Comparison of biocompatibility in cellulose triacetate dialysis membranes with homogeneous and asymmetric structures

Abstract

Background: Historically, cellulose-based materials have been used for manufacturing hemodialysis membranes and remain to date as the commonly used materials. Though cellulose triacetate (CTA) membrane originally has a homogeneous structure, recently, CTA membrane with asymmetric structure (ATA®) was developed. By a new spinning technology, irregularities or roughness in the inner surface of ATA have become less than those of the conventional CTA membrane. In this study, a comparison was made between CTA and ATA® membranes in order to evaluate the effect of physical structure of the membrane on the biocompatibility. Methods: We compared the biocompatibility of the following two dialyzers with different triacetate membrane: FB-190UHβ with CTA, and FA-190F with ATA® (both from Nipro, Osaka, Japan). Heparin of 40 units/mL was put in a syringe, and test blood was collected from healthy volunteers. Then, the dialyzer and blood circuit were filled with the test blood. Subsequently, the blood was circulated by a roller pump at the rate of 200 mL/min. We measured the platelet counts, platelet factor 4 (PF4), β-Thromboglobulin (β-TG), and CD41 and CD42b platelet surface markers at 30, 120, and 240 min. Results: The average platelet counts at 30, 120, 240 min in CTA and ATA® were similar. The average β-TG and PF4 increased from 87.0 ± 49.0 ng/mL and 30.7 ± 17.3 ng/mL to 1198.5 ± 1017.2 ng/mL and 698.2 ± 574.6 ng/mL with CTA and to 774.3 ± 811.6 ng/mL and 509.0 ± 417.3 ng/mL with ATA®, respectively. The average expression of CD41 and CD42b decreased to 82.8 ± 9.7% and 80.1 ± 11.6% with CTA and 81.9 ± 14.3% and 80.2 ± 13.6% with ATA®, respectively. Conclusions: Observed dialyzers showed less platelet activation as commercial products, and differences between CTA and ATA® were not significant in terms of PF4, β-TG, CD41, and CD42b.