Platelet–Microcapsule Hybrids Leverage Contractile Force for Targeted Delivery of Hemostatic Agents

We report a cell-mediated, targeted drug delivery system utilizing polyelectrolyte multilayer capsules that hybridize with the patient’s own platelets upon intravenous administration. The hybridized platelets function as the sensor and actuator for targeted drug delivery and controlled release in our system. These capsules are biochemically and mechanically tuned to enable platelet adhesion and capsule rupture upon platelet activation and contraction, enabling the targeted and controlled “burst” release of an encapsulated biotherapeutic. As platelets are the “first responders” in the blood clot formation process, this platelet-hybridized system is ideal for the targeted delivery of clot-augmenting biotherapeutics wherein immediate therapeutic efficacy is required. As proof-of-concept, we tailored this system to deliver the pro-clotting biotherapeutic factor VIII for hemophilia A patients that have developed inhibitory antifactor VIII antibodies. The polyelectrolyte multilayer capsules physically shield th...