EMBOLIC DEVICES

• US 20120289995A1
• Filed: 04/18/2012
• Published: 11/15/2012
• Est. Priority Date: 04/18/2011
• Status: Active Grant

• Current Assignee: Terumo Corporation
• Original Assignee: Microvention Incorporated (Terumo Corporation)
• Inventors: Constant, Michael, Cruise, Gregory M., Garretson, Josh
• Granted Patent: US 9,456,823 B2
• Time in Patent Office: Days
• US Class Current: 606/200
• CPC Class Codes: A61B 17/1214 Coils or wires
• CPC Class Codes: A61B 17/1215 comprising additional materials, e.g. thrombogenic, having filaments, having fibers, being coated
• CPC Class Codes: A61B 2090/3966 Radiopaque markers visible in an X-ray image
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• 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 31/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61L 31/14 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• 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: A61M 2025/0042 Microcatheters, cannula or the like having outside diameters around 1 mm or less
• CPC Class Codes: A61M 25/0097 characterised by the hub connectors A61M39/10
• CPC Class Codes: A61M 25/0122 with fluid drive by external fluid in an open fluid circuit
• CPC Class Codes: C08F 222/385 Monomers containing two or more (meth)acrylamide groups, e.g. N,N'-methylenebisacrylamide
• CPC Class Codes: C08L 71/02 Polyalkylene oxides

Abstract

Described herein are apparatus, compositions, systems and associated methods to occlude structures and malformations of the vasculature with radiopaque hydrogel filaments with delayed controlled rates of expansion. Further described is a device for implantation in an animal comprising a difunctional, low molecular weight ethylenically unsaturated shapeable macromer; an ethylenically unsaturated monomer; and a radiopaque element, wherein said device contains no support members. Methods of forming such devices are also disclosed.

Claims

1. An expansile device for implantation comprising:

a polymeric filament including a poly (ethylene glycol) 10,000 macromer;

an ethylenically unsaturated monomer; and

at least one visualization element,

wherein the expansile device includes no metal support members.

2. The expansile device according to claim 1, further comprising a multifunctional, ethylenically unsaturated cross-linker.

3. The expansile device according to claim 1, wherein the expansile device has reduced beam hardening artifacts when imaged using computed tomography.

4. The expansile device according to claim 1, wherein the at least one visualization element is selected from metallic powders, gadolinium, superparamagnetic iron oxide particles, or a combination thereof.

5. The expansile device according to claim 4, wherein the at least one visualization element is barium sulfate.

6. The expansile device according to claim 1, wherein the expansile device has a diameter of less than about 0.03 inches.

7. The expansile device according to claim 1, wherein the expansile device is substantially non-resorbable.

8. The expansile device according to claim 1, wherein the expansile device is biodegradable.

9. The expansile device according to claim 1, wherein the ethylenically unsaturated monomer is pH sensitive.

10. The expansile device according to claim 1, including sodium acrylate, N,N-methylenebisacrylamide, barium sulfate, and 2,2′

-azobis(2-methylpropionaamidine)dihydrochloride.

11. A method of forming an environmentally responsive hydrogel comprising:

a. preparing a polymerization solution comprising a poly (ethylene glycol) macromer;

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. treating said polymerized hydrogel in a non-physiological pH for a predetermined amount of time thereby creating an environmentally responsive hydrogel.

12. The method according to claim 11, wherein step b further comprises polymerizing the polymerization in a tube thereby creating a polymerized hydrogel filament.

13. The method according to claim 11, wherein the non-physiological pH is acidic.

14. The method according to claim 11, wherein the non-physiological pH is basic.

15. The method according to claim 11, wherein the solvent is selected from isopropanol, ethanol, water, dichloromethane, and acetone.

16. The method according to claim 11, wherein the poly (ethylene glycol) macromer has a molecular weight of about 5,000 g/mole to about 15,000 g/mole.

17. The method according to claim 16, wherein the poly (ethylene glycol) macromer has a molecular weight of about 10,000 g/mole.

18. The method according to claim 11, wherein the at least one ethylenically unsaturated monomer is a pH sensitive monomer selected from acrylic acid, methacrylic acid, amino methacrylate, or amino methacrylamide.

19. The method according to claim 11, wherein the polymerization solution further comprises a cross-linker.

20. The method according to claim 11, wherein the cross-linker is N,N′

-methylenebisacrylamide.

21. A hydrogel filament consisting essentially of about 25% w/w poly(ethylene glycol) 10,000 diacrylamide, about 11% w/w sodium acrylate, about 1% w/w N,N-methylenebisacrylamide, about 63% barium sulfate, and about <

1% 2,2′

-azobis(2-methylpropionaamidine)dihydrochloride.

22. A hydrogel filament consisting essentially of about 29% w/w poly(ethylene glycol) 10,000 diacrylamide, about 12% w/w sodium acrylate, about 1% w/w N,N-methylenebisacrylamide, about 58% barium sulfate, and about <

1% 2,2′

-azobis(2-methylpropionaamidine)dihydrochloride.