CN113730576B - Application of nano photo-thermal material in preparation of laser depilation drug - Google Patents

Abstract

The invention belongs to the technical field of depilation, and particularly discloses a nano photo-thermal material for laser depilation and a preparation method thereof, wherein the nano photo-thermal material comprises photo-thermal dye and a carrier, and the photo-thermal dye is wrapped by the carrier to form nano particles; the particle size of the nano-particles is 50-300nm. The preparation method of the nano photothermal material comprises the following steps: and mixing the photo-thermal dye and the carrier to prepare the nano photo-thermal material. The hair is promoted to fall off based on the nano photothermal material, the nano photothermal material with photothermal effect is coated on the part, the nano photothermal material is easy to be enriched on hair follicle parts after being coated on skin parts due to small particle size of the nano photothermal material, the photothermal effect is generated by absorbing the light energy of laser through the nano photothermal material, the light energy is quickly converted into heat energy, and the hair follicles are necrotized by means of the heat energy, so that the aim of preventing the hair from growing is fulfilled.

Description

Application of nano photo-thermal material in preparation of laser depilation drug

Technical Field

The invention belongs to the technical field of depilation, and particularly relates to a laser depilation nano photothermal material and a preparation method thereof.

Background

The most common depilation mode at present is laser depilation, which utilizes the selective photothermal effect of laser, and laser can penetrate through the surface layer of skin to reach the root hair follicle of hair by reasonably adjusting the energy pulse width of laser wavelength. Melanin in the hair follicle selectively absorbs light energy and converts it to heat energy, the resulting thermal effect causing the follicle to necrose and the hair to no longer grow. However, hair follicles have a fixed growth cycle, divided into anagen, catagen and telogen phases. Only the hair follicle in the anagen phase has a large form and is sensitive to light, and the hair follicle in other phases has a small form and is easy to escape the action of laser, so that the hair follicle which is not completely damaged still grows out in the next growth cycle, and needs to be subjected to laser treatment for many times. In addition, the laser depilation process can cause obvious pain, and the depilation part can cause side effects of slight red and swelling, sensitive skin, heat or pruritus and the like, so that a plurality of people cannot tolerate the laser depilation treatment for a plurality of times.

The current clinical laser depilation treatment steps are: the hair of the part needing to be unhaired is shaved short, ointment such as aloe gel is coated on the upper surface of the part to relieve pain caused by laser unhairing, then the wavelength is adjusted, melanin in the hair follicle can absorb light energy excited by laser and convert the light energy into heat energy, and the hair follicle in the growth period is burned.

Therefore, there is a need to develop a depilatory material, which can destroy the hair follicles in each growth cycle at one time, increase the depilatory efficiency, and reduce the number of times of depilation.

Disclosure of Invention

The invention provides a laser depilation nano photothermal material and a preparation method thereof, which aim to solve one or more technical problems in the prior art and at least provide a beneficial selection or creation condition.

The invention conception of the invention is as follows: the nanometer photothermal material is used for promoting hair loss, the nanometer photothermal material carrying photothermal effect (photothermal effect: the effect that the material converts light energy into heat energy due to the change of temperature) is coated on the part, the particle size of the nanometer photothermal material is small, the nanometer photothermal material is easy to be enriched on hair follicle parts after being coated on skin parts, the photothermal effect is generated by the nanometer photothermal material through absorbing the light energy of laser, the light energy is rapidly converted into the heat energy, and the hair follicles are necrotized by the heat energy, so that the purpose that the hair does not grow any more is achieved.

In order to overcome the technical problems, the invention provides a nano photothermal material in a first aspect.

Specifically, the nano photo-thermal material comprises a photo-thermal dye and a carrier, wherein the carrier wraps the photo-thermal dye to form nano particles; the particle size of the nano-particles is 50-300nm.

