CN112353756B

CN112353756B - Preparation method of medical slow-release gel with microporous structure and cold compress gel for treating dermatitis and eczema

Info

Publication number: CN112353756B
Application number: CN202011403460.0A
Authority: CN
Inventors: 张先正; 刘新华; 牛美婷; 曾旋
Original assignee: Wuhan University WHU
Current assignee: Wuhan University WHU
Priority date: 2020-12-02
Filing date: 2020-12-02
Publication date: 2022-06-14
Anticipated expiration: 2040-12-02
Also published as: CN112353756A

Abstract

The invention belongs to the technical field of biological medicines, and particularly relates to a preparation method of a medical slow-release gel with a microporous structure and a cold compress gel for treating dermatitis and eczema, which comprises the following steps: mixing a certain amount of solution A prepared from a synthetic biomedical polymer material and a certain amount of solution B prepared from a natural polymer material or a natural polymer modified material according to a certain proportion, uniformly mixing, and drying at a certain temperature to form gel, thus obtaining the medical slow-release gel with the microporous structure. The medical slow-release gel with the microporous structure, which is prepared by the invention, consists of a natural high polymer material or a natural high polymer modified material and a synthetic biomedical high polymer material, and a gel network with a controllable microporous structure is formed by a physical crosslinking method of the gel, so that the gel is breathable and is favorable for slow-controlled release of medicines; and the biological compatibility is good, the non-toxic and non-irritant effects are achieved, and the biological adhesion is good.

Description

Preparation method of medical slow-release gel with microporous structure and cold compress gel for treating dermatitis and eczema

Technical Field

The invention belongs to the technical field of biological medicines, and particularly relates to a preparation method of medical slow-release gel with a microporous structure and cold compress gel for treating dermatitis and eczema.

Background

The hydrogel is a strong water-absorbing material formed by crosslinking high-molecular monomers, is a high-molecular material with a three-dimensional network structure, and is formed by covalent bond or non-covalent bond crosslinking. Most of the hydrogels are chemically crosslinked by monomer crosslinking agents, but the hydrogel has the disadvantage that the structure contains a small amount of substances such as small-molecule monomers and crosslinking agents, and the compatibility of the hydrogel is influenced. The hydrogel obtained by the physical crosslinking method has high biocompatibility and biological safety because an additional chemical crosslinking agent is not required to be added. The conventional hydrogel can be attached to an ulcer surface, but is easy to fall off, and generally dissolves and disappears within a few minutes, so that the drug permeation effect is insufficient. The existing sustained-release gel is difficult to achieve the purposes of continuous protection and long-term wound treatment due to the fact that complex body surface environments are dissolved completely or fall off due to poor adhesion after local administration. The mechanical property of the hydrogel material prepared by natural polymers is poor, and the 'burst release' phenomenon of the hydrogel drug carrier is serious, so that at present, many researchers at home and abroad are devoted to the research on improving the mechanical property of the hydrogel drug carrier.

The drug slow release system is a novel drug delivery system which is made up by using material with high biological safety, good biocompatibility and biodegradability as carrier or medium, combining it with drug in physical or chemical adsorption mode to make it into correspondent dosage form, and making it be passed through the modes of diffusion action and osmosis action so as to make the small drug molecules be released in human body continuously and slowly at stable and controllable speed and proper concentration. The biological advantage of the drug sustained-release system is that the problems of overlarge human body local drug concentration, low drug utilization rate, large toxic and side effects, short drug half-life period and the like caused by the traditional drug delivery mode can be effectively solved. The loose porous structure of the hydrogel enables the hydrogel to be loaded with drugs, and the amount and the rate of drug slow release can be regulated and controlled through mechanisms such as swelling and intelligent environmental response, so that the drug slow release is realized. In addition, the hydrogel has good biocompatibility, and can adapt to different environments in a human body after being modified.

