Potential of dual-skinned, high-flux membranes to reduce backtransport in hemodialysis

Paul J. Soltys, Andrew Zydney, John K. Leypoldt, Lee W. Henderson, Norma J. Ofsthun

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Background. Potential backfiltration of cytokine-inducing material is a clinical concern during hemodialysis conducted with high-flux membranes. Novel hollow-fiber membranes were developed that had asymmetric convective solute transport properties, aimed at reducing the passage of potentially harmful molecules from dialysate to blood, while maintaining the desired fluid and solute movement from blood to dialysate. Methods. Sieving coefficient as a function of molecular weight was measured in vitro using polydisperse dextrans. Measurements were conducted using two different flat-sheet membranes in series or using hollow fiber membranes having two integrally formed skin layers. Based on measured experimental parameters, model calculations simulated the performance of a clinical-scale dialyzer containing these new membranes versus that of a commercially available high-flux dialyzer. Results. Asymmetric convective solute transport was demonstrated using both commercial flat-sheet and newly developed hollow-fiber membranes. For two flat-sheet membranes in series, the extent of asymmetric transport was dependent on the order in which the solution was filtered through the membranes. For the hollow-fiber membranes, the nominal molecular weight cut-off was 20 kD in the blood-to-dialysate direction and 13 kD in the dialysate-to-blood direction. For this membrane, model calculations predict that clearance of a β2-microglobulin-sized molecule (11,800 D) would be significantly greater from blood to dialysate than in the reverse direction, even under conditions of zero net ultrafiltration. Conclusion. A novel hollow-fiber dialysis membrane was developed that allows greater convective solute transport from blood to dialysate than from dialysate to blood.

Original languageEnglish (US)
Article number4491750
Pages (from-to)818-828
Number of pages11
JournalKidney International
Issue number2
StatePublished - 2000

All Science Journal Classification (ASJC) codes

  • Nephrology


Dive into the research topics of 'Potential of dual-skinned, high-flux membranes to reduce backtransport in hemodialysis'. Together they form a unique fingerprint.

Cite this