JP2005080747A - Skin aging preventing method with powerful pulsing ray - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for preventing the cell death by optical traumata such as UV-A or UV-B in the skin cell, and the skin textile from optical aging. <P>SOLUTION: The skin is irradiated with IPL having a wavelength of 400 to 1,200 nm, and the intracellular section of the skin cell forming the cuticle, the corium and/or the tela subcutanea is instantly heated in such a manner that a thermal burn may not occur on the skin, especially on the cuticle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for preventing skin aging using electromagnetic radiation. The present invention specifically relates to the epidermis, dermis and dermis by photoaging caused by light such as ultraviolet rays by applying strong light including wavelengths of visible light to near-infrared region, particularly intense pulsed light, to the skin. The present invention relates to a method for preventing skin aging which protects cell death of skin cells forming subcutaneous tissue.

  The skin that envelops the entire human body protects the inside of the body from all external factors such as dust, germs, chemicals, and ultraviolet rays. At the same time, it feels pain, heat and cold, and has the role of adjusting body temperature by sweating. In this way, the skin is an important organ indispensable for maintaining the life of the human body.

  Skin cells that form the epidermis, dermis and / or subcutaneous tissue are mainly keratinocytes, followed by fibroblasts, outer pigment cells (melanocytes), Langerhans cells (immune system cells), and defective endothelium. Cells are mixed.

  Recently, there is a strong desire to maintain external youthfulness and / or prevent skin aging. On the other hand, cells at a depth of 0.1 to 1.7 mm from the outer surface of the skin may be killed by ultraviolet rays having a wavelength of 320 to 400 nm. Currently, there is a well-known method of avoiding exposure to sunlight (ultraviolet rays) by applying sunscreen cream to the skin to block sunlight.

  Unfortunately, however, none of these known methods are effective in protecting against the death of skin cells that form the epidermis, dermis and / or subcutaneous tissue. Vitamin C ion introduction is a known method that is said to suppress cell death, but the stability of vitamin C is low. In this case, since ions are to be introduced deeply, most of vitamin C is oxidized, and the effect of removing active oxygen inside the cell cannot be expected. There is a method of chemically peeling the skin with a drug in order to increase the iontophoresis rate of vitamin C. Trichloroacetic acid or phenol is often used for chemical peeling of the skin. In this method, the peel depth cannot be adjusted, and there is a possibility of pigment change and a risk of scratches.

  There is a method of forcibly taking vitamin C orally into the body by supplements, etc., and therefore into the skin cells, but it takes a long time to digest and take it into the cells, and it lacks immediate effect and is practical. I can't say there is.

  Even if a large amount of vitamin C is ingested into the body and thus into the skin cells, there is a limit to the allowable amount. When ingested vitamin C cannot be consumed in the body, it is excreted together with urine, but it is known as a well-known fact that stones may form because the calcium component in urine and vitamin C combine when excreted. .

  Irradiation of intense pulsed rays on the skin has been conventionally used for treatment of skin rejuvenation and the like (see, for example, Patent Document 1). This patent discloses a method and apparatus for regenerating the elasticity of collagen and skin by applying intense pulsed rays to the skin to heat and contract the collagen inside the skin.

  In addition, irradiation with intense pulsed light on the skin has been mainly used for the treatment of skin abnormalities such as spots, freckles, and capillary dilatation, lesions, and so on. In other words, intense pulsed light has been used to irradiate cells in the lesion area of the skin and cause the cells in the lesion area to die and be removed.

Furthermore, when using a device that emits intense pulsed light, it is known that there are fundamental differences in effects depending on the pulse conditions such as energy density (dose), pulse width, delay time, and irradiation conditions such as the number of irradiations. It has been. In the prior art, it is known that even if a strong pulsed light (hereinafter also referred to as IPL (abbreviation of Intense Pulsed Light)) is irradiated at a relatively weak energy density, there is no therapeutic effect on skin lesions. IPL irradiation with weak energy density (dose) has not been adopted.
JP-A-9-103507 (page 3-6, FIG. 3) Therefore, photoaging of skin cells by ultraviolet rays such as UV-A or UV-B has been left as an unsolved problem. To date, no effective prophylactic treatment for photoaging has been known. Therefore, it was never expected that the cell death due to photoaging of the skin cells forming the skin could be prevented by irradiating the skin with IPL under specific conditions.

  From the above description, there is a demand for the emergence of an effective method for protecting the cell death of the skin cells forming the epidermis, dermis and / or subcutaneous tissue without affecting the human body such as the epidermis of the skin. It is easily understood what has been done.