Currently, the treatment of eczema is mainly: external treatment with medicine, oral administration with Chinese patent medicine, acupuncture, edible dietary supplement or probiotic supplement, etc. The external treatment of the medicine is one of the most direct and effective means for treating eczema, common external treatment medicines comprise external application medicines, external washing medicines and the like, and ointments and gels are simple and common external preparations. However, the common ointment has short efficacy, is difficult to absorb, needs to be used for a long time, and is easy to relapse after healing. The gel contains a large amount of liquid, has mild matrix, can be suitable for facial and infantile eczema, and has better absorption effect than ointment. Therefore, the development of an eczema gel product which has high transdermal absorption rate, good antibacterial and anti-inflammatory effects, long efficacy and difficult recurrence and is simple and convenient to use is a difficult problem to solve urgently at present.

Disclosure of Invention

One of the purposes of the invention is to provide a preparation method of medical slow-release gel with a microporous structure, and the prepared medical slow-release gel with the microporous structure has good biocompatibility, no toxicity and no stimulation, forms a system with a network microporous structure, has good biological adhesion, and is beneficial to slow and controlled release of small-molecule drugs.

The invention also aims to provide the cold compress gel for treating the dermatitis and the eczema, which can quickly relieve itching, has good antibacterial and anti-inflammatory effects, long efficacy and difficult recurrence, is simple and convenient to use, and has high utilization rate of the medicine.

The scheme adopted by the invention for realizing one purpose is as follows: a preparation method of medical sustained-release gel with a micropore structure comprises the following steps: mixing a certain amount of solution A prepared from a synthetic biomedical polymer material and a certain amount of solution B prepared from a natural polymer material or a natural polymer modified material according to a certain proportion, uniformly mixing, and drying at a certain temperature to form gel, thus obtaining the medical slow-release gel with the microporous structure.

Preferably, the synthetic biomedical polymer material, the natural polymer material or the natural polymer modified material is a polymer material containing a polyhydroxy or polyamino structure.

Preferably, the synthetic biomedical polymer material is any one or two of polyethylene, polyvinylpyrrolidone, polyurethane, polylactic acid, polyvinyl alcohol and polymethyl methacrylate.

Preferably, the natural polymer material or natural polymer modified material is at least one of chitin, cellulose, hyaluronic acid, methylcellulose, collagen, sodium carboxymethylcellulose, trehalose, chitosan, and the like.

More preferably, the synthetic biomedical polymer material at least comprises polyvinylpyrrolidone (PVP), and the natural polymer material or natural polymer modified material at least comprises Chitosan (CHI). Polyvinylpyrrolidone is a hydrophilic polymer material with high biocompatibility, and the polyvinylpyrrolidone has a hydrogen bond receptor and is easily crosslinked with a polymer material containing hydrogen bond ligands such as amino and hydroxyl through the action of hydrogen bonds. The addition of the chitosan has the function of regulating the pore size of the gel matrix, and the chitosan has a large amount of amino groups, so that the hydrogen bond interaction of a gel network can be enhanced, and the pore size of the gel matrix is further reduced.

Preferably, the concentration of the synthesized biomedical polymer material in the solution A is 0.5-2 wt%; the concentration of the natural polymer material or the natural polymer modified material in the solution B is 0.1 to 5 weight percent.

Preferably, the weight ratio of the synthetic biomedical polymer material to the natural polymer material or the natural polymer modified material in the mixed solution is 45:55-95: 5.

Preferably, drying is carried out at 50-100 ℃ until the residual solution is 20-50% of the volume of the starting solution.

The scheme adopted by the invention for realizing one of the purposes is as follows: a cold compress gel for treating dermatitis and eczema comprises the medical slow release gel with a micropore structure prepared by the preparation method and auxiliary materials; the auxiliary materials at least comprise the following components: natural plant extract, anti-inflammatory immunosuppressant and humectant.

Preferably, in the cold compress gel for treating dermatitis and eczema, the mass percent of the natural plant extract is 0.2% -2%; the mass percentage of the anti-inflammatory immunosuppressant is 0.01-1%; the mass percentage of the humectant is 0.1-1%.

