Borneolum type cinnamomum burmanni leaf carbon quantum dots as well as preparation method and application thereof

Abstract

The invention discloses a borneol type cinnamomum burmanni leaf carbon quantum dot as well as a preparation method and application thereof. The preparation method comprises the following steps: cleaning fresh borneol type cinnamomum burmannii leaves, drying and crushing to obtain borneol type cinnamomum burmannii leaf powder, mixing the borneol type cinnamomum burmannii leaf powder with a solvent, and carrying out solvothermal reaction; centrifuging the reaction product, filtering the obtained supernatant with a 0.22 [mu] m filter membrane, dialyzing the obtained filtrate, and drying the dialysate to obtain the borneol type cinnamomum burmanni leaf carbon quantum dots. The preparation method is simple and easy to operate, and large-scale production is realized. The borneol type cinnamomum burmannii leaf carbon quantum dots obtained by the preparation method are excellent in permeation promotion effect and have the effects of resisting inflammation and inhibiting scar hyperplasia.

Description

Technical Field

[0001] The invention relates to a carbon quantum dot, in particular to a borneol-type burman wood leaf carbon quantum dot and a preparation method and application thereof. Background Art

[0002] Borneol, also known as natural borneol, is mainly composed of dextrorotatory borneol and is a precious raw material for medicine, daily chemicals and food.

[0003] The skin is the largest organ in the human body. It protects against the outside world by resisting external substances and preventing water loss. Transdermal drug delivery is a convenient alternative to subcutaneous injection and oral administration routes, avoiding the first-pass effect in the liver. This method also has the advantages of being painless, non-invasive, easy to use, and controlled release. It is estimated that by 2026, the global transdermal drug delivery market will reach US$10.67 billion. This growth trend reflects the increasing popularity and acceptance of transdermal drug delivery technology around the world. However, the skin acts as an external barrier to prevent exogenous compounds (including drugs) from entering the body, which poses a major challenge to transdermal drug delivery. The skin mainly consists of three layers: epidermis, dermis, and subcutaneous tissue. How to increase the penetration rate of the stratum corneum and improve the absorption pathway of the stratum corneum is of great significance for improving the bioavailability of the active ingredients in the drug and enhancing the efficacy of the drug ingredients.

[0004] Scars usually occur secondary to surgical trauma, burns or other traumas. They are fibrotic lesions of skin tissue caused by pathological healing of wounds after injury. Scar formation usually has three stages, namely the inflammatory stage, the proliferation stage, and the remodeling stage. In the inflammatory stage, tissue damage stimulates an inflammatory response, and chemotactic mast cells, neutrophils, macrophages and other inflammatory cells migrate to the wound surface, releasing growth factors and inflammatory factors. Excessive release will directly or indirectly promote fibroblast (HSF) proliferation, collagen gene expression and collagen synthesis increase; in the proliferation stage, it further stimulates the massive production of HSF and ECM; in the remodeling stage, because the excessive accumulation of ECM is difficult to be absorbed or remodeled by the body in time, fibrotic lesions occur.

[0005] The formation of scars can bring extremely serious adverse effects to the patient's body and mind. For this reason, more and more people choose to use external scar creams, scar creams, scar essential oils and other methods to treat scars. However, due to the existence of the skin barrier, such external application products usually need long-term use to show a more obvious scar removal effect. How to improve the transdermal absorption effect of scar removal products, and in the process of promoting skin regeneration, regulate the inflammatory response in stages, reduce or even prevent melanin deposition, so as to quickly achieve a good scar removal effect through external application, is still a huge challenge. At present, commonly used chemical penetration enhancers include azone, surfactants, etc., but there are problems such as poor stability and the penetration effect needs to be improved. Or nanoliposomes and nanoemulsions are used to load drugs, but they are faced with high preparation costs and limited drug loading. Therefore, designing safe, efficient and stable nano transdermal scar inhibitors is a technical problem that needs to be solved by technicians in this field. Summary of the invention

[0006] The primary purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and provide a method for preparing borneol-type burman wood leaf carbon quantum dots.

[0007] Another object of the present invention is to provide borneol-type burman wood leaf carbon quantum dots obtained by the above-mentioned preparation method.

