Devices and methods for removing tattoo ink from skin

Abstract

The present disclosure relates to a kit of parts for removing tattoo ink from skin, comprising: a first microneedle array comprising a plurality of microneedles configured to penetrate a layer of skin in which the tattoo ink is embedded; and a second microneedle array comprising a plurality of hydrogel-forming microneedles configured to penetrate the layer of skin, the plurality of hydrogel-forming microneedles being configured to absorb interstitial fluid in the layer of skin upon penetrating the layer of skin, wherein, in use, the first microneedle array is applied to a target area of skin and the plurality of microneedles is inserted into the layer of skin to deliver an ink-removal solution to the layer of skin to release the embedded tattoo ink, and the second microneedle array is applied to the target area of skin after a predetermined time period from applying the first microneedle array.

Description

[0001] DEVICES AND METHODS FOR REMOVING TATTOO INK FROM SKIN

[0002] FIELD

[0003] The present technology relates to devices and methods for removing pigments, in particular tattoo ink pigments, from the skin.

[0004] BACKGROUND

[0005] Tattoos are conventionally removed by laser treatments, in which laser is used to irradiate the ink pigments embedded in the skin tissue to heat the pigments. With sufficient heat the pigments break down into small fragments that are eventually cleared away by the lymphatic system. This technique is costly and labour intensive, often requiring multiple sessions and a long period of time (e.g. up to 2 years) to remove the pigments sufficiently. Moreover, while the laser is configured to target only ink pigments, laser treatments can lead to damages to the skin tissues in and around the treatment area. Further, apart from black pigment that absorbs all wavelengths, a different wavelength of laser is required to treat each colour pigment, further increasing the complexity of the procedure.

[0006] An alternative approach is chemical removal techniques, in which a chemical remover is introduced into the skin by means of conventional tattoo machines or by applying the chemical remover to the skin topically. The former is costly, laborious, while the latter generally leads to unsatisfactory results, and both can cause damages to the skin and lead to scar tissue formation.

[0007] Another technique to this approach is to introduce the chemical solution, such as a solution containing lactic acid, into the skin via a wound. The solution causes skin inflammation and the body exudes the tattoo pigments embedded in the skin via the wound. However, such techniques can cause damages to the treated skin areas and can cause infection if the wound is not treated properly.

[0008] One such technique is proposed in EP3284505B1, in which a chemical solution containing lactic acid is introduced into the skin via an array of hollow microneedles. The chemical solution is left in the skin for a period of 15 to 45 minutes to release the embedded pigments, and then the pigments are removed through the hollow microneedles by means of a negative pressure (suction). The concentration of the chemical solution needed in order to release the embedded pigments within the treatment time must be sufficiently high, which can lead to undesirable damages to the skin. Moreover, to enable the use of a negative pressure that is sufficiently high to remove the released pigments, the microneedles must be sufficiently strong to withstand the pressure, which increases the size as well as the cost of the microneedles.

[0009] The Applicant therefore believes there remain scopes for improving the devices and methods used in tattoo removal.

[0010] SUMMARY

[0011] An aspect of the present technology provides a method of removing tattoo ink from skin, comprising: applying a first microneedle array to a target area of skin, the first microneedle array being formed of a plurality of microneedles configured to penetrate a layer of skin in which the tattoo ink is embedded; inserting the plurality of microneedles into the layer of skin to deliver an inkremoval solution to the layer of skin to release the embedded tattoo ink; applying a second microneedle array to the target area of skin after a predetermined time period from applying the first microneedle array, the second microneedle array being formed of a plurality of hydrogel-forming microneedles configured to penetrate the layer of skin; and inserting the plurality of hydrogelforming microneedles into the layer of skin to allow the plurality of hydrogelforming microneedles to absorb interstitial fluid in the layer of skin together with the released tattoo ink.

[0012] According to embodiments of the present technology, an ink-removal solution is introduced to a layer of skin in which tattoo ink is embedded (e.g. the dermis) through applying a first microneedle array (e.g. a patch) to an appropriate target area of skin. The ink-removal solution is delivered to the layer of skin within the target area upon insertion of the plurality of microneedles of the first microneedle array. Various ways of delivering the inkremoval solution is possible as discussed below. The ink-removal solution releases the tattoo ink in the layer of skin over a predetermined period of time to allow the tattoo ink to be extracted, then a second microneedle array is applied to the same target area of skin to extract the released tattoo ink. For example, the ink-removal solution may break down the static macrophages that encapsulate the smaller tattoo ink particles to release the small particles into interstitial fluid in the skin layer, enabling the pigment particles to be extracted together with interstitial fluid. As for the larger ink particles, these are generally encapsulated by multiple cells (e.g. with the majority being macrophages) in a similar manner to immunoreaction to other foreign bodies. In this case, the inkremoval solution again induces an immunoreaction that attacks these larger particles. The second microneedle array comprises a plurality of hydrogelforming microneedles that are configured to absorb interstitial fluid from the layer of skin upon insertion into the skin. Inserting the hydrogel-forming microneedles into the skin layer draws interstitial fluid from the skin layer towards the hydrogel-forming microneedles under osmotic and capillary actions, and as such, released tattoo ink is absorbed by the hydrogel-forming microneedles together with interstitial fluid. Through the use of the first microneedle array, it is possible to deliver ink-removal solution to the appropriate target skin area effectively with significantly less damages to the skin compared to other techniques of releasing tattoo ink from the encapsulating cells such as laser treatment or topical application of a chemical remover. Moreover, through the use of the second microneedle array, it is possible to extract the released tattoo ink from the layer of skin effectively with a much- reduced risk of damaging the area of skin and minimal manual labour.

