This technology describe the synthesis of cross-linked polymeric materials in the form of macroporous gels based on poly (2-hydroxyethyl methacrylate), capable of sequestering the anticoagulant heparin from aqueous solutions, physiological solutions and biological fluids. They are morphologically elastic and mechanically stable materials, and show high specificity and selectivity for heparin as demonstrated by the negligible adsorption of specific blood proteins such as antithrombin III, albumin and total proteins. Preliminary tests to assess blood compatibility have also shown that macroporous hydrogels do not activate hemolysis, complement C3 and do not interfere with leukocyte and platelet counts. For these properties they could find a real application in the development of blood filters useful in surgery and dialysis to restore normal coagulation parameters after the use of heparin. The development of such devices could make more controllable the hemorrhagic events occasionally occurring during major surgeries, and, for patients that undergo to hemodialysis, could limit the onset of diseases caused by chronic use of heparin.
The development of these filters could bring significant improvements to the safety and quality life of patients who undergo the anticoagulant. Assuming the insertion of a hypothetical neutralizing filter in the circuit of the extracorporeal circulation machine, before the blood re-enters the circulation, the side effects and hemorrhagic risks could be eliminated. Moreover, also the risks due to protamine administration, the only antidote to heparin currently used, would be avoided. In fact, to the best of our knowledge, despite the numerous efforts evidenced by the dedicated literature, coagulation control is still regulated by protocols that afford the use of protamine. The only device, recently marketed, which allows the correct execution of dialysis using lower doses of heparin, is a dialyzer consisting of a heparinized membrane, whose use is reserved only for patients with a high risk of bleeding. The hypothetical filter proposed, also due to the low cost of the raw materials, could be developed as a disposable device, and usually be placed side by side with machines for extracorporeal blood circulation.
Italy, EPO, USA