[0008] Another object of the present invention is to provide an application of the above-mentioned borneol-type burman wood leaf carbon quantum dots.

[0009] The purpose of the present invention is achieved through the following technical solutions:

[0010] A method for preparing borneol-type burman wood leaf carbon quantum dots comprises the following steps:

[0011] (1) washing fresh borneol-type Cinnamomum burmanii leaves, drying them, and crushing them to obtain borneol-type Cinnamomum burmanii leaf powder, and storing it away from light for later use;

[0012] (2) mixing the borneol-type burman tree leaf powder obtained in step (1) with a solvent to perform a solvothermal reaction;

[0013] (3) centrifuging the product after the solvothermal reaction, filtering the obtained supernatant using a 0.22 μm filter membrane, and dialyzing the obtained filtrate;

[0014] (4) Drying the dialysate to obtain borneol-type Cinnamomum burmanii leaf carbon quantum dots.

[0015] The degree of pulverization in step (1) is preferably such that the pulverization can pass through a 60-mesh sieve.

[0016] The solvent described in step (2) is preferably at least one of anhydrous ethanol, acetone and water; preferably anhydrous ethanol.

[0017] The amount of the solvent in step (2) is preferably calculated based on 20 to 40 mL of solvent per 0.2 g of borneol-type Cinnamomum burmanii leaf powder; more preferably, 30 mL of solvent per 0.2 g of borneol-type Cinnamomum burmanii leaf powder.

[0018] The solvent thermal reaction conditions in step (2) are 150-280° C. for 4-12 h; preferably 150-200° C. for 4-8 h; more preferably 180° C. for 6 h.

[0019] The centrifugation conditions in step (3) are preferably 5000-15000 rpm for 3-20 min; more preferably 10000 rpm for 5 min.

[0020] The specification of the dialysis bag used in the dialysis described in step (3) is preferably 500Da.

[0021] The dialysis time in step (3) is preferably 6 to 48 hours, more preferably 12 hours.

[0022] The drying step described in step (4) is preferably as follows: first rotary evaporation for concentration, then freeze drying; or first rotary evaporation for concentration, then drying in a blast drying oven, and finally freeze drying.

[0023] The drying conditions are preferably a temperature of 50-80° C. and a time of 12-24 hours; more preferably a temperature of 60° C. and a time of 24 hours.

[0024] A kind of borneol-type burman wood leaf carbon quantum dots are obtained by the above preparation method.

[0025] The borneol-type Cinnamomum burmanii leaf carbon quantum dots have good transdermal penetration promoting effect and anti-inflammatory activity.

[0026] Therefore, the above-mentioned borneol-type burman wood leaf carbon quantum dots are used in the preparation of skin care products.

[0027] The skin care product is a skin care product which at least has the effects of anti-inflammatory and inhibiting scar hyperplasia.

[0028] A skin care product contains the borneol-type burman wood leaf carbon quantum dots.

[0029] The skin care product further contains at least one of whitening active ingredients, moisturizing ingredients and firming ingredients; preferably, it further contains at least one of niacinamide, arbutin, glabridin and hyaluronic acid.

[0030] Compared with the prior art, the present invention has the following advantages and effects:

[0031] (1) The present invention provides a method for preparing borneol-type Cinnamomum burmanii leaf carbon quantum dots, which is simple, easy to operate, and can achieve large-scale production. The borneol-type Cinnamomum burmanii leaf carbon quantum dots obtained by the preparation method can be used as a penetration enhancer to achieve the penetration enhancement effect on the effective ingredients in cosmetic transdermal drugs, and the cosmetic penetration enhancement effect is increased. Moreover, the borneol-type Cinnamomum burmanii leaf carbon quantum dots, which are the source of the borneol-type Cinnamomum burmanii leaf, are rich in resources and easy to obtain. The present invention improves the comprehensive utilization of the resources of the borneol-type Cinnamomum burmanii tree and has great economic value.

[0032] (2) The borneol-type Cinnamomum burmanii leaf carbon quantum dots provided by the present invention have excellent physical properties of carbon quantum dots themselves, such as nanoscale size, strong tissue penetrability, and good stability. Compared with the chemical penetration enhancer azone that has been widely used on the market, the carbon quantum dots can show a better penetration-enhancing effect at a lower concentration.