[0013] There may be various ways to deliver the ink-removal solution to the layer of skin in which the tattoo ink is embedded, and the plurality of microneedles of the first microneedle array may be configured as required based on the desired method of delivery. In some embodiments, the plurality of microneedles of the first microneedle array may comprise a plurality of hollow microneedles, and the ink-removal solution may be delivered to the layer of skin by injecting the inkremoval solution to the layer of skin through the hollow microneedles. Forming the first microneedle array as a plurality of hollow microneedles is technically straightforward, and the resulting first microneedle array may be easily stored as it does not contain components that may break down or degrade over time or when exposed e.g. to heat or moisture.

[0014] In some embodiments, the plurality of microneedles of the first microneedle array may be coated with the ink-removal solution, and the ink-removal solution may be delivered to the layer of skin by allowing the ink-removal solution to dissolve in the layer of skin. Delivering the ink-removal solution as such allows the desired amount of the solution to be delivered easily in a single step.

[0015] In some embodiments, the plurality of microneedles of the first microneedle array may at least partially be formed of the ink-removal solution in a solid form, and the ink-removal solution may be delivered to the layer of skin by allowing the plurality of microneedles to at least partially dissolve into the layer of skin. Delivering the ink-removal solution as such allows the desired amount of the solution to be delivered easily in a single step.

[0016] In some embodiments, the plurality of microneedles of the first microneedle array may comprise a plurality of hydrogel-forming microneedles impregnated with the ink-removal solution, and the ink-removal solution may be delivered to the layer of skin by allowing the plurality of hydrogel-forming microneedles of the first microneedle array to release the ink-removal solution into the layer of skin. Delivering the ink-removal solution as such allows the desired amount of the solution to be delivered easily in a single step. Moreover, the hydrogelforming microneedles allow a slow and controlled release of the ink-removal solution into the layer of skin.

[0017] In some embodiments, the second microneedle array may comprise an osmolyte configured to facilitate osmosis of interstitial fluid from the layer of skin towards the plurality of hydrogel-forming microneedles of the second microneedle array, the method may further comprise allowing the osmolyte to be released in the layer of skin adjacent the plurality of hydrogel-forming microneedles. The presence of an osmolyte adjacent the hydrogel-forming microneedles of the second microneedle array promotes osmosis from the layer of skin to the hydrogel-forming microneedles. The osmolyte may be provided in a dry form, e.g. as a coating on the surface of the second microneedle array or embedded in the hydrogel-forming microneedles, and when the hydrogelforming microneedles are inserted into the layer of skin, the osmolyte dissolves and its presence increases an osmotic pressure in the area around the hydrogelforming microneedles to facilitate osmosis of interstitial fluid (together with the released tattoo ink) from the skin layer to the hydrogel-forming microneedles.

[0018] Different concentration or strength of ink-removal solution may be used and delivered through the first microneedle array to the appropriate layer of skin and as such, different lengths of time may be required to allow the ink-removal solution to release the embedded tattoo ink sufficiently for extraction. The first microneedle array may sometimes be required to remain on the target area of skin over a period of time longer than a treatment appointment would normally allow. In some embodiments, the predetermined time period may be less than one hour, one or more hours, one or more days.

[0019] In some embodiments, the method may further comprise providing a plurality of first microneedle arrays, and applying a first microneedle array to a target area of skin comprises applying at least one of the plurality of first microneedle arrays for one or more days and applying at least another one of the plurality of first microneedle arrays for one or more days before applying the second microneedle array. The first microneedle array may be applied more than once over a period of time. For example, the first microneedle array may be made e.g. as a single-use patch, and the current patch is replaced by a new patch daily over a period of one or more days. The plurality of first microneedle arrays may each be provided with different dosage or strength of the inkremoval solution so as to deliver different doses of ink-removal solution a period of one or more days, for example to introduce an initial high dose to cause an immunoreaction followed by a lower dose to sustain a low inflammatory state. Applying or re-applying the first microneedle array daily over a period of one or more days allows sufficient time and amount of ink-removal solution to release the tattoo ink embedded in the skin layer. In doing so, it is possible to use lower concentration or strength ink-removal solution to reduce the risk of damaging the skin while achieving desirable results.

