Sulfonated RAFT Copolymers as Heparin Mimetics: Synthesis, Reactivity Ratios, and Anticoagulant Activity

Area of Science:

• Polymer Chemistry
• Biomaterials Science
• Pharmacology

Background:

• Heparin, a glycosaminoglycan, is a vital anticoagulant drug for preventing thrombosis, particularly during surgery.
• Current heparin use is limited by its heterogeneity and animal-tissue origin, necessitating safer, synthetic alternatives.
• Limitations of natural heparin include batch variability and potential immunogenic responses.

Purpose of the Study:

• To synthesize a library of heparin mimetic copolymers using reversible addition-fragmentation chain transfer (RAFT) polymerization.
• To evaluate the anticoagulant activities of these novel synthetic polymers.
• To explore structure-activity relationships to guide the development of improved heparin mimetics.

Main Methods:

• Synthesis of copolymers via RAFT polymerization using four distinct sulfonated monomers.
• Characterization of polymer composition and molecular weight using 1H NMR spectroscopy and gel permeation chromatography.
• Assessment of anticoagulant efficacy using activated partial thromboplastin time (aPTT) and thrombin clotting time (TCT) assays.

Main Results:

• A library of heparin mimetic copolymers was successfully prepared with controlled polymerization techniques.
• Monomer reactivity ratios were determined for key monomer combinations, aiding in copolymer design.
• The synthesized copolymers exhibited varying degrees of anticoagulant activity, indicating potential as heparin alternatives.

Conclusions:

• Reversible addition-fragmentation chain transfer polymerization is a viable method for creating heparin mimetic copolymers.
• The developed synthetic polymers demonstrate potential for anticoagulant applications, addressing limitations of natural heparin.
• Further research into structure-activity relationships can optimize these mimetics for clinical use.