The selected photo-thermal dye is a photo-thermal material, has the characteristic of absorbing near infrared light and can induce strong photo-thermal effect, namely, after the photo-thermal dye absorbs the light radiation energy, the absorbed light energy can be changed into heat energy to cause the temperature to rise. The effect of carrier is mainly the parcel photothermal dye makes photothermal dye keep better stability, and the carrier parcel photothermal dye forms the nanoparticle, and the particle diameter of nanoparticle is little, when using as nanometer photothermal material, can make it enrich in the hair follicle position better, absorbs the light energy rapidly and converts into heat energy to the realization burns out the hair follicle, when making the hair shed, no longer grows. Meanwhile, the photothermal dye lacks stability in blood circulation, is easy to be cleared out of the body under the influence of aggregation, and cannot generate other side effects on the body.

Preferably, the photothermal dye is at least one selected from the group consisting of indocyanine green, prussian blue, cuS, znS, and indocyanine green derivatives. These photothermal dyes have good near-infrared light absorption characteristics and can induce strong photothermal effects, and the indocyanine green derivative contains NH ₂ Amino, COOH carboxyl, NHS activated lipids, MAL maleimide, SH thiol, N ₃ Azide, ALK alkyne, biotin, and the like.

As a further improvement of the above scheme, the mass ratio of the photothermal dye to the carrier is (1-2): 1.

preferably, the carrier comprises a polylactic acid-glycolic acid copolymer. Specifically, the polylactic acid-glycolic acid copolymer is a nano material, and the polylactic acid-glycolic acid copolymer (PLGA) is formed by random polymerization of two monomers, namely lactic acid and glycolic acid, is a degradable functional polymer organic compound, and has good biocompatibility, no toxicity and good encapsulation and film forming performances. The PLGA is used as a carrier of the photothermal dye to wrap the photothermal material to form the nano-particles.

As a further improvement of the scheme, the raw material component for preparing the nano photothermal dye also comprises at least one of a first solvent, a second solvent and an emulsifier besides the photothermal dye and the carrier.

Preferably, the first solvent comprises a methanol solution.

Preferably, the second solvent comprises an acetonitrile solution.

Preferably, the emulsifier comprises an aqueous PVA solution.

The invention provides a preparation method of a nano photothermal material.

Specifically, the preparation method of the nano photothermal material comprises the following steps: and mixing the photo-thermal dye and a carrier to prepare the nano photo-thermal material.

As a further improvement of the above scheme, a method for preparing a nano photothermal material comprises the following steps:

adding the photo-thermal dye into a first solvent, and carrying out ultrasonic mixing and dissolving to prepare a photo-thermal dye solution;

adding the carrier into a second solvent, and carrying out ultrasonic mixing and dissolving to prepare a carrier solution;

mixing the photo-thermal dye solution and the carrier solution, adding the mixture into an emulsifier under magnetic stirring, and carrying out vortex to prepare an emulsion;

and magnetically stirring the emulsion, performing centrifugal separation, sucking out supernatant, using water with the same volume as the supernatant to resuspend the particle precipitate, and centrifuging to obtain the nano photothermal material.

The third aspect of the invention provides an application of the nano photothermal material.

In particular to the application of the nano photo-thermal material in laser depilation.

Preferably, the laser in the laser depilation has a near infrared wavelength, and the near infrared wavelength is 780-1100nm.

Still preferably, the nano photothermal material may be applied to hair follicles of skin sites of the face, armpit, hand or leg, and the nano photothermal material is used in combination with a laser when applied to the skin of the face, armpit, hand or leg of the subject.

Compared with the prior art, the technical scheme of the invention at least has the following technical effects or advantages:

the existing laser depilation technology has the function that some small hair follicles are easy to hide from laser, only the hair follicles in the growth period have larger shapes and are sensitive to light, the hair follicles in other periods have smaller shapes and are easy to escape from the laser, so the hair follicles which are not completely damaged still can grow out in the next growth period, and the laser action needs to be carried out for many times. The nano photothermal material with photothermal dye wrapped by the carrier is prepared, the nano photothermal material and the laser act together, the photothermal effect of the nano photothermal material is generated by means of the light energy of the laser, and meanwhile, the nano photothermal material is controlled to be nano particles, the small-size effect of the nano particles can be better enriched in hair follicle parts, the light energy is quickly absorbed and converted into heat energy, the necrosis of the hair follicles in various periods is promoted, the hair removal effect is obviously improved, and the laser hair removal times are reduced.

