New Method For Monitoring Heparin

An analytical method developed by a research team in Germany could improve the use of heparin as a blood anticoagulant (J. Am. Chem. Soc., DOI: 10.1021/ja109699s). The polysaccharide heparin is used as an anticoagulant during surgery, and its effects are reversed by the addition of the polypeptide protamine. The doses of both drugs are controlled according to an assay that measures a quantity called the activated clotting time (ACT). Werner Mäntele and coworkers at Goethe University, in Frankfurt, measured complexes formed by heparin and protamine with light scattering and analytical ultracentrifugation. They found that the two biomolecules form nanoparticles under physiological conditions and that nanoparticle formation is enhanced at heparin-protamine ratios of 1:2, suggesting that an excess of protamine is required to neutralize heparin. The intensity of the light scattering is directly related to the quantity of heparin. Therefore, monitoring nanoparticle formation could serve as the basis for quantitative heparin determination and as a replacement for the ACT assay, the researchers suggest. The first clinical tests of the method have been successfully performed, Mäntele says.