Oxidized microbial cellulose and use thereof

Abstract

This application describes a bioresorbable biocellulose suitable for medical and surgical applications. In particular, the invention describes periodate oxidized microbial cellulose that can be produced to have any mechanical and degradation profile, depending on the desired application of the oxidized cellulose.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Gross observation of oxidized microbial cellulose explants at 4 weeks.

FIG. 2: Effect of Periodate:Cellulose Ratio on the Oxidation (%) of Biocellulose.

FIG. 3: Degradation product formation over the course of 7 days for biocellulose samples oxidized with and without NaCl in the oxidation solution. A/(g of cellulose) refers to the absorbance at 232 nm divided by the mass of cellulose (g) as determined by weighing the dried cellulose sample.

FIG. 4: Change in suture pull-out force over seven days for oxidized biocellulose following the SCD process.

FIG. 5: X-ray diffractograms of non-oxidized (A), 10% oxidized (B), and 28% oxidized (C) biocellulose.

Claims

1. A method of making a bioresorbable oxidized biocellulose comprising (i) producing microbial cellulose and (ii) oxidizing the microbial cellulose with a solution of sodium meta-periodate.

2. The method of making the bioresorbable oxidized biocellulose of claim 1, further comprising pre-soaking the biocellulose in an aqueous solution containing an electrolyte prior to the oxidation procedure.

3. The method of claim 2 wherein the electrolyte is NaCl.

4. The method of claim 2 wherein the microbial cellulose is produced by Acetobacter xylinum.

5. The method of claim 2 wherein the desired degree of oxidation is achieved by varying a factor selected from the group consisting of periodate concentration, periodate solution volume, periodate:cellulose ratio, supporting electrolyte concentration, pre-soak in supporting electrolyte solution, reaction temperature, reaction duration, and a combination thereof.

6. The method of claim 5 wherein the molarity of periodate ranges from 0.005M to 1.0M.

7. The method of claim 5 wherein the ratio of periodate to cellulose ranges from 0.05 to 10.

8. The method of claim 5 wherein the temperature is between 5° C. and 50° C.

9. The method of claim 5 wherein the solution is reacted for 30 minutes to 24 hours.

10. The method of claim 5 wherein the supporting electrolyte concentration is in the range of 0.001M to 1.0M.

11. The method of claim 1, further comprising a pre-oxidation soak in an aqueous solution that does not contain an electrolyte.

12. The method of claim 2 wherein the pre-oxidation soak contains a salt from the group of alkali metals, transition metals and polyelectrolytes.

13. The method of claim 2 wherein the pre-oxidation soak ranges from 30 minutes to 24 hours.

14. The method of claim 2 wherein the oxidized biocellulose is dried by a method selected from the group consisting of at least one of air-drying, oven drying, manually dehydration, solvent dehydration, drying over a desiccant, drying under vacuum, lyophilization, and supercritical fluid drying.

15. The method of claim 14 wherein the oxidized biocellulose is solvent dehydrated with acetone, methanol, ethanol, 1-propanol, iso-propanol, 1-butanol, 2-butanol, tetrahydrofuran, or glycerol.

16. The method of claim 14 wherein the oxidized biocellulose is solvent dehydrated with methanol or acetone followed by exchange with supercritical CO2.

17. The method of claim 14 wherein the material is placed in a chamber at a temperature ranging from 20° C. to 100° C.

18. A method for making a bioresorbable medical material comprising (i) producing microbial cellulose and (ii) oxidizing the microbial cellulose with a solution of sodium meta-periodate.

19. The method of claim 18, further comprising pre-soaking the biocellulose in an aqueous solution containing an electrolyte prior to the oxidation procedure.

20. The bioresorbable medical material of claim 18 wherein the medical material is selected from the group consisting of sutures, hemostats, wound coverings, implantable tissue substitutes, tissue engineering matrices, or adhesion prevention devices.

21. The method of claim 18, wherein the medical material is used for repair and/or regeneration of a musculoskeletal tissue, a neurological tissue, such as the dura,; cardiovascular tissue, abdominal tissue, bladder neck suspension, gastroplasty, hernia repair, gastrointestinal closure, guided tissue regeneration for a dental application, or a bulking agent for plastic or reconstructive surgery.