Thromboresistance of Polyurethane Plates Modified with Quaternized Chitosan and Heparin

To obtain modified polyurethane (PU) plates, quaternized chitosan (QuatCh; degree of substitution 50%, degree of deacetylation 87%) and unfractionated heparin (UFH) were applied in layers to the plate surfaces. The relief of the surface of the plates was studied via atomic-force microscopy (AFM). After processing, the root-mean-square roughness and the height of the unevenness of the PU profile of the plates significantly increased. The value of the contact angle of the modified PU plates decreased from 86.1° ± 11.3° to 63.2° ± 3.68°. Donor blood and the blood recalcification time test were used to assess the in vitro resistance of the PU plates to the appearance of blood clots on the surface (thromboresistance, TR). When the modified PU plates were incubated with blood for 20–180 min, the TR reached 78.43 ± 4.02–88.94 ± 1.98%. The recalcification time of human blood containing PU plates coated with QuatCh–UFH (483 ± 22.64 s for 20 min of incubation and576.5 ± 24.64 s for 40 min of incubation) significantly differed from the recalcification time of human blood containing PU plates without coating (257.5 ± 12.84 s for 20 min of incubation and 273.3 ± 16.6 s for 40 min of incubation). Thus, layer-by-layer modification of the PU plates with QuatCh and UFH led to a high resistance to the appearance of blood clots on the surface.