Anti-microbial materials
First Claim
1. An anti-microbial form of silver material, comprising:
- silver metal, or an alloy or compound thereof, in a crystalline form having sufficient atomic disorder such that the material, in contact with an alcohol or a water based electrolyte, releases atoms, ions, molecules or clusters containing silver on a sustained basis at a concentration sufficient to provide a localized anti-microbial effect, said material having a positive rest potential, when measured against a saturated calomel reference electrode, in 1M potassium hydroxide, wherein the atomic disorder in the material provides irregularities in surface topography and inhomogeneities in structure on a nanometer scale and is caused by high concentrations of one or more of point defects in a crystal lattice, vacancies, line defects, dislocations, interstitial atoms, amorphous regions and grain and sub grain boundaries, relative to a normal ordered crystalline state for silver metal, and wherein the anti-microbial effect is sufficient to generate a zone of inhibition of greater than 5 mm.
3 Assignments
0 Petitions
Accused Products
Abstract
Anti-microbial coatings and method of forming same on medical devices are provided. The coatings are preferably formed by depositing an anti-microbial, biocompatible metal by vapour deposition techniques to produce atomic disorder in the coating such that a sustained release of metal ions sufficient to produce an anti-microbial effect is achieved. Preferred deposition conditions to achieve atomic disorder include a lower than normal substrate temperature, and one or more of a higher than normal working gas pressure and a lower than normal angle of incidence of coating flux. Anti-microbial powders formed by vapour deposition or altered by mechanical working to produce atomic disorder are also provided. Novel anti-microbial silver materials are defined, characterized by having a positive rest potential, a Trec /Tm less than 0.33, and a grain size less than 200 nm. Anti-microbial fine grain or nanocrystalline materials are provided, together with methods of preparation, wherein the anti-microbial metal if deposited in a matrix with atoms or molecules of a different material such as other biocompatible metals (ex. Ta), trapped or absorbed oxygen, or compounds of anti-microbial metals or biocompatible metals (ex. Ag0 or TaO).
281 Citations
34 Claims
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1. An anti-microbial form of silver material, comprising:
silver metal, or an alloy or compound thereof, in a crystalline form having sufficient atomic disorder such that the material, in contact with an alcohol or a water based electrolyte, releases atoms, ions, molecules or clusters containing silver on a sustained basis at a concentration sufficient to provide a localized anti-microbial effect, said material having a positive rest potential, when measured against a saturated calomel reference electrode, in 1M potassium hydroxide, wherein the atomic disorder in the material provides irregularities in surface topography and inhomogeneities in structure on a nanometer scale and is caused by high concentrations of one or more of point defects in a crystal lattice, vacancies, line defects, dislocations, interstitial atoms, amorphous regions and grain and sub grain boundaries, relative to a normal ordered crystalline state for silver metal, and wherein the anti-microbial effect is sufficient to generate a zone of inhibition of greater than 5 mm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. An anti-microbial form of silver material, comprising:
silver metal, or an alloy or compound thereof, in a crystalline form, having irregularities in surface topography, and having a positive rest potential, when measured against a saturated calomel reference electrode, in 1M potassium hydroxide and having a ratio of its temperature of recrystallization to its melting temperature, in degrees K, Trec/Tm, less than 0.33, and which, in contact with an alcohol or a water based electrolyte, releases atoms, ions, molecules or clusters containing silver on a sustained basis at a concentration sufficient to provide a localized anti-microbial effect which is sufficient to generate a zone of inhibition of at least 5 mm. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
Specification