Patent EA-002284-B1 (EA)
Title: Anti-microbal coatings having indicator properties and wound dressings
Inventor: BURRELL ROBERT EDWARD
IPC: A61L29/16
Filed: 1998-02-17
Abstract: 1. A multilayer anti-microbial material comprising: a base layer of a partly reflective material capable of generating an interference colour when covered with a partly reflective, partly light transmissive top layer; a top layer formed over said base layer, said top layer being a partly reflective, partly light transmissive thin film containing at least one anti-microbial metal and having a thickness such that an interference colour is produced, said top layer having a refractive index different from that of the base layer, and the anti-microbial metal being formed with sufficient atomic disorder such that the top layer, in contact with an alcohol or water based electrolyte, releases ions, atoms, molecules or clusters of the anti-microbial metal into the alcohol or water based electrolyte at a concentration sufficient to provide a localized anti-microbial effect on a sustainable basis. 2. The material of claim 1, wherein the material in the base layer is a metal selected from the group consisting of Ag, Au, Pt, Pd, Cu, Ta, Al and alloys or compounds of one or more of these metals, in a partly reflective form. 3. The material of claim 2, wherein the anti-microbial metal in the top layer is selected from the group consisting of Ag, Au, Pt, Pd, Ir, Sn, Cu, Sb, Bi, Zn, and alloys or compounds of one or more of these metals. 4. The material of claim 3, wherein the material in the base layer and the anti-microbial metal in the top layer is a metal selected from the group consisting of Au, Ag, Pt, Pd, and Cu in a partly reflective form, and is formed by vapour deposition with sufficient atomic disorder. 5. The material of claim 4, wherein the metal in the base layer and top layer is Ag, Pt or Au. 6. The material of claim 4, wherein the top layer is a thin film of a composite material formed by co-, sequentially or reactively depositing the anti-microbial metal by vapour deposition in a matrix with atoms or molecules of a different material to create atomic disorder in the matrix, said different material being selected from the group consisting of biocompatible metals, oxygen, nitrogen, hydrogen, boron, sulphur or halogens, or an oxide, nitride, carbide, boride, halide, sulphide oe htdride of either or both of an anti-microbal metal or a biocompatible metal. 7. The material of claim 6, wherein the biocompatible metal is selected from the group consisting of Ta, Ti, Nb, V, Hf, Zn, Mo, Si and Al, and wherein the antimicrobial metal is selected from the group consisting of Ag, Au, Pt, Pd, and Cu. 8. The material of claim 6, wherein the anti-microbial metal is silver and said different material is one or both of silver oxide and atoms or molecules containing oxygen trapped or absorbed in the matrix. 9. The material of claim 1, wherein the top layer is less than 400 nm thick, and the base layer is at least 25 nm thick. 10. The material of claim 8, wherein the top layer is between 5 and 210 nm thick, and the base layer is at least 60 nm thick. 11. The material of claim 8, wherein the top layer is about 40 - 160 nm thick and the base layer is at least about 300 nm thick. 12. A medical device provided with the base and top layers of claim 1 which is selected from a group of devices arrangements, fastening devices, fibers, clothes or materials for use in medicine, public health or personal hygiene and manufactured of any material icluding steel, aluminum or alloys thereof, latex, nylon, selicon, polyesters, glass, ceramics, paper, fabric, plastic or caoutchouc, and including orthopedic pins, plates, implantates, tracheotomy tubes, catheters, insulin pumps, wound dressings, drainages, shunts, bandaging materials, connecting devices, prostheses, cardiostimulators, needles, dental prostheses, ventilation pipes, surgical instruments, bandages on wounds, one-time hygienic and sterile packings, clothes, footwear, items of personal hygeine, including swadling bands and hygienic soft packs, and also biomedical and biothechnical equipment laboratory equipment, including tables, railings and coatings for walls. 13. A process for producing a multilayer anti-microbial material capable of indicating exposure to an alcohol or water based electrolyte, comprising: providing a base layer of a partly reflective material capable of generating an interference colour when covered with a partly reflective, partly light transmissive top layer; providing a top layer over said base layer, said top layer being a partly reflective, partly light transmissive thin film containing at least one anti-microbial metal and having a thickness such that an interference colour is produced, said top layer having a refractive index different from that of the base layer, and said anti-microbial metal being formed with sufficient atomic disorder such that the top layer, in contact with an alcohol or water based electrolyte, releases ions, atoms, molecules or clusters of the anti-microbial metal into the alcohol or water based electrolyte at a concentration sufficient to provide a localized anti-microbial effect on a sustainable basis. 