be passed through such as the blood-brain barrier, the transit time and delivery challenges can be greatly different. Once a drug reaches at its destination, it needs to be released at an appropriate rate for it to be effective. If the drug is released too rapidly it might not be completely absorbed, or it might cause gastro-intestinal irritation and other side effects. The drug delivery system must positively impact the rate of absorption, distribution, metabolism, and excretion of the drug or other substances in the body. In addition, the drug delivery system must allow the drug to bind to its target receptor and influence that receptor’s signaling and action, as well as other drugs, which might also be active in the body.Nanotechnology can offer new drug delivery solutions in the following areas.

a)     Drug Encapsulation: One major class of drug delivery systems is materials that encapsulate drugs to protect them during transit in the body. Drug encapsulation materials include liposomes and polymers (i.e. Polylactide (PLA) and Lactide-co-Glycolide (PLGA)) which are used as microscale particles. The materials form capsules around the drugs and permit timed drug release to occur as the drug diffuses through the encapsulation material. The drugs can also be released as the encapsulation material degrades or erodes in the body. Nanoparticle encapsulation is also being investigated for the treatment of neurological disorders to deliver therapeutic molecules directly to the central nervous system beyond the blood-brain barrier, and to the eye beyond the blood-retina barrier. Applications could include Parkinson’s, Huntington’s, Alzheimer’s, ALS and diseases of the eye.

b)    Functional Drug Carriers: Another class of drug delivery systems where nanotechnology offers interesting solutions is in the area of nanomaterjals that carry drugs to their destination sites and also have functional properties. Certain nanostrucfures can be controlled to link with a drug, a targeting molecule, and an imaging agent, then attract specific cells and release their payload when required.

6.     Implantable devices: Nanotechnology offers sensing technologies that provide more accurate and timely medical information for diagnosing disease, and miniature devices that can administer treatment automatically if’ required. Health assessment can require medical professionals, invasive procedures and extensive laboratory testing to collect data and diagnose disease. This process can take hours, days or weeks for scheduling and obtaining results. Some medical information is extremely time sensitive such as finding out if there is sufficient blood flow to an organ or tissue after transplant or reconstructive surgery, before irreversible damage occurs.

Certain medical tests such as biopsies are subjective and can provide inconclusive or incorrect results. In a false negative result where a needle misses the tumor and then samples a normal tissue, the cancer may go untreated and can impact a patient’s chances for long-term survival.Example applications are as follows.

a)     Retina Implants: Retinal implants are in development to restore vision by electrically stimulating functional neurons in the retina One approach being developed by various groups including a project at Argonne National Laboratory is an artificial retina implanted in the back of the retina. The artificial retina uses a miniature video camera.

b)    Cochlear Implants: A new generation of smaller and more powerful cochlear implants is intended to be more precise and offer greater sound quality.

7.     Surgical aids:

a)     Operating Tools: Medical devices that contain nano and micro technologies will allow surgeons to perform familiar tasks with greater precision and safety, monitor physiological and biomechanical parameters more accurately, and perform new tasks that are not currently done.

b)    Surgical Robotics: Robotic surgical systems are being developed to provide surgeons with unprecedented control over precision instruments. This is particularly useful for minimally invasive surgery. Instead of manipulating surgical instruments, surgeons use their thumbs and fingers to move joystick handles on a control console to maneuver two robot arms containing miniature instruments that are inserted into ports in the patient. The surgeon’s movements transform large motions on the remote controls into micro-movements on the robot arms to greatly improve mechanical precision and safety.

8.     Diagnostic tools:

a)     Genetic Testing: Nano and micro technologies provide new solutions for increasing the speed and accuracy of identifying genes and genetic materials for drug discovery and development, and for treatment-linked disease diagnostics products. Dyes are not always precise or sufficiently sensitive

b)    Ultra-sensitive Labeling and Detection Technologies: Several new technologies are being developed to improve the ability to label and detect unknown target genes. At Genicon, gold nanoparticle probes are being treated with chemicals that cling to target genetic materials and illuminate when the sample is exposed to light.