Preferably, the natural plant extract is from the herbal plant mint, and is any one or two of menthol, peppermint oil, menthyl ester, mint and menthone; the anti-inflammatory immunosuppressant belongs to macrolide antibiotics and is any one of tacrolimus, sirolimus, erythromycin and derivatives thereof, amphotericin B and pentamycin; the humectant is at least one of polyethylene glycol, glycerol, propylene glycol, sorbitol, sodium hyaluronate, 1, 2-hexanediol and the like.

Synthetic biomedical polymers, natural polymer materials or natural polymer modified materials, natural plant extracts and immunosuppressants are approved by the national drug administration, are all used in commercial products, and belong to biomedical materials with high biological safety and excellent biocompatibility. The natural plant extract adopted by the invention belongs to cyclic terpene alcohol essence perfume.

The cold compress gel has good biological adhesion, can quickly form a uniform gel film with a micro-porous structure at a smearing part, is breathable, is favorable for slow and controlled release of medicaments, and simultaneously constructs a physical barrier to prevent invasion of external pathogens, thereby realizing effective relief and treatment of dermatitis and eczema.

The invention has the following advantages and beneficial effects:

the medical slow-release gel with the microporous structure prepared by the preparation method disclosed by the invention is composed of a natural high polymer material or a natural high polymer modified material and a synthetic biomedical high polymer material, a gel network with a controllable microporous structure is formed by a physical crosslinking method of the gel, and the gel is breathable and is favorable for slow-release of a medicament; and the biological compatibility is good, the non-toxic and non-irritant effects are achieved, and the biological adhesion is good.

The cold compress gel disclosed by the invention can quickly relieve itching, has good antibacterial and anti-inflammatory effects, long efficacy and long time, is difficult to relapse, is simple and convenient to use, has good biological adhesion, greatly reduces the using amount of an anti-inflammatory immunosuppressant, and is beneficial to the slow-controlled release of small-molecule drugs, so that the utilization efficiency of the drugs is remarkably improved, and the biological safety of the gel is improved. Plays an important role in the treatment of atopic dermatitis, psoriasis, and some autoimmune diseases.

The cold compress gel has obvious treatment and improvement effects on dermatitis and eczema at various ages, the existing glucocorticoid eczema ointment or cold compress gel in the market still has the defects of short efficacy, high use frequency, large stimulation, large toxic and side effects and the like, and the cold compress gel has a controllable micropore gel network structure, so that the use dosage of an anti-inflammatory immunosuppressant can be greatly reduced, the slow release of a small molecular drug is realized, the stimulation effect is obviously reduced, the use efficacy is long, the toxic and side effects are low, and the cold compress gel has good itching relieving, inflammation diminishing, antibacterial and moisturizing functions. In addition, the cold compress gel can uniformly form a layer of film on the part of dermatitis and eczema, construct a physical barrier to prevent the invasion of external pathogens, simultaneously enable the skin to fully absorb the drugs, locally shrink blood vessels, relieve inflammatory reaction and promote the wound repair of the ulcerated part of eczema, thereby treating or relieving the symptom of dermatitis and eczema.

Drawings

FIG. 1 is a scanning electron micrograph of gel matrices containing different mass fractions of chitosan prepared in example 1;

FIG. 2 is a scanning electron micrograph of the gel matrix prepared in examples 2 and 3;

FIG. 3 is a graph of the antimicrobial effect of gel matrices of chitosan of different mass percentages of example 5;

FIG. 4 shows the results of the cytotoxicity tests of gel matrices of different mass percentages of chitosan of example 6;

FIG. 5 is the effect of 2, 4-Dinitrochlorobenzene (DNCB) induced eczema on the backs of mice treated with the cold compress gel of example 7, the left graph shows the effect before treatment, and the right graph shows the effect after two weeks of cold compress gel application treatment;

FIG. 6 is a graph showing the in vivo anti-inflammatory effect of the cold compress gel after two weeks of eczema treatment in the example, wherein A is a pathological section of the back of a normal mouse, B is a pathological section of the skin of the back of an eczema mouse, and C is a pathological section of the skin of the back of an eczema mouse after two weeks of eczema treatment.