Drawings

FIG. 1 is a schematic diagram of the application of the nano photo-thermal material to laser depilation;

FIG. 2 is a particle size distribution diagram of the nano photo-thermal material prepared in example 1 of the present invention;

FIG. 3 is a graph showing the results of hair loss in example 2 of the present invention.

Detailed Description

The present invention is described in detail below by way of examples to facilitate understanding of the present invention by those skilled in the art, and it is to be specifically noted that the examples are provided only for the purpose of further illustrating the present invention and are not to be construed as limiting the scope of the present invention.

The experimental animals in the following examples were C57 mice, available from the medical experimental animals center of guangdong province; indocyanine green was purchased from Sigma-Aldrich (cat # 1340009); polylactic-co-glycolic acid (PLGA) is available from MedChem Express Inc. (Cat. No: HY-B2247); polyvinyl alcohol (PVA); methanol (chromatographic grade); acetonitrile (chromatographic grade); the experimental water was ultrapure water.

Example 1

The nano photothermal material is prepared from raw materials including indocyanine green, polylactic acid-glycolic acid copolymer, methanol solution, acetonitrile solution and PVA (polyvinyl acetate) aqueous solution, wherein the indocyanine green is wrapped by the polylactic acid-glycolic acid copolymer to form nanoparticles, the particle size of the nanoparticles is 220-300nm, and the mass ratio of the indocyanine green to PLGA is 1.67:1.

a preparation method of a nano photothermal material comprises the following steps:

adding 10mg of indocyanine green into 1mL of methanol solution, and performing ultrasonic mixing and dissolving to prepare indocyanine green solution;

adding 6mg of PLGA into 3mL of acetonitrile solution, and carrying out ultrasonic mixing and dissolving to obtain a PLGA solution;

mixing the indocyanine green solution and the PLGA solution, adding the mixture into 5mL of PVA aqueous solution with the content of 5 percent under magnetic stirring, and vortexing the mixture for 30 seconds to prepare uniform emulsion;

magnetically stirring the emulsion at 700rpm/min for 10min, and centrifuging at 16000g/min for 20min;

stirring the emulsion by magnetic force, centrifuging, sucking out the supernatant, resuspending the particles with ultrapure water having the same volume as the supernatant for precipitation, centrifuging at 16000g/min for 6min, repeating the step three times to obtain the indocyanine green-PLGA nano photothermal material, wherein the particle size measurement result of the indocyanine green-PLGA nano photothermal material is shown in FIG. 2, and the concentration of the ordinate in FIG. 2 is the mass concentration of the indocyanine green-PLGA nano photothermal material corresponding to different particle sizes.

Example 2

An application experiment of the nano photothermal material prepared in the embodiment 1 in laser depilation is performed, wherein the working principle of the laser depilation is shown in fig. 1, and the specific steps are as follows:

c57 mice of 8 weeks old are anesthetized by intraperitoneal injection of 0.1% pentobarbital sodium, hairs on the backs of the C57 mice are removed by using WENTING depilatory cream, the backs of the mice are wiped clean by using clear water and divided into upper backs and lower backs, the upper backs and the lower backs are respectively provided with a 3mm circle and used as treatment parts, and mark is carried out by using a mark pen;

dipping 40 mu L of indocyanine green-PLGA nano photothermal material by using a wet cotton swab, and coating the indocyanine green-PLGA nano photothermal material on a treated part on the upper back of a mouse to serve as an experimental part; the treated area of the lower back of the mouse was left untreated and served as a control area. As shown in fig. 3, a dotted line frame a indicates an experimental site, and a dotted line frame B indicates a control site.

Irradiating the treatment parts of the upper back and the lower back with a laser wavelength of 808nm for 5min respectively, wherein the irradiation range is 3mm, monitoring the temperature of the back skin of the mouse in real time by using a thermal infrared imager, controlling the body surface temperature at 37-40 ℃, and carrying out ice compress on the parts subjected to laser for 30s.

The hair growth of the treated areas on the upper and lower backs of the mice was observed, and the results are shown in fig. 3, and it can be seen from fig. 3 that the hair shedding effect of the experimental area with the dotted line frame a applied with indocyanine green-PLGA nano photothermal material and the laser is significantly better than that of the control area with the dotted line frame B applied with the laser only.

