Surface modification with an antithrombin-heparin complex for anticoagulation: studies on a model surface with gold...

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Biomedical Engineering

Background:

• Blood coagulation poses a significant challenge for biomaterial biocompatibility.
• Surface modification is crucial for developing effective anticoagulant biomaterials.
• Antithrombin-heparin (ATH) complexes offer potential for enhanced anticoagulant properties.

Purpose of the Study:

• To investigate antithrombin-heparin (ATH) as a surface modifier for preventing blood coagulation.
• To compare different immobilization methods for ATH on gold substrates.
• To evaluate the anticoagulant potential of ATH-modified surfaces against heparinized surfaces.

Main Methods:

• Immobilization of ATH on gold using direct chemisorption, dithiobis(succinimidyl propionate) (DSP), and polyethylene oxide (PEO) linkers.
• Surface characterization using water contact angles and X-ray photoelectron spectroscopy.
• Quantification of ATH and heparin densities via radioiodination and quartz crystal microbalance.

Main Results:

• ATH immobilization density varied with method, highest on DSP.
• ATH-modified surfaces demonstrated significantly greater binding of antithrombin (AT) from buffer and plasma compared to heparinized surfaces.
• PEO-modified surfaces, with or without ATH, inhibited non-specific protein adsorption.

Conclusions:

• ATH surfaces exhibit superior AT binding and selectivity over heparinized surfaces.
• ATH immobilization represents a promising strategy for enhancing the anticoagulant potential of biomaterials.
• The choice of linker molecule influences ATH surface density and protein binding characteristics.