[0020] A second aspect of the present technology provides a microneedle patch for use in extracting tattoo ink from skin, the microneedle patch comprising a plurality of hydrogel-forming microneedles configured to penetrate a layer of skin into which the tattoo ink is embedded, the plurality of hydrogel-forming microneedles being configured to, upon insertion into the layer of skin, absorb interstitial fluid comprising released tattoo ink from the layer of skin.

[0021] In some embodiments, the second microneedle array may comprise an osmolyte configured to facilitate osmosis of interstitial fluid from the layer of skin towards the plurality of hydrogel-forming microneedles of the microneedle patch when released into the layer of skin adjacent the plurality of hydrogel-forming microneedles.

[0022] There may be various substances suitable for use as the osmolyte as desired. For example, the osmolyte may be a form of sugar. In some embodiments, the osmolyte is maltose.

[0023] The plurality of hydrogel-forming microneedles may be formed of any suitable material as desired, as long as the material is sufficiently hard when dry and forms a hydrogel when exposed to a fluid. In some embodiments, the plurality of hydrogel-forming microneedles comprises a hydrophilic polymer.

[0024] A third aspect of the present technology provides a kit of parts for removing tattoo ink from skin, comprising: a first microneedle array comprising a plurality of microneedles configured to penetrate a layer of skin in which the tattoo ink is embedded; and a second microneedle array comprising a plurality of hydrogel-forming microneedles configured to penetrate the layer of skin, the plurality of hydrogel-forming microneedles being configured to absorb interstitial fluid in the layer of skin upon penetrating the layer of skin, wherein, in use, the first microneedle array is applied to a target area of skin and the plurality of microneedles is inserted into the layer of skin to deliver an ink-removal solution to the layer of skin to release the embedded tattoo ink, and the second microneedle array is applied to the target area of skin after a predetermined time period from applying the first microneedle array.

[0025] In some embodiments, the plurality of microneedles of the first microneedle array may comprise a plurality of hollow microneedles configure, upon insertion into the layer of skin, to deliver the ink-removal solution to the layer of skin by injecting the ink-removal solution to the layer of skin through the hollow microneedles.

[0026] In some embodiments, the plurality of microneedles of the first microneedle array may be coated with the ink-removal solution, the ink-removal solution coating may be configured, upon insertion of the plurality of microneedles of the first microneedle array into the layer of skin, to dissolve into the layer of skin.

[0027] In some embodiments, the plurality of microneedles of the first microneedle array may at least be partially formed of the ink-removal solution in a solid form, and the solid form ink-removal solution may be configured, upon insertion of the plurality of microneedles of the first microneedle array into the layer of skin, to at least partially dissolve into the layer of skin.

[0028] In some embodiments, the plurality of microneedles of the first microneedle array may comprise a plurality of hydrogel-forming microneedles impregnated with the ink-removal solution, and the plurality of hydrogel-forming microneedles of the first microneedle array may be configured, upon insertion of the plurality of microneedles of the first microneedle array into the layer of skin, to release the ink-removal solution into the layer of skin.

[0029] In some embodiments, the second microneedle array may comprise an osmolyte configured to facilitate osmosis of interstitial fluid from the layer of skin towards the plurality of hydrogel-forming microneedles of the second microneedle array when released in the layer of skin adjacent the plurality of hydrogel-forming microneedles.

[0030] There may be various solutions suitable for use as the ink-removal solution as desired. In some embodiments, the ink-removal solution comprises lactic acid. Lactic acid occurs naturally in the body and is therefore harmless. Other active substances may additionally or alternatively be used as desired.

[0031] In some embodiments, a concentration of the lactic acid may be in a range of 0.01-20% by volume. Through using a lower lactic acid concentration in the ink-removal solution, it is possible to reduce the risk of damaging the skin.

[0032] A fourth aspect of the present technology provides a method of removing tattoo ink from skin, comprising: (a) applying a first microneedle array to a target area of skin, the first microneedle array being formed of a plurality of microneedles configured to penetrate a layer of skin in which the tattoo ink is embedded; (b) inserting the plurality of microneedles into the layer of skin to deliver an ink-removal solution to the layer of skin to release the embedded tattoo ink, the ink-removal solution comprising lactic acid at a concentration in a range of 0.01-20% by volume; (c) repeating steps (a) and (b) daily over one or more days; (d) applying a third microneedle array to the target area of skin, the third microneedle array being formed of a plurality of hollow microneedles configured to penetrate into the layer of skin; and (e) extracting the released tattoo ink by applying a negative pressure through the plurality of hollow microneedles.

[0033] According to an alternative embodiment of the present technology, the application of the first microneedle array is repeated over one or more days (e.g.l to 5 days, 5 to 10 days, 10 to 20 days, 20 to 30 days, over 30 days, etc.) using a lower lactic acid concentration in the ink-removal solution, which reduces the risk of damaging the skin while achieving satisfactory ink-removal results. The released tattoo ink may then simply be removed using a third microneedle array having hollow microneedles and applying a negative pressure (e.g. suction) through the hollow microneedles to extract the released tattoo ink.

