Evaluation of blood adsorption onto dialysis membranes by time-of-flight secondary ion mass spectrometry and near-field infrared microscopy

Abstract

Blood adsorption onto the inside surface of hollow fiber dialysis membranes was investigated by means of time-of-flight secondary ion mass spectrometry (TOF-SIMS) and near-field infrared microscopy (NFIR) in order to evaluate the biocompatibility and permeability of dialysis membranes. TOF-SIMS is useful for the imaging of particular molecules with a high spatial resolution of approximately 100 nm. In contrast, infrared spectra provide quantitative information and NFIR enables analysis with a high spatial resolution of less than 1 μm, which is close to the resolution of TOF-SIMS. A comparison was made of one of the most widely used dialysis membranes made of polysulfone (PSf), that has an asymmetric and inhomogeneous pore structure, and a newly developed asymmetric cellulose triacetate (ATA) membrane that also has an asymmetric pore structure, even though the conventional cellulose triacetate membrane has a symmetric and homogeneous pore structure. As a result, it was demonstrated that blood adsorption on the inside surface of the ATA membrane is more reduced than that on the PSf membrane. Graphical abstract Analysis of blood adsorption on inside surface of hollow fiber membrane.

Proteomic Characterization of a New asymmetric Cellulose Triacetate Membrane for Hemodialysis

“…The different pore size distribution between the two materials (homogeneous for CTA, smaller‐sized pores on the inside surface than on the outer surface for ATA) could also play a role . The low tendency of ATA polymer to adsorb proteins has also been shown in a recent study by means of TOF‐SIMS and near‐field infrared microscopy …”

Assessment of removal and adsorption enhancement of high-flux hemodialyzers in convective therapies by a novel in vitro uremic matrix

“…Thus, differences in the adsorbed mass due to convection were barely detected. Moreover, the specific adsorption potential of PA, PS and CTA membranes in HD were focused on essential proteins and immunoglobulins as obtained by several studies [32][33][34][35] . Our results are in total agreement with the data presented, among others, by Urbani et al 36 , as we found that β 2 -microglobulin was detected in greater quantities in PS membranes than in CTA membranes, whereas albumin was more present in CTA than in PS in the non-convective modality.…”

Physical Processes in Polymeric Filters Used for Dialysis

“…Modern polymer technologies allow fabrication of synthetic membranes with predetermined geometry of pores (see, for the review, [151,152,153,154,155,156,157,158,159,160,161]). Silicon membranes are convenient objects for the analysis of the effects of pore size and pore geometry.…”

“…Since HD blood purification demands multidisciplinary efforts, both improvements in engineering and continued search for the optimal filters in biomedicine need to proceed along with clinical studies of new synthetic materials. The main goal of the improved filtration in hemodialysis (HD) is to designing artificial polymer membranes for dialysis capillary filters that have special properties [155,156,157,158,159,160]. This general perspective involves several aspects.…”

“…There are special requirements for membranes that are used in hemodialysis, such as adequate diffusion and convection characteristics, sieving coefficients, a cut-off point similar to that of glomerulus [155,156], adequate ultrafiltration rate, suitable biocompatibility properties, non-toxicity of the material, as well as the non-degradable stability under sterilization (which may affect physical properties of the filters) and low-cost solutions [155,161]. In addition, reproducibility of dialysis and constant performance during the entire procedure is a prerequisite of HD [155,161].…”