[0033] (3) Traditional scar removal products usually only regulate tissue repair and collagen deposition in one direction, such as promoting tissue repair, inhibiting collagen deposition or promoting collagen degradation. The borneol-type Cinnamomum burmanii leaf carbon quantum dots provided by the present invention fully consider the different needs for tissue repair at various stages of wound healing: wound healing is divided into three stages, namely the inflammatory stage, the proliferation stage and the remodeling stage. In the inflammatory and proliferation stages, it is necessary to promote angiogenesis and wound healing and simultaneously fight inflammation. Therefore, the borneol-type Cinnamomum burmanii leaf carbon quantum dots provided by the present invention generate red light under laser excitation, and the red light can stimulate cell metabolism, promote fibroblast proliferation and collagen synthesis. In addition, the red light it emits can penetrate the surface layer of the skin and reach the dermis. In the dermis, red light can activate mitochondria in cells, increase the production of adenosine triphosphate (ATP), and provide energy for the metabolic activities of cells. It can promote the generation of new blood vessels, provide better nutrition supply for the skin, and restore the skin to normal function and appearance faster. This helps to accelerate the repair of damaged skin, promote wound healing, and reduce scar formation.

[0034] (4) The borneol-type Cinnamomum burmanii leaf carbon quantum dots provided by the present invention also have antioxidant activity. When whitening ingredients are added to the preparation of cosmetics, tyrosinase activity is inhibited, melanin deposition is prevented, and the skin color at the scar becomes darker, thereby further preventing the formation of scars. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is the UV-visible spectra of the borneol-type Cinnamomum burmanii leaf carbon quantum dots (MCD) prepared in Example 1 and Example 2, and the photographs of the borneol-type Cinnamomum burmanii leaf carbon quantum dots under sunlight and a handheld 365nm UV lamp.

[0036] Figure 2 It is an in vitro permeation curve diagram of carbon quantum dots prepared in Example 1 and Example 2 to promote nicotinamide.

[0037] Figure 3 This is a graph showing the detection results of the carbon quantum dots prepared in Example 1 inhibiting ROS induced by CuSO4.

[0038] Figure 4 This is a graph showing the detection results of the carbon quantum dots prepared in Example 1 inhibiting CuSO4-induced NO. DETAILED DESCRIPTION

[0039] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0040] Example 1: Preparation of borneol-type Cinnamomum burmanii leaves carbon quantum dots

[0041] Wash and dry the borneol-type Cinnamomum burmanii leaves, then dry them, crush them through a 60-mesh sieve, and obtain borneol-type Cinnamomum burmanii leaf powder. Weigh 0.2g of borneol-type Cinnamomum burmanii leaf powder, add 30mL of anhydrous ethanol, transfer the solution to a hydrothermal reactor lined with tetrafluoroethylene, react at 180°C for 6h, and cool to room temperature. Transfer the solution in the reactor to a 50mL centrifuge tube, centrifuge at 10000rpm for 5min, take the supernatant and filter it with a 0.22μm filter membrane, and then dialyze it in anhydrous ethanol with a 500Da dialysis bag for 12h. The dialyzed solution is concentrated by rotary evaporation, the concentrated solution is collected and placed in a blast drying oven at 60°C for 24h, and freeze-dried, and the final powder is the purified fluorescent carbon quantum dots, referred to as MCD-E.

[0042] The size and morphology of the borneol-type Cinnamomum burmanii leaf carbon quantum dots were observed using a JEM-1400FLASH transmission electron microscope. The results of the transmission electron microscope observation showed that the average particle size of the carbon quantum dots was about 2.850nm, the lattice spacing was 0.214nm, and the high-resolution electron microscope had a graphitized core structure. Figure 1 As shown, full wavelength scanning is performed by ultraviolet spectrophotometer, and its main peak of fluorescence emission is located near 674nm, with a peak at 414nm; borneol-type cinnamomum burmanii leaf carbon quantum dot alcohol solution (the freeze-dried fluorescent carbon quantum dot powder of this embodiment is dispersed in 1% v / v ethanol solution, with a concentration of 0.37% w / w) is visible to the naked eye under 365nm handheld ultraviolet lamp. Under different excitation wavelengths, its emission wavelength will change accordingly, and the highest quantum yield is 29.09%. Taking quinine sulfate as the standard, the fluorescence quantum yield of the borneol-type cinnamomum burmanii leaf carbon quantum dot alcohol solution of the sample to be tested is directly obtained by the "fluorescence quantum yield" software of the fluorescence spectrophotometer.

