Platelet adhesion onto segmented polyurethane surfaces modified by PEO- and sulfonated PEO-containing block copolymer additives

Abstract

Polyethylene oxide (PEO) surfaces were prepared by the addition of PEO- and sulfonated PEO-containing amphiphilic block copolymers as surface-modifying additives in a segmented polyurethane (PU). PEO-PPO-PEO triblock copolymers (Pluronics) with different PEO chain lengths (from 2 to 80) were used as additives. The prepared film surfaces were characterized by the measurement of dynamic water contact angles and electron spectroscopy for chemical analysis. It was observed that the PU films containing 10 wt% of PEO additives were surface-saturated with the additives regardless of their PEO chain length, but the PEO chains were more projected from the film surfaces containing the additives with longer PEO chains. The water absorption of the films increased largely with the increasing PEO chain length of the additives. The addition of PEO additives produced film surfaces that were in a gel-like state. The films demonstrated some extraction of the PEO additives. However, the additives with higher molecular weights were entrapped more stably into the PU matrix. The mechanical properties (tensile strength and elongation) of the films were changed by the addition of PEO additives, but the differences were not significant compared to the control PU. The platelet adhesion on the film surfaces decreased with increasing PEO chain length of the additives. The film surface containing additives with long PEO chains (chain length of 80) was particularly effective in preventing platelet adhesion. The effect of negatively charged sulfonate groups on the prevention of platelet adhesion appeared only on the film surfaces containing additives with short PEO chains. For longer PEO chains, the chain mobility effect was more dominant than the negative charge effect on the prevention of platelet adhesion.

Non-fouling biomaterials based on blends of polyethylene oxide copolymers and polyurethane: simultaneous measurement of platelet adhesion and fibrinogen adsorption from flowing whole blood

“…For these materials fibrinogen adsorption and platelet adhesion decreased as PEO block size in the copolymers decreased. In contrast, in a study of blends of PU and Pluronics (PEO-PPO-PEO block copolymers), Lee et al found that platelet adhesion decreased with increasing chain length of the PEO block [12]. The PEO-copolymers in these two studies were similar except for the middle block: poly(ether-urethane) of molecular weight 4750 in the present work and polypropylene oxide of molecular weight 1740 in the Pluronics.…”

“…Blending small amounts of PEO-containing amphiphilic copolymers into a PU matrix is a simple and effective approach to the preparation of PEO-modified PU surfaces [12][13][14][15][16][17]. The PEO-containing copolymers accumulate at the aqueous-material interface and provide antifouling properties through the action of the PEO segments.…”

Preparation and Characterization of Hydrophilic PLGA/Tween 80 Films and Porous Scaffolds

“…The hydrophobic alkyl chain may provide homogeneous distribution and stable entrapment of Tween 80 in PLGA matrix through hydrophobic interactions. The short PEG chains in Tween 80 may provide the hydrophilicity and enhanced cell adhesion on the PLGA surface [16,19].…”

“…One merit to utilize Tween 80 as a hydrophilic additive to fabricate hydrophilic PLGA films or scaffolds is that the Tween 80 in the PLGA matrix is not easily leached out into water or cell culture medium owing to hydrophobic interactions between a relatively long alkyl chain in Tween 80 and hydrophobic PLGA chain. Short PEG chains in Tween 80 may also enhance cell adhesion on the surfaces [16]. PLGA=Tween 80 films and scaffolds with different Tween 80 compositions up to 20 wt% were fabricated by solvent casting and melt-molding particulate-leaching methods, respectively.…”

Development of Novel Submicron Textured Polyether(Urethane Urea) for Decreasing Platelet Adhesion

“…Two approaches have dominated device development: supracellular textures may be applied to induce passivation via the accumulation of a neointima that is strongly attached to the surface, 1-3 or very smooth material designed to resist formed element and fibrin deposition may be used. 4 Although a featureless surface finish, a bulk material having advantageous surface chemistry, and modification of surface chemistry 5,6 have all been found to be useful, deposition-resistant circulatory support devices rely significantly upon maintenance of sufficient wall shear stresses to prevent thrombus formation. Although clinically useful adult devices have been developed, wall shear requirements remain a difficult design constraint, particularly as devices are scaled down in size.…”