Plasma protein adsorption to highly permeable hemodialysis membranes

W. R. Clark, W. L. Macias, Bruce Molitoris, N. H L Wang

Research output: Contribution to journalArticle

64 Citations (Scopus)

Abstract

Although membrane adsorption of plasma proteins is one of several factors determining the biocompatibility and mass transfer characteristics of a hemodialyzer, this process has not been evaluated rigorously. We performed an equilibrium and kinetic analysis of the binding of proteins of differing molecular weight to highly permeable membranes of differing hydrophobicity and surface change. Hydrophobic, anionic polyacrylonitrile (PAN) and hydrophilic, uncharged cellulose triacetate (CT) membrane fragments were incubated in buffer containing radioiodinated β2-microglobulin (β2m) or bovine serum albumin (BSA). From an initial solution concentration of 50 mg/liter, both membranes adsorbed significantly more β2m than BSA at equilibrium (PAN, 352 ± 30 vs. 32.1 ± 2.4 ng; CT, 87.0 ± 0.6 vs. 30.8 ± 1.7 ng). These results were consistent with membrane pore exclusion of BSA. Comparison of the slopes of the equilibrium isotherm lines (concentration range, 0 to 220 mg/liter) showed the PAN binding affinity for β2m and BSA was 28 and 1.4 times that of CT, respectively. In kinetic studies, the approach to equilibrium versus (time)( 1/2 ) was assessed. For all protein-membrane combinations, this relationship was linear, consistent with a diffusion-controlled process. This latter characteristic permitted the determination of β2m membrane diffusivity values for both PAN and CT, which were found to be 0.30 and 3.25 x 10-7 cm2/sec, respectively. These data suggest membrane hydrophobicity more significantly influences the binding of low-molecular weight proteins than that of pore-excluded proteins. In addition, these results demonstrate electrostatic membrane-protein interactions may influence the kinetics of both the adsorption and transmembrane mass transfer of plasma proteins.

Original languageEnglish (US)
Pages (from-to)481-488
Number of pages8
JournalKidney International
Volume48
Issue number2
StatePublished - 1995
Externally publishedYes

Fingerprint

Adsorption
Renal Dialysis
Blood Proteins
Membranes
Bovine Serum Albumin
Hydrophobic and Hydrophilic Interactions
Membrane Proteins
Molecular Weight
Artificial Kidneys
Porins
Static Electricity
Carrier Proteins
Buffers
cellulose triacetate
polyacrylonitrile
Proteins

ASJC Scopus subject areas

  • Nephrology

Cite this

Clark, W. R., Macias, W. L., Molitoris, B., & Wang, N. H. L. (1995). Plasma protein adsorption to highly permeable hemodialysis membranes. Kidney International, 48(2), 481-488.

Plasma protein adsorption to highly permeable hemodialysis membranes. / Clark, W. R.; Macias, W. L.; Molitoris, Bruce; Wang, N. H L.

In: Kidney International, Vol. 48, No. 2, 1995, p. 481-488.

Research output: Contribution to journalArticle

Clark, WR, Macias, WL, Molitoris, B & Wang, NHL 1995, 'Plasma protein adsorption to highly permeable hemodialysis membranes', Kidney International, vol. 48, no. 2, pp. 481-488.
Clark, W. R. ; Macias, W. L. ; Molitoris, Bruce ; Wang, N. H L. / Plasma protein adsorption to highly permeable hemodialysis membranes. In: Kidney International. 1995 ; Vol. 48, No. 2. pp. 481-488.
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