[0043] Example 2: Preparation of borneol-type Cinnamomum burmanii leaves carbon quantum dots

[0044] Wash and dry the borneol-type Cinnamomum burmanii leaves, then dry them, crush them through a 60-mesh sieve, and obtain borneol-type Cinnamomum burmanii leaf powder. Weigh 0.2g of borneol-type Cinnamomum burmanii leaf powder, add 20mL of deionized water, transfer the solution to a hydrothermal reactor lined with tetrafluoroethylene, react at 180°C for 6h, and cool to room temperature. Transfer the solution in the reactor to a 50mL centrifuge tube, centrifuge at 10000rpm for 15min, take the supernatant and filter it with a 0.22μm filter membrane, and then dialyze it in deionized water with a 500Da dialysis bag for 12h. The dialyzed solution is concentrated by rotary evaporation and freeze-dried, and the final powder is the purified fluorescent carbon quantum dots, referred to as MCD-W.

[0045] Observation by transmission electron microscopy shows that the average particle size of the carbon quantum dots is about 5.215nm, and high-resolution electron microscopy shows a graphitized core structure. Figure 1 As shown, its main peak of fluorescence emission is located near 360nm, and the highest quantum yield is 9.89%. The fluorescence quantum yield is directly calculated by the "fluorescence quantum yield" software of the fluorescence spectrophotometer, and quinine sulfate needs to be set as the standard. The borneol-type burman tree leaf carbon quantum dot aqueous solution (the freeze-dried fluorescent carbon quantum dot powder of this embodiment is dispersed in deionized water, and the concentration is 0.37% w / w) is visible to the naked eye under the irradiation of a 365nm handheld ultraviolet lamp.

[0046] Example 3: Study on the effect of borneol-type burman tree leaf carbon quantum dots on promoting nicotinamide transdermal penetration

[0047] (1) Preparation of ex vivo skin

[0048] Purchase pig skin and store it at -20℃. In order to simulate the real physiological state of skin and improve the accuracy of the experiment, some pretreatment is done on the skin before installing it into the transdermal diffusion instrument. The skin is soaked in PBS (pH 7.4) for 30 minutes, and the temperature is controlled at 32-37℃, which is close to the body temperature of the pig.

[0049] (2) Experimental procedures

[0050] The treated pig skin stratum corneum was fixed upward on the Franz diffusion cell, with the stratum corneum facing the supply pool. After adding a magnetic rotor to the receiving chamber, the receiving liquid was added to the scale, and the bubbles were exhausted to make the liquid close to the skin. Isotonic PBS (pH 7.2) was used as the receiving liquid and injected into the receiving pool. The setting parameters were: water bath temperature (32±0.2)℃ constant temperature, speed (300.0±1.0)rpm, after 30min of equilibrium, 0.5mL of the transdermal drug delivery preparation was placed in the supply pool. After applying a nicotinamide solution with a concentration of 1% by mass and a borneol-type cinnamomum burmanii leaf carbon quantum dots (MCDs) solution with a concentration of 0.37% by mass (the freeze-dried sample was dissolved in a 1% ethanol solution or aqueous solution), the interval sampling time was set at 0.5, 1, 1.5, 2, 4, 6, and 8h, respectively. Each time, 2.0mL of the transdermal receiving liquid sample was drawn from the receiving pool, and 2.0mL of the same receiving liquid at the same temperature was added to the receiving pool, and the sample volume was replaced with the receiving liquid. The solution samples were filtered through a 0.45 μm Millipore filter, analyzed by UV spectrophotometry, and the cumulative permeation per unit area was calculated. In addition, a positive control group and a negative control group were set up, the positive control group was a 1% azone solution by mass percentage, and the negative control group was a 1% nicotinamide solution by mass percentage.

[0051] (3) Sample determination

[0052] In the transdermal diffusion experiment, the absorbance of the sample was measured directly after sampling, the sample was measured three times in parallel, and the concentration was calculated based on the standard curve.

