Prospects for Clinical Applications of Polymer-Coated Haemoconcentrator on Extracorporeal Circuit in Cardiopulmonary Bypass Surgeries

Abstract

Purpose Extracorporeal circulation circuits used in cardiopulmonary bypass surgeries are increasingly being coated with polymer materials to reduce the thrombogenicity of extracorporeal devices. However, a haemoconcentrator, which corrects haematocrit and electrolyte imbalances, is not coated with polymers. In this study, we sought to assess the filtration performance of polymer-coated haemoconcentrators in order to obtain insight into their prospects for use in clinical applications. Methods In vitro experiments were performed to evaluate the water pressure and flow properties of polymer-coated haemoconcentrators by comparing 3 polymer-coated haemoconcentrators with 3 non-coated haemoconcentrators. The cross-sectional surfaces of both types of haemoconcentrators were observed using a scanning electron microscope (SEM). Results The slopes of the regression lines for estimating the filtrated fluid flow as a function of the transmembrane pressure were 6.286 ± 0.320 for polymer-coated haemoconcentrators and 3.712 ± 0.170 for non-coated haemoconcentrators. These slopes were found to be significantly different and indicate that the filtration velocity is enhanced in polymer-coated haemoconcentrators over that in non-coated haemoconcentrators. However, the hollow fibre damage observed by SEM was not shown to contribute to higher filtration flow in the polymer-coated haemoconcentrator. Taking these results into consideration, we hypothesise that a polymer coating makes a foreign surface on a hollow fibre slippery, owing to the hydrophobicity of the polymer, thereby enhancing the velocity of the filtration. Conclusions The results of this preliminary investigation suggest that a polymer coating can enhance the filtration performance of a haemoconcentrator and that polymer-coated haemoconcentrators might be useful in clinical applications.

Antithrombotic properties of hemofilter coated with polymer having a hydrophilic blood-contacting layer

“…To clarify the features of BPCA-coated hemofilters, we previously performed experiments to confirm that the BPCA coating did not disturb functions of diffusion and filtration and found that there is no malfunction of filtration and diffusion in BPCA-coated hemofilters. 8,9 Therefore, further investigation of BPCA-coated hemofilters to evaluate the antithrombotic effects is justified.…”

Hemodialysis Membrane Coated with a Polymer Having a Hydrophilic Blood-Contacting Layer can Enhance Diffusional Performance

“…We previously reported that BPA coating of membranes can enhance the filtration rate without physical alteration of the membranes, and concluded that the decrement of drag resulting from water-filled layers on BPA contributed to this enhancement ( 10 , 16 , 20 ). Similarly, the following laws can explain the reason why decrement of drag results in molecular transfer enhancement.…”

“…In our previous study, a hemoconcentrator, which has similar function as the hemodialyzer in cardiopulmonary bypass circuit, was probatively coated with BPA and investigated as regards hydrokinetics. BPA coating resulted in an enhancement of the filtration rate ( 16 ). However, the filtration rate enhancement leads to the possibility that the sieving coefficient of substances that are targeted to be dialyzed are altered, and those were not examined.…”

High Cut-off Membranes in Acute Kidney Injury and Continuous Renal Replacement Therapy

“…In the meantime, research that aims to explain the immunomodulatory pathogenesis of several critical illnesses will be helpful in order to better understand the role, the indications and the timing of HCO therapy. Future developments may include a sequential approach in which different therapeutic modalities, biomaterials and devices (45–52) can be used in sequence or in parallel with HCO membranes.…”