[0034] A fifth aspect of the present technology provides a method of removing tattoo ink from skin, comprising: generating an output beam of laser radiation; directing the output beam of laser radiation to a target area of skin to release tattoo ink from a layer of skin in which the tattoo ink is embedded; applying a microneedle array to the target area of skin, the microneedle array being formed of a plurality of hydrogel-forming microneedles configured to penetrate the layer of skin; and inserting the plurality of hydrogel-forming microneedles into the layer of skin to allow the plurality of hydrogel-forming microneedles to absorb interstitial fluid in the layer of skin together with the released tattoo ink.

[0035] Implementations of the present technology each have at least one of the above-mentioned objects and / or aspects, but do not necessarily have all of them. It should be understood that some aspects of the present technology that have resulted from attempting to attain the above-mentioned object may not satisfy this object and / or may satisfy other objects not specifically recited herein.

[0036] Additional and / or alternative features, aspects and advantages of implementations of the present technology will become apparent from the following description, the accompanying drawings and the appended claims.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Embodiments will now be described, with reference to the accompanying drawings, in which: FIG. 1 shows exemplary implementations of a microneedle array for delivering an ink-removal solution;

[0039] FIG. 2 shows an exemplary microneedle array comprising hydrogel-forming microneedles;

[0040] FIG. 3 shows an exemplary microneedle array suitable for application of negative pressure; and

[0041] FIG. 4 shows a flow diagram of an exemplary method of removing tattoo ink from skin.

[0042] DETAILED DESCRIPTION

[0043] As discussed above, the use of high strength chemical solutions, such as a solution containing high concentration (e.g. 10-40% by volume) of lactic acid, is often required in conventional liquid removal techniques to ensure embedded tattoo ink is released from the encapsulating cells and ready for extraction during a treatment. At such high concentration, damages to the skin layers can occur, potentially leading to undesirable outcomes.

[0044] Conventional extraction techniques that rely on chemically induced inflammation and wound formation in the skin can lead to infections, while the use of a high negative pressure to extract released tattoo ink necessitates microneedles that are sufficiently strong to withstand the pressure, leading to increased costs.

[0045] Therefore, there remain scopes for improving the devices and methods for removing tattoo ink from skin.

[0046] Techniques of the present technology combine the use of microneedle patches as means for delivering an ink-removal solution (e.g. comprising lactic acid) to the appropriate layer of skin (e.g. the dermis), and the use of an extraction microneedle patch comprising either hydrogel-forming microneedles or hollow microneedles to remove the solubilized tattoo ink pigments.

[0047] According to embodiments of the present technology, an ink-removal solution is introduced to a layer of skin in which tattoo ink is embedded (e.g. the dermis) through applying a first microneedle array (e.g. a patch) to an appropriate target area of skin. The ink-removal solution is delivered to the layer of skin within the target area upon insertion of the plurality of microneedles of the first microneedle array. The ink-removal solution releases the tattoo ink embedded in the layer of skin over a predetermined period of time to allow the tattoo ink to be extracted, then a second microneedle array is applied to the same target area of skin to extract the released tattoo ink. In an embodiment, the second microneedle array comprises a plurality of hydrogelforming microneedles that are configured to absorb interstitial fluid from the layer of skin upon insertion into the skin. Inserting the hydrogel-forming microneedles into the skin layer draws interstitial fluid from the skin layer towards the hydrogel-forming microneedles under osmotic and capillary actions, and as such, released tattoo ink is absorbed by the hydrogel-forming microneedles together with interstitial fluid. Through the use of the first microneedle array, it is possible to deliver ink-removal solution to the appropriate target skin area effectively with minimal damages to the skin. Moreover, through the use of the second microneedle array, it is possible to extract the released tattoo ink from the layer of skin effectively with a reduced risk of damaging the area of skin and a significant reduction in manual labour.

[0048] In an alternative embodiment of the present technology, the application of the first microneedle array is repeated over one or more days using a low- strength ink-removal solution. The repeated application of a low-strength solution reduces the risk of damaging the skin while achieving satisfactory inkremoval results. The released tattoo ink may then simply be extracted using a third microneedle array having hollow microneedles and applying a negative pressure (e.g. suction) through the hollow microneedles.

[0049] In an implementation example, the first microneedle array may be implemented as a single-use microneedle patch loaded (described in more detail below) with an ink-removal solution such as a solution comprising lactic acid. Multiple single-use microneedle patches may be used, e.g. replaced daily on the appropriate target area of skin, to provide a sustained injection of ink-removal solution into the intradermal space for a predetermined time period sufficiently long to enable the ink-removal solution to release the embedded tattoo ink in the target area of skin, e.g. 1 to 5 days, 5 to 10 days, 10 to 20 days, 20 to 30 days, over 30 days, etc., depending e.g. on the strength of the ink-removal solution. In particular, the ink-removal solution may break down the static macrophages that encapsulate the tattoo ink pigments, releasing the pigments into the interstitial fluid. The loose tattoo ink pigments become soluble in lymph fluids which enables the pigments to be extracted using a suitable extraction method together with interstitial fluid.

