Biocompatible cationic polymeric cryogel: smart material for biomedical applications

Heparin is a highly sulfated glycosaminoglycan commonly used as anticoagulant drug during clinical procedures, such as cardiovascular surgery or extracorporeal blood purification (dialysis), to avoid the unfavorable formation of clots.1 High concentrations of circulating heparin require neutralization due to possible serious bleeding complications. The intravenous administration of the heparin antagonist protamine sulfate is routinely clinically performed, but is frequently associated with adverse reactions.2 Therefore, there is a need for a valid and safe alternative to achieve heparin removal from blood or plasma, such as a extracorporeal filter, a matrix, or an adsorbent. Recently we have developed and characterized a functionalized cationic polymeric macroporous material able to selectively adsorb the anticoagulant drug heparin both in vitro and in human plasma.3 This material showed a high heparin capture efficiency and a good blood compatibility, as indicated by negligible adsorption of albumin, antithrombin III, and total protein, and may thus be suitable for the design and development of extracorporeal heparin removal device. In this contribution we will report the latest results concerning the development of a new synthetic procedure that allows to obtain a set of macroporous cationic polymeric cryogels with various compositions and different performances towards heparin neutralization. The same material, due to its macroporous structure, biocompatibility and high affinity for heparin, has also been preliminary tested as support for application in cell growth and tissue engineering.