EMBOLIC DEVICES

• US 20130302251A1
• Filed: 04/17/2013
• Published: 11/14/2013
• Est. Priority Date: 04/18/2012
• Status: Active Grant

• Current Assignee: Microvention Incorporated (Terumo Corporation)
• Original Assignee: Microvention Incorporated (Terumo Corporation)
• Inventors: Constant, Michael, Keeley, Edward Michael, Garretson, Joshua, Cruise, Gregory M.
• Granted Patent: US 9,011,884 B2
• Time in Patent Office: Days
• US Class Current: 424/9.3
• CPC Class Codes: A61K 47/30 Macromolecular organic or inorganic compounds, e.g. inorganic polyphosphates
• CPC Class Codes: A61K 47/34 Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyesters, polyamino acids, polysiloxanes, polyphosphazines, copolymers of polyalkylene glycol or poloxamers A61K47/10 takes precedence
• CPC Class Codes: A61K 49/0404 containing barium sulfate
• CPC Class Codes: A61K 49/126 Linear polymers, e.g. dextran, inulin, PEG
• CPC Class Codes: A61K 51/1213 Semi-solid forms, gels, hydrogels, ointments, fats and waxes that are solid at room temperature
• CPC Class Codes: A61K 9/0019 Injectable compositions; Intramuscular, intravenous, arterial, subcutaneous administration; Compositions to be administered through the skin in an invasive manner non-active ingredients are additionally classified in A61K47/00
• CPC Class Codes: A61K 9/0024 Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L
• CPC Class Codes: A61L 2430/36 for embolization or occlusion, e.g. vaso-occlusive compositions or devices
• CPC Class Codes: A61L 31/048 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61L 31/145 Hydrogels or hydrocolloids
• CPC Class Codes: A61L 31/18 Materials at least partially X-ray or laser opaque
• CPC Class Codes: C08L 33/26 Homopolymers or copolymers of acrylamide or methacrylamide
• CPC Class Codes: Y10T 428/298 Physical dimension

Abstract

Described herein are apparatus, compositions, systems and methods for occluding vascular structures and vascular malformations with radiopaque hydrogel filaments. The filaments can contain no support members and can be CT and MR compatible. Methods of forming such filaments are also disclosed.

Claims

1. An hydrogel for implantation comprising:

a shapeable polymeric filament formed from a combination of precursors comprising trimethylolpropane ethoxylate triacrylamide;

at least one ethylenically unsaturated acrylamide monomer and at least one ethylenically unsaturated methacrylate monomer; and

a crosslinker; and

comprising at least one visualization agent; and

wherein the hydrogel includes no metal support members.

2. The hydrogel according to claim 1, having reduced beam hardening artifacts when imaged using computed tomography.

3. The hydrogel according to claim 1, wherein the at least one visualization agent is selected from metallic powders, gadolinium, superparamagnetic iron oxide particles, barium sulfate or a combination thereof.

4. The hydrogel according to claim 1, wherein the polymeric filament has a diameter of less than about 0.03 inches.

5. The hydrogel according to claim 1, wherein the polymeric filament is substantially non-resorbable.

6. The hydrogel according to claim 1, wherein the polymeric filament is biodegradable.

7. The hydrogel according to claim 1, wherein the at least one ethylenically unsaturated acrylamide monomer is t-butyl acrylamide.

8. The hydrogel according to claim 1, wherein the at least one ethylenically unsaturated methacrylate monomer is hydroxyethyl methacrylate.

9. The hydrogel according to claim 1, wherein the ethylenically unsaturated acrylamide monomer and ethylenically unsaturated methacrylate monomer are a combination of hydroxyethyl methacrylate and t-butyl acrylamide.

10. The hydrogel according to claim 1, wherein the difunctional, shapeable macromer is trimethylolpropane ethoxylate triacrylamide 900.

11. The hydrogel according to claim 1, wherein the cross-linker is N,N′

-methylenebisacrylamide.

12. A method of forming a hydrogel comprising:

a. preparing a polymerization solution comprising trimethylolpropane ethoxylate triacrylamide;

at least one ethylenically unsaturated monomer; and

at least one visualization element in a solvent;

b. polymerizing the polymerization solution to create a polymerized hydrogel; and

c. drying the polymerized hydrogel thereby forming the hydrogel.

13. The method according to claim 12, wherein step b further comprises polymerizing the polymerization solution in a tube thereby creating a polymerized hydrogel filament having the shape of the internal volume of the tube.

14. The method according to claim 12, wherein the solvent is selected from isopropanol, ethanol, water, dichloromethane, and acetone.

15. The method according to claim 12, wherein the at least one ethylenically unsaturated monomer is t-butyl acrylamide.

16. The method according to claim 12, wherein the at least one ethylenically unsaturated monomer is hydroxyethyl methacrylate.

17. The method according to claim 12, wherein the ethylenically unsaturated monomer is a combination of hydroxyethyl methacrylate and t-butyl acrylamide.

18. The method according to claim 12, wherein the polymerization solution further comprises a multifunctional cross-linker.

19. The method according to claim 12, wherein the cross-linker is N,N′

-methylenebisacrylamide.

20. A method of forming a hydrogel comprising:

drying a hydrogel filament, wherein the hydrogel filament is polymerized from a polymerization solution comprising a trimethylolpropane ethoxylate triacrylamide 900 macromer;

at least one ethylenically unsaturated monomer; and

at least one visualization element in a solvent.

21. A hydrogel filament consisting essentially of about 27% w/w trimethylolpropane ethoxylate triacrylamide 900, about 6% w/w t-butyl acrylamide, about 2% hydroxyethyl methacrylate, about 0.5% w/w N,N-methylenebisacrylamide, about 64% barium sulfate, and about 0.5% 2,2′

-azobisisobutyronitrile.

22. A hydrogel filament consisting essentially of about 30% w/w trimethylolpropane ethoxylate triacrylamide 900, about 6% w/w t-butyl acrylamide, about 2% hydroxyethyl methacrylate, about 0.75% w/w N,N-methylenebisacrylamide, about 48% barium sulfate, and about 0.5% 2,2′

-azobisisobutyronitrile.