[0050] FIG. 1 shows various examples of ink-removal solution delivery mechanism using a microneedle array / patch 100a, 100b, 100c, lOOd. There may be various ways to deliver the ink-removal solution to the layer of skin in which tattoo ink 150 is embedded, and a microneedle array may be configured as required based on the desired method of delivery. Preferably, the microneedle array comprises a plurality of microneedles with a length between 0.3mm and 3.5mm, preferably 0.5mm to 3mm and most preferably from 0.6mm to 2mm, to ensure the microneedles reach the desired skin layer (e.g. the dermis) to deliver the inkremoval solution to the desired skin layer. The microneedle array may have a needle density of 100 needles / 0.8cm2to 1000 needles / 0.8cm2, preferably 300 needles / 0.8cm2to 600 needles / 0.8cm2. In cases where the needle density exceeds 300 needles / 0.8cm2, an application device (not shown) may be provided to assist with the penetration of the needles into the skin tissues. In practice, needles density is generally determined based on the required payload but it may additionally or alternatively be determined on other bases.

[0051] In a preferred embodiment, a plurality of microneedles 130 of the microneedle array 100c is at least partially formed of the ink-removal solution in a solid form. In this case, the microneedles formed of solid ink-removal solution penetrate the skin to reach the desired skin layer, and the ink-removal solution is delivered to the skin layer by allowing the microneedles 130' to slowly dissolve (at least partially) into the skin layer. In doing so, a desired amount of inkremoval solution may be delivered to the desired skin layer easily and accurately in a single step.

[0052] In an alternative embodiment, the microneedle array 100a comprises a plurality of hollow microneedles 110. In this case, the ink-removal solution can be delivered to the desired layer of skin by injecting the ink-removal solution to the layer of skin through the hollow microneedles 110'. In a further embodiment, a plurality of microneedles 120 of the microneedle array 100b is coated with the ink-removal solution. When the microneedles 120 are inserted into the skin, reaching to the desired skin layer, the ink-removal solution is delivered to the layer of skin by allowing the inkremoval solution to dissolve from the microneedles 140' into the layer of skin.

[0053] In a yet further embodiment, the microneedle array lOOd comprises a plurality of hydrogel-forming microneedles 140 that is impregnated with the inkremoval solution. When the hydrogel-forming microneedles 140 penetrates the skin into the desired skin layer, the ink-removal solution is delivered to the layer of skin by allowing the plurality of hydrogel-forming microneedles 140' to slowly release the ink-removal solution into the layer of skin.

[0054] In a preferred embodiment, the ink-removal solution is a solution containing lactic acid. The strength of the ink-removal solution may vary as desired, for example, by varying the concentration of lactic acid. Varying the strength or concentration of the ink-removal solution may in turn vary the amount of time required for the ink-removal solution to release encapsulated tattoo ink. In embodiments where lactic acid is used as an active substance in the ink-removal solution, the concentration of lactic acid may for example vary between 0.01% and 20% by volume, preferably 0.1% - 10%.

[0055] The ink-removal solution loaded microneedle patch 100a, 100b, 100c or lOOd may be applied in a single application (e.g. if a higher-strength inkremoval solution is used), or multiple microneedle patches 100a, 100b, 100c or lOOd may be applied in multiple applications over a predetermined period of time (e.g. if a lower-strength ink-removal solution is used). In the former case, the microneedle patch may be left on the skin for less than an hour, one or more hours, or one or more days, as required, until the ink-removal solution has sufficient time to be released into the desired skin layer and release the embedded tattoo ink. In the latter case, a new microneedle patch may be applied to the same target skin area e.g. once every day for a period of several days, e.g. 1 to 5 days, 5 to 10 days, 10 to 20 days, 20 to 30 days, over 30 days, etc., until a sufficient amount of ink-removal solution has been released into the desired skin layer and has sufficient time to release the embedded tattoo ink. After application of the first microneedle patch 100, whether in a single application or multiple applications, over a predetermined time period, the released tattoo ink may be extracted using a suitable extraction method.

[0056] FIG. 2 shows an exemplary extraction method using a second microneedle patch 200 that comprises a plurality of hydrogel-forming microneedles 210. The hydrogel-forming microneedles 210 are configured to absorb fluid. When inserted into the skin layer in which the tattoo ink 250 is embedded, the hydrogel-forming microneedles 210 begins to absorb interstitial fluid in the skin layer which flows towards the hydrogel-forming microneedles 210' through osmosis and capillary action, and in doing so, the active substance from the inkremoval solution and the released ink particles are absorbed by the hydrogelforming microneedles 210'.

