In vitro evaluation of anti-calcification and anti-coagulation on sulfonated chitosan and carrageenan surfaces.

In recent years, great effort has been devoted to the development of biomaterials that come into contact with blood. The surfaces of these materials need to be of suitable mechanical strength, and present anti-thrombogenic and anti-calcification properties. Chitosan is a natural polymer that has attracted attention due to its potential to act as a biomaterial. However, chitosan contains amino groups in its structure that may promote thrombogenesis and calcification. A strategy to reduce these properties constitutes the introduction of sulfonate groups (R-SO3-) in the chitosan chain. Another interesting biopolymer with similar characteristics to those of heparin is carrageenan, which has sulfate groups in its structure. As such, we evaluated “in vitro” calcification and thrombogenic processes on surfaces of pristine and sulfonated chitosan and on polyelectrolyte complexes (PEC) of chitosan and carrageenan. Results indicate that PEC demonstrate significant reductions in calcification and thrombogenic potential, probably due to the presence of sulfonate groups in both the carrageenan and treated chitosan.