Share:
Nanomedicine nanoparticles in medicine
contents
- definition
- What is special about Nano?
- Common nanomaterials
- nanomedicine
- Magnetic Particle Imaging
- Artificial organs
- Nanotech and science fiction
- Nanomedicine risks
definition
It's about 10,000 times smaller than the average of a human hair, one nanometer is a millionth of a millimeter. Today, there are already various artificially produced nanoproducts - in sunscreen, for example, nanoparticles of titanium dioxide, in clothing silver nanoparticles, and in food packaging.
Image: Cybrain - fotolia The EU Commission defines: "Nanomaterial is a natural, process-derived or manufactured material containing particles in an unbound state, as an aggregate or agglomerate, and where at least 50 percent of the particles in the size distribution have one or more external dimensions in the range of 1 Nanometers to 100 nanometers. (...) By way of derogation (...), fullerenes, graphene flakes and single-walled carbon nanotubes with one or more external dimensions below 1 nanometer are nanomaterials. "
First of all, nanotechnology should produce things smaller and thus more precise. Second, it allows access to atoms and molecules, creating new materials and entire material systems.
There are natural nanoparticles such as soot particles, proteins in the blood or fat particles in the milk. Synthetic nanoparticles produce researchers either intentionally or as a side effect, for example, when diesel burns.
What is special about Nano?
Nano-structures develop special functions at the level of atoms and molecules, both in animate and inanimate matter. The last decades have been characterized by research: the first thing was to capture nano systems.
Today, scientists apply this knowledge in living systems - this is the basis of Naon medicine. Like any new technology that interferes with the body, it also carries risks. For example, nanocapsules are designed to deliver medicines right where they are located in the body, and promises, for example, tremendous advances in cancer medicine. But these nanoparticles could penetrate cell walls, collect in the body or ignite the respiratory tract.
Common nanomaterials
Nanosilver: Silver kills germs, and science uses this in nanoparticles, for example as a surface layer on door handles, in wound dressings or in textiles - nanosilver helps against the smell of sweat.
Soot particles can be artificially produced to serve as a black pigment in paints, but also as an antistatic additive in plastics.
Carbon nanotubes are constructed of carbon, very stable and so strengthen plastics. Today you will find yourself in bikes of the extra class.
Titanium dioxide refines surfaces to repel dirt. It promotes decomposition of organic materials by sunlight, for example, keeping the color of building facades clean.
Nanoparticles in zinc oxide absorb the UV radiation of the sun and are therefore found in sunscreen. In addition, the industry uses it in screens of liquid crystals or LEDs. Zinc oxide coatings also promote the action of solar cells.
nanomedicine
The American visionary Robert Freitas sees nanomedicine reach a golden age: Nanorobots of the near future are intended to repair genetic damage, artificially produced red blood cells prevent heart attacks - nanomachines kill viruses, repair cells or recharge the blood with oxygen.
Medicine promises a lot of nanotechniques. More than 100 drugs already contain nanoparticles, along with diagnostic methods and devices that use nanoprocessing. In the case of drugs, it is less about new active ingredients than about new effectiveness: Nanocapsules, which release the substances only in the environment of certain molecules, should transport the active ingredients directly to the target.
Many physicians expect a milestone in medicine for the treatment of neurological diseases that are related to blood and brain. Because nanoparticles can break through this "blood-brain barrier". This opens up new perspectives, for example, for Alzheimer's and Parkinson's, possibly also for multiple sclerosis.
Nanos-equipped devices, floors, walls and furniture in clinics could promote sterility. Resistant bacteria can probably better combat this. Wound dressings already contain nano-silver, for example in case of burn injuries.
Nanotechnology should also improve diagnostics: the nanoparticles are prepared so that they adhere to organs or cells. For example, tumor tissue can be detected with nano-iron oxide particles.
This leads to the probable nanotherapies of the near future: In cancer medicine, nanotechnology is likely soon to detect and combat tumors. Today, doctors are already experimenting with cancer treatment, in which magnetic nano-iron oxide particles electromagnetically heat the tumor, thereby destroying the cancer cells.
For example, nanocapsules could contain pancreatic cells, release insulin in the blood, and thus treat diabetes.
There is already a toothpaste, Theramed S.O.S. Sensitive on the basis of nanoparticles. She uses nanoparticles to build up a layer of artificial tooth material; so the teeth should feel less pain.
Hydroxyapatite is similar to the minerals of bone and dental implants are better implanted with its half, the nanomaterial shortens the process to up to two weeks, in contrast to conventional 2-4 months.
Nanoporous silicon or titanium dioxide is characterized by hole structures. These stimulate bone growth on the implants and stop inflammation by releasing active substances like a sponge.
Nanotechnology will certainly also be of particular importance in other implantations, because surfaces made of nanoparticles can be used to link biological organs and artificial devices better than with conventional methods. Whether pacemakers or endoprostheses such as artificial knee, hip or shoulder joints: Nano layers probably reduce the defense of the body against foreign bodies.