[0057] The hydrogel-forming microneedles 210 may be formed of any suitable and desirable material using a suitable method. For example, the hydrogel-forming microneedles 210 may be formed of a hydrophilic polymer such as Gantrez S-97 (a co-polymer of poly (methylvinylether co. maleic acid), e.g. dried by evaporation and then heat cured.

[0058] To promote and facilitate osmosis of the interstitial fluid (and therefore the tattoo ink) towards the hydrogel-forming microneedles 210, in some embodiments, the extraction microneedle patch 200 may be provided with an osmolyte that increases osmotic pressure in the region near the hydrogelforming microneedles 210, to promote osmosis of interstitial fluid from the skin layer towards the hydrogel-forming microneedles 210. In such embodiments, the osmolyte may be provided as a coating, embedded in the hydrogel-forming microneedles 210 or otherwise, and is released into the layer of skin adjacent the hydrogel-forming microneedles 210 when the hydrogel-forming microneedles 210 are inserted into the skin layer.

[0059] The application of the extraction microneedle patch 200 may for example be carried out by a healthcare professional or an authorized physician. The extracting microneedle patch 200 may be applied multiple times, dependent on the specific characteristics of the tattoo to be removed. If any remnants of the active substance from the ink-removal solution and / or small amount of the released tattoo ink remain in the skin layer, these will eventually be eliminated via the lymphatic system.

[0060] FIG. 3 shows an alternative extraction method using a hollow microneedle patch 300 which comprises a plurality of hollow microneedles 310. In use, the hollow microneedles 310 are inserted into the desired skin layer after the embedded tattoo ink is released. The hollow microneedle patch 300 further comprises an attachment 320 configured to attach to a pressure device 330 (e.g. an electrically powered vacuum pump) capable of provide a range of negative pressure. Once the hollow microneedles 310 are inserted, the device 330, attached to the hollow microneedle patch 300 via attachment 320, can be switched on to provide a negative pressure (e.g. suction) at a suitable level to extract the released tattoo ink (as well as active substance from the ink-removal solution remained in the skin layer) from the intradermal space through the hollow microneedles 310.

[0061] Extraction using the hollow microneedle patch 300 and application of a negative pressure may for example be carried out by a healthcare professional or an authorized physician.

[0062] FIG. 4 shows a flow diagram depicting a method of removing tattoo ink from skin according to an embodiment. The method 400 begins at S410, by applying a first microneedle array, e.g. in the form of a microneedle patch, to a target area of skin. The first microneedle array is formed of a plurality of microneedles that are configured to penetrate a layer of skin (e.g. the dermis) in which the tattoo ink is embedded, and the first microneedle array is preferably applied to a target area of skin where the tattoo ink is visible.

[0063] At S420, the plurality of microneedles of the first microneedle array is inserted into the layer of skin to deliver an ink-removal solution to the layer of skin to release the embedded tattoo ink. For example, the plurality of microneedles of the first microneedle array may be inserted into the layer of skin by application of sufficient pressure e.g. by manually pressing down onto the first microneedle array.

[0064] After a predetermined time period (e.g. minutes, hours, days) from applying the first microneedle array, at S430, a second microneedle array is applied to the target area of skin. The second microneedle array may e.g. be formed of a plurality of hydrogel-forming microneedles configured to penetrate the layer of skin.

[0065] Then, at S440, the plurality of hydrogel-forming microneedles is inserted into the layer of skin to allow the plurality of hydrogel-forming microneedles to absorb interstitial fluid in the layer of skin together with the released tattoo ink. Again, the plurality of microneedles of the second microneedle array may, for example, be inserted into the layer of skin by application of sufficient pressure e.g. by manually pressing down onto the first microneedle array.

[0066] In some embodiments, it may be desirable to apply a new first microneedle array, or re-apply the same first microneedle array with a new dose of inkremoval solution, periodically over the course of the predetermined time period before applying the second microneedle array. For example, a new first microneedle array may be applied to the target area of skin daily over one or more days (e.g. 7 days). This allows sufficient time and amount of ink-removal solution to release the embedded ink without using high-strength or high- concentration ink-removal solution that may cause damages to the skin. This optional step is shown in FIG. 4 as path A.

[0067] In an alternative embodiment, the first microneedle array is applied to a target area of skin (S410) and the plurality of microneedles is inserted into the layer of skin to deliver the ink-removal solution to the layer of skin to release the embedded tattoo ink (S420) using an ink-removal solution that comprises lactic acid at a concentration in a range of 0.01-20% by volume. Then, along path A, a new first microneedle array is applied, or the same first microneedle array is replenished with a new dose of ink-removal solution and reapplied, daily over one or more days, e.g. 7 days.

[0068] Then, along path B, at S450, a third microneedle array is applied to the target area of skin. The third microneedle array is formed of a plurality of hollow microneedles that is configured to penetrate into the layer of skin. The plurality of hollow microneedles is inserted into the layer of skin e.g. by manual pressure. Lastly, at S460, the released tattoo ink is extracted by applying a negative pressure (e.g. suction) through the plurality of hollow microneedles.

