News Column

"Device and Method for Sterilization of Instruments and Surfaces" in Patent Application Approval Process

May 27, 2014

By a News Reporter-Staff News Editor at Life Science Weekly -- A patent application by the inventor ROCK, GAIL (OTTAWA, CA), filed on March 15, 2013, was made available online on May 15, 2014, according to news reporting originating from Washington, D.C., by NewsRx correspondents (see also Patents).

This patent application has not been assigned to a company or institution.

The following quote was obtained by the news editors from the background information supplied by the inventors: "Contamination of surfaces with infectious microorganisms such as HIV, hepatitis and other viruses and bacteria presents a serious health hazard. Screening procedures may miss contaminants, and known sterilization procedures may not effectively inactivate all infectious viruses and other microorganisms.

"Generally, medical instruments are sterilized by using heat, steam, chemicals and/or a combination of these. In some instances, for example, these approaches cause damage to the instrument. Alternatively, if these approaches are only used for only brief exposure, these approaches may not be very effective in sterilizing.

"Alternative sterilization efforts may not be sufficient or are overly burdensome. For example, alcohol may be used to clean tonometers. However, alcohol has limited effect with diseases such as adenoviruses. Ocular lenses, which are often used by ophthalmologists in the operating rooms and in the office to examine the eye, may be cleaned by a system which uses gluteraldehyde (CIDEX). However, this requires extensive washing to remove the agent and ten hours for complete treatment.

"Ultraviolet light alone can kill some pathogens but, in the absence of a photoactivatable substance, this reaction may not be sufficient. Basic instruments using UV or blue light are used for cleaning false teeth or toothbrushes, as well as treating acne, are well known in the art. In this regard, these instruments have inadequate overall light exposure to decontaminate all surfaces or all pathogens. Furthermore, while UV light, used alone, is known to cause nucleic acid damage to cells, exposure to UV light alone also causes up-regulation of cellular repair mechanisms. In the literature it has been reported that viruses inactivated by UV light alone will reactivate a small percentage of the time due to up-regulation of the host cell's nucleic acid repair mechanisms (see U.S. Pat. No. 7,901,673).

"Combined exposure to a photoactivatable substance and a photoactivator has been shown to effectively inactivate a wide range of pathogens in blood. Solvent detergent methods of blood component decontamination work by dissolving phospholipid membranes surrounding viruses such as HIV, and may cause some alterations to plasma proteins. See, Rock, G., et al. (2010), 'A comparison of methods of pathogen inactivation of FFP,' Vox Sanguinis 2010, 100, 1-10.

"The use of photoactivatable substances, compounds which absorb light of a defined wavelength and transfer the absorbed energy to an energy acceptor, has been proposed for sterilization (see European Patent application 0 196 515). The use of non-endogenous photoactivatable substances such as porphyrins, psoralens, acridine, toluidines, flavine (acriflavine hydrochloride), phenothiazine derivatives, and dyes such as neutral red, and methylene blue, as blood additives is suggested. Protoporphyrin, which occurs naturally within the body, can be metabolized to form a photoactivatable substance; however, its usefulness is limited in that it degrades desired biological activities of proteins. Chlorpromazine is also exemplified as one such photoactivatable substance; however its usefulness is limited by the fact that it should be removed from any fluid administered to a patient after the decontamination procedure because it has a sedative effect.

"Goodrich, R. P., et al. (1997), 'The Design and Development of Selective, Photoactivated Drugs for Sterilization of Blood Products,' Drugs of the Future 22:159-171, provides a review of some photoactivatable substances including psoralens, and some of the issues of importance in choosing photoactivatable substances for decontamination of blood products. The use of texaphyrins for DNA photocleavage is described in U.S. Pat. Nos. 5,607,924 and 5,714,328. The use of sapphyrins for viral deactivation is described in U.S. Pat. No. 5,041,078. Inactivation of extracellular enveloped viruses in blood and blood components by Phenthiazin-5-ium dyes plus light is described in U.S. Pat. No. 5,545,516. The use of porphyrins, hematoporphyrins, and merocyanine dyes as photoactivatable substance agents for eradicating infectious contaminants such as viruses and protozoa from body tissues such as body fluids is disclosed in U.S. Pat. No. 4,915,683 and related U.S. Pat. No. 5,304,113.