  The object of the present invention is to protect against photoaging of skin cells forming the epidermis, dermis and / or subcutaneous tissue, particularly skin cell death due to photodamage caused by UV-A, UV-B, etc. and skin photoaging due to photodamage. Is to provide a way to do.

  In accordance with the present invention, the skin is irradiated with strong light including wavelengths in the visible to near-infrared region, which is electromagnetic radiation, particularly IPL, and the epidermis, dermis and / or subcutaneous tissue is applied so that no skin, especially epidermis burns occur. It has been found that if the inside of the formed skin cells is heated instantaneously, skin cell death due to photodamage of these skin cells and skin photoaging due to photodamage can be prevented.

  It has been found that by irradiating IPL under such conditions, skin cell death due to photoinjury of skin cells by UV-A, UV-B, etc. and skin photoaging due to photoinjury can be protected.

  The method of the present invention is prominent in the photoaging of skin cells forming the epidermis, dermis or subcutaneous tissue, particularly in the prevention of cell death due to photoinjury such as UV-A and UV-B, and the prevention of skin photoaging by photoinjury. Has an effect.

  The effect of preventing skin cancer, wrinkle formation and inflammation caused by excessive skin turnover due to cell death of skin cells due to ultraviolet rays such as UV-A and UV-B is also highly expected.

  In the method of the present invention, an intense light source including wavelengths in the visible to near-infrared region, particularly an IPL light source, a housing in which the IPL light source is disposed, an opening for the housing to direct the IPL light source toward the skin, the vicinity of the opening, etc. An apparatus having an optical filter or the like disposed in the can be used. The IPL device also includes a timing circuit for adjusting the elapsed time from the application of a cooling substance to the skin to the irradiation of a relatively weak IPL and the like, and an element coupled to an IPL light source such as a microprocessor. In addition, the IPL device has a pulse forming circuit, and is configured to be able to control the duration of the pulse emitted by the IPL light source according to the pulse duration (hereinafter also referred to as pulse width) input, And a delay time circuit between pulses configured to produce a delay between successive IPLs. The apparatus includes a reflector near the light source, a light guide disposed near the aperture, means for reducing the temperature of the cooling material, and the like.

  In the method of the present invention, the apparatus having the basic configuration described above is used. Specifically, for example, a device having the above basic configuration such as a Naturite (registered trademark) device, a Naturite Neo (registered trademark) device, or a vasculite device can be used. It is not limited. Since a relatively weak IPL is used, a simpler apparatus than the conventional apparatus can be used safely.

  In the method of the present invention, these devices are used to irradiate the skin with a relatively weak IPL, such as to prevent cell death of skin cells forming the epidermis, dermis and / or subcutaneous tissue. The epidermis and the outer skin layer of the skin can be protected by cooling with light transmissive substances such as water, lotion, ice, gel and crystals. The temperature distribution in the skin can be controlled by variously controlling the delay time between pulses, the duration of the pulse, etc., and by adjusting the wavelength range such as irradiation IPL with an optical filter It is.

  In the method of the present invention, a light source including light in a wavelength range of 400 to 1200 nm is used as a light source such as IPL. IPL is incoherent light such as flash lamps and / or coherent light such as various laser lights. Although a light source will not be specifically limited if it is a light source containing the light of the wavelength range of 400-1200 nm, An arc lamp is preferable. The arc lamp is a strobe discharge tube, a fluorescent lamp, a mercury lamp, a sodium lamp, a metal halide lamp, a xenon lamp, or the like. A preferred light source is a linear arc lamp. Most preferred are linear arc lamps with reflectors.

  If the light source, such as IPL, also includes light having a wavelength outside the range of 400-1200 nm, one or more optical filters are used to exclude light having wavelengths below 400 nm and above 1200 nm be able to. The optical filter is an ultraviolet absorption filter, an infrared absorption filter, an interference filter, or the like.

  The wavelength of the IPL or the like to be irradiated is preferably 500 to 1,200 nm, more preferably 515 to 1,200 nm.

  The surface temperature of the skin where the IPL is irradiated is maintained in a temperature range where there is no problem by balancing the strength of the cooling of the skin surface and the strength of the IPL to be irradiated.

