Better control over the delivery of drugs to specific sites in the body at specific times would reduce unwanted side effects and improve medical treatment dramatically. ‘Smart’ polymers are promising materials for controlling drug delivery, since they change their properties in response to specific stimuli.
However, they usually require continuous stimulation to maintain these changes. Now, researchers led by Takao Aoyagi at the MANA, National Institute for Materials Science, Japan, have developed an approach that could allow more subtle control and timing of drug delivery.
The new technique uses hydrogels, which are a type of ‘smart’ polymer made of water-soluble long-chain molecules. The team first showed that they could control the acidity inside a hydrogel by loading it with a compound called o-NBA. This releases protons, which increases acidity, when irradiated with UV light. When o-NBA-loaded hydrogel was irradiated, acidity increased inside; if only part of the gel was irradiated, acidity throughout increased gradually as protons diffused.
Aoyagi and his colleagues then loaded hydrogel with o-NBA and L-DOPA, a precursor of the brain chemical dopamine that is used in the treatment of Parkinson’s disease. The change of acidity in the gel upon UV irradiation caused L-DOPA to be released because the acidity disrupted the interaction of L-DOPA with the molecules in the gel.
Irradiation with UV not only enhanced overall L-DOPA release from the hydrogel, but also caused an extra ‘explosive’ release five hours after irradiation. This allowed the drug release to be timed, as well as triggered, in a controlled way.
Being able to control the release of drugs from hydrogels by triggering a change in acidity could help to design programmable drug delivery techniques that offer improved targeting of treatment.
National Institute for Materials Science
Prapatsorn Techawanitchai, Naokazu Idota, Koichiro Uto, Mitsuhiro Ebarab and Takao Aoyagi (2012) A smart hydrogel-based time bomb triggers drug release mediated by pH-jump reaction. Science and Technology of Advanced Materials Vol. 13 (2012) p. 064202.
Further Reports about: Advanced Investigator Grant > Aoyagi > hydrogels > information technology > L-DOPA > Materials Science > Parkinson’s Disease > Smart polymers > water-soluble long-chain molecules
More articles from Materials Sciences:
Accelerated corrosion testing of silver provides clues about performance in atmospheric conditions
04.12.2013 | NACE International
New Effect Couples Electricity and Magnetism in Materials
28.11.2013 | Vienna University of Technology
Quantum entanglement, a perplexing phenomenon of quantum mechanics that Albert Einstein once referred to as “spooky action at a distance,” could be even spookier than Einstein perceived.
Physicists at the University of Washington and Stony Brook University in New York believe the phenomenon might be intrinsically linked with wormholes, hypothetical features of space-time that in popular science fiction can provide a much-faster-than-light shortcut from one part of the universe to another.
But here’s the catch: One couldn’t actually ...
A star is formed when a large cloud of gas and dust condenses and eventually becomes so dense that it collapses into a ball of gas, where the pressure heats the matter, creating a glowing gas ball – a star is born.
New research from the Niels Bohr Institute, among others, shows that a young, newly formed star in the Milky Way had such an explosive growth, that it was initially about 100 times brighter than it is now. The results are published in the scientific journal, Astrophysical Journal Letters.
The young ...
EPFL scientists have shown how to achieve a dramatic increase in the capacity of optical fibers; Their simple, innovative solution reduces the amount of space required between the pulses of light that transport data
Optical fibers carry data in the form of pulses of light over distances of thousands of miles at amazing speeds. They are one of the glories of modern telecommunications technology.
However, their capacity is limited, because the pulses of light need to be lined up one after the other in ...
NASA's Hurricane and Severe Storms Sentinel airborne mission known as HS3 wrapped up for the 2013 Atlantic Ocean hurricane season at the end of September, and had several highlights. HS3 will return to NASA’s Wallops Flight Facility in Wallops Island, Va., for the 2014 Atlantic hurricane season.
During the 2013 mission, two unmanned Global Hawks flew from Wallops for the first time. The mission highlights included studying the Saharan Air Layer, following the genesis of a tropical storm, finding a unique hybrid core or center circulation in a redeveloped storm, obtaining measurements on the strongest side of ...
Nanosponges that soak up a dangerous pore-forming toxin produced by MRSA (methicillin-resistant Staphylococcus aureus) could serve as a safe and effective vaccine against this toxin.
This "nanosponge vaccine" enabled the immune systems of mice to block the adverse effects of the alpha-haemolysin toxin from MRSA—both within the bloodstream and on the skin. Nanoengineers from the University of California, San Diego described the safety and efficacy of this nanosponge vaccine in the December 1 issue of ...
04.12.2013 | Health and Medicine
04.12.2013 | Materials Sciences
04.12.2013 | Ecology, The Environment and Conservation
04.12.2013 | Event News
12.11.2013 | Event News
29.10.2013 | Event News