Abstract: The disclosed invention provides a system and method of artificially retarding fibrin-based blood clot degradation via the sustained release of a protease inhibitor, such as, for example, aprotinin or tranexamic acid (“TA”). The sustained release of the protease inhibitor is accomplished through incorporation within a biodegradable polymer microsphere to produce a protease inhibitor formulation. Next, the formulation along with fibrinogen and thrombin is applied to a wound site where an outer surface of the polymer microsphere degrades in a proteolytic environment to expose and release the incorporated protease inhibitor to the surrounding hydrogel or sealant or clot matrix at the wound site.