IP Library Granted Patent US 8,211,310
Granted Patent B2
US 8,211,310 · App. 12/807,597 · Granted Jul 3, 2012

Size-selective polymer system

Assignee: Cytosorbents, Inc.
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Quick Facts
Patent No.
US 8,211,310
App. No.
12/807,597
Granted
Jul 3, 2012
Kind
B2
Abstract

A size-selective hemocompatible porous polymeric adsorbent system is provided, the polymer system comprises at least one polymer with a plurality of pores, and the polymer has at least one transport pore with a diameter from about 250 Angstroms to about 2000 Angstroms, and the polymer has a transport pore volume greater than about 1.8% to about 78% of a capacity pore of volume of the polymer.

Claims (20)

1. A polymer system consisting of polymers defining a porous structure wherein the porous structure consists of pores with diameters in the range of 17 Angstroms to about 2000 Angstroms, said porous structure comprising transport pores with diameters from about 250 Angstroms to about 2000 Angstroms and effective pores with diameters greater than 100 Angstroms to about 250 Angstroms, said polymer system having a transport pore volume greater than about 1.8 to about 78% of a capacity pore volume of said system and an effective pore volume greater than about 22 to less than about 98.2% of the capacity pore volume.

2. The system of claim 1 wherein said pores are measured using a micromeretics ASAP 2010 porisimeter.

3. The system of claim 1 wherein said polymer system is capable of sorbing protein molecules greater than 20,000 to less than 50,000 Daltons from blood and excluding the sorption of blood proteins greater than 50,000 Daltons.

4. The system of claim 1 wherein said polymer system has a total pore volume from about 0.315 cc/g to about 1.516 cc/g.

5. The polymer system of claim 1 wherein said polymers are biocompatible.

6. The polymer system of claim 1 wherein said polymers are hemocompatible.

7. The polymer system of claim 1 wherein the geometry of said polymer system is a spherical bead.

8. The polymer system of claim 1 wherein said polymer system is used in direct contact with whole blood to sorb protein molecules selected from a group consisting essentially of cytokines and β 2 -microglobulin and exclude the sorption of large blood proteins, said large blood proteins being selected from a group consisting essentially of hemoglobin, albumin, immunoglobulins, fibrinogen, serum proteins and other blood proteins larger than 50,000 Daltons.

9. The polymer system of claim 1 wherein said polymer system has an internal surface selectivity for adsorbing proteins smaller than 50,000 Daltons, having little to no selectivity for adsorbing vitamins, glucose, electrolytes, fats, and other hydrophilic small molecular nutrients carried by the blood.

10. The polymer system of claim 1 wherein said polymer system is made using suspension polymerization.

11. The polymer system of claim 1 wherein said polymers are constructed from aromatic monomers of styrene and ethylvinylbenzene with a crosslinking agent selected from a group consisting essentially of divinylbenzene, trivinylcyclohexane, trivinylbenzene, divinylnaphthalene, divinylsulfone, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate and mixtures thereof.

12. The polymer system of claim 1 wherein the polymer system is made using droplet suspension polymerization using a stabilizing agent selected from a group consisting essentially of hemocompatibilizing polymers, said polymers being poly(N-vinylpyrrolidinone), poly(hydroxyethyl acrylate), poly(hydroxyethyl methacrylate), hydroxylethyl cellulose, hydroxypropyl cellulose, salts of poly(acrylic acid), salts of poly(methacrylic acid), poly(dimethylaminoethyl acrylate), poly(dimethylaminoethyl methacrylate), poly(diethylaminoethyl acrylate), poly(diethylaminoethyl methacrylate), poly(vinyl alcohol) and mixtures thereof.

13. The polymer system of claim 1 wherein said polymers are made hemocompatible by exterior coatings selected from a group consisting essentially of poly(N-vinylpyrrolidinone), poly(hydroxyethyl acrylate), poly(hydroxyethyl methacrylate), hydroxyethyl cellulose, hydroxypropyl cellulose, salts of poly(acrylic acid), salts of poly(methacrylic acid), poly(dimethylaminoethyl methacrylate), poly(dimethylaminoethyl acrylate), poly(diethylaminoethyl acrylate), poly(diethylaminoethyl methacrylate), poly(vinyl alcohol) and mixtures thereof.

14. The polymer system of claim 13 wherein said polymers are made hemocompatible by surface grafting of the hemocompatible exterior coatings concomitantly with formation of the polymer system.

15. The polymer system of claim 13 wherein said polymers are made hemocompatible by surface grafting of the hemocompatible exterior coatings onto the preformed polymer system.

16. The polymer system of claim 1 wherein said polymers have an external surface with a negative ionic charge, said negative ionic charge prevents albumin from entering said pores.

17. A size selective polymer defining a porous structure wherein the porous structure consists of pores with diameters in the range of 17 Angstroms to about 2000 Angstroms, said porous structure comprising transport pores with diameters from about 250 Angstroms to about 2000 Angstroms and effective pores with diameters greater than 100 Angstroms to about 250 Angstroms, said porous structure having a transport pore volume greater than about 1.8 to about 78% of a capacity pore volume of said porous structure and an effective pore volume greater than about 22 to less than about 98.2% of the capacity pore volume.

18. A size selective polymer system consisting of polymers defining a porous structure wherein the porous structure consists of pores with diameters in the range of 17 Angstroms to about 2000 Angstroms, said porous structure comprising transport pores with diameters from about 250 Angstroms to about 2000 Angstroms and effective pores with diameters greater than 100 Angstroms to about 250 Angstroms, said polymer system having a transport pore volume greater than about 1.8 to about 78% of a capacity pore volume of said system and an effective pore volume greater than about 22 to less than about 98.2% of the capacity pore volume, said polymer has an external surface with a negative ionic charge, said negative ionic charge prevents albumin from entering said pores.

19. The polymer of claim 17 wherein said pores are measured using a micromeretics ASAP 2010 porisimeter.

20. The polymer of claim 18 wherein said pores are measured using a micromeretics ASAP 2010 porisimeter.

Assignments (2)
SECURITY INTEREST Recorded Jun 28, 2024
From: CYTOSORBENTS CORPORATION
To: AVENUE CAPITAL MANAGEMENT II, L.P.
Reel/Frame 067964/0382 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 7, 2017
From: CYTOSORBENTS, INC.
To: CYTOSORBENTS CORPORATION
Reel/Frame 044698/0348 →
Continuity (2)
Continuation In Part 11601931 · Nov 20, 2006
Related Publication 20110070424A1 · Mar 24, 2011