"The reactivity of psoralen derivatives with viruses has been studied. See, Hearst and Thiry (1977) Nuc. Acids Res. 4:1339-1347; and Talib and Banerjee (1982) Virology 118:430-438. U.S. Pat. No. 4,124,598 suggests the use of psoralen derivatives to inactivate RNA viruses. U.S. Pat. No. 4,169,204 suggests that psoralens may provide a means for inactivating viruses for the purpose of vaccine production but presents no experimental support for this proposition. European patent application 0 066 886 teaches the use of psoralen inactivated cells, such as virus-infected mammalian cells, for use as immunological reagents and vaccines. Hanson (1983) in: Medical Virology II, de la Maza and Peterson, eds., Elsevier Biomedical, New York, pp. 45-79, reports studies which have suggested that oxidative photoreactions between psoralens and proteins may occur. U.S. Pat. Nos. 4,693,981 and 5,106,619 disclose the use of psoralens to prepare inactivated viral vaccines. These patents disclose preparing vaccines by treating viruses with furocoumarins and long wavelength UV light for a time period sufficiently long enough to render the virus non-infectious but less than that which may result in degradation of its antigenic characteristics under conditions which limit the availability of oxygen and other oxidizing species. U.S. Pat. No. 4,402,318 discloses a method of producing a vaccine by adding methylene blue and exposing the vaccine to light and an electric field concurrently to completely inactivate the viruses, bacteria, cells and toxins. U.S. Pat. No. 6,165,711 discloses a process for disintegrating nucleic acids to make vaccines by exposing biologically active material to phenothiazine and a laser beam.

"The mechanism of action of psoralens is described as involving preferential binding to domains in lipid bilayers, e.g. on enveloped viruses and some virus infected cells. Photoexcitation of membrane-bound agent molecules leads to the formation of reactive oxygen species such as singlet oxygen which causes lipid peroxidation. A problem with the use of psoralens is that they attack cell membranes of desirable components of fluids to be decontaminated, such as red blood cells, and the singlet oxygen produced during the reaction also attacks desired protein components of fluids being treated.

"U.S. Pat. No. 4,727,027 discloses the use of furocoumarins including psoralen and derivatives for decontamination of blood and blood products, but teaches that steps must be taken to reduce the availability of dissolved oxygen and other reactive species in order to inhibit denaturation of biologically active proteins. Photoinactivation of viral and bacterial blood contaminants using halogenated coumarins is described in U.S. Pat. No. 5,516,629, U.S. Pat. No. 5,587,490 and U.S. Pat. No. 5,418,130 disclose the use of substituted psoralens for inactivation of viral and bacterial blood contaminants. The latter patent also teaches the necessity of controlling free radical damage to other blood components. U.S. Pat. No. 5,654,443 teaches new psoralen compositions used for photodecontamination of blood. U.S. Pat. No. 5,709,991 teaches the use of psoralen for photodecontamination of platelet preparations and removal of psoralen afterward. U.S. Pat. No. 5,120,649 and related U.S. Pat. No. 5,232,844 disclose the need for the use of 'quenchers' in combination with photoactivatable substances which attack lipid membranes, and U.S. Pat. No. 5,360,734 addresses this problem of prevention of damage to other blood components.

"Photoactivatable substances which attack nucleic acids are known to the art. U.S. Pat. No. 5,342,752 discloses the use of compounds based on acridine dyes to reduce parasitic contamination in blood matter comprising red blood cells, platelets, and blood plasma protein fractions. These materials, although of fairly low toxicity, do have some toxicity e.g. to red blood cells. U.S. Pat. No. 5,798,238 discloses the use of quinolone and quinolone compounds for inactivation of viral and bacterial contaminants.

