Medical devices having antimicrobial coatings thereon

Abstract

The present invention provides a medical device, preferably a contact lens, which a core material and an antimicrobial metal-containing LbL coating that is not covalently attached to the medical device and can impart to the medical device an increased hydrophilicity. The antimicrobial metal-containing coating on a contact lens of the invention has a high antimicrobial efficacy against microorganisms including Gram-positive and Gram-negative bacterial and a low toxicity, while maintaining the desired bulk properties such as oxygen permeability and ion permeability of lens material. Such lenses are useful as extended-wear contact lenses. In addition, the invention provides a method for making a medical device, preferably a contact lens, having an antimicrobial metal-containing LbL coating thereon.

Description

The present invention generally relates to a medical device having an antimicrobial metal-containing layer-by-layer coating thereon and to a method for making the medical device of the invention. BACKGROUND Contact lenses are often exposed to one or more microorganisms during wear, storage and handling. They can provide surfaces onto which the microorganisms can adhere and then proliferate to form a colony. Microbial adherence to and colonization of contact lenses may enable microorganisms to proliferate and to be retained at the ocular surface for prolonged periods and thereby may cause infection or other deleterious effects on the ocular health of the eye in which the lens is used. Therefore, it is desirous to make various efforts to minimize and / or eliminate the potential for microorganism adhesion to and colonization of contact lenses. Many attempts have been made to develop antimicrobial medical devices. Two approaches have been proposed. One approach is to incorporate antim...

AI Technical Summary

Benefits of technology

is to provide an antimicrobial coating which has a hig

Problems solved by technology

Contact lenses are often exposed to one or more microorganisms during wear, storage and handling.

Microbial adherence to and colonization of contact lenses may enable microorganisms to proliferate and to be retained at the ocular surface for prolonged periods and thereby may cause infection or other deleterious effects on the ocular health of the eye in which the lens is used.

There are some disadvantages associated with this approach for making antimicrobial contact lenses.

Polymeric composition's having antimicrobial properties may not possess all properties desired for contact lenses, especially extended-wear contact lenses, which hinders their practice uses.

Antimicrobial coatings containing leachable antimicrobial agents may not be able to provide antimicrobial activity over the period of time when used in the area of the human body.

However, antimicrobial compounds in such coatings may exhibit diminished activity when comparing the activity of the unbound corresponding antimicrobial compounds in solution, unless assisted by hydrolytic breakdown of either the bound antimicrobial compounds or the coating itself.

Like the above-described approach, the antimicrobial coating may not be able to provide desired surface properties such as hydrophilicity and / or lubricity and also may have adverse effects on the desired bulk properties of a medical device (for example, the oxygen permeability of a contact lens).

However, such antimicrobial coatings have disadvantages and are unsatisfactory.

The overuse of antibiotics can lead to proliferation of antibiotic-resistant microorganisms.

Other coatings may not have broad spectrum antimicrobial activity, may produce ocular toxicity or allergic reactions, or may adversely affect lens properties required for ensuring corneal health and for providing the patient with good vision and comfort.

Moreover, surgical and device related infection remains to be one of the main clinical and economic challenges in the field of medical devices and in health care industry in general.

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