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approaches based on surfactants and difunctional crosslinking agents can affect the structure, GAG content, biocompatibility and calcification potential of these tissues. Because of this, different postreatment methods have been suggested showing some improvements but until today, the vascular graft or heart valve obtained do not fulfill all the requirements for a long term use. In addition to this safety concerns, these treatments are not yet cost effective. Therefore, methods that preserve simultaneously the mechanical properties of collagen and the properties of the GAG matrix are desirable. Finally, those approaches that made use of enzymatic methods and low toxicity chemical such natural products and aminoacids as crosslinking agents seem promising alternatives.
