Synthesis, characterization, and platelet adhesion studies of novel aliphatic polyurethaneurea anionomers based on polydimethylsiloxane-polytetramethylene oxide soft segments

Abstract

Two novel aliphatic polyurethaneurea anionomers were synthesized based on polydimethylsiloxane (PDMS)-polytetramethylene oxide (PTMO) soft segments. The hard segments consisted of either 4,4'-methylene dicyclohexyl diisocyanate (H12MDI), sulfonic acid-containing diol and 1,4-butandiol (BD) or H12MDI, carboxylic acid-containing diol and BD. The nonionic counterpart chain extended with BD was prepared. In addition, the base nonionic polyurethaneurea containing a pure PDMS soft segment, which is denote H-D-BD, was also studied for comparison. The effects of soft segment type and ion incorporation on the physical properties, surface properties, and plateled adhesion are discussed. The ionic polyurethaneureas exhibited poor phase separation, a smaller fraction of PTMO present at the surface, and a smaller contact angle. On the other hand, it also showed a larger fraction of PDMS present at the surface and a higher water absorption value than its nonionic counterpart. H-D-BD had more phase-separated structure, a larger fraction of PDMS present at the surface, and larger contact angle but lower water absorption value than the PTMO-containing polyurethaneureas. The in vitro platelet adhesion experiments indicated that the ionic groups, especially for carboxylate, and surface enrichment PDMS soft segment could effectively inhibit platelet adhesion.

In vitro Biocompatibility of PTMO-based Polyurethanes and those Containing PDMS Blocks

“…As to the effect of PDMS in blood compatibility, Lim et al [9] showed that the PDMS-based poly(urea)urethanes possessed a hydrophobic surface due to enrichment of the PDMS component at the interface and had lower adherent platelet and fibrinogen deposition compared with a polymer without PDMS. Chen et al [12] also demonstrated that surface enrichment of PDMS soft segment could effectively inhibit platelet adhesion on polyurethane. On the contrary, Okkema et al [13] studied the effect of substituting PTMO soft segment with 5 and 15 wt% of PDMS-containing polyols, and found that the polymer surface became more hydrophilic with increasing PDMS content.…”