Antimicrobial coating for inhibition of bacterial adhesion and biofilm formation

Abstract

The present invention provides antimicrobial coatings for coating substrate surfaces, particularly medical devices, for preventing bacterial adhesion and biofilm formation by inhibiting microbial growth and proliferation on the coating surface. The antimicrobial coatings are composed of a hydrogel and a bioactive agent including a substantially water-insoluble antimicrobial metallic material that is solubilized within the coating. Antimicrobial coating formulations for obtaining such coatings, and coating methods are also described.

Description

RELATED APPLICATION[0001]This application claims the benefit of U.S. Provisional Application No. 60 / 566,576, filed on Apr. 29, 2004. The entire teachings of the above application is incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates to an antimicrobial coating for coating a substrate surface, particularly medical devices that are likely to become contaminated or have become contaminated with microorganisms as a result of bacterial adhesion and proliferation and methods for preventing biofilm formation by inhibiting microbial growth and proliferation on the surface of medical devices.BACKGROUND OF THE INVENTION[0003]Colonization of bacteria on the surfaces of medical devices and healthcare products, particularly in implanted devices, result in serious patient problems, including the need to remove and / or replace the implanted device and to vigorously treat secondary infection conditions. Considerable efforts, therefore, have been directed towar...

AI Technical Summary

Benefits of technology

[0010]The present invention is based upon the realization that a substantially water-insoluble antimicrobial material can be incorporated into a hydrophilic polymeric coating in a substantially “solubilized’ form wherein the water insoluble antimicrobial material is dispersed homogeneously in a three dimensional hydrogel network gel, formed by a hydrophilic polymer in a substantia...

Problems solved by technology

Colonization of bacteria on the surfaces of medical devices and healthcare products, particularly in implanted devices, result in serious patient problems, including the need to remove and/or replace the implanted device and to vigorously treat secondary infection conditions.

Formation of biofilms on the surface of medical devices can be detrimental to the integrity of the medical device, present health risks, and prevent sufficient flow through the lumens of medical devices.

Although coating or cleaning medical devices with antimicrobial agents, such as antibiotics or antiseptics, can be effective in killing or inhibiting growth of free-floating or “planktonic” organisms not adhered to the device surface, such antimicrobial agents are generally much less active against the microorganisms that are deeply embedded within the biofilm due to their inability to penetrate the biofilm.

The failure of the antimicrobial agents to sufficiently remove the microorganisms is therefore largely due to the protective effect of the biofilm which prevents diffusion of antimicrobial deep into the biofilm layer to eliminate the microorganisms proliferating within therein.

Biofilm associated problems experienced with implantable medical devices such as catheters, particularly catheters designed for urinary tract infections, pose a significant risk for catheterized patients of acquiring secondary infection such as nosocomial infection in a hospital environment.

Such infections can result in prolonged hospital stay, administration of additional antibiotics, and increased cost of post-operative hospital care.

Although, the use of antimicrobially coated catheters wherein antibiotic agents or antimicrobial compounds are dispersed within the coating have been reported to reduce the incidence of catheter associated bacteriuria, such coatings have proven to be largely ineffective in preventing bacterial adhesion and biofilm formation on the catheter surface for extended periods, and therefore do not sufficiently retard the onset of bacterial infection.

Silver nitrate however, can cause toxic side effects at these concentrations, and does cause discoloration of the skin (Argyria).

Unlike antibiotics, the potential for bacterial to become silver ion resistant is therefore quite low.

However, it is also recognized that silver compounds capable of providing bactericidal levels of silver ion have reduced photostability, and tend to discolor in presence of light and or heat as a result of photoreduction of Ag+ ...

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