ANTIBACTERIAL IMPLANT COATING COMPOSITION, METHOD OF IMPLANT COATING AND ANTIBACTERIAL COATED IMPLANT

Abstract

The invention relates to an antibacterial implant coating composition including a graft copolymer comprising a (meth)acrylic acid-based backbone and phosphonate side chains, wherein at least one phosphonate side chain is linked to a guanidine oligomer through an N—P bond.

Claims

1. An antibacterial implant coating composition comprising a graft copolymer comprising: a (meth)acrylic acid-based backbone and phosphonate side chains, wherein at least one phosphonate side chain is linked to a guanidine oligomer through a N—P bond.

2. The antibacterial implant coating composition according to claim 1, wherein a proportion of phosphonate side chains linked to a guanidine oligomer through a N—P bond is 0.8 to 6 mol % and especially 0.9 to 5 mol %, based on the total proportion of phosphonate side groups in mol %.

3. The antibacterial implant coating composition according to claim 1, wherein the phosphonate side chains not linked to the guanidine oligomer are not hydrolyzed, partially hydrolyzed or fully hydrolyzed.

4. The antibacterial implant coating composition according to claim 3, wherein a proportion of partially hydrolyzed and fully hydrolyzed phosphonate side groups is 5 to 30 mol % and especially 7 to 20 mol %, based on the total proportion of phosphonate side groups in mol %.

5. The antibacterial implant coating composition according to claim 1, wherein the molecular weight of the graft copolymer (Mw) satisfies the following equation:
5kDa<Mw<40kDa.

6. The antibacterial implant coating composition according to claim 1, wherein the guanidine oligomer is at least one compound represented by the following formulas: ##STR00004## wherein each one of n is an integer from 2 to 10, preferably from 3 to 6, and especially 5, and wherein “˜” represents a bonding position to the phosphorus atom of a phosphonate side chain.

7. The antibacterial implant coating composition according to claim 1, wherein the molecular weight of the guanidine oligomer is 800 to 1300 g/mol.

8. The antibacterial implant coating composition according to claim 1, wherein the graft copolymer comprises the following structural unit: ##STR00005## wherein each one of P represents a phosphonate group, wherein n represents an integer from 2 to 10, preferably from 3 to 6, and especially 5, and wherein an undulation in the (meth)acrylic acid-based backbone represents a bonding position to an adjacent (meth)acrylic acid moiety.

9. The antibacterial implant coating composition according to claim 1, wherein the graft copolymer comprises at least one of the following structural units: ##STR00006## wherein each one of n represents an integer from 2 to 10, preferably from 3 to 6, and especially 5, and wherein an undulation in the (meth)acrylic acid-based backbone represents a binding position to an adjacent (meth)acrylic acid moiety.

10. The antibacterial implant coating composition according to claim 1, further comprising water.

11. A method for coating an implant using an antibacterial coating comprising the steps of: dissolving or dispersing the implant coating composition according to claim 1 in a solvent, providing and degreasing an implant, applying the solution or dispersion of the implant coating composition to the implant, and bonding the implant coating composition to the implant under the action of temperatures in a range of 50 to 200° C.

12. The method according to claim 11, further comprising a washing step and a subsequent drying step after binding of the implant coating composition.

13. The method according to claim 11, wherein applying the solution or dispersion of the implant coating composition is carried out by spin coating or using a dipping or spraying method.

14. The method according to claim 11, wherein a concentration of the implant coating composition in the solvent is 2 to 20 mg/ml and especially 8 to 12 mg/ml.

15. The antibacterial coated implant comprising a coating formed from the implant coating composition according to claim 1.

16. The antibacterial coated implant according to claim 15, wherein the implant comprises titanium, zirconium, tantalum, stainless steel, zirconia or PEEK and/or wherein an average layer thickness of the antibacterial coating is 5 to 50 nm and especially 15 to 25 nm.

Description

[0040] Further details, advantages and features of the present invention will arise from the following description of embodiments while reference will be made to the drawing, wherein:

[0041] FIG. 1 is a schematic representation of an implant coated with an antibacterial coating according to one embodiment of the invention.

[0042] FIG. 1 shows a detailed schematic representation of an implant 1 coated with an antibacterial coating 10 according to one embodiment of the invention. The antibacterial coated implant 1 comprises a base body 2 comprising, for example, titanium, zirconium, tantalum, stainless steel, zirconium oxide or PEEK. On a surface 3 of the base body 2, the antibacterial coating 10 is arranged with an average layer thickness S of 5 to 50 nm and especially 15 to 25 nm.

[0043] The antibacterial coating 10 is formed from an antibacterial implant coating composition comprising a graft copolymer having a (meth)acrylic acid-based backbone and phosphonate side chains, wherein at least one phosphonate side chain is linked to a guanidine oligomer through an N—P bond. At least one additional phosphonate side chain, which is not linked to a guanidine oligomer by an N—P bond, is bonded to the implant surface 3, thereby providing good adhesion of the graft copolymer to the base body 2.

The antibacterial coating 10 on the base body 2 of the implant was obtained as follows:

[0044] First, the implant coating composition described above was dissolved or dispersed in a solvent such as water, ethanol or methanol. Next, an implant to be coated was provided and degreased. Subsequently, the solution or dispersion of the implant coating composition was applied to the surface 3 of the base body 2 of the implant, e.g. by spin coating or using a dipping or spraying method, followed by bonding the implant coating composition to the implant under the action of temperatures in a range of 50 to 200° C., thereby forming the antibacterial coating 10 between the surface 3 of the implant 10 and the implant coating composition by establishing bonds between the surface 3 of the implant and the phosphonate side chains of the graft copolymer of the implant coating composition. Herein, a concentration of the implant coating composition in the solvent was 2 to 20 mg/ml.

[0045] The antibacterial coated implant 1 was characterized by having durable excellent antibacterial functionality resulting from the antibacterial coating 10 having high cell compatibility. Coating of the implant using the antibacterial coating 10 was carried out in a manner of uniformly covering and using technically conventional means.

[0046] In addition to the foregoing written description of the invention, explicit reference herein will be made to the graphic representation of the invention in FIG. 1 for supplementary disclosure thereof.

LIST OF REFERENCE NUMBERS

[0047] 1 antibacterial coated implant [0048] 2 base body [0049] 3 surface [0050] 10 antibacterial coating