Ultraviolet activated antimicrobial surfaces
The invention is directed to an ion plasma deposition (IPD) method adapted to coat polymer surfaces with highly adherent antimicrobial films. A controlled ion plasma deposition (IPD) process is used to coat a metal or polymer with a selected metal/metal oxide. Exposing the coated surface to ultraviolet light significantly improves the antimicrobial properties of the deposited coatings.
1. An antibacterial bilayer coated medical device,
comprising;
a metal and metal oxide ion plasma deposited nanoparticulate first layer on a medical device surface, said first layer consisting of metal and metal oxide nanoparticulates substantially free of macroparticulates;
a metal and metal oxide ion plasma deposited second layer over the first layer, said second layer consisting of mixed sizes of metal and metal oxide medium size macroparticulates ranging from 100 nm up to about 1 micron;
wherein ultraviolet (UV) light irradiation of the nanoparticulates and macroparticulates during the ion plasm deposition activates ground state oxygen in the metal oxide to a reactive oxygen species to provide an enhanced antimicrobially active coating on the medical device.
2. The coated medical device of claim 1 wherein the nanoparticulates range in size from two atoms up to approximately 100 nm.
3. The coated medical device of claim 1 wherein the medical device comprises a metal or nonmetal.
4. The coated medical device of claim 1 wherein the medical device comprises a polymer or glass.
5. The coated medical device of claim 1 wherein the metal of the deposited metal/metal oxide is selected from the group consisting of tantalum, titanium, zirconium, hafnium, silicon, iron, cobalt, chromium, zinc, alloys, and combinations thereof.
6. The coated medical device of claim 1 which is selected from the group consisting of stents, catheters, valves and implants.
7. The coated medical device of claim 1 wherein the bilayer thickness is about 100 nm.
8. The coated medical device of claim 1 wherein the first, second or first and second layers consist of mixed metal and metal oxide macroparticles selected from groups consisting of:
(i) silver (Ag) and silver oxides (AgO and Ag 2 O);
(ii) copper (Cu) and copper oxides (CuO and Cu 2 O); and
(iii) titanium (Ti) and titanium oxides (TiO and TiO 2 ).
9. The coated medical device of claim 8 wherein the first and second layers consist of mixed silver metal and silver metal oxides AgO and Ag 2 O.
10. The coated medical device of claim 9 wherein said layers consist of the silver metal oxides AgO and Ag 2 O.