Affinity supports for hemoperfusion

A coated support prepared by a method to coat a particulate support with a biocompatible membrane-type coating of pore size of at least 20 angstroms, wherein the coating prevents the leaching of fine particles from a matrix formed by the method, which method comprises:

• preparing a suspension of the particulate support, wherein said support is functionalized or derivatized with an affinity ligand,
• in a solvent containing dissolved biocompatible polymer in an amount 0.1-1% of the weight of the support;
• and
• removing the solvent from the suspension, under conditions which result in a thin, integral membrane.

A coated support prepared by a method to coat a particulate support with a biocompatible membrane-type coating of pore size at least 20 angstroms, wherein the coating prevents the leaching of fine particles from a matrix formed by the method, which method comprises:

• preparing a suspension of the particulate support, wherein said support is functionalized or derivatized with an affinity ligand,
• in a solvent containing dissolved biocompatible polymer in an amount 0.1-1% of the weight of the support, said solvent further containing a dissolved compatible pore-controlling component in an amount 0.5-5% of the weight of said polymer;
• removing the solvent from the suspension;
• and
• removing the pore-controlling component from the coating, under conditions which results in a thin, integral membrane.