Segmented polyurethanes based on poly(dimethylsiloxane), currently used for
biomedical applications, have sub-optimal biocompatibility which reduces
their efficacy. Improving the endothelial cell attachment and
blood-contacting properties of PDMS-based copolymers would substantially
improve their clinical applications. We have studied the surface properties
and in vitro biocompatibility of two series of segmented
poly(urethane-dimethylsiloxane)s (SPU-PDMS) based on hydroxypropyl- and
hydroxyethoxypropyl- terminated PDMS with potential applications in
blood-contacting medical devices. SPU-PDMS copolymers were characterized by
contact angle measurements, surface free energy determination (calculated
using the van Oss-Chaudhury-Good and Owens-Wendt methods), and atomic force
microscopy. The biocompatibility of copolymers was evaluated using an
endothelial EA.hy926 cell line by direct contact assay, before and after
pre-treatment of copolymers with multicomponent protein mixture, as well as
by a competitive blood-protein adsorption assay. The obtained results
suggested good blood compatibility of synthesized copolymers. All copolymers
exhibited good resistance to fibrinogen adsorption and all favored albumin
adsorption. Copolymers based on hydroxyethoxypropyl-PDMS had lower
hydrophobicity, higher surface free energy, and better microphase separation
in comparison with hydroxypropyl-PDMS-based copolymers, which promoted better
endothelial cell attachment and growth on the surface of these polymers as
compared to hydroxypropyl-PDMS-based copolymers. The results showed that
SPU-PDMS copolymers display good surface properties, depending on the type of
soft PDMS segments, which can be tailored for biomedical application
requirements such as biomedical devices for short- and long-term uses.
Surface characterization, hemo- and cytocompatibility of segmented poly(dimethylsiloxane)-based polyurethanes
