How Tiny is Nano?
Nanorobotic is an emerging field in Robotic technology. They are complex, intelligent robots of very small size of the order of 10-9 m i.e. one billionth of a meter. These tiny machines perform specific tasks at nano-scale dimensions. They mimic human behavior and thus are capable of actuation, sensing, signalling, information processing and manipulation at nano scale.
Atoms are in the nano scale. In human body they are the building blocks of fats, hair, bones and DNA. Cells are built by DNA and other molecules; sometimes cells malfunction and cause disease. A nano robot can grab a cell and repair it, which makes it easier to cure a disease that have never been cured before.
It is expected that nano-robots will find solutions for most of the nano medicine problems such as cancer, cerebral aneurysm, examination of a given tissue, surveying its biochemical features in great detail etc.
Components of Nanorobots
The exterior of nano-robots consists of diamondoid material to which artificial glycocalyx surface is attached. minimizes fibrinogen adsorption and bio-activity, ensuring sufficient bio-compatibility to avoid immune system attack.
Nano-robots also have sensors to detect obstacles which might require a new trajectory. Sensor design and capabilities depend on the specific biomedical application for which the nanobot is developed. Currently the nano-robots are capable of detecting obstacles over a range of about 1 mm and within an angular resolution equivalent to a diameter of 100 nm at that range.
The substructures in a nano-robot include:
- Payload : It is an empty section that holds a small dose of drug. The nano-robots could traverse in the blood and release the drug to the site of infection/injury.
- Micro-camera : The nano-robot may include a miniature camera. The operator can steer the nano-robot when navigating through the body manually.
- Electrodes : The electrode mounted on the nano-robot could form the battery using the electrolytes in the blood. These protruding electrodes could also kill the cancer cells by generating an electric current.
- Lasers : It lasers could burn the harmful material like arterial plaque, blood clots or cancer cells.
- Ultra sonic signal generators : Using ultra sonic signals nano-robots target and destroy kidney stones.
- Swimming tail : The nano-robot will require a means of propulsion once inside the body, as they travel against the flow of blood in the.
Nano-robots in Medical Science
Nano-robots are expected to revolutionize the way medical conditions and disease are treated. Tiny enough to slip into the bloodstream, nano-robots will find and treat disease and restore the lost tissues at the cellular level. Although there are objections and ethical, the eventual benefit are enormous.
Nano-robots can be used for:
- Targeted Drug Delivery- Specific areas can be targeted with nano bullets or treated with smart bombs. Other nano particles may be used to starve cancer, providing an alternative to chemotherapy.
- Diagnostics- Monitoring, diagnosing and fighting sickness will be the work of microscopic agents. Nano-robots will be able to monitor neuro-electric signals and stimulate bodily systems.
- Regenerative Medicine- Complex procedures like growing new organs may also be possible with the help of tiny nano-robotics. Methods of creating new tissue are still under investigation. Nano-robots will be used to orchestrate cell repair as well.
To treat certain eye problems special robots are needed. Intraocular implants slowly release drugs near the retina. But placing them and eventually fishing them out when they are empty are challenging tasks.
Institute of Robotics in Zurich have recently developed an electromagnetically-controlled robot that can be injected to the eye using 23-gauge needle. It can be positioned with precision to the site where the drug is needed.
Nano-robots are coated with dye-containing nano-spheres to measure oxygen concentration in the eye to make quick diagnoses when the vision unexpectedly fails. Oxygen delivery in the retina can be interrupted due to diseases like glaucoma. Vision suddenly fails in such cases. Quick diagnoses and treatment are essential to restore the vision.
One way to measure oxygen is to make use of a peripheral effect of many fluorescent dyes — the ability of oxygen to rapidly reduce their fluorescence. Nano-spheres on the bots are excited by laser to induce fluorescence. When translated across the retina, the bot can then build up an image of the oxygen profile.
Damaged Tissue Repairing
Medical science aims for the creation of nanobots that are capable of repairing damaged tissues without causing pain and trauma to the patients. Stem cells produce new cells which in turn generates many different types of damaged cells. If stem cells are simply injected into damaged tissues they may wander from the spot. This makes the method less efficient.
Researchers in the field of nanotechnology showed that the therapy would be much more effective if the stem cells are attached to nano-fibers and these nano-fibers are injected at the exact location of the damaged cells.
