Sustained-release formulations that release drugs over longer periods of time are not the final step in the evolution of “intelligent” drug delivery systems. Modern pharmaceuticals are being designed to be released only in a specific, diseased organ; on cues from our circadian rhythm; or under specific physiological conditions.
In the journal Angewandte Chemie, a team of American and Korean researchers has now introduced “microbottles” with “corks” that release their contents only when the temperature rises above a defined level.
Our circadian rhythms can cause our reaction to a drug to vary with time. Certain conditions and symptoms can also fluctuate with our circadian rhythm. Some pharmaceuticals, such as beta blockers, chemotherapy drugs, and cortisone treatments thus come with recommendations for timing doses. The “intelligent” control drug release based on changing physiological conditions is an extension of these ideas.
Temperature in particular could be a useful regulator for such systems. Our body temperature varies throughout the day and in response to certain physiological states or phases, like disease. An “intelligent” blood pressure reducing drug could be released when body temperature and blood pressure rise due to stress. Inflammation usually causes the temperature of the affected area to rise, so a drug could be directed only to these hot areas. Alternatively, a diseased area of the body, such as a tumor, could be locally warmed to release chemotherapy drugs on the spot, causing fewer side effects.
Previous types of temperature-controlled microcontainers suffered from a slow loading process, low cargo capacity, or premature release of the drug. Younan Xia and a team at the Georgia Institute of Technology, Emory University in Atlanta (USA), and Yonsei University in Seoul (Korea) have now developed a new variety of corked “microbottle” for drugs. The cork melts at a defined temperature and releases the bottle’s contents.
To produce their capsules, the researchers embedded the bottom half of some polystyrene spheres in a thin polymer film and soaked them with a mixture of toluene and water. Because toluene and water do not mix well, the toluene diffused into the spheres. The spheres were then flash-frozen and freeze-dried. The toluene evaporated, exiting trough the tops of the spheres, leaving behind an opening and a cavity. Now the little bottles can quickly and easily be filled.
To cork the bottles, the researchers applied a film of the cork material to a support and pressed it onto the support holding the vessels. Ethanol vapors cause the cork material to flow together around the vessels, hermetically sealing them. By changing the ratio of the materials used in the corks, tetradecanol and lauric acid, the melting points of the corks can be adjusted into a biologically useful range.About the Author
Copy free of charge. We would appreciate a transcript of your article or a reference to it.
The original article is available from our online pressroom at http://pressroom.angewandte.org.
At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History
New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy