American Society of Hirudotherapy

Supramolecular Prodrug Hydrogel for One-Week Protection Against Thrombosis

Basic science / preclinical published in Small (2025)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Research reportDrug DevelopmentSalivary PharmacologyZhang W et al. · Small, 2025

Abstract

In clinical anticoagulant therapy, the drug Bivalirudin (Biva) presents a lower incidence of adverse events and more predictable pharmacokinetics in comparison to heparin. However, its short half-life of ≈20 min leads to poor patient compliance and increased medical burden. Here, a long-acting anticoagulant hydrogel based on Biva for antithrombotic treatment is described. The fusion peptide (d-RADA)8-B that integrates Biva, a D-type self-assembly motif, and an activated factor X (FXa)-responsive motif exhibits both supramolecular reservoir and prodrug-like properties. After subcutaneous injection, the anticoagulant peptide forms a semi-solid depot with protease-degradation resistance and slowly disassembles to release prodrug (d-RADA)8-B into the bloodstream. The circulating prodrug acts as an inert sentinel, which can be activated to release Biva to inhibit thrombus formation when exposed to the thrombus-related protease FXa. One week after the administration of (d-RADA)8-B, significant embolism suppression is observed in animal models of carotid artery thrombosis and pulmonary embolism without increasing hemorrhagic side effects. This study demonstrates a concise strategy to engineer a supramolecular anticoagulant hydrogel with long-term, high drug loading, and on-demand antithrombotic activation.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal Article
Indexed MeSH termsProdrugsAnimalsThrombosisHydrogelsHirudinsPeptide FragmentsAnticoagulantsRecombinant ProteinsMiceHumans

Summary

Engineered supramolecular prodrug hydrogel using bivalirudin (the leech-hirudin-derived direct thrombin inhibitor) with a FXa-responsive linker, achieving one-week sustained thrombosis prevention in animal models without increased bleeding risk.

Why This Matters for Hirudotherapy

This study described a supramolecular prodrug hydrogel based on bivalirudin for sustained anticoagulation, using a fusion peptide incorporating bivalirudin, a D-type self-assembly motif, and a factor Xa-responsive activation element. After subcutaneous injection in animal models of carotid artery thrombosis and pulmonary embolism, the hydrogel provided approximately one week of embolism suppression without increased hemorrhagic side effects. The abstract does not mention hirudin, leeches, or leech therapy, and no defensible connection to hirudotherapy or the leech secretome can be drawn from this article. The work is preclinical, involving only animal models with no human data, and is not relevant to ASH's domain.

Citation

Supramolecular Prodrug Hydrogel for One-Week Protection Against Thrombosis.

Zhang W et al. · Small, 2025

Added to ASH library: May 27, 2026 · Site last updated: June 18, 2026

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