This method could be useful for accident victims whose tissues have been damaged due to forceful trauma or for patients recovering from heart attack which damages heart cells, reducing the ability of the heart to pump blood. Normally these damaged cells can't recover and when ample damage has occurred, heart transplantation is the only option left.
Though the treatment has not yet been carried out on humans, lab animals have shown significant recovery when injected with nano-fibers to which stem cells are attached. Nano-fibers are made with bio-degradable materials such as polymers, or biological molecules like peptides and proteins, which ultimately dissolves leaving behind regenerated tissue. These nano materials are known as scaffolds.
If the researchers succeed, this therapy could provide relief for patients suffering from damaged spinal cord, regenerating cartilage in the joints to relieve arthritis and nerve cells in brain to treat Parkinson's disease.
Radiation and chemotherapy which are used in the treatment of cancer usually target a large area. Toxicity of these drugs used destroys the cancerous cells as well as the healthy ones. Thus treatment of cancer is laden with additional medical issues which at times may be life threatening.
Team of researchers working under Professor Ido Bachelet in Bar-Ilan University of Israel achieved a breakthrough in cancer research when they developed nanotechnology to deploy nanobots inside a cancer patient to seek and destroy malignancy. Nanobots propel through the bloodstream and administer drug to the targeted cancerous cell with precision. This ensures integrity of the organ and surrounding healthy tissues.
Nanobots are made from a single strand of DNA in the shape of a clamshell. It can be either in 'on' state or 'off' state. In the 'off' state they remain tightly shut so as not to affect healthy tissues. They carry multiple payloads of drug at a time. When the target spot is reached they are programmed to go into 'on' state and release the drug at the desired spot.
When they enter a tumor, the nano-robots can detect in a wholly autonomous fashion the oxygen-depleted tumor areas, known as hypoxic zones, and deliver the drug to them. This hypoxic zone is created by the substantial consumption of oxygen by rapidly proliferative tumor cells. Hypoxic zones are known to be resistant to most therapies, including radiotherapy.
Till Dec 2014 Prof. Bachelet's team developed nanobots capable identifying upto 12 different cancerous cells.
Slowing the Aging Process
There exists an age old question - Can old age be defeated?
The main reason for old age, wrinkles and eventual death is the inability of the DNA to exactly reproduce or regenerate a dead cell. Over the life span of a person cells regenerate many times and every time they deviate a little from the original i.e. losing some of the details and some of the quality. The cells ultimately become so much damaged that it produces all the signs of old age both internally and externally.
Researchers believe that nanobots can interfere with and delay the aging process by entering the bloodstream and performing two functions:
- Scan the body for early signs of fatal disease.
- Report the problem to a computer or resolve the issue then and there by repairing/ destroying the damaged tissues.
Ray Kurzweil, a computer scientist and winner of the US National Medal of Technology, says that around 2050 human being will have a strong chance of living up to 10 times the current average.
Heart Bypass Surgery
Nano robots can be used to clear the clogged arteries. They are injected into the body via the femoral artery in the leg. They use the circulatory system to move inside the body. Nanobots are guided to the site of the plaque by a long range sensor such as dye.
Once the plaque is detected, it is grounded into micro particles using the rotating needle and diamond chipped burr. Cutting procedure is monitored using the camera attached to the nano-machine. When the surgery is complete, the nanobot is removed from the system by guiding it to anchor a blood vessel that is readily accessible from outside and a small surgery is performed to remove it.
Dental nanobots have a nano-computer to store and perform pre-programmed actions. They are also able to receive and process signal from external stimuli.
Nanobots can be used to induce anesthesia. Patient's gum is instilled with colloidal suspension containing millions of active, analgesic robots that respond to inputs supplied by the dentist. Upon activation they block the sensory nerves from transmitting the sensation of pain, Anesthesia is reversible. After completion of the procedure nanobots can unblock the nerves.
Nanobots are also capable of locating hypersensitive teeth and sealing the dentin tubes with desensitizing agents. This provides a better relief to the patient than the conventional method.
Nanobots can reduce the time needed for orthodontic therapy. They are able to manipulate directly the periodontal structures.
The techniques described here may sound fictional, but the research to turn these into reality is progressing very fast.. Nano robots hold a lot of promise in eradicating diseases to reversing the aging process to treating cancer effectively. Once nanobots are available they are expected to revolutionize the diagnostic procedure.
Programmable and controllable micro-scale robots comprised of nano-scale parts fabricated to nano-meter precision will allow medical doctors to execute curative and reconstructive procedures in the human body at the cellular and molecular levels.