DEVICE CAPABLE OF HAVING ANTIMICROBIAL, IN PARTICULAR BACTERIOSTATIC OR BACTERICIDAL, ACTIVITY

Abstract

A device configured for antimicrobial, in particular bacteriostatic or bactericidal, activity, and a method for manufacturing the device. The device includes a device body having a surface. The device body is configured to anchor thermal nanoparticles supporting optical resonance, in particular localized surface plasmon resonance, at its surface. The device body includes thermal nanoparticles supporting optical resonance, in particular localized surface plasmon resonance, bonded to the surface of the device body. The thermal nanoparticles are capable of increasing their temperature by light irradiation in a wavelength range that matches with the wavelength of the optical resonance, in particular localized surface plasmon resonance, of the thermal nanoparticles. The device body also includes an antimicrobial substance that is releasable from the device body.

Claims

1. A device configured for antimicrobial activity, the device comprising: a device body having a surface, wherein the device body is configured to anchor thermal nanoparticles supporting optical resonance at its surface, wherein the device body comprises: thermal nanoparticles supporting optical resonance bonded to the surface of the device body, wherein the thermal nanoparticles are configured to increase their temperature by light irradiation in a wavelength range that matches with a wavelength of an optical resonance of the thermal nanoparticles; and an antimicrobial substance, wherein the antimicrobial substance is releasable from the device body.

2. The device according to claim 1, wherein the antimicrobial substance is releasable from the device body in an ionic condition.

3. The device according to claim 1, wherein the antimicrobial substance is present in an ionic condition.

4. The device according to claim 1, wherein the antimicrobial substance comprises a metal or an alloy.

5. The device according to claim 1, wherein the antimicrobial substance is embodied as metallic cations.

6. The device according to claim 1, wherein the antimicrobial substance is supported by a carrier.

7. The device according to claim 6, wherein the carrier is embodied as particles having a mean diameter from 100 nm to 20 μm.

8. The device according to claim 6, wherein the carrier is a open-pored carrier.

9. The device according to claim 6, wherein the antimicrobial substance has a proportion from 0.01% by weight to 15% by weight related to a total weight of the carrier.

10. The device according to claim 6, wherein the antimicrobial substance and the carrier altogether have a proportion from 0.01% by weight to 20% by weight related to the total weight of the device body.

11. The device according to claim 6, wherein the carrier is a zeolite.

12. The device according to claim 1, wherein the thermal nanoparticles comprise a material selected from the group consisting of gold, silver, copper, zinc, titanium, a semiconductor, an oxide, a metal oxide, a non-metallic material like silicone or a combination thereof.

13. The device according to claim 1, wherein the device body further comprises a preferably non-degradable or non-absorbable material.

14. The device according to claim 1, wherein the device body comprises or is a textile structure.

15. The device according to claim 1, wherein the device is a medical device.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0121] For better understanding of what has been disclosed, some figures are attached which schematically or graphically and solely by way of non-limiting example show a practical case of embodiment.

[0122] FIG. 1 graphically shows the evolution of the temperature increase of meshes in ° C./W, as a function of gold nanoparticles content in NR/μm.sup.2.

[0123] FIG. 2 schematically shows a section of a cross-sectional or longitudinal cut of a medical device according to the present invention under light irradiation.

[0124] FIG. 3 schematically shows the release of silver ions in ng/mg mesh under light irradiation (laser, 810 nm, 16 W/cm.sup.2-3× seconds) as a function of time (h) of a surgical mesh.

[0125] FIG. 4 shows the SEM (Scanning Electron Microscopy) microscopy of the surface of Optilene® Mesh LP surface, wherein the surface is modified with gold nanoparticles anchored to the mesh surface but lacking releasable silver ions.

[0126] FIG. 5 shows the SEM (Scanning Electron Microscopy) microscopy of the surface of Optilene® Mesh LP, wherein the mesh surface is modified with gold nanoparticles anchored to the mesh surface and wherein the mesh is further modified with zeolite carriers containing releasable silver ions.

DETAILED DESCRIPTION

[0127] FIG. 1 graphically shows the evolution of the temperature increase of meshes in ° C./W, as a function of gold nanoparticles content in NR/μm.sup.2.

[0128] The mesh with the notation “Mesh” is Optilene® Mesh LP comprising rod-shaped gold nanoparticles bonded to its surface, but lacking releasable silver ions.

[0129] The mesh with the notation “Mesh-Ag 1” is Optilene® Mesh LP comprising rod-shaped gold nanoparticles bonded to its surface, and comprising a zeolite (AW10D) containing releasable silver ions.

[0130] The mesh with the notation “Mesh-Ag 2” is Optilene® Mesh LP comprising rod-shaped gold nanoparticles bonded to its surface, and comprising a zeolite (AW10D) containing releasable silver ions, wherein the content of releasable silver ions is higher than the content of releasable silver ions of “Mesh-Ag 1”.