[0053] (4) Establishment of nicotinamide standard curve

[0054] 1) Preparation of standard solution

[0055] Accurately weigh 0.3000g of nicotinamide standard into a 50mL beaker, dissolve it with water, transfer it to a 100mL volumetric flask, and dilute it to the mark with water to form a standard stock solution (3000μg / mL). Then draw 10.00mL of the standard stock solution into a 100mL volumetric flask, dilute it to the mark with water as the standard working solution (300μg / mL).

[0056] 2) Determine the absorbance and draw a standard curve

[0057] 0, 1.00, 2.00, 4.00, 6.00, 8.00, 10.00 mL of nicotinamide standard solution (300 μg / mL) were respectively pipetted into a 100 mL volumetric flask and diluted to the mark with water. The mass concentrations of the standard solutions in this series are 0, 3.000, 6.000, 12.000, 18.000, 24.000, 30.000 μg / mL, respectively. A standard curve was drawn with the absorbance A at 262 nm versus the mass concentration C. The nicotinamide concentration is linearly related to the absorbance in the range of 0.000 to 30.000 μg / mL, with a linear regression equation of A = 0.1068x-0.1503 and a correlation coefficient R 2 =0.9827.

[0058] (5) Transdermal absorption data processing method

[0059] In the process of ultraviolet spectrophotometry, the concentration of nicotinamide in the receiving pool was calculated by measuring the absorbance of the solution and substituting it into the linear regression equation A = 0.1068x-0.1503, and the cumulative permeation per unit area (Q n , μg / cm 2 ). Cumulative permeability per unit area Q n The slope of the graph is the transdermal rate, i.e., the steady-state permeation rate Js (μg / cm 2 *h). The permeability enhancement factor (ER) is calculated by the formula (ER = Js / Js0).

[0060]

[0061] Among them, C n is the concentration of the sample obtained at the nth time point (μg / mL), V is the receiving cell solvent (mL), Ci is the concentration of the sample obtained at the (i=n-1)th time point (μg / mL), Vi is the sampling volume (mL), S is the effective transdermal area (cm 2 ).

[0062] The in vitro permeation results of borneol-type Cinnamomum burmanii leaves carbon quantum dots (0.37%) for nicotinamide (1%) are shown in Tables 1 and Figure 2 From Table 1 and Figure 2 It can be seen that the borneol-type Cinnamomum burmanii leaves carbon quantum dots can significantly improve the transdermal absorption rate of nicotinamide. The 8h cumulative permeation amount of the MCDs-W group (0.37%) is 94.744μg / cm 2 , which was 3.2 times that of the blank group and 2.1 times that of the positive azone control group (1%); the 8-hour cumulative permeation of the MCDs-E group (0.37%) was 165.383 μg / cm 2, which is 5.5 times that of the blank group and 3.7 times that of the positive azone control group (1%). The penetration-enhancing effect of 0.37% borneol-type Cinnamomum burmanii leaf carbon quantum dot alcohol solution or aqueous solution is significantly better than the penetration enhancers already used on the market, such as azone. At the same concentration, the aqueous solution of borneol-type Cinnamomum burmanii leaf carbon quantum dot is 6 times that of the azone group, and the alcohol solution of borneol-type Cinnamomum burmanii leaf carbon quantum dot is 10 times that of the azone group.

[0063] Table 1 Cumulative permeation per unit area of ​​borneol-type Cinnamomum burmanii leaves carbon quantum dots promoting nicotinamide (Nia) transdermal absorption

[0064]

[0065]

[0066] Example 4: Study on the inhibitory effect of borneol-type burman wood leaf carbon quantum dots on CuSO4-induced zebrafish inflammation model.

[0067] Referring to the method for preparing borneol-type burman wood leaf carbon quantum dots in Example 1, MCD-E was obtained and an anti-inflammatory experiment was conducted on zebrafish.

[0068] (1) Inhibition of oxidative stress in zebrafish

[0069] 2′,7′-Dichlorofluorescein diacetate (DCF-DA): Weigh 4 mg DCF-DA into a 1.5 mL centrifuge tube and dissolve it in 1 mL DMSO to obtain a 4 mg / mL DCF-DA mother solution. Then dilute the mother solution 200 times with PBS to obtain a 20 μg / mL DCF-DA aqueous solution and store it at -20°C in the dark.

