Targeted SERPIN (TaSER): A dual‐action antithrombotic agent that targets platelets for SERPIN delivery

BACKGROUND Occlusive thrombi are not homogeneous in composition. The core of a thrombus is rich in activated platelets and fibrin while the outer shell contains resting platelets. This core is inaccessible to plasma proteins. We produced a fusion protein (targeted SERPIN-TaSER), consisting of a function-blocking VH H against glycoprotein Ibα (GPIbα) and a thrombin-inhibiting serine protease inhibitor (SERPIN; α1-antitrypsin 355 AIAR358 ) to interfere with platelet-driven thrombin formation. AIM To evaluate the antithrombotic properties of TaSER. METHODS Besides TaSER, we generated three analogous control variants with either a wild-type antitrypsin subunit, a non-targeting control VH H, or …