The output energy density (dose) of the irradiated IPL is relatively weak 0.1 to 49 J / cm ² , preferably 0.1 to 40 J / cm ² , more preferably 0.5 to 30 J / cm ^2. It is. The numerical range of the output energy density (dose) of the irradiated IPL is set to a low value compared to the numerical range that has been used for the treatment of skin lesions such as stains, freckles, and capillary dilation, and so on. . It is preferable that the irradiation conditions are gentle compared to the conventional conditions.

  The pulse duration (pulse width) of IPL is 0.1 to 1,000 msec, preferably 1 to 30 msec, and more preferably 2 to 10 msec. The pulse duration need not be the same for the first shot, which is the first pulse, and the second shot, which is the subsequent pulse, and may vary.

  The delay time between IPL pulses is 0.1 to 1,000 msec, preferably 1 to 100 msec, and most preferably 10 to 60 msec. It can be said that the longer the delay time than the length conventionally used for treatment, the better the cell damage can be reduced.

  The pulse form of IPL is one time or multiple pulses, preferably multiple pulses, preferably 2 to 5 multiple pulses, and more preferably 2 to 3 multiple pulses.

  The irradiation area of the IPL may be arbitrary as long as there is no problem in operation, but is preferably 10 × 35 mm, for example, and is variable.

  As a cooling condition, for example, a cold transparent gel may be applied to the entire face or an irradiated portion before the IPL irradiation. Alternatively, the skin surface can be cooled from the outside during IPL irradiation to avoid overheating of the epidermis. A pre-cooled transparent substance such as water, lotion, ice or cold gel can be applied to the skin and allowed to cool during irradiation.

  When irradiating human skin with IPL, it is preferable to irradiate the same site with multiple IPLs a few times in the protective treatment of the day, and it is preferable not to irradiate many times. The irradiation schedule of the present invention is not particularly limited, but it is desirable to continuously irradiate many different times on a long time. In the case of IPL irradiation in the prior art, it was customary to treat 5 days every 3 weeks.

  In the present invention, it is preferable to irradiate (pass) a small number of times with a single protective treatment. In the case of a stain, in the case of a stain, in order to raise the temperature of the stain area to a level necessary for the treatment, a plurality of treatments are performed multiple times in one treatment, that is, so-called “overlap” is performed.

  The main effects of the method of the present invention are estimated as follows. When relatively weak IPL is irradiated to cells that form the skin, the internal pigment (chromophore) inside the skin cells that form the epidermis, dermis and / or subcutaneous tissue absorbs the IPL and the like, and the temperature rises instantaneously. By generating weak active oxygen, the antioxidant power inside the cell is enhanced, and by removing active oxygen in the cell nucleus, it protects cell death due to photoaging of skin cells without damaging the skin epidermis. Presumed.

  If excessive melanin pigment is produced on the skin due to excessive exposure to ultraviolet rays or the like, excess melanin pigment remains without peeling off. As a result, it deposits and causes skin spots. Therefore, it is important to suppress this excessive melanin pigment production. The production of melanin is also promoted by active oxygen produced in the skin exposed to ultraviolet rays. Since active oxygen oxidizes skin cells, tyrosinase enzyme acts on melanocytes in the skin to produce melanin pigments in order to prevent damage to the skin cells due to oxidation. Therefore, it is important to suppress both the action of tyrosinase enzyme and the action of active oxygen in order to prevent skin blemishes. In view of this cycle, the effectiveness of the present invention becomes clear.

Reference example 1
Human skin dermis fibroblasts were attached to the bottom of a 24-well microplate (manufactured by Iwaki Glass) (10,000 cells / well) and cultured for 18 hours at 37 ° C. and 100% relative humidity. IPL multiple pulse irradiation was performed using a registered trademark apparatus. The conditions of the IPL irradiation are as follows: the wavelength is 560 nm, the pulse width is 2.8 ms for the first shot, the second shot is 5.0 ms, the delay time is 20 ms, and the output energy density (dose) is changed to 15, 19, or 23 J / cm ^2. The number of irradiations was changed to 1, 2, or 3 times. The fibroblasts after IPL irradiation were cultured for 6 hours under conditions of a temperature of 37 ° C. and a relative humidity of 100%, and then UV-B irradiation was performed. The UV-B irradiation conditions were an irradiation intensity of 1,000 μW / cm ² and an irradiation time of 45 sec. The fibroblasts were cultured for 45 hours at 37 ° C. and 100% relative humidity after UV-B irradiation. After adding the WST-1 reagent, the cells were further cultured for 3 hours under the conditions of a temperature of 37 ° C. and a relative humidity of 100%, and the viability of the fibroblasts was determined by a biochemical assay. Cell viability was measured according to the WST-1 / absorption plate reader method based on mitochondrial dehydrogenase activity. A control experiment was also conducted under the same conditions as above except that no IPL irradiation was performed.