[0070] Wild-type zebrafish were selected, and 3dpf zebrafish embryos with normal development were selected and randomly assigned to 12-well plates, with 10 tails per well. The culture water in the 12-well plate was removed without harming the embryos, and then 2mL of different concentrations of borneol-type burman tree leaf carbon dot alcohol solution was quickly added to each well to pre-treat the embryos with drugs for 4h. Next, 10μmol / L CuSO4 (final concentration) was added to the 12-well plate and incubated for 1h to set up the MCD-E drug group; a blank control group and a 0.5% DMSO+CuSO4 model group were also set up. After modeling and incubation, the zebrafish seedlings were washed 3 times with deionized water, and then 20μg / mL DCF-DA solution was added. After thorough mixing, the culture plate panel was covered and wrapped with aluminum foil, and incubated in a constant temperature incubator at 28.5±1.0℃ in the dark for 40min. After treatment, zebrafish fry were anesthetized with 0.1% tricaine solution, fixed with 5% methylcellulose, observed and photographed under a fluorescence microscope, and the fluorescence intensity was calculated using Image J software.

[0071] (2) Inhibition of NO levels in zebrafish

[0072] 4-Amino-5-methylamino-2,7-difluorofluorescein diacetate (DAF-FM DA): Measure 10 μL of DAF-FMDA stock solution into a 50 mL centrifuge tube, add 10 mL of the buffer in the kit (diluted 1000 times), mix well and dispense into EP tubes. The concentration is 5 μM and store at -20°C away from light.

[0073] Wild-type zebrafish were selected, and 3dpf zebrafish embryos with normal development were selected and randomly assigned to 12-well plates, with 10 tails per well. The culture water in the 12-well plate was removed without harming the embryos, and then 2mL of different concentrations of borneol-type burman tree leaf carbon dot alcohol solution was quickly added to each well to pre-treat the embryos with drugs for 4 hours. Next, 10μmol / L CuSO4 (final concentration) was added to the 12-well plate and incubated for 1 hour to set up the MCD-E drug group; a blank control group and a 0.5% DMSO+CuSO4 model group were also set up. After modeling and incubation, the zebrafish seedlings were washed 3 times with deionized water, and then 5μmol / L DAF-FM DA solution was added. After thorough mixing, the culture plate panel was covered and wrapped with aluminum foil, and incubated in a constant temperature incubator at 28.5±1.0℃ in the dark for 40 minutes. After treatment, zebrafish fry were anesthetized with 0.1% tricaine solution, fixed with 5% methylcellulose, observed and photographed under a fluorescence microscope, and the fluorescence intensity was calculated using Image J software.

[0074] (3) Experimental results

[0075] 1) The results of inhibiting oxidative stress in zebrafish Figure 3 As shown, from Figure 3 It can be seen that the model group has increased ROS generation compared with the blank group, and the relative fluorescence intensity has increased significantly, proving that the modeling is successful. The ROS generation in the MCD-E-treated group is lower than that in the model group, especially at a low sample concentration of 25 μg / mL, which is lower than the blank group, indicating that the borneol-type Cinnamomum burmanii leaf carbon quantum dots relieve inflammation by inhibiting the generation of ROS induced by CuSO4.

[0076] 2) The results of inhibiting NO levels in zebrafish are as follows Figure 4 As shown, from Figure 4 It can be seen that the NO production in the model group increased compared with the blank group, and the relative fluorescence intensity increased significantly, proving that the model was successful. In the concentration range of less than 100 μg / mL, the NO production in the MCD-E-treated group was significantly lower than that in the model group, but as the concentration of MCD-E increased, the NO production increased and exceeded that of the model group, indicating that at high concentrations, MCD-E would induce enhanced inflammation, but at low concentrations, the borneol-type Cinnamomum burmanii leaf carbon quantum dots relieved inflammation by inhibiting the production of NO induced by CuSO4.

[0077] Example 5: The scar removal effect of the present invention is further illustrated by a rabbit ear hypertrophic scar experiment:

[0078] (1) Experimental Materials

[0079] 1) Experimental animals

[0080] SD adult New Zealand white rabbits, clean grade, weighing 2.3-2.5kg, of either sex, were provided by the Experimental Animal Center of South China University of Technology. The feeding conditions were: separate cages, normal diet, and adaptive feeding for 24 hours before the experiment.

