Leech bionic Hirudin fusion protein prodrug loaded microneedles for long-term inhibition of thrombosis.

The clinical use of anticoagulant drugs for thrombosis is limited by short half-life and bleeding risk, requiring frequent administration and close monitoring. Here, inspired by leech mouthparts, we present a hirudin-based fusion protein prodrug incorporated with microneedles (MNs) for long-term antithrombotic therapy to achieve a simplified dosing regimen, continuous protection, and on-demand antithrombotic bioactivity recovery. Genetic-engineered anticoagulant prodrugs are precisely customized by fusing hirudin to elastin-like polypeptides with adjustable assembly characteristics. The introduction of elastin-like polypeptides can shield the biological activity of hirudin, drive the self-assembly of fusion proteins, and prolong their half-life in vivo. The fusion protein prodrugs circulate in the blood as sentinels and accumulate in the thrombus site with the assistance of the clot-targeted motif. Under the catalysis of FXa during thrombosis, the fusion protein prodrugs adaptively restore anticoagulant activity to inhibit thrombus formation. Notably, the assembled prodrugs were integrated into an MN matrix made of silk fibroin and chitosan through photopolymerization for long-term controlled release and facile self-administration. It was proved that the bionic MNs conveniently provide long protection against thrombosis without increasing bleeding events. These excellent performances indicate that the bionic MN patch has broad application prospects in thrombosis and related diseases.