Development of an in vitro fibrin clot model to evaluate fibrinolytic agents for wound care application

Objective: To describe an in vitro fibrin clot model that could reliably assess the fibrinolytic activity of enzymatic debriding agents for wound care application. Method:A model of a fibrin clot was reconstructed in vitro by mixture of human fibrinogen and alpha-thrombin supplemented with factor XIII.These clots were then treated with enzymatic ointments. Fibrinolytic activity was investigated by measuring D-dinner levels, using an automated immunoturbidimetric Liatest D-dimer assay. Results: Collagenase and papain-urea ointments demonstrated fibrinolytic activity which was macroscopically visible.Their effect was identical on the in vitro reconstructed fibrin clot and ex vivo collected wound fibrin clot; collagenase and papain-urea both induced a complete degradation and dissolution of both fibrin clots after 24 hours of treatment.This was associated with an increase in D-dinner concentration. Conclusion: This reconstructed fibrin clot in vitro model has the potential to predict the efficacy of fibrinolytic agents and therefore appears to be a suitable model for in vitro assays.