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
Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel
Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
26.04.2017 | Materials Sciences
26.04.2017 | Agricultural and Forestry Science
26.04.2017 | Physics and Astronomy