Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers want to turn acid-loving microbes into safe drug-carriers

05.11.2015

Usually the microbe S. islandicus is found in hot and acidic volcanic springs, but now the microbe has also found its way to the labs of University of Southern Denmark. Here researchers have for the first time showed that the exotic microbe is capable of delivering drugs to the human body.


This is the natural environment of S. islandicus, Kamchatka Peninsula

Credit: Kamchatka Visions

The microbe S. islandicus has a strange and unique talent for thriving in acidic environments. This talent would allow the microbe to safely pass through the human stomach, where harsh acidic conditions rule, and this makes the microbe interesting for scientists working with delivering drugs to the human body.

"One of the major challenges in pharmacy is to find ways to carry and protect drugs on their passage through the stomach. Many drugs may be absorbed through the intestines, so it would be a great help to be able to transport drugs safely through the stomach to the intestines", explains Sara Munk Jensen, Ph.D. student at both the Nordic Center for Earth Evolution (NordCEE), Department of Biology and the Department of Physics, Chemistry and Pharmacy, University of Southern Denmark (SDU).

Transport and protect drugs

Jensen has just completed her Ph.D. work on how to use lipids from the cell membranes of extremophilic microorganisms to design drug carriers that transport and protect drugs in the human body.

This is relevant for different drugs as growth hormones, vaccines and insulin. Many diabetics need to daily inject insulin directly into their body, and they would benefit greatly by taking insulin in a tablet instead. Not only is it easier to take a tablet than inject; when insulin is absorbed from the small intestine it is released into the body in a more natural way than when injected, and this has the potential to improve the patient's treatment.

They love it hot

Here enters the acid-loving microbe S. islandicus the scene. S. islandicus is a microorganism, which resembles bacteria, but it is just as different from a bacterium as humans are. S. islandicus is an extremophilic archaeon, meaning that it loves extreme conditions. Some extremophile archaea love to live in oxygen-free environments, others in saline environments, and S. islandicus requires an environment that is 75-80 degrees Celsius hot and has a pH of 2-3. These living conditions are found in volcanic springs in places like Iceland, Italy, Russia and North America.

Jensen and her colleagues now report in the journal International Journal of Pharmaceutics that they have managed to use S. islandicus to construct a nano-capsule that can transport drugs safely through the stomach.

Loading molecules with dye

The researchers isolated lipids from the cell membrane of S. islandicus in the laboratory and used these to construct liposomes (synthetic fat capsules). Liposomes are available in many different forms - some are e.g. used in cosmetics to transport nourishing substances into the skin. After construction, the new molecules were loaded with a dye and placed in solutions equivalent to the acidic environment in the stomach. After one and a half hours it was time to see if some of the liposomes had survived the exposure and if they still retained their content of dye. One and a half hours app. equals the time that a tablet must be able to withstand the hostile environment of the stomach before natural peristaltics pushes it forward to the intestines.

Some of the liposomes in the experiment were destroyed -- but not all. Ca. 10 pct. survived the strong acidic solution and still contained the dye after one and a half hour.

Jensen is satisfied with this result:

"We started with a completely crude extract of membrane molecules from S. islandicus. Normally, rather pure compounds are employed when making liposomes, but here I took all the fat molecules to see how far you can get with crude, non-purified material. If 10 pct. of the liposomes created on this basis can survive, then it is plausible that even more will survive if we begin to purify the molecules", explains Jensen.

She believes that some 85 pct. the liposomes need to survive the journey through the stomach before drug companies can start developing oral peptide-drugs like insulin, vaccines, etc.

What did the researchers do in the lab?

S. islandicus was grown for four days at 75 degrees Celsius. The researchers isolated all the cell-membrane molecules from the culture and combined them with conventional phospholipids (special fats from egg yolk or soybean oil) and cholesterol in order to make liposomes. The mixture was: 18 pct. S. islandicus fat molecules and 78 pct. phospholipids/cholesterol. The constructed liposomes were loaded with a dye, so that the researchers could keep track of whether the liposomes would last or be destroyed when exposed to bile salts from gastric juice. The liposomes were tested at a low and a high bile salt concentration. In the low concentration 75 pct. of the liposomes were still intact after 1.5 hours. But only 10 pct. were still intact at the high concentration. Both the low and high concentrations are within the range that is natural in a normal human stomach, namely 4 and 8 mM (one thousandth of the number of molecules per liter). In fact, the concentration in normal healthy individuals varies between 0.3 and 9.6 mM.

###

Ref International Journal of Pharmaceutics, Volume 493, Issues 1-2, 30 September 2015, Pages 63-69. Liposomes containing lipids from Sulfolobus islandicus with state intestinal bile salts: An approach to oral drug delivery? Sara Munk Jensena, b, Camilla Jahn Christensenb, 1, Julie Maria Petersenb, 1, Alexander H. Treuscha, Martin Brandl, b. a Department of Biology and Nordic Center for Earth Evolution, University of Southern Denmark. b Department of Physics, Chemistry and Pharmacy, University of Southern Denmark.

Photos S. islandicus in its natural environment on the Kamchatka peninsula (credit Visions of Kamchatka) + photo of S. islandicus grown in SDU's laboratory (credit Sara Munk Jensen).

Contact:

Sara Munk Jensen
45-6550-2739
saramj@biology.sdu.dk

Media Contact

Birgitte Svennevig
birs@sdu.dk

http://www.sdu.dk/

Birgitte Svennevig | EurekAlert!

Further reports about: acidic concentration drugs human body liposomes microbe microbes stomach survive

More articles from Health and Medicine:

nachricht A 'half-hearted' solution to one-sided heart failure
24.11.2017 | Boston Children's Hospital

nachricht New study points the way to therapy for rare cancer that targets the young
22.11.2017 | Rockefeller University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>