Filtration medium sequence for biomaterial purification

1. A filtration medium sequence comprising:

a first filtration medium comprising an anion exchange nonwoven substrate, wherein the anion exchange nonwoven substrate comprises a plurality of quaternary ammonium groups; and

(ii) a second filtration medium comprising a functionalized microporous membrane wherein the functionalized microporous membrane comprises a plurality of guanidyl groups;

wherein the first filtration medium is positioned upstream of the second filtration medium.

2. The filtration medium sequence of claim 1 , wherein the first filtration medium comprises at least 0.1 mmol of quaternary ammonium groups per gram of the first filtration medium.

3. The filtration medium sequence of claim 1 , wherein the second filtration medium comprises at least 0.01 mmol of guanidyl groups per gram of the second filtration medium.

4. The filtration medium sequence of claim 1 , wherein the first filtration medium comprises a polymer grafted to the surface of a nonwoven substrate wherein the polymer comprises interpolymerized monomeric units of:

(a) 80 to 98 wt. % of an aminoalkyl (meth)acryloyl monomer;

(b) 2 to 20 wt. % of a poly(alkylene oxide) monomer; and

(c) 0 to 10 wt. % of a second hydrophilic monomer.

5. The filtration medium sequence of claim 1 , wherein the first filtration medium comprises a polymer grafted to the surface of a nonwoven substrate wherein the polymer comprises interpolymerized monomeric units of:

(a) 10 to 50 wt. % of a quaternary ammonium-containing ligand monomer;

(b) 10 to 80 wt. % of an amide monomer;

(c) 10 to 40 wt. of an oxy monomer; and

(d) 0 to 30 wt. % of a poly(alkylene oxide) monomer.

6. The filtration medium sequence of claim 1 , wherein the functionalized microporous membrane comprises a free-radically grafted guanidyl-functional (meth)acryloyl monomer, wherein the guanidyl-functional (meth)acryloyl monomer comprises at least one of:

wherein

R 1 is H or C 1 -C 4 alkyl;

R 2 is a (hetero)hydrocarbyl group;

each R 3 is independently H or hydrocarbyl;

R 4 is H, C 1 -C 12 alkyl or N(R 3 ) 2 ;

R 5 is H or hydrocarbyl;

X 1 is —O—- or —NR 3 −;

o is 0 or 1, and

n is 1 or 2.

7. The filtration medium sequence of claim 6 , wherein the free-radically grafted guanidyl-functional (meth)acryloyl monomer is grafted to a primer layer disposed on a microporous membrane, wherein the primer layer comprises a cross-linked polyamine polymer having ethylenically unsaturated polymerizable groups, wherein the cross-linked polyamine polymer having ethylenically unsaturated polymerizable groups is a reaction product of: (a) a polyamine polymer; (b) a polyfunctional crosslinking agent for the polyamine polymer; and (c) a monomer having an amine-reactive functional group and an ethylenically unsaturated polymerizable group.

8. The filtration medium sequence of claim 6 , wherein the free-radically grafted guanidyl-functional (meth)acryloyl monomer is grafted on a microporous membrane in the presence of a Type II photoinitiator.

9. The filtration medium sequence of claim 1 , further comprising a non-functionalized filtration medium disposed between the first filtration medium and the second filtration medium.

10. A filter device comprising

a fluid inlet;

a fluid outlet; and

a filtration medium sequence fluidly connecting the fluid inlet and the fluid outlet, wherein

the filtration medium sequence according to claim 1 .

11. A method of filtration of a biological fluid, the method comprising:

(a) providing the biological fluid, wherein the biological fluid comprises a targeted biomolecule and contaminants, and

(b) contacting the biological fluid with the filtration medium sequence of claim 1 to obtain a filtrate.

12. The method of claim 11 , wherein the targeted biomolecule is a protein.

13. The filtration medium sequence of claim 1 , wherein the anion exchange nonwoven substrate has an effective fiber diameter of 1 to 6 micrometer.

14. The filtration medium sequence of claim 1 , further comprising a non-functionalized filtration medium disposed between the first filtration medium and the second filtration medium.

15. The filter device of claim 10 , wherein the filtration media is formed into a media cylinder comprising a plurality of pleats.

16. The filter device of claim 10 , further comprising a core, wherein the second filtration medium is wound around the core and the first filtration medium is wound around the second filtration medium.

17. The filter device of claim 10 , wherein the filter device further comprising

a separator element;

an edge seal;

wherein the separator element comprises

a central core in fluid communication with the fluid inlet;

a first side; and

a second side; and

wherein the filter media further comprises

a first media disk positioned on the first side of the separator element and having an outer circumferential edge and an inner circumferential edge; and

a second media disk positioned on the second side of the separator element and having an outer circumferential edge and an inner circumferential edge; and

wherein the outer circumferential edges of the first and second media disks are connected by the edge seal and the inner circumferential edges of the first and second media disks are connected to the central core and wherein the upstream side of the first and second media disk comprises the first filtration medium.

18. The method of claim 11 , wherein the biological fluid has turbidity of at least 40 NTU.

19. The method of claim 11 , wherein the biological fluid has a concentration of DNA of at least 10 5 pg/mL.

20. The method of claim 11 , wherein the biological fluid has a first host cell protein concentration and the filtrate has a second host cell protein concentration, wherein the second host cell protein concentration is at least 50% lower than the first host cell protein concentration.