Comparison of structure, strength and cytocompatibility of a fibrin matrix supplemented either with tranexamic acid or aprotinin.

Fibrin sealants are used as hemostats, sealants, tissue adhesives, and as matrix for substances/cells in a number of surgical and tissue engineering procedures. Main characteristics of fibrin are high tensile strength, adhesive strength, biocompatibility, and resorption. A major adverse event would be premature fibrin lysis and recurrent bleeding. This must be prevented by fibrinolysis inhibitors. The most common fibrinolysis inhibitors used are aprotinin and tranexamic acid (t-AMCA). Comparison of commercially available fibrin sealants utilizing aprotinin or t-AMCA revealed a lower sealing efficacy in an in vivo lung resection model for a t-AMCA containing product. Therefore, we compared the influence of t-AMCA and aprotinin on structure, mechanical properties, and cytocompatibility of a fibrin matrix. In our experiments, we found that substitution of aprotinin with t-AMCA reduced the tensile strength and formation of fibrin fibers and affected viability of a fibroblast cell-line. In conclusion, t-AMCA negatively affects physical and biological properties of fibrin relevant for clinical application as well as tissue regeneration. Copyright 2006 Wiley Periodicals, Inc.