There are different kinds of photosensitizers, each one with a specific excitation wavelength. During photosensitizer photoactivation, an excitable electron is promoted to a higher energy level, and the photosensitizer reaches a first excited singlet state. The first excited singlet state decays to a lower energy level by emitting fluorescence or, alternatively, by a process of intersystem crossing to a state named triplet. The triplet state is long lived and, because of this feature, it is able to react with triplet oxygen molecules and other biomolecules or to emit phosphorescence. When the photosensitizer in the triplet state transfers energy to triplet oxygen, very reactive species called singlet oxygen are produced. Both the photosensitizer in the triplet state and the singlet oxygen are unstable molecules and for this reason they are responsible, in biological tissues, for the damage to polyunsaturated lipids, nucleic acids, and protein after photosensitizer irradiation.
A direct reaction between the photosensitizer in the triplet state and a biomolecule is called a Type 1 reaction and this process leads to photosensitizer blanching. Production of the singlet oxygen by the photosensitizer in the triplet state is called a Type 2 reaction and regenerates the photosensitizer in the ground state. Although both the Type 1 reaction and the Type 2 reaction can damage cells, more significant damage is induced by the Type 2 reaction than the Type 1 reaction.
Catheters are traditionally used to infuse fluids, such as saline solution, various medicaments, and/or total parenteral nutrition into a patient. Such catheters may also be used to withdraw blood from a patient, and/or monitor various parameters of the patient's vascular system. To introduce a catheter into a patient, an introducer needle may be used, which may include a sharp distal tip. The catheter may include an over-the-needle peripheral intravenous (“IV”) catheter mounted over the introducer needle. An inner surface of the catheter may tightly engage an outer surface of the introducer needle to prevent catheter peel back and facilitate insertion of the catheter into a blood vessel. The sharp distal tip of the introducer needle may extend beyond the distal tip of the catheter to enable insertion of the catheter at a shallow angle through skin of the patient and into the blood vessel.
To verify proper placement of the needle and the catheter in the blood vessel, the clinician may confirm the presence of “flashback” blood in a flashback chamber associated with the catheter and needle assembly. Once proper placement is confirmed, the clinician may then apply pressure to the blood vessel to occlude the vessel, thereby reducing further blood flow through the introducer needle and catheter. The clinician may then withdraw the needle from the catheter to enable continued access to the blood vessel through the catheter.
The catheter is susceptible to bacteria, which may infect and harm the patient. Similarly, other vascular access devices, as well as ultrasound devices, dressings, pumps, and other medical devices that come into close proximity with the patient may be susceptible to bacteria, which may infect and harm the patient. There is a need for a material that is capable of increasing antimicrobial resistance of medical devices.
The subject matter claimed in the present disclosure is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one example technology area where some implementations described in the present disclosure may be practiced.
The present disclosure relates generally to medical devices and related methods that facilitate decontamination and antimicrobial resistance. In some embodiments, a medical device may include a body and a photosensitizer integrated with the body. In some embodiments, the photosensitizer may include methylene blue, new methylene blue, Nile blue, rose bengal, toluidine blue O, crystal violet, or another suitable photosensitizer. In some embodiments, the body may include multiple photosensitizers integrated with the body.
The photosensitizer may be integrated with the body in various ways. For example, the body may be formed by a base resin, and the photosensitizer may be compounded with the base resin. In some embodiments, the base resin may include polyphenylsulfone, polyurethane, or silicone. In some embodiments, a concentration of the photosensitizer within the base resin may be between 0.05% and 5%.
As another example, the medical device may include a coating disposed on a surface of the body, and the photosensitizer may be disposed within the coating. In some embodiments, a concentration of the photosensitizer within the coating may be between 0.05% and 5%. As yet another example, the medical device may include a catheter adapter and a catheter extending distally from the catheter adapter. In these embodiments, the catheter may be co-extruded with the photosensitizer and another material. As a further example, the body may be formed by the base resin, and the photosensitizer is imbibed into the base resin.
In some embodiments, the medical device may include a needleless connector or a cap. In some embodiments, the medical device may include an ultrasound transducer. In some embodiments, the medical device may include a dressing, a surgical mesh, a pump, or another suitable medical device.
In some embodiments, a method of disinfection of the medical device may include providing the medical device. In some embodiments, the method may include administering to the photosensitizer integrated with the body a light dose in a range between 0.5 J/cm2 and 320 J/cm2. In some embodiments, the light dose may be administered for a duration between 1 second and 1 hour.
In some embodiments, the method may include integrating the photosensitizer with the body of the medical device. In some embodiments, integrating the photosensitizer with the body of the medical device may include compounding the photosensitizer with the base resin. In some embodiments, integrating the photosensitizer with the body of the medical device may include applying the coating on a surface of the medical device. In some embodiments, the medical device may include the catheter adapter and the catheter, and integrating the photosensitizer with the body of the medical device may include co-extruding the catheter with the photosensitizer and another material. In some embodiments, integrating the photosensitizer with the body of the medical device may include imbibing the photosensitizer into the base resin.
It is to be understood that both the foregoing general description and the following detailed description are examples and explanatory and are not restrictive of the present disclosure, as claimed. It should be understood that the various embodiments are not limited to the arrangements and instrumentality illustrated in the drawings. It should also be understood that the embodiments may be combined, or that other embodiments may be utilized and that structural changes, unless so claimed, may be made without departing from the scope of some embodiments of the present disclosure. The following detailed description is, therefore, not to be taken in a limiting sense.