[0069] FIG. 5 shows a further alternative embodiment of a method 500 of removing tattoo ink from skin based on laser tattoo removal treatment. The method beings at S510 by generating, using suitable laser treatment equipment, an output beam of laser radiation at a suitable predetermined frequency (wavelength). The generated output beam is then directed to a target area of skin to release the tattoo ink that is embedded in a layer of skin in the target area (S520).

[0070] Then, at S530, a microneedle array is applied to the target area of skin. The microneedle array is formed of a plurality of hydrogel-forming microneedles that is configured to penetrate into the layer of skin.

[0071] At S540, the plurality of hydrogel-forming microneedles is inserted into the layer of skin, e.g. by manual pressure, to allow the plurality of hydrogel-forming microneedles to absorb interstitial fluid in the layer of skin together with the released tattoo ink.

[0072] According to the present embodiment, hydrogel-forming microneedle arrays as described herein may be used in combination with conventional laser tattoo removal treatment to more effectively remove tattoo ink from the skin. Thus, ink pigments that have been broken down by laser irradiation into small fragments may be removed from the skin quickly through the use of hydrogelforming microneedle array instead of waiting to be cleared away by the lymphatic system. It is therefore possible to reduce the time required to remove a tattoo using laser removal treatments.

[0073] The examples and conditional language recited herein are intended to aid the reader in understanding the principles of the present technology and not to limit its scope to such specifically recited examples and conditions. It will be appreciated that those skilled in the art may devise various arrangements which, although not explicitly described or shown herein, nonetheless embody the principles of the present technology and are included within its scope as defined by the appended claims.

[0074] Furthermore, as an aid to understanding, the above description may describe relatively simplified implementations of the present technology. As persons skilled in the art would understand, various implementations of the present technology may be of a greater complexity.

[0075] In some cases, what are believed to be helpful examples of modifications to the present technology may also be set forth. This is done merely as an aid to understanding and not to limit the scope or set forth the bounds of the present technology. These modifications are not an exhaustive list, and a person skilled in the art may make other modifications while nonetheless remaining within the scope of the present technology. Further, where no examples of modifications have been set forth, it should not be interpreted that no modifications are possible and / or that what is described is the sole manner of implementing that element of the present technology.

[0076] Moreover, all statements herein reciting principles, aspects, and implementations of the technology, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof, whether they are currently known or developed in the future.

[0077] It will be clear to one skilled in the art that many improvements and modifications can be made to the foregoing exemplary embodiments without departing from the scope of the present techniques.

Claims

CLAIMS1. A method of removing tattoo ink from skin, comprising: applying a first microneedle array to a target area of skin, the first microneedle array being formed of a plurality of microneedles configured to penetrate a layer of skin in which the tattoo ink is embedded; inserting the plurality of microneedles into the layer of skin to deliver an ink-removal solution to the layer of skin to release the embedded tattoo ink; applying a second microneedle array to the target area of skin after a predetermined time period from applying the first microneedle array, the second microneedle array being formed of a plurality of hydrogel-forming microneedles configured to penetrate the layer of skin; and inserting the plurality of hydrogel-forming microneedles into the layer of skin to allow the plurality of hydrogel-forming microneedles to absorb interstitial fluid in the layer of skin together with the released tattoo ink.

2. The method of claim 1, wherein the plurality of microneedles of the first microneedle array comprises a plurality of hollow microneedles, and the inkremoval solution is delivered to the layer of skin by injecting the ink-removal solution to the layer of skin through the hollow microneedles.

3. The method of claim 1, wherein the plurality of microneedles of the first microneedle array is coated with the ink-removal solution, and the ink-removal solution is delivered to the layer of skin by allowing the ink-removal solution to dissolve in the layer of skin.

4. The method of claim 1, wherein the plurality of microneedles of the first microneedle array is at least partially formed of the ink-removal solution in a solid form, and the ink-removal solution is delivered to the layer of skin by allowing the plurality of microneedles to at least partially dissolve into the layer of skin.

5. The method of claim 1, wherein the plurality of microneedles of the first microneedle array comprises a plurality of hydrogel-forming microneedles impregnated with the ink-removal solution, and the ink-removal solution is delivered to the layer of skin by allowing the plurality of hydrogel-formingmicroneedles of the first microneedle array to release the ink-removal solution into the layer of skin.

6. The method of any preceding claim, wherein the second microneedle array comprises an osmolyte configured to facilitate osmosis of interstitial fluid from the layer of skin towards the plurality of hydrogel-forming microneedles of the second microneedle array, the method further comprising allowing the osmolyte to be released in the layer of skin adjacent the plurality of hydrogel-forming microneedles.

7. The method of any preceding claim, wherein the predetermined time period is less than one hour, one or more hours, one or more days.

