Adsorbent composed of porous beads of chitosan and adsorption method using same

A carrier for use in chromatography, composed of porous beads of crosslinked chitosan constituted of glucosamine, wherein said crosslinked chitosan is obtained by crosslinking uncrosslinked chitosan with a crosslinking agent selected from the group consisting of dicarboxylic acids and halides thereof represented by formula (I):

• ##STR5## wherein X represents a chlorine or bromine atom or a hydroxyl group;
• Y represents a cyclohexylene, phenylene, methylphenylene or dimethylphenylene group;
• m is 0 or 1, and n is 0 or an integer of from 1 to 7;
• and diisocyanates represented by formula (III):
• OCN--CH.sub.2).sub.n.(Y).sub.m.(CH.sub.2).sub.n NCO (III)
• wherein Y, m and n are as defined above;
• wherein
• an .omega.-carboxylalkanoyl group is bonded to at least a part of the amino groups of the glucosamine constituting the chitosan and at least a part of the amino groups of said crosslinking agent of the formula (III) when present bonded to the chitosan, provided that the remaining unreacted amino groups are acylated.

A method for adsorbing and removing an interleukin-2 inhibitor from a fluid containing said inhibitor, comprising contacting said fluid with an adsorbent composed of porous beads of crosslinked chitosan constituted of glucosamine and having protein A bonded to said porous beads of crosslinked chitosan, wherein said crosslinked chitosan is obtained by crosslinking uncrosslinked chitosan with a crosslinking agent selected from the group consisting of dicarboxylic acids and halides thereof represented by formula (I):

• ##STR6## wherein X represents a chlorine or bromine atom or a hydroxyl group;
• Y represents a cyclohexylene, phenylene, methylphenylene or dimethylphenylene group;
• m is 0 or 1;
• and n is 0 or an integer of from 1 to 7;
• and diisocyanates represented by formula (III):
• OCN--CH.sub.2).sub.n.(Y).sub.m.(CH.sub.2).sub.n NCO (III)
• wherein Y, m and n are as defined above;
• said protein A being covalently bonded via a bonding group to at least a part of the amino groups of the glucosamine constituting said chitosan and at least a part of the amino groups of said crosslinking agent of the formula (III) when present bonded to said chitosan, said bonding group comprising a combination group having a carboxyl group introduced by reaction of said amino groups with an alkane-dicarboxylic anhydride having from 4 to 16 carbon atoms;
• provided that
• substantially all of the amino groups other than the amino groups to which said protein A is bonded via the combination group having the carboxyl group are acylated with an acyl group having from 2 to 6 carbon atoms,
• wherein said contacting is for a time sufficient to allow for the adsorption and removal of said interleukin-2 inhibitor from said fluid.

A method for absorbing an intended substance by affinity chromatography, comprising contacting a fluid containing said substance with an adsorbent comprising porous beads of crosslinked chitosan constituted of glucosamine and having protein A or a lectin covalently bonded to said porous beads of crosslinked chitosan, wherein said crosslinked chitosan is obtained by crosslinking uncrosslinked chitosan with a crosslinking agent selected from the group consisting of dicarboxylic acids and halides thereof represented by formula (I):

• ##STR7## wherein X represents a chlorine or bromine atom or a hydroxyl group;
• Y represents a cyclohexylene, phenylene, methylphenylene or dimethylphenylene group;
• m is 0 or 1, and n is 0 or an integer of from 1 to 7,
• and diisocyanates represented by formula (III):
• OCN--CH.sub.2).sub.n.(Y).sub.m.(CH.sub.2).sub.n NCO (III)
• wherein Y, m and n are as defined above;
• said protein A or lectin being covalently bonded via a bonding group to at least a part of the amino groups of the glucosamine constituting said chitosan and at least a part of the amino groups of the crosslinking agent of formula (III) when present bonded to said chitosan, said bonding group comprising a combination group having a carboxyl group introduced by reaction of said amino groups with an alkane-dicarboxylic anhydride having from 4 to 16 carbon atoms;
• provided that
• substantially all of the amino groups other than the amino groups to which protein A or lectin is bonded via the bonding group are acylated with an acyl group having from 2 to 6 carbon atoms, wherein said contacting is for a time sufficient to allow for the adsorption of said substance to said adsorbent.

A method for adsorbing and removing an immunoglobulin from a fluid containing same, comprising contacting said fluid with adsorbent porous beads of crosslinked chitosan constituted of glucosamine, wherein said crosslinked chitosan is obtained by crosslinking uncrosslinked chitosan with a crosslinking agent selected from the group consisting of dicarboxylic acids and halides thereof represented by formula (I):

• ##STR8## wherein X represents a chlorine or bromine atom or a hydroxyl group;
• Y represents a cyclohexylene, phenylene, methylphenylene or dimethylphenylene group;
• m is 0 or 1;
• and n is 0 or an integer of from 1 to 7;
• and diisocyanates represented by formula (III):
• OCN--CH.sub.2).sub.n.(Y).sub.m.(CH.sub.2).sub.n NCO (III)
• wherein Y, m and n are as defined above.