  The cell viability results obtained from the above experiment are shown in FIG. The value of the cell viability is a relative value when the cell is not irradiated with ultraviolet rays and is 100%. The bar graph values are the average of the results of three experiments conducted separately. The height of the line shown at the top of the bar graph indicates the standard deviation value of the cell viability of the triplet (triple specimen) cell culture set for each measurement point for the representative examples of these experiments.

  From FIG. 1, it is apparent that the method of the present invention is effective in protecting cell death. Compared in detail, the lower dose was better.

Reference example 2
Human skin dermis fibroblasts were attached to the bottom of the glass tube (10,000 cells / well) and cultured for 18 hours under conditions of a temperature of 37 ° C. and a relative humidity of 100%. The following culture was also performed under the same conditions. Thereafter, IPL multiple pulse irradiation was performed using a vasculite apparatus. The conditions of the IPL irradiation are as follows: the wavelength is 515 or 550 nm, the pulse width is the first shot 2.8 ms, the second shot is 5.0 ms, the delay time is 20 ms, and the output energy density (dose) is 3.5, 10, 20, 30 Or 40 J / cm ^2, and the number of irradiations was 1 or 2 times. The fibroblasts after IPL irradiation were cultured for 6 hours, and then UV-B irradiation was performed. The UV-B irradiation conditions were an irradiation intensity of 1,000 μW / cm ² and an irradiation time of 75 sec. The fibroblasts were cultured for 45 hours after UV-B irradiation. After adding the WST-1 reagent, the cells were further cultured for 3 hours, and the viability of fibroblasts was determined by biochemical assay. Cell viability was measured according to the WST-1 / absorption plate reader method based on mitochondrial dehydrogenase activity. A control experiment was also conducted under the same conditions as above except that no IPL irradiation was performed.

  The cell viability results obtained from the above experiment are shown in FIG. The cell viability, the value of the bar graph, and the height of the line marked at the top of the bar graph are the same as in Reference Example 1.

From FIG. 2, it is apparent that the method of the present invention is effective in protecting cell death of skin cells. The overall irradiation wavelength was 515 nm better than 550 nm. Further, an excellent effect was obtained at a weak dose of 3.5 J / cm ² .

Reference example 3
The keratinocytes HaCaT of the human skin epidermis were attached to the bottom of the glass cylinder (5,000 cells / well) and cultured for 18 hours under conditions of a temperature of 37 ° C. and a relative humidity of 100%. The following culture was also performed under the same conditions. Thereafter, IPL multiple pulse irradiation was performed using a vasculite apparatus. The conditions of the IPL irradiation are as follows: the wavelength is 515 or 550 nm, the output energy density (dose) is 3 or 10 J / cm ² , and the pulse width is 1.4 ms for the first shot when the output energy density is 3 J / cm ² . When 2 shots are 2.5 ms and the output energy density is 10 J / cm ² , the first shot is 2.8 ms, the second shot is 5.0 ms, the delay time is 20 ms, and the number of irradiations is 1 or 2 times. The keratinocytes after IPL irradiation were cultured for 6 hours, and then irradiated with UV-B. The UV-B irradiation conditions were an irradiation intensity of 1,000 μW / cm ² and an irradiation time of 120 sec. The keratinocytes were cultured for 45 hours after UV-B irradiation. After adding WST-1 reagent, the cells were further cultured for 3 hours, and the survival rate of keratinocytes was determined by biochemical assay. Cell viability was measured according to the WST-1 / absorption plate reader method based on mitochondrial dehydrogenase activity. A control experiment was also conducted under the same conditions as above except that no IPL irradiation was performed.

  The results of cell viability obtained from the above experiment are shown in FIG. The cell viability, the value of the bar graph, and the height of the line marked at the top of the bar graph are the same as in Reference Example 1.

From FIG. 3, it is clear that the method of the present invention is effective in protecting cell death of epidermal cells of the skin. The output energy density of 3.5 was better than 10 J / cm ² .

