Vitamin E as a Functional and Biocompatibility Modifier of Synthetic Hemodialyzer Membranes: An Overview of the Literature on Vitamin E-Modified Hemodialyzer Membranes

Abstract

Along with one century of history, research has provided many solutions for hemodialysis (HD) biomaterials, encompassing several generations of copolymers that have found wide application in the development of hollow-fiber dialyzer membranes. Polysulfone-based biomaterials have gained increasing consideration and are now the gold standard in the production of biocompatible hemodialyzers. However, even the highest biocompatibility now available cannot exclude that dialyzer membranes and the overall extracorporeal circulation may produce at the subclinical level immunoinflammatory reactions and thus an increased cardiovascular risk of patients on regular HD therapy. The lipophilic antioxidant and radical scavenger vitamin E has been used (as α-tocopherol) to modify cellulosic and synthetic hollow-fiber membranes with the ultimate goal to neutralize harmful reactive species and to mimic lipid structures of blood cell plasmalemma and lipoprotein particles. Besides filtration and biocompatibility, this modifier has introduced a third function of dialyzer membranes, namely ‘antioxidant bioactivity’. Vitamin E can also serve as a template molecule to produce synthetic redox-active and -silent (non-antioxidant) modifiers for future generations of dialyzer membranes. This mini-review article describes the evolution of vitamin E-derived copolymers as a generation of biomaterials that has offered a clinical challenge and still represents a chance to further improving the quality of HD therapy.

Complement and Cardiovascular Disease - The Missing Link in Haemodialysis Patients?

“…Given these potential biases, it is difficult to straightforwardly accept the conclusions drawn by the authors in this paper that, contrary to past trials [3,4,5], suggest the absence of an effect of VE treatment on surrogate markers of complement activation.…”

Evaluation of the Impact of a New Synthetic Vitamin E-Bonded Membrane on the Hypo-Responsiveness to the Erythropoietin Therapy in Hemodialysis Patients: A Multicenter Study

“…The prevention of oxidative stress linked to the bio-incompatibility of the dialysis procedure may be obtained with either the supplementation of antioxidant vitamins [7] or by using vitamin E (ViE)-coated dialyzers [8,9]. Given the link between chronic inflammation, oxidative stress and anemia pathogenesis, it has been hypothesized that high-flux HD using a biocompatible ViE membrane may improve anemia and ESA response [10].…”

Effects of Vitamin E-Coated versus Conventional Membranes in Chronic Hemodialysis Patients: A Systematic Review and Meta-Analysis

“…Vitamin E has been used since the early 1990s as a blood surface modifier of cellulosic first and then synthetic hollow-fiber membranes with the aim of further improving biocompatibility and eventually providing antioxidant protection to blood cell membranes and circulating lipoproteins [3,4] . This is a unique example of 'bioactive' membranes with antioxidant properties that have been well characterized in vitro [5] and in vivo [6] .…”