Already today hydroxyapatite can be injected as a paste to build up a jaw. Such nanomaterial is well tolerated because it resembles the mineral parts in the bone. The next step should be hydroxyapatites, which are combined with carbon nanotubes in a composite matrix and serve as bone cement.
Accident victims may soon benefit from replacement tissues in the form of nanoscale glass-collagen composites that carry artificial skin and artificial bones. In addition, implants with nanotechnology should be more stable than conventional ones.
As early as 1998, Abraxis BioScience LLC in the US made clinical trials of nanomedicine against cancer. The agent Abaxane was finally approved. It consists of insoluble paclitaxel and albumin, this albumin binds to the protein SPARC, which is affected by pancreatic cancer - unlike other drugs.
Nanos was developed by Tekmira Pharmaceuticals of Canada for lipoproteins that are thought to be hypercholesterolemic in the liver. However, a trial patient showed symptoms like a flu, then the experiment was stopped.
The French Bioalliance Pharma used the drug dexorubicin nanoparticles against liver cancer. But three subjects died of lung problems.
In the EU is approved a nanotherapy of brain tumors - the hyperthermia. In this case, iron oxide particles are injected into the brain and excited there with magnetic waves. They heat the tumor and kill it. Magnetic Particle Imaging (MPI) can also be used to film the heart and blood vessels.
Michael Bamberg of the German Cancer Society said: "Hyperthermia will become the fourth pillar of cancer therapy - in addition to surgery, radiotherapy and chemotherapy. His idea is based on proven cure successes in breast cancer, skin cancer, tumors, intestinal and cervical rhinorrhea.
Rapid tests with nanosensors to detect cancer, nanohormontests, nanobots to repair cells, and nanoparticles to heal paralyzed spinal cord injuries are planned. Some researchers believe that giving paraplegics a normal life again. But it is still about basic research.
Magnetic Particle Imaging
A new imaging technique, Magnetic Particle Imaging, introduced researchers from Philips Healthcare in 2005. They presented three-dimensional films of the heart, vessels, and tumors, and that was impossible with any other procedure.
This technique would make it possible to detect heart problems much faster than before. The doctor would have to film the heart and his environment only from the outside and could immediately detect damage in the heart wall or cardiac muscle weaknesses. For this, he only has to inject the patient with magnetic nanoparticles. However, conventional heart diagnostics sometimes take months.
Artificial organs
Nanotechnology makes one think what was science fiction recently, namely to artificially create organs and even organisms. Interdisciplinary researchers want to combine nanotechnology with biotech, information science and cognitive science to create artificial intelligence and increase human capabilities beyond natural boundaries.
Long life through artificial organs. Picture: benschonewille- fotolia This is not a fixed idea, but already partially reality. This is how skin and cartilage can be produced artificially today. For larger organs, nanoscience has failed to supply oxygen and nutrient cells. It's not working yet and that's why the cells are dying out.
But the Massachusetts Institute of Technology at Cambridge, USA is developing a method to solve just this problem. A computer designs the pattern of a cell network and etches it on a silicon surface. This pattern is then transferred to biological material, two layers are overlaid and sealed. The cells can adhere to this structure. The cells themselves are grown in Petri dishes. Liver and kidney cells remained intact for two weeks.
The researchers implanted rats with a "nano-liver" with a layer of cells. A liver needs about 30-50 such layers to function. The nano-fabric survived a week.
Nanotech and science fiction
Greg Bear established "nanotechnology in science fiction as a central theme in" Blood Music "in 1985. A researcher breeds molecules and brings them a form of intelligence. He injected himself with one of these cultures.
The Nanobots multiply now and act independently in the body: His visual acuity increases, he no longer suffers from colds. The Nanos are constantly evolving and creating an ideal environment: from the servant, they become the ruler of their host body. You reprogram and control the researcher.
This offers advantages for the inventor: The survival of nanos depends on the health of the host body, and they are constantly improving their abilities.
But they do not change the host in the way that would be best for him, but how the nano-organisms themselves have ideal living conditions. Now scientific progress becomes a horror.
Andreas Eschbach invented self-sufficient nanorobots that kill cancer cells in "Herr aller Dinge" "virus-sized nanocells that recognize cancer cells by their signatures. To control them, they are connected by radio with the doctor, so they can make any erroneous actions; The wireless connection goes straight to the doctor's brain, which is traversed by nanodial leads to conduct the healing cells. Their operation is as follows: The machines do not simply dissolve the cancer cells; that would be too dangerous, because then your body would be flooded with more waste than it can drain. Instead, they invade the cell and trigger apoptosis, the cellular mechanism of controlled self-destruction. Most of the remains are eaten by your leukocytes. Anything left over, the submarines transport themselves, deposit it in your bladder or bowel. "
Nanotechnology plays a role in many novels: as a central plot, as a marginal event or as a backdrop.
Bruce Sterling, an inventor of Cyperpunk literature, devoted himself to his visions of the future of nanotechnology since the late 1990s. He sees himself as a futurist and said that with the breakthrough of the Internet, much had happened that he had written about in fiction - that's why he was now dealing with a technique that was only in its infancy.
