Method and substance for obtaining surfaces with antimicrobial properties
View Patent ↗The present invention involves the use of photosensitizers to provide antibacterial surfaces on consumer and industrial items. This approach avoids the used of chemicals and solutions that may be toxic. The inventions also avoids the use of chemical compositions that might form degradation products which may be unacceptable to healthy persons or irritating to persons who may have allergies or are otherwise sensitized. According to the invention, photosensitizers with specific properties and specific design features are selected to make practical use of photosensitizers in the consumer and industrial market place. It is important to select a photosensitizer with an activation spectrum that is matched to the environmental conditions under which the surface to be protected is required to exhibit its antimicrobial properties. This means that the illumination energy and intensity levels expected need to yield enough singlet oxygen to destroy the targeted microbes. It is also possible to select photosensitizers that are activated only by wavelengths prominently present in certain illumination lamps, such as those lamps commonly present in a laboratories, medical offices, pharmacies and food service areas, thereby making the surfaces antimicrobial only on demand when the illumination lamps are turned on.
1. A method for imparting antimicrobial properties to a surface comprising:
a) selecting a photosensitizer capable of being activated by an environmental condition, under which said surface is required to exhibit antimicrobial activity;
b) preparing a photosensitizer containing formulation from said photosensitizer in a topically available form, wherein said photosensitizer is preferentially modified to have a targeting molecule attached;
c) applying said photosensitizer containing formulation to said surface, wherein said photosensitizer is bonded to said surface and;
d) exposing said photosensitizer to said environmental condition.
2. The method of claim 1 wherein said environmental condition is ambient light.
3. The method of claim 1 wherein said environmental condition is a specific illumination source, operating at wavelengths above the ultraviolet region of the electromagnetic spectrum.
4. The method of claim 1 wherein said topically available form is as a spray.
5. The method of claim 1 wherein said topically available form is a solution.
6. The method of claim 1 wherein said bond being cleavable by singlet oxygen.
7. The method of claim 1 wherein said targeting molecule is selected to target and be attractive to predetermined microbes.
8. The method of claim 6 wherein said surface bonded with said photosensitizer is exposed to short periods of said environmental condition to release singlet oxygen and cleave said linking mechanism, followed by a period of no exposure to said environmental condition to allow microbes to contact or absorb said photosensitizer, and then long periods of said environmental condition to produce singlet oxygen to destroy said microbes.
9. A product having a surface coated with a photosensitizer containing formulation for imparting antimicrobial properties to a surface, comprising a photosensitizer in a topically available form capable of being activated by environmental conditions, under which said surface is required to exhibit antimicrobial activity, wherein said photosensitizer is preferentially modified to have a targeting molecule attached, said targeting molecule selected to target and be attractive to predetermined microbes, said surface having a removable protective layer that protects said photosensitizer from activation illumination and oxygen, wherein said removable protective layer is selected from the group consisting of metal foil, plastic film and paper sheeting.
10. A product having a multitude of layers, where each of said layers is comprised of a sheet having an upper surface coated with a photosensitizer containing formulation, each of said sheets protecting an upper surface on a next lower sheet, from activation illumination and oxygen.
11. The product of claim 10 wherein said photosensitizer is preferentially modified to have a targeting molecule attached, said targeting molecule selected to target and be attractive to predetermined microbes.