Example embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
Referring now to
In some embodiments, the medical device 10 may include a body 12 and a photosensitizer integrated with the body 12. In some embodiments, the body 12 may include any portion of the medical device 10 that contacts or is near the patient. In some embodiments, the medical device 10 may include the ultrasound transducer, and the body 12 may include a distal end 14 of the ultrasound transducer. In some embodiments, the photosensitizer may include methylene blue, new methylene blue, Nile blue, rose bengal, toluidine blue O, crystal violet, or another suitable photosensitizer.
In some embodiments, the photosensitizer may be integrated with the body 12 in various ways. In some embodiments, the body 12 may be formed by a base resin, and the photosensitizer may be compounded with the base resin. In some embodiments, the base resin may include polyphenylsulfone, polyurethane, silicone, or another suitable base resin. In some embodiments, a concentration of the photosensitizer within the base resin may be between 0.05% and 5%.
In some embodiments, the body 12 may be formed by the base resin, and the photosensitizer may be imbibed into the base resin. In some embodiments, imbibing may include dissolving the photosensitizer in methyl ethyl ketone (MEK), tetrahydrofuran (THF), or another suitable solvent to form a solution. In some embodiments, imbibing may include exposing the body 12 to the solution such that the body 12 absorbs the solution and swells. In some embodiments, the body 12 may be co-extruded with the photosensitizer and another material using a die.
In some embodiments, the body 12 may actively resist colonization of bacteria by releasing reactive oxidative species (ROS) in response to a light dose. In some embodiments, the light dose, which may be in a range between 0.5 J/cm2 and 320 J/cm2, may be administered to the photosensitizer integrated with the body 12. In some embodiments, the light dose may be administered for a duration between 1 second and 1 hour. In some embodiments, the light dose may be red light (about 700-635 nm), yellow light (about 590-560 nm) or ultraviolet (UV) light, such as, for example, UV C light. In some embodiments, the body 12 may passively resist colonization of bacteria under ambient light, which may be administered to the photosensitizer integrated with body 12. In some embodiments, the photosensitizer may produce lower levels of ROS in response to the ambient light than the photosensitizer produces in response to the light dose in the range between 0.5 J/cm2 and 320 J/cm2.
In some embodiments, the light dose may activate the photosensitizer, and the photosensitizer may reach a first excited singlet state as an excitable electron is promoted to a higher energy level. The first excited singlet state may decay to a lower energy level by a process of intersystem crossing to a state named triplet. The triplet state may be long lived and, because of this feature, the photosensitizer is able to react with triplet oxygen molecules and other biomolecules. When the photosensitizer in the triplet state transfers energy to triplet oxygen, an ROS called singlet oxygen may be produced. Both the photosensitizer in the triplet state and the singlet oxygen are unstable molecules and for this reason they may provide decontamination and antimicrobial resistance to the body 12. In some embodiments, varying wavelengths of light may be administered to the body 12 at different times and/or the body 12 may include multiple photosensitizers, which may be activated in response to different wavelengths of light.
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In some embodiments, an extension tube 24 may extend from the catheter adapter 16. In some embodiments, a distal end of the extension tube 24 may be integrated with or coupled to a side port 26 of the catheter adapter 16. In some embodiments, a proximal end of the extension tube 24 may be integrated with or coupled to an adapter 28, which may include a Y-adapter or another suitable adapter.
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In some embodiments, the dressing 32 may be configured for use with the medical device, such as the catheter 18 (see, for example,
In some embodiments, the body 12 may take any geometric shape. In some embodiments, the body 12 may be disk-shaped. In some embodiments, a shape of the body 12 may include an oval, triangle, square, rectangle, pentagon, hexagon, octagon, etc. In some embodiments, the body 12 may be fabricated of any physiologically compatible material that is capable of being impregnated or imbibed with the photosensitizer. In some embodiments, the body 12 may be constructed of oxidized cellulose foam, collagen fibrils, alginate hydrogel, or another suitable material.
In some embodiments, the body 12 may include an aperture 36 for reception of the medical device. In some embodiments, the slit 34 may extend from the aperture 36 to an outer perimeter 38 of the body 12. In some embodiments, the slit 34 may enable the body 12 to fully surround and contact the skin insertion site, through which the medical device, such as, for example, the catheter 18 (see
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In some embodiments, each of the light sources 46 may emit a light dose having a particular wavelength of light. In some embodiments, the first light source 46a may emit a first wavelength, the second light source 46b may emit a second wavelength, and the third light source 46c may emit a third wavelength. For example, the first light source 46a may emit UVC light, the second light source 46b may emit red light, and the third light source 46c may emit yellow light. In some embodiments, the light sources 46 may include light emitting diodes (LEDs). In some embodiments, the light sources 46 may be activated at different times from each other and/or for different durations. In some embodiments, in response to activation of the light sources 46 different photosensitizers integrated with the body 12 may be activated, leading to free radical production and decontamination of the medical device 10 disposed within the chamber 40.
All examples and conditional language recited in the present disclosure are intended for pedagogical objects to aid the reader in understanding the present disclosure and the concepts contributed by the inventor to furthering the art and are to be construed as being without limitation to such specifically recited examples and conditions. Although embodiments of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the present disclosure.
This application claims the benefit of U.S. Provisional Patent Application No. 63/027,750, filed on May 20, 2020, entitled “MEDICAL DEVICE HAVING A PHOTOSENSITIZER AND RELATED METHODS,” which is incorporated herein in its entirety.
Number | Date | Country | |
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63027750 | May 2020 | US |