Comparison of a charcoal sorbent fiber with commercial charcoals for hemoperfusion

A charcoal sorbent fiber (Enka, F.R.G.), was assessed for impurities, surface area, and adsorptive properties of its native charcoal, and compared with other uncoated activated charcoals. In vivo and in vitro hemocompatibility of the fiber were assessed as well as the adsorptive properties for endogenous toxins. The charcoal of the fiber had few impurities and a high surface area of 1,200 m2/g charcoal. For measuring the adsorptive speeds, 2 g of the uncoated charcoals were milled and screened to a particle size of 150-250 microns (Enka; 30-40 microns) and then mixed with the solutions of the individual solutes. The charcoal types of Enka, used in the charcoal sorbent fiber, and of Sutcliffe Speakman, used in the acrylic hydrogel coated charcoal, exhibited the highest adsorptive rates for bromthalein (middle molecular weight marker) and inulin (high molecular weight marker). No hematological differences among the various charcoals were found during the in vivo hemoperfusions. In the in vitro hemoperfusions with heparinized fresh blood, the fibers showed the lowest loss of leucocytes and thrombocytes. In the in vitro evaluation of the absorbents for hepatic support, the charcoal fiber and the petroleum pitch charcoal of Asahi had the best adsorptive properties for substances in the low molecular weight range.