Neutrophil elastase inhibitor rescues the stability and activity of rα1-ACT in nonhealing human wounds. A, exudate (#1) obtained from a nonhealing wound was incubated with SSR 69071 to reach different final concentrations as indicated and then rα1-ACT was added. At the indicated time points, intact rα1-ACT protein was quantified by LC-MS analysis. B, SSR 69071 or PBS (control) was added to exudates obtained from nonhealing wounds (#1, #5, #11, and #12) and then rα1-ACT was added; after 12 h, rα1-ACT activity was quantified by ELISA.