Reference example 4
The keratinocytes HaCaT of the human skin epidermis were attached to the bottom of the glass cylinder (5,000 cells / well) and cultured for 21 hours under conditions of a temperature of 37 ° C. and a relative humidity of 100%. The following culture was also performed under the same conditions. Thereafter, IPL multiple pulse irradiation was performed using a basculite apparatus. The conditions of the IPL irradiation are as follows: the wavelength is 550 nm, the output energy density (dose) is 3 J / cm ² , and the pulse width is constant for the second shot 2.5 ms, the first shot is 0.5, 1.4, or When the first shot is constant 1.4 ms, the second shot is changed to 0.5, 2.5, or 4.5 ms, the delay time is 20 ms, and the number of irradiations is 1, 2 or 3 Times. The keratinocytes after IPL irradiation were cultured for 3 hours and then irradiated with UV-B. The UV-B irradiation conditions were an irradiation intensity of 1,000 μW / cm ² and an irradiation time of 120 sec. The keratinocytes were cultured for 45 hours after UV-B irradiation. After adding WST-1 reagent, the cells were further cultured for 3 hours, and the survival rate of keratinocytes was determined by biochemical assay. Cell viability was measured according to the WST-1 / absorption plate reader method based on mitochondrial dehydrogenase activity. A control experiment was also conducted under the same conditions as above except that no IPL irradiation was performed.

  The results of cell viability obtained from the above experiment are shown in FIG. The cell viability, the value of the bar graph, and the height of the line marked at the top of the bar graph are the same as in Reference Example 1.

  From FIG. 4, it is clear that the method of the present invention is effective in protecting cell death of epidermal cells of the skin. Among these results, the conditions of the first shot of 1.4 ms, the second shot of 2.5 ms, and the IPL twice irradiation were excellent.

Reference example 5
The keratinocytes HaCaT of the human skin epidermis were attached to the bottom of the glass cylinder (10,000 cells / well) and cultured for 23 hours under conditions of a temperature of 37 ° C. and a relative humidity of 100%. The following culture was also performed under the same conditions. Then, IPL multiple pulse irradiation was performed using a naturite apparatus. The conditions for the IPL irradiation are a wavelength of 560 nm, an output energy density (dose) of 19 J / cm ² , a pulse width of 2.8 ms for the first shot, 5.0 for the second shot, and a delay time of 20 ms. And the number of times of irradiation was set to 2 times. The keratinocytes after IPL irradiation were cultured for 1 hour, and then UV-A irradiation was performed. The UV-A irradiation conditions were an irradiation intensity of 16.53 J / cm ² / min and an irradiation time of 135 sec. The keratinocytes were cultured for 45 hours after UV-A irradiation. After adding WST-1 reagent, the cells were further cultured for 3 hours, and the survival rate of keratinocytes was determined by biochemical assay. Cell viability was measured according to the WST-1 / absorption plate reader method based on mitochondrial dehydrogenase activity. A control experiment was also conducted under the same conditions as above except that no IPL irradiation was performed.

  From these experiments, the cell viability obtained in the experiment of the present invention under the above conditions was 41%, which was better than the 35% of the control experiment. From this experimental result, it is clear that the method of the present invention is effective in protecting cell death of epidermal cells of the skin.

The model experiment result of this invention which irradiated the fibroblast of the human skin dermis while changing the output energy density of IPL is shown. The model experiment result of this invention which irradiated the wavelength and output energy density of IPL with respect to the fibroblast of human skin dermis is shown. The model experiment result of this invention which irradiated the keratinized HaCaT cell of human skin epidermis while changing the output energy density of IPL is shown. The model experiment result of this invention which irradiated the irradiation time of IPL with respect to the keratinized HaCaT cell of human skin epidermis is shown.

Claims (6)

The skin is irradiated with a pulsed light, and the inside of the skin cells forming the epidermis, dermis and / or subcutaneous tissue is instantaneously heated so as not to cause burns of the skin, particularly the epidermis. A method for protecting cell death due to photodamage such as B. The skin is irradiated with a pulsed light, and the inside of the skin cells forming the epidermis, dermis and / or subcutaneous tissue is instantaneously heated so as not to cause burns of the skin, particularly the epidermis. -A method for protecting skin photoaging due to photoinjury such as B. The method of Claim 1 or 2 with which the irradiation light to the skin of the said pulsed light has a wavelength range of 400-1,200 nm. The method of Claim 1 or 2 that the irradiation light to the skin of the said pulsed light has an output energy density of 0.1-49 J / cm < ² >. The method of Claim 1 or 2 with which the irradiation light to the skin of the said pulsed light has a delay time between pulses of 0.1-1,000 msec. The method of Claim 1 or 2 that the irradiation light to the skin of the said pulsed light is a multiple pulse.

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