[0081] 2) Test drug

[0082] The model group was administered with 0.9% sodium chloride solution; treatment group 1 was administered with MCD-E, treatment group 2 was administered with MCD-W, treatment group 3 was administered with the alcohol extract of borneol-type cinnamomum burmanii leaf powder obtained by the method of Example 1, and treatment group 4 was administered with the water extract of borneol-type cinnamomum burmanii leaf powder obtained by the method of Example 2.

[0083] The steps for preparing the alcohol extract of borneol-type Cinnamomum burmanii leaf powder are as follows: wash and dry the borneol-type Cinnamomum burmanii leaves, then crush them through a 60-mesh sieve to obtain borneol-type Cinnamomum burmanii leaf powder. Weigh 0.2g of borneol-type Cinnamomum burmanii leaf powder, add 30mL of anhydrous ethanol, soak at room temperature for 6h, centrifuge at 10000rpm for 5min, take the supernatant and filter it with a 0.22μm filter membrane, concentrate the filtered solution by rotary evaporation, collect the concentrated solution, place it in a blast drying oven at 60°C and dry it for 24h, and freeze-dry it. The final powder is the alcohol extract of borneol-type Cinnamomum burmanii leaf powder.

[0084] The steps for preparing the aqueous extract of borneol-type Cinnamomum burmanii leaf powder are as follows: wash and dry the borneol-type Cinnamomum burmanii leaves, then dry them, crush them through a 60-mesh sieve, and obtain borneol-type Cinnamomum burmanii leaf powder. Weigh 0.2g of borneol-type Cinnamomum burmanii leaf powder, add 20mL of deionized water, soak at room temperature for 6h, centrifuge at 10000rpm for 5min, take the supernatant and filter it with a 0.22μm filter membrane, freeze-dry the filtered solution, and the final powder is the aqueous extract of borneol-type Cinnamomum burmanii leaf powder.

[0085] 3) Dosage reagent

[0086] The dosage of treatment groups 1-4 was 2 mL / kg, with a drug concentration of 50 μg / mL.

[0087] (2) Experimental methods

[0088] 1) Rabbit ear scar model

[0089] Six large-eared white rabbits were taken out of the cage and fixed. After disinfecting the skin of one ear edge with alcohol cotton balls, 3% sodium pentobarbital was extracted with a syringe and slowly injected through the rabbit ear edge vein at a dosage of 1 mL / kg. The ventral skin of the rabbit ear was disinfected with alcohol cotton balls, and four square incisions with a side length of 1 cm were made on the ventral sides of the rabbit ears with a scalpel. The incisions were 2 cm apart, and the full layer of skin was removed until the surface of the perichondrium, and the perichondrium was completely removed. After the wound was compressed with dry cotton balls to stop bleeding, chloramphenicol eye ointment was applied. The wound was exposed and no bandage was required. Wound healing and scar formation were observed from the first day after surgery. At the same time, two pieces of excised skin tissue were retained for each rabbit and fixed in 10% formalin. After fixation for 24 hours, they were routinely paraffin preserved for HE staining and immunohistochemical staining to observe the expression of TGF-β1. A total of 12 samples were used as the normal group.

[0090] 2) Grouping and treatment

[0091] One month later, four rabbits were randomly selected, and one piece of hyperplastic mass was taken from each rabbit for pathological section observation, which was consistent with the characteristics of granulation tissue. Two months later, the hyperplastic mass was cut for histopathological observation in the same way, which was consistent with the characteristics of hyperplastic scar tissue. 72 scars with obvious hyperplasia were selected and divided into a model group and a treatment group. 0.9% sodium chloride solution or the test drug of the present invention was applied to the scar locally, twice a day, for 1 month of treatment. There were 12 samples in each group. The scar tissue samples were fixed with 10% neutral formalin, embedded in paraffin, and sliced ​​continuously at 4μm thickness for HE staining. The slices were dewaxed, antigen blocked, antigen heat repaired, and immunohistochemically stained. The scar hyperplasia index (HI), fibroblast density (NA) and cumulative optical density value (AOI) were calculated.

