Methods for processing biological tissue

• US 20060154230A1
• Filed: 01/11/2005
• Published: 07/13/2006
• Est. Priority Date: 01/11/2005
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Cunanan, Crystal M., Cambron, Ronald E., Ochoa, Alexandro
• Granted Patent: US 7,989,157 B2
• Time in Patent Office: Days
• US Class Current: 435/1.100
• CPC Class Codes: A01N 1/02 Preservation of living parts
• CPC Class Codes: A01N 1/0226 Physiologically active agents, i.e. substances affecting physiological processes of cells and tissue to be preserved, e.g. anti-oxidants or nutrients

Abstract

A method for processing biological tissue used in biological prostheses includes providing a tissue procurement solution formed from a phosphate buffered saline (PBS) solution and a chelating agent. The tissue is transferred from the tissue procurement solution and undergoes chemical fixation. The fixed tissue is then immersed in a series of fresh bioburden reduction process (BRP) solutions to extract phospholipids. The tissue procurement solution reduces the bioburden on the stored tissue and preserves tissue architecture by minimizing tissue swelling. The tissue procurement solution further reduces calcium from the incoming water and/or tissue, and inhibits enzymes that digest the collagen matrix. The serial immersion of the tissue in the fresh bioburden solutions ensures optimal extraction of phospholipids thereby mitigating subsequent calcification of the tissue.

Claims

1. A solution for storing biological tissue used in a biological prostheses comprising a mixture of phosphate buffered saline (PBS) solution having a concentration of at least 50 mM and a chelating agent.

2. The solution of claim 1, wherein the PBS solution has a concentration of at least 100 mM.

3. The solution of claim 1, wherein the solution has a pH within the range of 6 to 8.

4. The solution of claim 3, wherein the solution has a pH within the range of 7.3 to 7.5.

5. The solution of claim 1, wherein the chelating agent is selected from the group consisting of EDTA, EGTA, polyoxyethylene, polyoxyglycol, poly-glyme, cyclic antibiotic, amino acid peptide, fullerene, dendrimer, polysaccharide, and polynucleic acid.

6. The solution of claim 1, wherein the mixture has an osmolarity value between the range of 290-310 mOsm.

7. The solution of claim 1, wherein the solution reduces the tissue bioburden level upon exposure to the solution.

8. The solution of claim 1, wherein the solution comprises an aqueous mixture of sodium chloride, potassium phosphate monobasic, sodium phosphate dibasic heptahydrate, and BDTA.

21. The solution of claim 1, wherein the chelating agent comprises EDTA.

9. A solution for storing biological tissue that is used in biological prostheses, comprising a mixture of a chelating agent and a buffer selected from the group consisting of a phosphate-based buffer, a citrate-based buffer, and a borate-based buffer, the buffer having a concentration of at least 100 mM.

10. The solution of claim 9, wherein the selected buffer is chemically inert with respect to glutaraldehyde.

22. The solution of claim 9, wherein the chelating agent comprises EDTA.

11-20. -20. (canceled)