Methods for producing a fibrin matrix comprising a fusion peptide are described herein. In some embodiments, the method includes providing three different components, including a first component containing fibrinogen or a fibrinogen precursor and optionally, transglutaminase or a transglutaminase precursor, a second component containing thrombin or a thrombin precursor, and a third component containing a fusion peptide. In these embodiments, neither the first component nor the second component includes the fusion peptide. In some embodiments, the first or second components are premixed with the third component. The first, second and third components are mixed to form a fibrin matrix comprising a covalently linked fusion peptide. The mixing is carried out in a time frame of not more than 5 days. A kit for producing the fibrin matrix comprising a covalently linked fusion peptide is also described herein.