Unit for filtering leukocytes with reduced platelet adhesion
The invention relates to a filtration unit for enabling the selective leucocytapheresis of a fluid containing blood platelets. The filtration unit includes an external pouch provided with an inlet orifice and an outlet orifice, the pouch enclosing a porous element interposed between the orifices. The porous element encloses a leucocytapheresis medium impregnated with a polymer, the polymer having the general formula -(A)m-(B)n- (I), wherein A is a unit originating from an alkoxyalkyl acrylate or alkoxyalkyl methacrylate monomer, B is a unit originating from a hydrophobic polymerisable monomer, and m and n are integers, the sum of which, m+n, is equal to 100, m being an integer greater than 80.
1 . A filtration unit for allowing the selective leukodepletion of a fluid containing blood platelets comprising an outer housing provided with at least one inlet port and at least one outlet port, the outer housing enclosing a porous element interposed between the ports, the porous element enclosing a leukodepletion medium impregnated with a polymer, the polymer having the general formula-(A)m-(B)n-(I), in which A is an alkoxyalkyl acrylate or an alkoxyalkyl methacrylate monomer, B is a hydrophobic polymerizable monomer, and m and n are integers of which the sum m+n is equal to 100, m being an integer greater than 80.
2 . The filtration unit according to claim 1 , wherein A has the following structure:
in which R1 is chosen from a group consisting of a hydrogen atom or the methyl group, R2 is a linear or branched C1-C4 alkylene bond and R3 is a linear or branched C1-C4 alkyl group.
3 . The filtration unit according to claim 1 , wherein A is ana methoxyethyl acrylate.
4 . The filtration unit according claim 1 , wherein m is an integer between 90 and 96.
5 . The filtration unit according to claim 1 , wherein B has one of the following two structures:
in which R4 is chosen from the group consisting of a hydrogen atom and a methyl group and R5 is a linear or branched C1-C6 alkyl group, or
in which R6 is chosen from the group consisting of a hydrogen atom and a methyl group and R7 is a C1-C6 alkyl group.
6 . The filtration unit according to claim 1 , B is is one of methyl methacrylate or vinyl acetate.
7 . The filtration unit according to claim 1 , wherein the number-average molar mass of the polymer is between 5,000 g/mol and 40,000 g/mol.
8 . The filtration unit according to claim 1 , wherein the weight-average molar mass of the polymer is between 15,000 g/mol and 115,000 g/mol.
9 . The filtration unit according to claim 1 , wherein the polymer has a polymolecularity index of between 1 and 6.
10 . The filtration unit according to claim 1 , wherein the quantity of polymer deposited on the leukodepletion medium is between 1 and 10 mg/g of leukodepletion medium.
11 . The filtration unit according to claim 1 , wherein the leukodepletion medium comprises polybutylene terephthalate or polyethylene terephthalate fibers.
12 . The filtration unit according to claim 1 , wherein the leukodepletion medium is formed by at least one layer of non-woven fabric.
13 . The filtration unit according to claim 12 , wherein the average pore diameter of the non-woven layer is between 3 and 15 μm.
14 . A system for the leukodepletion of a fluid containing blood platelets, comprising:
a filtration unit according to claim 1 , and
a bag for collecting the filtrate, the bag being connected by a tube to an outlet port of the filtration unit.
15 . The bag system according to claim 14 , in which the filtration unit comprises a flexible outer housing and a rigid case configured to contain the filtration unit and prevent the filtration unit from swelling during filtration.
16 . A filtration unit for allowing the selective leukodepletion of a fluid containing blood platelets comprising an outer housing provided with at least one inlet port and at least one outlet port, the outer housing enclosing a porous element interposed between the ports, the porous element enclosing a leukodepletion medium impregnated with a polymer, the polymer having the general formula-(A)m-(B)n-(I), in which A is an alkoxyalkyl acrylate or an alkoxyalkyl methacrylate monomer, B is a hydrophobic polymerizable monomer, and m and n are integers of which the sum mtn is equal to 100, m being an integer greater than 80; and wherein B is a monomer chosen from the group consisting of an alkyl acrylate, an alkyl methacrylate and a vinyl alkylate.
17 . A filtration unit for allowing the selective leukodepletion of a fluid containing blood platelets comprising an outer housing provided with at least one inlet port and at least one outlet port, the outer housing enclosing a porous element interposed between the ports, the porous element enclosing a leukodepletion medium impregnated with a polymer, the polymer having the general formula-(A)m-(B)n-(I), in which A is an alkoxyalkyl acrylate or an alkoxyalkyl methacrylate monomer, B is a hydrophobic polymerizable monomer, and m and n are integers of which the sum m+n is equal to 100, m being an integer greater than 80; and wherein B does not contain a basic nitrogen group.