[0092] 3) Test results

[0093] ①Scar hyperplasia index and fibroblast density

[0094] The results showed that the hypertrophic scar index of rabbit ears in the treatment group and the model group was significantly different between the two groups (P < 0.05), and the number of fibroblasts per unit area in the treatment group was significantly reduced compared with the model group (P < 0.05), especially No. 1, which was better than other groups. The results are shown in Table 2.

[0095] Table 2 Comparison of the effects of the tested drugs on HI and NA of rabbit ear scars (X±SD) (n=12)

[0096]

[0097]

[0098] Note: Compared with the model group, *P<0.05, **P<0.01.

[0099] ② Results of immunohistochemical staining of TGF-β1 expression

[0100] Compared with the normal group, the expression of TGF-β1 in fibroblasts of the model group and the treatment group was significantly increased, but the expression of TGF-β1 in fibroblasts No. 1 and No. 2 in the treatment group was significantly lower than that in the model group. The results are shown in Table 3.

[0101] Table 3 TGF-β1 immunohistochemistry results of rabbit ear tissues in each group (X±SD) (n=12)

[0102] Group Cumulative optical density Normal group 532.87±116.23 Model Group 1638.62±352.51*** Treatment Group 1 993.56±332.65*^^ Treatment Group 2 1123.23±285.31**^ Treatment Group 3 1494.21±389.71*** Treatment Group 4 1565.81±436.25***

[0103] Note: Compared with the normal group, * indicates P < 0.05, ** indicates P < 0.01, *** indicates P < 0.001; compared with the model group, ^ indicates P < 0.05, ^^ indicates P < 0.01, ^^^ indicates P < 0.001.

[0104] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing borneol-type burman wood leaf carbon quantum dots, characterized in that The steps include: (1) washing fresh borneol-type Cinnamomum burmanii leaves, drying them, and crushing them to obtain borneol-type Cinnamomum burmanii leaf powder, and storing it away from light for later use; (2) mixing the borneol-type burman tree leaf powder obtained in step (1) with a solvent to perform a solvothermal reaction; (3) centrifuging the product after the solvothermal reaction, filtering the obtained supernatant using a 0.22 μm filter membrane, and dialyzing the obtained filtrate; (4) Drying the dialysate to obtain borneol-type Cinnamomum burmanii leaf carbon quantum dots.

2. The method for preparing borneol-type burman wood leaf carbon quantum dots according to claim 1, characterized in that: The solvent in step (2) is at least one of anhydrous ethanol, acetone and water; The solvent thermal reaction conditions in step (2) are 150-280° C. for 4-12 hours.

3. The method for preparing carbon quantum dots from borneol-type burman wood leaves according to claim 1, characterized in that: The degree of pulverization in step (1) is such that the product can pass through a 60-mesh sieve; The centrifugal conditions described in step (3) are 5000-15000 g for 3-20 min.

4. The method for preparing carbon quantum dots from borneol-type burman wood leaves according to claim 1, characterized in that: The amount of the solvent in step (2) is calculated based on 20-40 mL of solvent per 0.2 g of borneol-type burman tree leaf powder; The specification of the dialysis bag used in the dialysis described in step (3) is 500Da; The dialysis time in step (3) is 6 to 48 hours; The drying steps described in step (4) are as follows: first rotary evaporation for concentration, then freeze drying; or first rotary evaporation for concentration, then drying in a blast drying oven, and finally freeze drying.

5. A borneol-type burman tree leaf carbon quantum dots, characterized in that: The method is obtained by the preparation method according to any one of claims 1 to 4.

6. Use of the borneol-type burman wood leaf carbon quantum dots according to claim 5 in the preparation of skin care products.

7. The use of the borneol-type burman tree leaf carbon quantum dots in the preparation of skin care products according to claim 6, characterized in that: The skin care product is a skin care product which at least has the effects of anti-inflammatory and inhibiting scar hyperplasia.

8. A skin care product, characterized in that: Contains the borneol-type burman wood leaf carbon quantum dots as described in claim 5.

9. The skin care product according to claim 8, characterized in that: It also contains at least one of a whitening active ingredient, a moisturizing ingredient, and a firming ingredient.

10. The skin care product according to claim 8, characterized in that: The invention also contains at least one of niacinamide, arbutin, glabridin and hyaluronic acid.

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