Use of a neutral or cationic polymer for preventing the activation of blood or plasma contact phase in contact with a semipermeable membrane

摘要

A neutral or cationic polymer is used to prevent the activation of a blood or plasma phase in contact with semi-permeable membranes of polyacrylonitrile. A neutral or cationic polymer is used to prevent activation of the contact phase of blood or plasma coming into contact with a semi-permeable membrane based on polyacrylonitrile (PAN) carrying fixed negative charges situated in an apparatus for the treatment of blood or plasma by extra-corporal circulation. The neutral or cationic polymer is combined with the semi-permeable membrane before or after formation of the membrane and before sterilization of the membrane. The overall ionic capacity of the semi-permeable membrane based on PAN and carrying fixed negative charges and including a neutral or cationic polymer, is negative. The absolute value of the overall ionic capacity of the semi-permeable membrane based on PAN and carrying fixed negative charges and including a neutral or cationic polymer is at most 10 % less than the overall ionic capacity of the same semi-permeable membrane without the neutral or cationic polymer. The modified PAN based semi-permeable membrane corresponds, before sterilization, with one or other of the following electric characteristics: (a) the electrokinetic index I is less than or equal to 0.8, where I is the logarithm to base 10 of the ratio Z/R where Z = the zeta potential in microvolts, expressed as an absolute value, of the surface of the membrane which comes into contact with the blood or plasma, and R = the electrical resistivity of the membrane expressed in ohm.cm; and (b) the Zeta potential Z is positive and is between 0 and +15 mV (terminals not included). Independent claims are included for: (A) the production of a device for the treatment of blood or plasma by extra-corporal circulation in contact with a semi-permeable membrane in the form of a flat membrane or a bundle of hollow fibers; and (B) a device for the treatment of blood or plasma by extra-corporal circulation, sterilized and ready to use, containing a semi-permeable membrane.