[0131] The results shown in FIG. 1 clearly confirm a substantial temperature increase under light in case of “Mesh-Ag 1” and “Mesh-Ag 2” compared to “Mesh”. Further, the results shown in FIG. 1 confirm that the temperature increase is higher in case of “Mesh-Ag 2” than in case of “Mesh-Ag 1”.

[0132] Thus, the results shown in FIG. 1 support that the temperature increase of a thermal nanoparticles modified device under light irradiation can be additionally enhanced in the presence of the zeolite carrier containing silver ions being releasable from the device. Further, the results of FIG. 1 support that the temperature rise under light irradiation is higher, the higher the content or proportion of the carrier containing releasable silver ions is.

[0133] FIG. 2 schematically shows a section of a cross-sectional or longitudinal cut of a medical device according to the present invention under light irradiation and the possible processes which may take place under this circumstance at the surface of the device.

[0134] The device 10 comprises a device body 20. The device body 20 comprises thermal gold nanoparticles 30 supporting localized surface plasmon resonance which are anchored or bonded to a surface 22 of the device body 20. Preferably, the thermal gold nanoparticles 30 have a rod-shape.

[0135] Further, the device body 20 comprises zeolite particles 40 supporting releasable silver ions, wherein the silver ions may be adsorbed onto a surface of the zeolite particles 40 and/or may be contained within pores and/or voids of the zeolite particles 40. Upon contact with water or body liquids, the silver ions are released from the device body 20.

[0136] Upon light irradiation 1, a temperature rise of the thermal gold nanoparticles 30, in particular of a thermal coating which is formed or comprises the thermal gold nanoparticles 30, and thus of the surface 22 of the device body 20 is induced. The temperature rise is advantageously significantly higher compared to a medical device which lacks releasable silver ions.

[0137] In addition, enhanced release of silver ions is induced under the light irradiation 1 compared to a medical device which lacks the thermal gold nanoparticles.

[0138] Advantageously, the zeolite particles 40 induce some surface roughness of the device body 20, thereby introducing an enhancement in the light interaction with the thermal gold nanoparticles 30, for example in form of diffuse light 3 and/or reflected light 5 which supports the temperature rise and in particular the enhanced release of silver ions.

[0139] Preferably, the device 10 is a medical device, in particular a surgical implant, preferably a surgical mesh, for example a surgical mesh for hernia or prolapse repair.

[0140] FIG. 3 schematically shows the release of silver ions in ng/mg mesh under light irradiation (laser, 810 nm, 16 W/cm.sup.2-3× seconds) as a function of time (h) of a surgical mesh. The mesh with the notation “Combined Au—Ag mesh” is modified with gold nanoparticles anchored to the surface of the mesh and further with releasable silver ions. The mesh with the notation “Combined Ag mesh” is modified with gold nanoparticles anchored to the surface of the mesh, but lacking releasable silver ions.

[0141] The release of silver ions was performed in 10 mM acetate buffer at pH 7 with 3 cycles of laser illumination (810 nm) with three pulses of 1 s at 16 W/cm.sup.2 each.

[0142] The cumulative quantity of released silver ions is shown and the results show clearly that the heating of “Combined Au—Ag mesh” upon light irradiation induces an enhanced release of silver ions to the external medium.

[0143] FIG. 4 shows the SEM (Scanning Electron Microscopy) microscopy of the surface of Optilene® Mesh LP surface, wherein the surface is modified with gold nanoparticles anchored to the mesh surface but lacking releasable silver ions.

[0144] FIG. 5 shows the SEM (Scanning Electron Microscopy) microscopy of the surface of Optilene® Mesh LP, wherein the mesh surface is modified with gold nanoparticles anchored to the mesh surface and wherein the mesh is further modified with zeolite carriers containing releasable silver ions.

Example 1: Preparation of Modified Surfaces of Meshes with or without the Antimicrobial Agent

[0145] The functionalization of three different polypropylene Optilene® Silver Meshes was carried out by cold plasma polymerization to obtain reactive amino groups on the polymeric mesh surface and citrate stabilized gold nanoparticles having a rod-shape were anchored to the surface of the mesh. The following three different meshes have been employed:

[0146] 1. Optilene® Mesh LP (without silver ions)

[0147] 2. Optilene® Silver Mesh LP with 125 ppm silver ions (in total) and

[0148] 3. Optilene® Silver Mesh LP with 250 ppm silver ions (in total)

[0149] The silver ions of the meshes recited under to 2. and 3. are supported by a zeolite carrier.