Example 3

Example 3 differs from example 1 in that: in example 3, the mass ratio of indocyanine green to PLGA is 1:1, the application experiment of the nano photo-thermal material in laser depilation is the same as that of the embodiment 2.

Example 4

Example 4 differs from example 1 in that: the mass ratio of indocyanine green to PLGA in example 4 was 2:1, the application experiment of the nano photothermal material in laser depilation is the same as that of the embodiment 2.

Example 5

Example 5 differs from example 1 in that: the mass ratio of indocyanine green to PLGA in example 5 was 0.8:1, the application experiment of the nano photo-thermal material in laser depilation is the same as that of the embodiment 2.

Example 6

Example 6 differs from example 1 in that: the mass ratio of indocyanine green to PLGA in example 6 was 2.2:1, the application experiment of the nano photothermal material in laser depilation is the same as that of the embodiment 2.

Comparative example 1

Comparative example 1 differs from example 1 in that: the particle size of the nano photothermal material prepared in the comparative example 1 is less than 50nm and 10-40nm, and the application experiment of the nano photothermal material in laser depilation is the same as that of the example 2.

Comparative example 2

Comparative example 2 differs from example 1 in that: the particle size of the nano photo-thermal material prepared in the comparative example 2 is larger than 300nm and is 310-360nm, and the application experiment of the nano photo-thermal material in laser depilation is the same as that in the example 2.

Comparative example 3

Comparative example 3 differs from example 2 in that: the nano photothermal material used in example 2 was replaced with aloe vera gel, and the other experimental steps and parameters were the same as those of example 2.

Results of the experiment

The photothermal nanomaterials prepared in examples 1, 3 to 6 and comparative examples 1 to 3 were subjected to the application test in laser depilation in the same manner as in example 2, and the hair regrowth rate at each test site was observed and counted after 10 days, wherein: hair regrowth ratio = the number of regenerated hairs/the number of original hairs × 100%, and the experimental results are shown in table 1.

Table 1: comparative table of hair regrowth rate of each example and comparative example

Sample(s)	Hair regeneration Rate (%)
		Example 1	0
Example 3	0
		Example 4	0
Example 5	3
		Example 6	1
Comparative example 1	4
		Comparative example 2	6
Comparative example 3	20

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications derived therefrom are intended to be within the scope of the present invention.

Claims (7)

1. The application of the nano photothermal material in the preparation of the laser depilation drug is characterized in that the nano photothermal material comprises a photothermal dye and a carrier, and the carrier wraps the photothermal dye to form nanoparticles; the particle size of the nano-particles is 50-300nm;

the photo-thermal dye is indocyanine green;

the mass ratio of the photothermal dye to the carrier is (1-2): 1; the carrier is polylactic acid-glycolic acid copolymer.

2. The use of claim 1, wherein the raw material components for preparing the nano photothermal material further comprise at least one of a first solvent, a second solvent, and an emulsifier.

3. The use of claim 2, wherein the first solvent comprises a methanol solution; the second solvent comprises acetonitrile solution.

4. Use according to claim 2, wherein the emulsifier comprises an aqueous solution of PVA.

5. The use according to claim 1, characterized in that said nano photothermal material is obtained by a preparation method comprising the following steps: and mixing the photo-thermal dye and a carrier to prepare the nano photo-thermal material.

6. The use according to claim 5, wherein the nano photothermal material is prepared by a preparation method comprising the following steps:

adding the photo-thermal dye into a first solvent, and carrying out ultrasonic mixing and dissolving to prepare a photo-thermal dye solution;

adding the carrier into a second solvent, and carrying out ultrasonic mixing and dissolving to obtain a carrier solution;

mixing the photo-thermal dye solution and the carrier solution, adding the mixture into an emulsifier under magnetic stirring, and carrying out vortex to prepare an emulsion;

and magnetically stirring the emulsion, performing centrifugal separation, sucking out supernatant, using water with the same volume as the supernatant to resuspend the particle precipitate, and centrifuging to obtain the nano photothermal material.

7. The use according to claim 1, wherein the laser has a wavelength of 780-1100nm.

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