8. The method of any preceding claim, further comprising providing a plurality of first microneedle arrays, and applying a first microneedle array to a target area of skin comprises applying at least one of the plurality of first microneedle arrays for one or more days and applying at least another one of the plurality of first microneedle arrays for one or more days before applying the second microneedle array.

9. A microneedle patch for use in extracting tattoo ink from skin, the microneedle patch comprising a plurality of hydrogel-forming microneedles configured to penetrate a layer of skin into which the tattoo ink is embedded, the plurality of hydrogel-forming microneedles being configured to, upon insertion into the layer of skin, absorb interstitial fluid comprising the released tattoo ink from the layer of skin.

10. The microneedle patch of claim 9, wherein the microneedle patch comprises an osmolyte configured to facilitate osmosis of interstitial fluid from the layer of skin towards the plurality of hydrogel-forming microneedles of the microneedle patch when released into the layer of skin adjacent the plurality of hydrogelforming microneedles.

11. The microneedle patch of claim 10, wherein the osmolyte is maltose.

12. The microneedle patch of any of claims 9 to 11, wherein the plurality of hydrogel-forming microneedles comprises a hydrophilic polymer.

13. A kit of parts for removing tattoo ink from skin, comprising: a first microneedle array comprising a plurality of microneedles configured to penetrate a layer of skin in which the tattoo ink is embedded; and a second microneedle array comprising a plurality of hydrogel-forming microneedles configured to penetrate the layer of skin, the plurality of hydrogelforming microneedles being configured to absorb interstitial fluid in the layer of skin upon penetrating the layer of skin, wherein, in use, the first microneedle array is applied to a target area of skin and the plurality of microneedles is inserted into the layer of skin to deliver an ink-removal solution to the layer of skin to release the embedded tattoo ink, and the second microneedle array is applied to the target area of skin after a predetermined time period from applying the first microneedle array.

14. The kit of parts of claim 13, wherein the plurality of microneedles of the first microneedle array comprises a plurality of hollow microneedles configure, upon insertion into the layer of skin, to deliver the ink-removal solution to the layer of skin by injecting the ink-removal solution to the layer of skin through the hollow microneedles.

15. The kit of parts of claim 13, wherein the plurality of microneedles of the first microneedle array is coated with the ink-removal solution, the ink-removal solution coating being configured, upon insertion of the plurality of microneedles of the first microneedle array into the layer of skin, to dissolve into the layer of skin.

16. The kit of parts of claim 13, wherein the plurality of microneedles of the first microneedle array is at least partially formed of the ink-removal solution in a solid form, and the solid form ink-removal solution is configured, upon insertion of the plurality of microneedles of the first microneedle array into the layer of skin, to at least partially dissolve into the layer of skin.

17. The kit of parts of claim 13, wherein the plurality of microneedles of thefirst microneedle array comprises a plurality of hydrogel-forming microneedles impregnated with the ink-removal solution, and the plurality of hydrogel-forming microneedles of the first microneedle array is configured, upon insertion of the plurality of microneedles of the first microneedle array into the layer of skin, to release the ink-removal solution into the layer of skin.

18. The kit of parts of any of claims 13 to 17, wherein the second microneedle array comprises an osmolyte configured to facilitate osmosis of interstitial fluid from the layer of skin towards the plurality of hydrogel-forming microneedles of the second microneedle array when released in the layer of skin adjacent the plurality of hydrogel-forming microneedles.

19. The kit of parts of any of claims 13 to 17, wherein the ink-removal solution comprises lactic acid.

20. The kit of parts of claim 19, wherein a concentration of the lactic acid is in a range of 0.01-20% by volume.

21. A method of removing tattoo ink from skin, comprising:(a) applying a first microneedle array to a target area of skin, the first microneedle array being formed of a plurality of microneedles configured to penetrate a layer of skin in which the tattoo ink is embedded;(b) inserting the plurality of microneedles into the layer of skin to deliver an ink-removal solution to the layer of skin to release the embedded tattoo ink, the ink-removal solution comprising lactic acid at a concentration in a range of 0.01-20% by volume;(c) repeating steps (a) and (b) over one or more days;(d) applying a third microneedle array to the target area of skin, the third microneedle array being formed of a plurality of hollow microneedles configured to penetrate into the layer of skin; and(e) extracting the released tattoo ink by applying a negative pressure through the plurality of hollow microneedles.

22. A method of removing tattoo ink from skin, comprising: generating an output beam of laser radiation;directing the output beam of laser radiation to a target area of skin to release tattoo ink from a layer of skin in which the tattoo ink is embedded; applying a microneedle array to the target area of skin, the microneedle array being formed of a plurality of hydrogel-forming microneedles configured to penetrate the layer of skin; and inserting the plurality of hydrogel-forming microneedles into the layer of skin to allow the plurality of hydrogel-forming microneedles to absorb interstitial fluid in the layer of skin together with the released tattoo ink.

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