IMPLANT MADE OF A BIOCORRODIBLE METALLIC MATERIAL HAVING A COATING MADE OF AN ORGANOSILICON COMPOUND

Abstract

An implant made of a biocorrodible metallic material having a coating made of an organosilicon compound.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is explained in greater detail in the following on the basis of exemplary embodiments and the associated drawings.

FIG. 1 shows a schematic representation to illustrate the procedures during coating of the implant surface;

FIG. 2 shows a schematic illustration of a coating, in which the organosilicon compound carries a reactive substituent terminally; and

FIG. 3 shows a schematic illustration of a coating in which the organosilicon compound is a polysiloxane.

DETAILED DESCRIPTION

FIG. 1 is used for illustrating the procedures during coating of an implant surface 10 made of a biocorrodible metallic material. The implant surface 10 has a OH functionality. The OH functionality bonds covalently to the implant surface 10 by reaction with the chlorosilane shown under water-free basic conditions. The residues R1 through R3 of the chlorosilane are established as previously noted.

FIG. 2 schematically illustrates the sequences during functionalization of the implant surface 10 using a silane, which, in addition to two methyl groups, has a long-chain, unbranched alkyl residue having a terminally situated reactive group (identified by F). The long-chain residue forms a hydrophobic barrier layer. Due to the long-chain alkyl residues, which form a homogeneous, dense layer, the function as a corrosion-inhibiting barrier layer is maintained even in areas of high mechanical deformation of the main body. The organosilicon layer adapts itself to the given steric boundary conditions, a closed layer being maintained by the strong hydrophobic force on the alkyl residues situated in parallel.

FIG. 3 shows a coating made of a covalently bonded polysiloxane.

EXAMPLES

Example 1

Stent Coating Using 3-aminopropyltriethoxysilane

Stents made of the biocorrodible magnesium alloy WE43 (93 wt.-% magnesium, 4 wt.-% yttrium (W), and 3 wt.-% rare earth metals (E) except for yttrium) were washed under ultrasound using isopropanol and dried.

A coating solution made of 18 ml water-free toluene, 2.2 ml aminopropyltriethoxysilane, and 1 ml triethylamine was used.

The stents were incubated for 4 hours at 75° C. in the coating solution, removed again, washed with toluene, and dried at approximately 90° C. for an hour in the vacuum furnace.

Example 2

Stent Coating Using 3-mercapto-propyl-trimethoxysilane

Stents made of the biocorrodible magnesium alloy WE43 (93 wt.-% magnesium, 4 wt.-% yttrium (W), and 3 wt.-% rare earth metals (E) except for yttrium) were washed using chloroform and dried.

A coating solution made of 90 wt.-% methanol, 6 wt.-% water, and 4 wt.-% 3-mercapto-propyl-trimethoxysilane (PropS-SH) was used. The pH value was adjusted to 4.5-5.5 by adding acetic acid

The stents were immersed at room temperature in the coating solution for 30 minutes, removed again, washed using methanol, and dried at approximately 60° C. for one hour in the vacuum furnace.

Example 3

Stent Coating Using n-octadecyltrichlorosilane

Stents made of the biocorrodible magnesium alloy WE43 (93 wt.-% magnesium, 4 wt.-% yttrium (W), and 3 wt.-% rare earth metals (E) except for yttrium) were washed using chloroform and dried.

A coating solution made of 95 wt.-% chlorobenzene and 5 wt.-% n-octadecyltrichlorsilane was used.

The stents were immersed under dried nitrogen for 5 minutes at room temperature in the coating solution. After the silanization, the stents were washed using chlorobenzene, cleaned for 10 minutes in ethanol under ultrasound, and dried at approximately 60° C. for one hour in the vacuum furnace.

All patents, patent applications and publications are incorporated by reference herein in their entirety.

Claims

1. An implant made of a biocorrodible metallic material having a coating made of an organosilicon compound of formula (1):

2. The implant of claim 1, wherein the biocorrodible metallic material is a biocorrodible alloy selected from the group consisting of magnesium, iron, and tungsten.

3. The implant of claim 2, wherein the biocorrodible metallic material is a magnesium alloy

4. The implant of claim 1, wherein the implant is a stent.

5. The implant of claim 1, wherein R1 and R2, established independently of one another, correspond to a substituent selected from the group consisting of methyl, ethyl, n-propyl, and i-propyl.

6. The implant of claim 1, wherein R1 and R2, established independently of one another, are a substituted or unsubstituted alkyl residue having 1 to 5 C atoms.

7. The implant of claim 1, wherein R3 is a substituted or unsubstituted alkyl residue having 5 to 15 C atoms, 1 to 3 C atoms being replaceable by a heteroatom selected from the group consisting of O, N, and S.

8. The implant of claim 1, wherein R3 carries a reactive substituent terminally.

9. A method for producing an implant made of a biocorrodible metallic material having a coating made of an organosilicon compound of formula (1):