Pharmaceutical commercials can cause the unsettling feeling that if the disease doesn't kill, the cure will, what with a drug's long list of side effects and warnings. Many therapeutic drugs administered by pill, cream, syringe, IV or liquid can be a hit or miss delivery system. Researchers report that only 1 of 100,000 molecules of an intravenous drug make it to the intended spot in the body.
"The big issues for making medicines more effective are getting drugs to where they are needed and keeping them from breaking down as they circulate through the body," said Alexis. "A way to improve targeting a drug and preventing it from being passed out of the body is putting it in envelopes — putting the drug inside something to protect it until it's at the right spot."
The envelopes Alexis uses are nanoparticles. Think of an M&M, with the nanoparticle being the hard outer candy shell and the chocolate being the medicine. The goal would be the same as for an M&M — to melt in the right place.
Nanotechnology operates on the molecular level. It involves engineering materials on such a small scale that the results can be seen only with electron and atomic force microscopes. Nano-engineers take advantage of natural forces — positive and negative electrical charges, attraction and repulsion, surface texture — to have materials self assemble.
"You would be surprised how we mimic what nature does," said Alexis. It is setting off a storm of innovations in many fields — biology, medicine, material science, computers, manufacturing, physics.
"Nanoparticles can be modified many ways,” said Alexis. “They can be coated so that they can be durable and stable. They can be patterned so that they match up like a key and a lock to connect to certain cells, tissues and organs. Some drugs are not taken up because of their physical and chemical properties."
A handful of nanoparticle medicines already have been approved for use treating diseases, particularly cancers. Alexis and other bioengineers are ushering in a new era in medicine.
A challenge for oral medicines, for example, is getting them to do some good before the body destroys them. A patient's metabolism can do its job too well taking a drug out of circulation.
Called "first-pass metabolism," the liver breaks down a drug during its first trip circulating through the body. The result is doctors must use greater amounts of oral medicines to achieve the therapeutic effect. Negative reactions from the higher doses or the inconvenience from prolonged treatment cause many patients to stop taking their medicines.
Nanoparticles can be made to survive the first pass. The particles also can be made to get beyond the body's immune system. Multi-layers on the nanoparticles or nanoshells can resist the body's defenses, enabling the medicine to last longer or reach the intended location.
Dendrimers are nanoparticles that could become the Swiss Army knives of targeted drug delivery. The particles can be made so that a number of different kinds of molecules could be attached to it. One group of molecules could fight the disease, another could enhance images to track the drug, a third could carry a chemical trigger to release the medicine by command from outside the body, another, still, that could send signals about results.
"We are moving ahead in nanoscience in laboratories throughout the world," said Alexis. "Nanoparticle functionalities become more and more complex and the next step is for the research to develop technologies allowing their transfer from the research bench to a pharmaceutical drug. New ways of targeting drugs that will be more effective and safe and more agreeable to patients is just over the horizon."
Peter Kent | EurekAlert!
Make way for the mini flying machines
21.03.2018 | American Chemical Society
New 4-D printer could reshape the world we live in
21.03.2018 | American Chemical Society
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
21.03.2018 | Physics and Astronomy
21.03.2018 | Materials Sciences
21.03.2018 | Life Sciences