POROUS BIOABSORBABLE IMPLANT

• US 20140239528A1
• Filed: 05/07/2014
• Published: 08/28/2014
• Est. Priority Date: 09/23/2008
• Status: Active Grant

• Current Assignee: Senorx Incorporated (Becton, Dickinson & Co)
• Original Assignee: Senorx Incorporated (Becton, Dickinson & Co)
• Inventors: Govil, Amit, Jones, Michael L., Lubock, Paul
• Granted Patent: US 10,786,604 B2
• Time in Patent Office: Days
• US Class Current: 264/28
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• CPC Class Codes: A61F 2/02 Prostheses implantable into the body closure means for urethra or rectum or for artificial body openings therefor A61F2/0004
• CPC Class Codes: A61L 2300/102 Metals or metal compounds, e.g. salts such as bicarbonates, carbonates, oxides, zeolites, silicates
• CPC Class Codes: A61L 2300/104 Silver, e.g. silver sulfadiazine
• CPC Class Codes: A61L 2300/44 Radioisotopes, radionuclides
• CPC Class Codes: A61L 27/54 Biologically active materials, e.g. therapeutic substances A61L27/227 takes precedence
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 27/58 Materials at least partially resorbable by the body
• CPC Class Codes: A61L 31/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 31/148 Materials at least partially resorbable by the body
• CPC Class Codes: A61L 31/18 Materials at least partially X-ray or laser opaque

Abstract

In one form, the invention is directed to a method for forming a porous implant suitable for a cavity from which tissue has been removed, including mixing soluble alginate and a radiopaque imaging agent with water; incorporating a gas or a pore forming agent into the alginate-water mixture; transferring the alginate-water mixture with the gas or the pore forming agent into a mold to form the mixture into a solid body of desired shape; removing the water from the body; and converting at least part of the soluble alginate to a less soluble alginate. In another form, the invention includes forming a mixture by mixing about 0.5 percent to about 4 percent by weight chitosan into an acidified aqueous solution containing 1 percent to 25 percent by weight acetic acid, along with about 0.5 percent to about 5 percent by weight of a powdered radiopaque imaging agent.

Claims

1-16. -16. (canceled)

17. A method for forming a porous implant suitable for a cavity from which tissue has been removed, comprising:

a. mixing soluble alginate and a radiopaque imaging agent with water;

b. incorporating a gas or a pore forming agent into the alginate-water mixture;

c. transferring the alginate-water mixture with the gas or the pore forming agent into a mold to form the mixture into a solid body of desired shape;

d. removing the water from the body; and

e. converting at least part of the soluble alginate to a less soluble alginate.

18. The method of claim 17, comprising inserting an orientation marker into the body, the orientation marker being spaced inwardly from exterior margins of the implant.

19. The method of claim 17, comprising inserting a plurality of radiopaque elements in an orientation lying in a plane.

20. The method of claim 17 wherein water is removed from the mixture by freeze drying or air drying.

21. The method of claim 17 wherein the soluble alginate is sodium alginate.

22. The method of claim 18 wherein the less soluble alginate is calcium alginate.

23. The method of claim 17, comprising sizing and shaping the porous implant so as to fit within the cavity and to conform tissue lining the cavity about the porous implant.

24. A method for forming a porous implant suitable for a cavity from which tissue has been removed, comprising:

forming a mixture by mixing about 0.5 percent to about 4 percent by weight chitosan into an acidified aqueous solution containing 1 percent to 25 percent by weight acetic acid, along with about 0.5 percent to about 5 percent by weight of a radiopaque imaging agent;

placing the mixture in a mold which presents a desired shape;

freezing the mixture to form a frozen body;

removing the frozen body from the mold;

placing the removed frozen body in a lyophilizer for freeze drying to remove water and to form a porous body;

neutralizing the porous body using a base or buffer;

rinsing the porous body with deionized water; and

drying the porous body to remove the deionized water.

25. The method of claim 24, wherein the radiopaque imaging agent is barium sulfate.

26. The method of claim 24, wherein the radiopaque imaging agent is a powder.

27. The method of claim 24, wherein the act of freezing comprises freezing the mixture at a temperature of minus one degree Celsius to minus 196 degrees Celsius for 6 hours to 12 hours.

28. The method of claim 24, wherein the frozen body is placed in the lyophilizer for 3 days.

29. The method of claim 24, wherein the act of neutralizing is performed by using ammonium hydroxide.

30. The method of claim 24, wherein the act of neutralizing is performed by using 5 percent to 20 percent by weight of ammonium hydroxide.

31. The method of claim 24, wherein the lyophilized body is neutralized in a 10 percent solution of ammonium hydroxide for one hour.

32. The method of claim 24, wherein the mixture consists of the acidified aqueous solution having 12.5 by weight percent acetic acid, 4 percent by weight chitosan, and 2 percent by weight barium sulfate.

33. The method of claim 24, comprising sizing and shaping the porous implant so as to fit within the cavity and to conform tissue lining the cavity about the porous implant.