Hemo- and Enterosorbents on the Base of Spherically Granulated Synthetic Carbons

The application of carbonaceous adsorbents in medicine has old traditions. Still antique doctors used charcoal for treatment of wounds. To the beginning of ?? century the therapeutic use range of active carbons (? C) essentially has extended as an outside means (treatment of purulent wounds and ulcers, disinfecting in surgical and dental surgery practice), and internal adsorption preparation (enterosorbents) for treatment of acute poisonings and many internal illnesses . More than 30 years ago, due to courageous activity of Greek nephrologist H.Yatzidis, AC have begun to be applied to direct purification of blood hemoperfusion. The development of the last direction was always conjugate with a solution of a problem of AC hemocompatibility. It means the prevention of coagulation of blood and sharp shift of its electrolyte balance on a layer of adsorbent, minimization of blood platelets and proteins loss, and also migration of carbon microparticles, toxic mineral and organic impurities from the adsorbents in blood. As one from effective solutions actually opened a possibility of broad practical use of hemoperfusion it is necessary to recognize offered by T.Chang a method of AC granule microcapsulation, i.e. their partial or full covering by natural or synthetic biocompatible polymers . It became hereinafter clear that microcapsulation to maintain good hemocompatibility of AC sharply reduces them adsorption and apparently catalytic properties, and consequently worsens therapeutic effect of hemoperfusion. Alternate direction in hemoperfusion the use of uncovered AC has received development in the former USSR under the direction of the academician Yu.Lopukhin . A principal point of existence and development of this direction was the obtaining in Ukraine the synthetic active carbons (SAC) from co-polymers and resins base for preparing of high qualitative biocompatible uncoated hemosorbents as well spherical oral adsorbents (enterosorbents). The technologies of SAC deriving and medicinal means on their basis (hemo and enterosorbents) are patented in Ukraine and Russia . Characterization of SAC: are prepared by pirolysis and consequent steam activation of spherically granulated industrial porous co-polymers or resins on the base of vinylpyridin or styrene, cross-linked by divinylbenzene or phenol-formaldehyde. Obtained corresponding nitrogen containing (SCN) or pure carbonaceous (SCS) SAC appear as spherical particles with a diameter of 0.25-1.2 mm. They have high mechanical strength on friction (not less than 80%), smooth surface of granules with a metal brightness, low contents of mineral impurities (less than 1%). Their porosity is characterized by developed micropores (Vmi = 0.55-0.85 cm/g) and macropores connected with transport channels of mesopore type with diameter 10-40 nm (Vma+me = 0.35-1.25 cm/g). As a rule, for SAC in an burn-off interval of 40-75% volumes of adsorption pores on benzene (Ws) are within the limits of 0.6-1.2 cm/g, and the specific surface areas on argon (Ssp) are within the limits of 1200-1600 m/g. These parameters are much higher, than at used on practice carbon hemosorbents on the base of capsulated AC. So, for example, hemosorbents in "classical" columns have parameters: "Adsorba 300/150?" (Gambro, Sweden) Ws = 0.49 cm/g, Ssp = 920 m/g; "Hemodetoxifier" (? -D, USA) Ws = 0.39 cm/g, Ssp = 690 m/g; " D ? ?-1" (Kuraray, Japan) Ws = 0.52 cm/g, Ssp = 810 m/g. SAC exhibit more expressed, than traditional AC, catalytic activity in responses of an electronic and acid-basic type. As result of this detoxifying effect when SAC contact with biological mediums can essentially amplify at the expense of catalytic neutralization of some harmful and toxic metabolites (decomposition of peroxides and hydroperoxides, oxidation of nitrogenous slugs, hydrolysis of carbohydrates and fats etc.).