Antimicrobial release system

Abstract

The present invention relates to medical devices that are inserted or implanted into patients and that have antimicrobial coatings that release free radicals into the vicinity of the device. These devices may have coatings that alter their rate of flow release or elution release of an antibacterial agent from a coating on the device upon external stimulation. The coating should therefore be responsive to external control such as by heating, external RF stimulus, sonic control, visible or ultraviolet light exposure and the like. By having control of the release rate, and in some structures without invasion of the patient by mechanical means in addition to the device itself, the release rate can be in response to need at the implant site. The class of compounds to be released are free radical generating or initiating compounds, or compounds that release free radicals upon immersion or stimulation, the free radicals acting as the antimicrobial agent.Medical devices that are inserted or implanted into patients and have antimicrobial coatings that release free radicals into the vicinity of the device. These devices may have coatings that alter their rate of flow release or elution release of an antibacterial agent from a coating on the device upon external stimulation. The coating should therefore be responsive to external control such as heating, external RF stimulus, sonic control, visible or ultraviolet light exposure and the like. By having control of the release rate, and in some structures without invasion of the patient by mechanical means in addition to the device itself, the release rate can be in response to need at the implant site. The compounds released comprise free radicals or free radical generating compounds that release free radicals upon immersion or stimulation, the free radicals acting as the antimicrobial agent.

1. A medical device for insertion into a patient, the device having a surface with a coating thereon or containing within its outermost layer, an antimicrobial amount of at least one compound that provides microbe-suppressing free radicals into an aqueous environment in contact with the device upon external stimulation of the coating, layer or compound, wherein the coating, layer or compound releases an amount of free radicals upon heating that increases in a rate of release from the coating to an aqueous environment by at least 20% when heated from 37° C.to 50° C. 
     
     
       2. The device of  claim 1  wherein the compound is in a coating comprising free radical releasing compounds selected from the group consisting of triazines, phosphonium salts, iodonium salts, sulfonium salts, biimidazoles, benzophenones, fibrates;, benoxaprofen, carprofen, ketopofen, naproxen, suprofen, Tiaprofenic tiaprofenic acid, bithionol, buclosamide, fenticlor, hexachlorophene, tetrachlorosalicylanilide, triclosane, tetracylclines tetracyclines, quinolones, lomefloxacin, nalidixic acid, ofloxacin, psoralens, diphenhydramine, thjazides thiazides, sulfonylureas, and azines. 
     
     
       3. The device of  claim 2  wherein the coating comprises at least 0.1% by weight of compounds that release an antimicrobially active amount of free radicals when in contact with an aqueous environment. 
     
     
       4. The device of  claim 2  wherein the coating comprises at least 0.005% by weight of compounds that release an antimicrobially active amount of free radicals when stimulated by heat or electromagnetic radiation. 
     
     
       5. The device of  claim 1  wherein the coating releases an amount of free radicals upon sonication that increases in a rate of release from the coating to an aqueous environment by at least 20%. 
     
     
       6. The device of  claim 1  wherein the coating comprises at least 0.00011% by weight of compounds that release free radicals when in contact with an aqueous environment. 
     
     
       7. The device of  claim 6  having an electromagnetic receiver that initiates heat generation in said device to elevate the temperature of the coating. 
     
     
       8. The device of  claim 7  wherein a battery is electrically attached to said device to power heat generation. 
     
     
       9. The device of  claim 6  wherein a transmitting wire is electrically attached to said device to power heat generation from an outside power source. 
     
     
       10. The device of  claim 1  wherein the coating comprises at least 0.005% by weight of compounds that release an antimicrobially active amount of free radicals when in contact with an aqueous environment. 
     
     
       11. The device of  claim 10  wherein the free radical releasing compound comprises a compound that releases halogen free radicals. 
     
     
       12. The device of  claim 1  wherein the compound generates free radicals upon stimulation by electromagnetic radiation. 
     
     
       13. The device of  claim 1  wherein the coating comprises at least 1.0% by weight of the compounds. 
     
     
       14. The device of  claim 1  wherein the coating comprises at least 1.5% by weight of the compounds. 
     
     
       15. The device of  claim 1  wherein the free radical releasing compound comprises a compound that releases halogen free radicals. 
     
     
       16. The device of  claim 1  wherein the coating comprises at least 0.005% by weight of compounds that release an antimicrobially active amount of free radicals when stimulated by heat or electromagnetic radiation. 
     
     
       17. A medical device for insertion into a patient, the device having a surface with a coating thereon or containing within its outermost layer, an antimicrobial amount of at least one compound that provides microbe-suppressing free radicals into an aqueous environment in contact with the device upon external stimulation of the coating, layer or compound, wherein the coating releases an amount of free radicals that increases in a rate of release from the coating or the outermost layer to an aqueous environment by at least 20% when stimulated by electromagnetic radiations at a temperature in a range of from 37° C. to 50° C. 
     
     
       18. The device of claim 17 wherein the compound is in a coating comprising free radical releasing compounds selected selected from the group consisting of triazines, phosphonium salts, iodonium salts, sulfonium salts, biimidazoles, benzophenones, fibrates, benoxaprofen, carprofen, ketopofen, naproxen, suprofen, tiaprofenic acid, bithionol, buclosamide, fenticlor, hexachlorophene, tetrachlorosalicylanilide, triclosane, tetracyclines, quinolones, lomefloxacin, nalidixic acid, ofloxacin, psoralens, diphenhydramine, thlazides, sulfonylureas, and azines. 
     
     
       19. The device of claim 18 wherein there is a coating that comprises at least 0.1% by weight of compounds that release an antimicrobially active amount of free radicals when in contact with an aqueous environment and irradiated with ultraviolet radiation. 
     
     
       20. The device of claim 17 wherein the coating comprises at least 0.005% by weight of metal oxide compounds that release an antimicrobially active amount of free radicals when stimulated by electromagnetic radiation comprising ultraviolet radiation. 
     
     
       21. The device of claim 17 wherein the coating comprises at least 0.00011% by weight of compounds that release free radicals when stimulated by electromagnetic radiation while the coating is in contact with an aqueous environment comprising ultraviolet radiation. 
     
     
       22. The device of claim 17 wherein the coating comprises at least 0.005% by weight of compounds that release an antimicrobially active amount of free radicals when irradiated with ultraviolet radiation at 37° C. while the coating is in contact with an aqueous environment.