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Biomedical subjects

W Piatkiewicz

Publications and source records attributed to W Piatkiewicz.

8 recordsLinked to original sources
PubMed1997

Pectin coated hollow fiber polypropylene membranes.

The aim of this study was to prepare a composite membrane for the selective, extracorporeal removal of human LDL-cholesterol. Pectin coated on a porous polypropylene membrane (PP) was used as an active LDL adsorber. Three types of membrane preparations were performed: coating of native PP, coating after chemical etching and gamma-irradiated coated PP. Pectin coated fibers (PCF) were examined under scanning electron microscope (SEM) and tested for hydraulic permeability. As a result of the coating of native and etched PP membrane, pectin layers of various thicknesses (2-16 microm) and porosity were obtained. Irradiation by gamma rays gave no insoluble pectin layers.

Biocompatible Materials↗
PubMed1994

A new pectin-based material for selective LDL-cholesterol removal.

A new material, natural polysaccharide-pectin, was tested for removal of human blood lipoproteins. Pectin was prepared in a granular form with the help of the specifically designed gelification device and tested in batch sorption experiments in vitro for removal of total cholesterol (TC), LDL-cholesterol (LDL-C), and HDL-cholesterol (HDL-C) from human plasma. Pectin granules removed 40% of TC, 45% of LDL-C, and 36% of HDL-C on average with respect to the initial amounts whereas corresponding values for LA-40 Kanegafuchi adsorbent were 69%, 81%, and 33% in the same experimental conditions (shaking 1 g of sorbent sample with 2 ml of plasma).

Adsorption↗
PubMed1988

Membrane plasma fractionation: effect of the surface area.

The influence of the surface area on the performance of plasma filters for dead-end mode of filtration is presented in this paper. Theoretical analysis of the dead-end filtration was performed and verified experimentally (using ENKA cellulose-diacetate PF-100 membranes) in respect to beta-lipoprotein. The theoretical model allows to optimize the course of the transmembrane pressure during plasma fractionation procedure in dependence of the surface area, initial concentration of macromolecules, total volume of the feed and membrane structure. The results indicate that the surface area effect is an important factor in the operation of membrane plasma fractionation and should be considered in the design of the plasma fractionation filter.

Blood Volume↗
PubMed1985

Theoretical formulation of sieving coefficient evaluation for membrane plasma separation.

Three different sieving coefficient definitions were theoretically investigated. It has been shown that the local sieving coefficient, characterizing membrane property, can be calculated under specified assumptions from input-output measurements. In contrast, the evaluation of the device sieving coefficient, useful in kinetic modeling, is validated in a situation in which calculation of the local sieving coefficient is connected with substantial error. The relationship between different sieving coefficient definitions is also given.

Blood↗
PubMed1978

Sorbent membranes: device designs, evaluations and potential applications.

The Enka sorbent membranes are designed to meet the requirements for the chronic extracorporeal treatment of body fluids with sorbents. The various configurations allow the construction of devices employing sorption alone, sorption plus filtration, or sorption plus filtration and dialysis. While conventional device designs can be employed, novel schemes are being explored to take advantage of the special structural features of the sorbent membranes. A general scheme for the evaluation of sorbents and, in particular, the sorbent membranes allows optimal use of sorbents in practical device designs. While the potential applications include those of sorbents in general, the unique configuration of the sorbent membranes with the possibilities of using multiple sorbents and of combining sorption with other transport processes should expand the therapeutic capabilities.

Adsorption↗