9.     Killing cancer cells: The device would circulate freely throughout the body, and would periodically sample its environment by determining whether the binding sites were or were not occupied. Occupancy statistics would allow determination of concentration. Today’s monoclonal antibodies are able to bind to only a single type of protein or other antigen, and have not proven effective against most cancers. The cancer killing device suggested here could incorporate a dozen different binding sites and so could monitor the concentrations of a dozen different types of molecules. The computer could determine if the profile of concentrations fit a pre-programmed “cancerous” profile and would, when a cancerous profile was encountered, release the poison.

10.  Regenerating  Tissues with the help of nanobots: Americans are spending a lot for anti-aging medicines, in coming years nanotechnology will be assisting the new anti-aging drive . What i can feel is nanotechnology can create nanobots that can be injected into our body and these nanobots will be capable of repairing damaged and old tissues. Well it sounds bit weird! Don’t worry we all will get used to it if after few decades!

11.  Super human powers: Imagine a human being who can run 100 miles without getting tired, a man/ woman  powerful enough to run as fast as 90 miles per second !These things are can be possible with nanotechnology,  nanobots  fused with quantum computers will be intelligent enough to alter  chemicals in our  body which can manipulate our functions to convert our self into powerful human!Some conservative people may object these nano ideas but later they will get used to it, during earlier days conservatives objected discoveries made by scientists like Copernicans etc.

12.  Transfusions&Perfusions:Respirocytes may be used as the active oxygen-carrying component of a universally transfusable blood substitute that is free of disease vectors such as hepatitis, venereal disease, malarial parasites or AIDS, storable indefinitely and readily available with no need for cross-matching.

13.  Treatment of Anemia: Oxygenating respirocytes offer complete or partial symptomatic treatment for virtually all forms of anemia.

14.  Fetal and Child-Related Disorders: Respirocytes may be useful in perinatal medicine, as for example infusions of device suspension to treat fetal anemia (erythroblastosis fetalis), neonatal hemolytic disease.

15.  Respiratory Diseases: The devices could provide an effective long-term drug-free symptomatic treatment for asthma, and could assist in the treatment of hemotoxic (pit viper) and neurotoxic (coral) snake bites; hypoxia, stress polycythemia and lung disorders. Respirocytes could also be used to treat conditions of low oxygen availability to nerve tissue, as occurs in advanced atherosclerotic narrowing of arteries, strokes, diseased or injured reticular formation in the medulla oblongata (controlling autonomic respiration)

16.  Cardiovascular and Neurovascular Applications: Respirocyte perfusion could be useful in maintaining tissue oxygenation during anesthesia, coronary angioplasty, organ transplantation, siamese-twin separation, other aggressive heart and brain surgical procedures, in postsurgical cardiac function recovery, and in cardiopulmonary bypass solutions.

Drawbacks of Nanorobots:

Some of the drawbacks of the Nanobots could be:

1.     There can be a formation of cluster of different Nanorobots which can harm the body blocking veins and other important parts.

2.     The installation cost of the Nanorobots is high so till now they are out of reach of most of the people.

3.     The maintenance of the Nanorobots after entering the body is too much difficult.

Conclusion and summary:

Nanotechnology as a diagnostic and treatment tool for patients with life threatening diseases showed how actual developments in new manufacturing technologies are enabling innovative works which may help in constructing and employing nanorobots most effectively for biomedical problems. Nanorobots applied to medicine hold a wealth of promise from eradicating disease to reversing the aging process (wrinkles, loss of bone mass and age related conditions are all treatable at the cellular level); nanorobots are also candidates for industrial applications.
Manipulating matter at molecular scale and influencing their behavior (dynamics and properties) is the biggest challenges for the nanorobotic systems. This field is still in very early stages of development and still a lot has to be figured out before any substantial outcome is produced.
The future of bio nanorobots (molecular robots) is bright. We are at the dawn of a new era in which many disciplines will merge including robotics, mechanical, chemical and biomedical engineering, chemistry, biology, physics and mathematics so that fully functional systems will be developed. However, challenges towards such a goal abound. Developing a complete database of different bio molecular machine components and the ability to interface or assemble different machine components are some of the challenges to be faced in the near future.