In 2002 Michael Crichton, the author of Jurassic Park "Prey", published. Researchers in Nevada are developing nanocameras for the military. But they make themselves independent and kill everything they encounter. They multiply and manipulate the thoughts and motor skills of their inventors. From the Nanos develops a super-organism that copies the shape of humans.
The nanos then behave like humans, they destroy the planet to get resources for their multiplication. Science fiction, thinking on what would be technically possible and designing a fictitiously realistic scenario, was not "Prey", but a stale story about "the ghosts I called" from the Faustian man who no longer has his technical monsters under control.
Angelika Fehrenbach wrote with "The Lotus Effect", however, a thriller that remains close to reality. A scientist from the University of Marburg realizes that a newly researched nanotechnology is risky, as the laboratory rats die in rows. She realizes that those responsible are keeping silent, researching and fighting for their lives.
Jeff Carlsson published "Plague Year" in 2007, in German the work appeared a year later as "Nano". Nanoparticles provide the background for a classic end-time epic. The plot is traditional: artificial intelligences make themselves independent and kill their inventors.
These Frankenstein creatures are nanorobots here. They multiply and kill all warm-blooded animals. People flee to the high mountains, because there the Nanos do not work. The survivors in the alpine winter meanwhile fight against cold and hunger. They try to push to a group on another summit, which has more food and a better shelter.
Carlson deals thoroughly with nanotechnology; However, this only provides the framework for the question: how do people behave in extreme situations?
A favorite idea of science fiction are self-acting nanorobots. These go through the body and eliminate every toxin, every tapeworm, they fix malformations on cells, heal internal injuries, they regenerate the cells and thus stop the aging - every day for 24 hours.
If there were such nanomachines, we could even live unhealthily, because they would eliminate any damage immediately.
Nanomedicine risks
American studies in 2002 showed some savings in nanoparticulate carcinoma, mainly because the nanoparticles had fewer side effects. Undesirable side effects, however, were a massive problem, with 100,000 people dying in the United States in one year.
The risks of nano-techniques are little researched and it is unknown which companies use which nano-substances. One problem is probably related to nanoparticles being released into the environment; they are smaller than fine dust and last a long time in the air.
Experts therefore call for a central register of reporting nanomaterials and investigations of each substance.
Nanoparticles in filter systems are unlikely to pose a health hazard during operation because they are tightly sealed in plastics. Problamatisch but in the future, the disposal, then threatens a similar effort as in asbestos.
All products that release nanoparticles into the environment should be avoided. Thus, the nano-silver particles in certain socks already dissolve in the first wash, get into the sewage and probably harm Baktierien in sewage treatment plants.
So far, nobody knows how right the risks of nano-material should be classified: Is it about the size, or are the properties of the substances important? Is it about the amount of substances in the environment as with other thresholds, or is the number and structure of the particles critical to the hazard??
Although nanotechnology is hardly known to most Europeans, every third in Germany does not know what it is. Those who say something about nanotechnology are generally positive about it.
It becomes clear that people who are familiar with the term nanotechnology have generally acquired knowledge on their own and, for that reason, rarely devalue or apologize uncritically.
Consumer protection groups demand that nanoparticles be removed from cosmetics and food until they can be classified as harmless. At Naturland, for example, nanoparticles are prohibited.
Nanomaterials in Germany can be considered both as active ingredients and as auxiliary substances, depending on how they are used. The German Medicines Act determines what the safety checks look like, ie both the consultation procedures and the pre-admission clinical trials, the approval procedures themselves and the follow-up and post-authorization reporting.
Ethics committees must approve clinical trials. The German Federal Institute for Drugs and Medical Devices monitors the approval.
Particularly controversial is the crossing of the blood-brain barrier. Although it makes it possible to improve the brain performance of Alzheimer's sufferers, it can also be used to increase performance in non-therapeutically induced people - with unpredictable side effects.
The EU prohibits research on methods to develop materials to improve healthy people. The ethics committees pay particular attention to their military mission: Nanotech medicines are designed to raise the concentration of soldiers or enable them to work continuously without sleep. Last but not least, nanotechnology opens up countless opportunities to develop synthetic biological agents.
However, ethics committees do not achieve much, because projects that use nanotechnology in this sense, take place in seclusion.
While real medical research today is massively pushing the functional replacement of damaged body parts with nanomedicine, ethicists are discussing the problem of organs and prostheses that are said to surpass the human original.
This discussion is not straightforward: which improvements of the body are medically necessary, acceptable or unacceptable is defined very differently in societies.
The debate on what is medically and technically possible with nanomedicine, and what is ethically justifiable, is currently taking place separately in Germany. (Dr. Utz Anhalt)
Specialist supervision: Barbara Schindewolf-Lensch (doctor)
Swell:
http://www.ingenieur.de/Fachbereiche/Mikro-Nanotechnik
http://www.nano.fraunhofer.de/de/nanotech.html
http://library.fes.de/pdf-files/stabsabteilung/05709.pdf
http://www.umweltbundesamt.de/themen/chemikalien/nanotechnik