PO-0759 Surface Modification Of A Polydimethylsiloxane Microfluidic Oxygenator With Dopamine And A Covalent Antithrombin-heparin Complex For The Prevention Of Thrombosis

Abstract

<h3>Introduction</h3> Prematurely born infants suffer respiratory insufficiency, our lab has developed a novel microfluidic oxygenator with polydimethylsiloxane (PDMS) gas transfer membranes to provide respiratory support. The objective of the work reported here was to modify the PDMS surfaces with a covalent antithrombin-heparin (ATH) complex to prevent coagulation and thrombosis due to blood-material contact. Specifically the ATH was attached to the PDMS using dopamine as a ‘bio-glue’. <h3>Materials and methods</h3> PDMS discs were incubated in a solution of dopamine hydrochloride and then in ATH solution. A separate set of PDMS discs were justed incubated in ATH. Uptake of ATH and adsorption of antithrombin (AT) from plasma (a measure of anticoagulant activity) to the various surfaces was measured using ¹²⁵I-labelled ATH and AT. Stability of ATH on surfaces was evaluated by measuring residual radioactivity after incubation in blood. <h3>Results</h3> ATH uptake on PDMS was higher with dopamine as glue (Fig. 1), ~74% of the original ATH was lost from PDMS+ATH after 3 h in blood, whereas only ~30% was lost from PDMS+DOP+ATH. The ATH surface with dopamine is adhesive, thus showed higher AT adsorption (42.3 ng/cm²) compared to PDMS (6.3 ng/cm²), and therefore should have higher anticoagulant activity. <h3>Conclusions</h3> An antithrombin-heparin complex (ATH) was attached to PDMS using dopamine as a bio-glue. The use of dopamine gave surfaces with higher concentration and greater stability of ATH. The bound ATH showed potential for anticoagulant activity through extensive adsorption of antithrombin from plasma.