Combination of two antithrombogenic methodologies for preventing thrombus formation on a poly(ether ether ketone)...

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Surface Engineering

Background:

• Poly(ether ether ketone) (PEEK) is a widely used biomaterial, but its thrombogenicity limits its application.
• Enhancing antithrombogenicity requires suppressing both platelet activation and coagulation system activation.

Purpose of the Study:

• To develop a PEEK surface with improved antithrombogenicity by combining zwitterionic and cationic polymer grafting with heparin immobilization.
• To investigate the effect of copolymer composition on surface properties and antithrombotic performance.

Main Methods:

• Grafting a random copolymer (PMT) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-methacryloyloxyethyl trimethylammonium chloride (TMAEMA) onto PEEK via photoinduced self-initiated graft polymerization.
• Immobilizing heparin onto the grafted surface through ionic binding with TMAEMA units.
• Characterizing surface ζ-potential and quantifying immobilized heparin amounts.

Main Results:

• The TMAEMA unit composition influenced surface ζ-potential and heparin immobilization.
• Heparin concentration plateaued at ≥30% TMAEMA, reaching ~2.0 μg/cm².
• The Hep/PMTx-g-PEEK with 50% TMAEMA showed reduced platelet adhesion and a 4-fold increase in blood coagulation time compared to poly(MPC)-g-PEEK.
• The poly(MPC) layer inhibited platelet adhesion and activation, while released heparin prevented coagulation system activation.

Conclusions:

• The combined approach of grafting a zwitterionic/cationic copolymer and immobilizing heparin effectively enhances PEEK antithrombogenicity.
• This dual strategy offers a promising method for prolonging the blood coagulation period of biomaterials.
• The developed surface modification strategy holds potential for improving the hemocompatibility of medical devices.