# US 9,040,093 B2 · Bone graft materials containing calcium phosphate and chitosan

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- Number: US 9,040,093 B2
- Document ID: US9040093B2
- Status: Granted
- Kind: B2
- Application number: 13/801,044
- Filed: 2013-03-13
- Published: 2014-09-18
- Granted: 2015-05-26
- Earliest claimed: 2013-03-13
- Assignees: Orthovita, Inc.
- Applicants: Orthovita, Inc.
- Inventors: Kristi L. Wagner
- Web page: https://patentgrep.com/patent/US9040093B2

## CPC

- A61K 33/42: Phosphorus; Compounds thereof
- A61K 31/722: Chitin, chitosan
- A61K 38/39: Connective tissue peptides, e.g. collagen, elastin, laminin, fibronectin, vitronectin, cold insoluble globulin [CIG]
- A61L 27/46: with phosphorus-containing inorganic fillers
- A61L 27/56: Porous materials, {e.g. foams or sponges}
- A61L 2430/02: for reconstruction of bones; weight-bearing implants
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)

## Abstract

Described herein are materials and methods for increasing the osteoconductivity of a bone graft material, reducing the risk of infection at a surgical site, and increasing hemostasis. The bone graft materials described herein contain calcium phosphate and a form of chitin. In another embodiment the bone graft materials further comprises collagen. Chitin has been demonstrated to provide increased rate of new calcium phosphate growth, increased hemostasis, as well as antimicrobial properties. Various methods for manufacturing the bone graft materials described herein are also contemplated.

## Claims

### Claim 1

A method for preparing a biocompatible bone graft material comprising calcium phosphate, chitosan, and, optionally, collagen comprising:
making a solution of acid in water;
adding chitosan to the acid solution to create a slurry;
incubating the slurry for 0.5 hour to about 5 days;
optionally, adjusting the pH of the slurry with a base to a pH of 4 to 8;
adding calcium phosphate and, optionally, collagen to the slurry to create a second slurry;
incubating the second slurry for 1 hour to about 24 hours to form an incubated second slurry;
drying the incubated second slurry to form a biocompatible bone graft material; and,
optionally, washing the biocompatible bone graft material.

### Claim 2 (depends on 1)

The method of claim 1, wherein the concentration of the acid in water is about 1% to about 20% volume by volume.

### Claim 3 (depends on 1)

The method of claim 1, wherein the concentration of chitosan in the acid solution is about 0.5% to about 20% weight by volume.

### Claim 4 (depends on 1)

The method of claim 1, wherein the concentration of the chitosan in the acid solution is about 0.5% to about 10% weight by volume.

### Claim 5 (depends on 1)

The method of claim 1, wherein the concentration of the chitosan in the acid solution is about 1% to about 5% weight by volume.

### Claim 6 (depends on 1)

The method of claim 1, wherein the slurry is incubated at a temperature of about room temperature to about 70° C.

### Claim 7 (depends on 1)

The method of claim 1, wherein the second slurry contains a ratio of calcium phosphate to chitosan-acid slurry of about 0.01 grams per ml to about 1 gram per ml.

### Claim 8 (depends on 1)

The method of claim 1, wherein the second slurry contains a ratio of calcium phosphate to chitosan-acid slurry of about 0.01 grams per ml to about 0.5 grams per ml.

### Claim 9 (depends on 1)

The method of claim 1, wherein the second slurry contains a ratio of calcium phosphate to chitosan-acid slurry of about 0.025 grams per ml to about 0.25 grams per ml.

### Claim 10 (depends on 1)

The method of claim 1, wherein the drying is selected from the group consisting of vacuum drying, air drying, and freezing and lyophilizing.

### Claim 11 (depends on 1)

The method of claim 1, wherein the collagen is added to the slurry to create the second slurry.

### Claim 12 (depends on 1)

The method of claim 1, wherein the incubating of the slurry is for about 4 hours to about 3 days.

### Claim 13 (depends on 12)

The method of claim 12, wherein the incubating of the slurry is for about 4 hours to about 24 hours.

### Claim 14 (depends on 1)

The method of claim 1, wherein the incubating of the second slurry is for about 1 hour to about 5 hours.

### Claim 15 (depends on 1)

The method of claim 1, further comprising wetting the biocompatible bone graft material with a fluid to form a flexible, moldable or flowable composition.