"Binding of DNA with photoactive agents has been exploited in processes to reduce lymphocytic populations in blood as taught in U.S. Pat. No. 4,612,007 and related U.S. Pat. No. 4,683,889.

"Riboflavin (7,8-dimethyl-10-ribityl isoalloxazine) has been reported to attack nucleic acids. U.S. Pat. Nos. 6,258,577 and 6,277,337 disclose the use of riboflavin and light to inactivate microorganisms which may be contained in blood or blood products. U.S. Pat. No. 6,268,120 discloses riboflavin derivatives which may be used to inactivate microorganisms. Photoalteration of nucleic acid in the presence of riboflavin is discussed in Tsugita, A, et al. (1965), 'Photosensitized inactivation of ribonucleic acids in the presence of riboflavin,' Biochimica et Biophysica Acta 103:360-363; and Speck, W. T. et al. (1976), 'Further Observations on the Photooxidation of DNA in the Presence of Riboflavin,' Biochim Biophys Acta 435:39-44. Binding of lumiflavin (7,8,10-trimethylisoalloxazine) to DNA is discussed in Kuratomi, K., et al. (1977), 'Studies on the Interactions between DNA and Flavins,' Biochimica et Biophysica Acta 476:207-217. Hoffmann, M. E., et al. (1979), 'DNA Strand Breaks in Mammalian Cells Exposed to Light in the Presence of Riboflavin and Tryptophan,' Photochemistry and Photobiology 29:299-303 describes the use of riboflavin and tryptophan to induce breaks in DNA of mammalian cells after exposure to visible fluorescent light or near-ultraviolet light. The article states that these effects did not occur if either riboflavin or tryptophan was omitted from the medium. DNA strand breaks upon exposure to proflavine and light are reported in Piette, J. et al. (1979), 'Production of Breaks in Single- and Double Stranded Forms of Bacteriophage phi X174 DNA by Proflavine and Light Treatment,' Photochemistry and Photobiology 30:369-378, and alteration of guanine residues during proflavine-mediated photosensitization of DNA is discussed in Piette, J., et al. (1981), 'Alteration of Guanine Residues during Proflavine Mediated Photosensitization of DNA,' Photochemistry and Photobiology 33:325-333. J. Cadet, et al. (1983), 'Mechanisms and Products of Photosensitized Degradation of Nucleic Acids and Related Model Compounds,' Israel J. Chem. 23:420-429, discusses the mechanism of action by production of singlet oxygen of rose bengal, methylene blue, thionine and other dyes, compared with mechanisms not involving production of singlet oxygen by which nucleic acid attack by flavin or pteron derivatives proceeds. Riboflavin is exemplified in this disclosure as having the ability to degrade nucleic acids. Korycka-Dahl, M., et al. (1980), 'Photodegradation of DNA with Fluorescent Light in the Presence of Riboflavin, and Photoprotection by Flavin Triplet-State Quenchers,' Biochimica et Biophysica Acta 610:229-234 also discloses that active oxygen species are not directly involved in DNA scission by riboflavin. Peak, J. G., et al. (1984), 'DNA Breakage Caused by 334-nm Ultraviolet Light is Enhanced by Naturally Occurring Nucleic Acid Components and Nucleotide Coenzymes,' Photochemistry and Photobiology 39:713-716 further explores the mechanism of action of riboflavin and other photosensitizers. However, no suggestion is made that such photoactivatable substances be used for decontamination according to embodiments of the devices and methods described herein.

"All publications referred to herein are hereby incorporated by reference to the extent not inconsistent herewith."

