One of the risks of any large operation is the occurrence of blood clots. To prevent this, patients are routinely given the anticoagulant heparin or related drugs. American scientists have now introduced a new approach to the production of synthetic heparin mimetics with better activity profiles.
Heparin has been used as an anticoagulant since 1935 to both treat and prevent the deep vein thrombosis that can result from operations, blood transfusions, or dialysis. Heparin is a substance produced by the body and consists of long chains of sugar (saccharide) molecules. The sugar building blocks contain a large number of sulfate groups.
Because heparin is obtained from animal tissues, its use does pose some problems. Contamination may lead to health risks. Furthermore, batches of the drug are often not homogeneous so the effectiveness of a given dose must be calculated case by case. In about 3 % of patients, long-term treatment with heparin leads to a dangerous autoimmune disease.
Low-molecular-weight drugs such as Arixtra, which contains only five sugar groups, have been developed as an alternative. Their disadvantage is the very complex and expensive process used to make them.
Linda C. Hsieh-Wilson and her team at the California Institute of Technology in Pasadena have now uncovered an interesting new angle: synthetic glycopolymers, long chains of molecules that have sugar molecules as side groups. The researchers chose to use two sugars typically found in heparin as side groups.
One of these sugars was equipped with an additional sulfate group. The synthesis of such glycopolymers is much simpler than the synthesis of natural polysaccharides, but it is still a complex undertaking, and it is made more difficult in this case because of the need to attach sulfate groups in a controlled fashion. The team was able to use a ring-opening metathesis polymerization reaction (ROMP) to make polymer chains of varying length with a maximum of 45 units.
The longer molecular chains demonstrate stronger activity than anticoagulants currently in clinical use. The additional sulfate group is critical to this effectiveness. Interestingly, systematic changes to the length of the chain and pattern of sulfate groups allow for fine-tuning of the anticoagulant effect. This makes it possible to make drugs with different activities from those previously in clinical use. For example, the glycopolymer containing 45 building blocks targeted the two major branches of the blood coagulation cascade to a different extent than both the small molecule and heparin polysaccharide drugs.About the Author
Linda C. Hsieh-Wilson | Angewandte Chemie
Russian scientists show changes in the erythrocyte nanostructure under stress
22.02.2019 | Lobachevsky University
How the intestinal fungus Candida albicans shapes our immune system
22.02.2019 | Exzellenzcluster Präzisionsmedizin für chronische Entzündungserkrankungen
An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, a so-called jet, emerging from the only gravitational wave event involving two neutron stars observed so far. With its high sensitivity and excellent performance, the 100-m radio telescope in Effelsberg played an important role in the observations.
In August 2017, two neutron stars were observed colliding, producing gravitational waves that were detected by the American LIGO and European Virgo detectors....
Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.
The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...
For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.
The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...
Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens
Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...
Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light
When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...
11.02.2019 | Event News
30.01.2019 | Event News
16.01.2019 | Event News
22.02.2019 | Physics and Astronomy
22.02.2019 | Materials Sciences
22.02.2019 | Life Sciences