14. The process of claim 13, wherein the material in the base layer is a metal selected from the group consisting of Ag, Au, Pt, Pd, Cu, Ta, A1 and alloys or compounds of one or more of these metals, in a partly reflective form. 15. The process of claim 14, wherein the anti-microbial metal in the top layer is selected from the group consisting of Ag, Au, Pt, Pd, Ir, Sn, Cu, Sb, Bi, Zn, and alloys or compounds of one or more of these metals. 16. The process of claim 15, wherein the material in the base layer and the anti-microbial metal in the top layer is a metal selected from the group consisting of Au, Ag, Pt, Pd, and Cu in a partly reflective form, and is formed by vapour deposition with sufficient atomic disorder such that the top layer, in contact with an alcohol or water based electrolyte, releases ions, atoms, molecules or clusters of the anti-microbial metal into the alcohol or water based electrolyte at a concentration sufficient to provide a localized antimicrobial effect on a sustainable basis. 17. The process of claim 16, wherein the metal in the base and top layer is Ag, Pt or Au. 18. The process of claim 17, wherein the top layer is a thin film of a composite material formed by co-, sequentially or reactively depositing the anti-microbial metal by vapour deposition in a matrix with atoms or molecules of a different material to create atomic disorder in the matrix, said different material being selected from the group consisting of biocompatible metals, oxygen, nitrogen, hydrogen, boron, sulphur or halogens, or an oxide, nitride, carbide, boride, halide, sulphide or hydride of either or both of an anti-microbial metal or a biocompatible metal. 19. The process of claim 19, wherein the biocompatible metal is selected from the group consisting of Ta, Ti, Nb, V, Hf, Zn, Mo, Si, and Al, and wherein the antimicrobial metal is selected from the group consisting of Ag, Au, Pt, Pd, and Cu. 20. The process of claim 18, wherein the anti-microbial metal is silver and said different material is one or both of silver oxide and atoms or molecules containing oxygen trapped or absorbed in the matrix. 21. The process of claim 13, wherein the top layer is less than 400 nm thick, and the base layer is at least 25 nm thick. 22. The process of claim 18, wherein the top layer is between 5 and 210 nm thick, and the base layer is at least 60 nm thick. 23. The process of claim 20, wherein the top layer is about 40 - 160 nm thick and the base layer is at least about 300 nm thick. 24. A medical device provided with the base and top layers of claim 1 which is selected from a group of devices arrangements, fastening devices, fibers, clothes or materials for use in medicine, public health or personal hygiene and manufactured of any material icluding steel, aluminum or alloys thereof, latex, nylon, selicon, polyesters, glass, ceramics, paper, fabric, plastic or caoutchouc, and including orthopedic pins, plates, implantates, tracheotomy tubes, catheters, insulin pumps, wound dressings, drainages, shunts, bandaging materials, connecting devices, prostheses, cardiostimulators, needles, dental prostheses, ventilation pipes, surgical instruments, bandages on wounds, one-time hygienic and sterile packings, clothes, footwear, items of personal hygeine, including swadling bands and hygienic soft packs, and also biomedical and biothechnical equipment laboratory equipment, including tables, railings and coatings for walls applied by the nethod of claim 13. 25. A multilayer, laminated wound dressing, comprising: a first, wound facing layer formed of a perforated, non-adherent material; a second layer laminated to the first layer, and being formed of an absorbent material; an optional third layer laminated to one or both of the first and second layers; at least one of the first, second and optional third layers, being formed from a plastic material; and the first, second and optional third layers being laminated together by ultrasonic welds spaced intermittently on the dressing so as to allow the dressing to be cut down in size without causing delamination. 26. The wound dressing of claim 25, wherein the first layer, includes a coating containing an anti-microbial metal. 27. The wound dressing of claim 25, wherein the first layer includes a thin film containing at least one anti-microbial metal, said anti-microbial metal being formed with sufficient atomic disorder such that the thin film, in contact with an alcohol or water based electrolyte, releases ions, atoms, molecules or clusters of the anti-microbial metal into the alcohol or water based electrolyte at a concentration sufficient to provide a localized anti-microbial effect on a sustainable basis. 28. The wound dressing of claim 25, wherein the first layer includes a multilayer anti-microbial coating comprising: a base layer of a partly reflective material capable of generating an interference colour when cov