[0150] For reproducibility purposes, the three mesh types were incubated in the same bath of rod-shaped gold nanoparticles in citrate buffer 20 mM pH 6.5. An excess of rod-shaped gold nanoparticles were used in order not to be limited by the quantity of rod-shaped gold nanoparticles. A determination of the content of gold nanoparticles was performed with ICP-OES (Inductively Coupled Plasma—Optical Emission Spectrometry) measurements and corresponding calculations of the number of rod-shaped gold nanoparticles per μm.sup.2 was done:

TABLE-US-00002 TABLE 2 Experimental result of the mesh surface modification Au (μg/mg) NR/μm.sup.2 Optilene ® Mesh LP without 2.018 373 silver ions Optilene ® Silver Mesh LP 2.2015 407 125 ppm silver ions Optilene ® Silver Mesh LP 2.1845 404 250 ppm silver ions

[0151] In SEM no significant difference on the fixation of rod-shaped gold nanoparticles were found in terms of quantity and/or organization on the silver ions containing meshes. The fixation of the rod-shaped gold nanoparticles to the mesh surface was not effected by zeolite particles containing silver ions in the polypropylene matrix (see FIGS. 4 and 5).

Example 2: Temperature Increase of a Surgical Mesh Upon Light Irradiation, Heating Enhancement

[0152] Two Optilene® Meshes each of which comprising gold nanoparticles being anchored to the mesh surface and additionally comprising releasable silver ions but differing in terms of content of the releasable silver ions (125 ppm and 250 ppm, respectively) where subjected to laser illumination (810 nm) over 30 seconds. The same illumination procedure was applied to an Optilene® Mesh being modified with gold nanoparticles bonded to its surface but lacking releasable silver ions.

[0153] The power used for the meshes without releasable silver ions, in the following abbreviated as “Au mesh”, was 0.435 W/cm.sup.2. The power used for the mesh comprising both the gold nanoparticles and releasable silver ions, in the following abbreviated as “Au—Ag mesh”, was 0.355 W/cm.sup.2 to avoid melting. There were no significant differences on the gold nanoparticles (rod-shape) detectable on the mesh surface in terms of quantity and/or organization on the different surfaces.

[0154] Surprisingly, the temperature increase was higher for the “Au—Ag meshes”. These findings are shown in the below table 3: (see also FIGS. 1 and 2)

TABLE-US-00003 TABLE 3 Summarized results of the temperature increase (average of 20 measurements for each mesh) Optilene ® Optilene ® Silver Optilene ® Silver Mesh Mesh LP Mesh LP LP without 125 ppm 250 ppm silver ions silver ions silver ions NR/μm.sup.2 377 407 404 Laser 0.435 0.355 0.355 (W/cm.sup.2) Δt ° C./W 151.4 180.9 192.2

Example 3: Enhanced Silver Ion Release Under Illumination Experiment Comparing “Au—Ag Mesh” with “Ag Mesh”

[0155] Ag mesh: 125 ppm Ag in polypropylene, Au—Ag mesh: 125 ppm Ag combined with rod-shaped gold nanoparticles anchored to the mesh surface.

[0156] Four pieces of each mesh were placed in petri dishes containing 40 ml of 10 mM acetate buffer with pH 7. The mesh samples were illuminated at 1.8, 3.8 and 5.8 hours and the medium was analyzed by ICP-MS (Inductively Coupled Plasma—Mass Spectrometry) at 2, 4 and 6 hours. The illumination was performed using laser light at 810 nm with 16 W/cm.sup.2 with three shots of 1 s each (see FIG. 3).

SUMMARY

[0157] The afore-described examples confirm a substantial increase of heating of surgical meshes under light irradiation, wherein the meshes comprise thermal gold nanoparticles supporting localized surface plasmon resonance anchored to the mesh surface and wherein the meshes additionally comprise releasable silver ions (as antimicrobial substance) in comparison to meshes having thermal gold nanoparticles bonded to the mesh surface but lacking releasable silver ions. Additionally, an enhanced silver ion release could be detected under light irradiation for surgical meshes which comprise both thermal gold nanoparticles being anchored to the mesh surface and releasable silver ions compared to surgical meshes which are merely modified with thermal gold nanoparticles being anchored to the mesh surface (i.e. lacking releasable silver ions). This advantageously leads to an optimized, in particular enhanced, antimicrobial, in particular bacteriostatic or bactericidal, activity of the surgical meshes. Moreover, the irradiation process permits a control of the combined antimicrobial concepts (physical antimicrobial concept which is induced by the thermal gold nanoparticles and chemical antimicrobial concept which is induced by the releasable silver ions). In other words, combination of thermal gold nanoparticles and releasable silver ions results in enhanced heating and boosted silver ions release from the respective equipped meshes during light irradiation, when necessary in a non-invasive manner, as many times it is desired, whenever it is necessary and, if desired, locally confined.