In addition to the background information obtained for this patent application, NewsRx journalists also obtained the inventor's summary information for this patent application: "An embodiment may be a device for decontaminating a medical device, the device may include: a compartment adapted to contain a medical device and a solution, the solution may include a photoactivatable substance; and a light system providing 360 degrees of exposure to the compartment. The compartment may provide an enclosure for the entire medical device contained therein. The compartment may include holding devices for holding a container, such as a bag or cup. The holding devices may be hooks or loops. The compartment may include multiple light sources. The compartment may have a reflective coating on some of (e.g., at least 25%), most of (e.g., at least 65%), or essentially the entire (e.g., at least 90%) surface of the compartment. The device may further include a container, the container adapted to be placed in the compartment. The container may be a bag system. The bag system may include a bag adapted to contain the medical device and solution, wherein the bag may include a seal and an input device for inputting and/or draining the solution. The seal may be essentially permanent, wherein the bag and/or seal is destroyed by breaking the seal to recover the object. Alternatively, the seal may be resealable. The input device may include a valve to control when the input device is open or closed. The light system may provide UV light.

"An embodiment may be a method for decontaminating a medical device, the method may include: placing a medical device in a compartment with a solution, the solution may include a photoactivatable substance; incubating the medical device in the solution to allow the photoactivatable substance to attach to pathogens; and exposing the compartment to 360 degrees of light exposure to activate the photoactivatable substance. The method may further include placing the medical device and solution in a container, and placing the container in the compartment. The method may include: placing the medical device in a bag and adding solution via an input device with a valve; and after exposing to light, draining the solution via the input device. The light may be UV light. The photoactivatable substance may be riboflavin with or without tryptophan.

"An embodiment may be a device for decontaminating a surface, the device may include: a concave piece adapted to surround a surface; and a light system providing 180 degrees of exposure to the surface. Essentially the entire surface-surrounding side of the concave piece may have a reflective coating.

"An embodiment may be a method for decontaminating a surface, the method may include: applying a solution with a photoactivatable substance to the surface; exposing the surface to 180 degrees of light exposure to activate the photoactivatable substance. The solution may be allowed to contact the surface for a sufficient period of time. The surface may be skin. The skin may include a wound or a proposed surgical incision site.

"An embodiment may be a device for introducing light into a nasal cavity, the device may include: a handle containing a power source; a light source; and a flexible arm connecting the handle and the light source, the light source providing about 360 degrees of UV light.

"An embodiment may be a method for disinfecting a nasal passage, the method may include: applying a solution to a nasal passage, the solution may include a photoactivatable substance; exposing the nasal passage to 360 degrees of light exposure to activate the photoactivatable substance.

"An embodiment may be a method for treating skin, the method may include adhering a skin perfusion chamber to the skin, applying a solution to the skin, the solution may include a photoactivatable substance; exposing the skin to light to activate the photoactivatable substance.


"The invention can be better understood with reference to the following drawings. The components of the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of embodiments the present invention.

"FIG. 1a shows an exemplary device, the device including an exemplary compartment.

"FIG. 1b shows an exemplary device in the shape of a rectangular prism, with rounded edges.

"FIG. 1c shows an exemplary device, which includes a container in the form of a cup.

"FIG. 2 shows an exemplary device adapted to provide a 180 degrees exposure of light to an object, such as a surface or a wound.

"FIG. 3 shows an exemplary device adapted to introduce light into a cavity, such as a body cavity, such as the nose.

"FIG. 4 shows an exemplary container in the form of a bag system.

"FIG. 5 shows an exemplary container in the form of a cup-like container.

"FIG. 6 shows an exemplary skin perfusion chamber.

"FIG. 7 shows an exemplary light for a flat surface."

URL and more information on this patent application, see: ROCK, GAIL. Device and Method for Sterilization of Instruments and Surfaces. Filed March 15, 2013 and posted May 15, 2014. Patent URL:

Keywords for this news article include: Patents, Viruses, Peptides, Proteins, Virology, Viral DNA, Chalcogens, Riboflavin, Tryptophan, Blood Cells, DNA Research, Legal Issues, Sterilization, Singlet Oxygen, Infection Control, Aromatic Amino Acids, Essential Amino Acids, Reactive Oxygen Species.

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Source: Life Science Weekly