Detailed Description

The following examples are provided to further illustrate the present invention for better understanding, but the present invention is not limited to the following examples.

Example 1:

the preparation method of the itching-relieving, inflammation-diminishing and antibacterial cold compress gel comprises the following specific steps:

(1) 0.5g of polyvinylpyrrolidone and 0.5g of polyvinyl alcohol are weighed and added into 50mL of ultrapure water, and the mixture is heated and stirred at 50 ℃ until the mixture is completely dissolved to form a polyvinylpyrrolidone/polyvinyl alcohol solution with the mass percentage of 2%.

(2) Weighing 2g of chitosan with high deacetylation degree, dissolving in 0.1 wt% of glacial acetic acid, and stirring overnight at normal temperature to completely dissolve all the chitosan to form a chitosan solution with the mass percentage of 2%.

(3) Taking a proper amount of the dissolved polyvinylpyrrolidone/polyvinyl alcohol solution, and respectively adding a proper volume of the chitosan solution dissolved by the method into the solution to obtain mixed solutions of polyvinylpyrrolidone/polyethylene and chitosan with the mass fraction ratios of 100:0, 95:5, 90:10, 85:15, 80:20, 70:30 and 60:40 respectively.

(4) And (3) placing the mixed solution in a constant-temperature oven at 70 ℃, drying until the residual solution is 40% of the volume of the initial solution to form a gel matrix, and naturally cooling to room temperature to obtain the gel matrix with the porous structure.

As shown in FIG. 1, which is a scanning electron micrograph of gel matrixes containing chitosan with different mass fractions, it can be seen that: the gel matrix prepared by the embodiment has a microporous structure, the pore size range is 20-150nm, and the gel matrix is suitable for entrapment and slow-controlled release of drug micromolecules and is suitable for practical use. The gel matrix prepared in the example is rapidly cooled in liquid nitrogen and is placed in a freeze dryer for freeze-drying for 12-48 hours, and the gel matrix presents a micropore network structure. .

Example 2:

provides a preparation method of medical slow-release gel with a micropore structure, which comprises the following steps:

(1) 0.5g of polyvinylpyrrolidone is added into 50mL of ultrapure water, and stirred at normal temperature until the polyvinylpyrrolidone is completely dissolved to form a polyvinylpyrrolidone solution with the mass percent of 1%.

(2) 0.2g of sodium carboxymethylcellulose (CMC-Na) is weighed and dissolved in ultrapure water, and the sodium carboxymethylcellulose is added and stirred at normal temperature to be completely dissolved to form a sodium carboxymethylcellulose solution with the mass percent of 0.2%.

(3) And (3) taking a proper amount of the dissolved polyvinylpyrrolidone solution, and adding a proper volume of the dissolved sodium carboxymethyl cellulose solution into the dissolved polyvinylpyrrolidone solution to ensure that the mass ratio of the polyvinylpyrrolidone to the sodium carboxymethyl cellulose is 45: 55.

(4) And (3) putting the mixed solution into a constant-temperature oven, heating at 100 ℃, drying until the residual solution is 20% of the volume of the initial solution to form a gel matrix, and naturally cooling to room temperature.

Example 3:

(2) Weighing 0.2g of sodium carboxymethylcellulose, dissolving the sodium carboxymethylcellulose in ultrapure water, stirring the solution at normal temperature while adding the solution to completely dissolve the sodium carboxymethylcellulose to form a sodium carboxymethylcellulose solution with the mass percent of 0.2%, adding the dissolved sodium carboxymethylcellulose solution into a polyvinylpyrrolidone solution according to a certain volume ratio, and uniformly mixing the solution, wherein the mass ratio of the polyvinylpyrrolidone to the sodium carboxymethylcellulose is 1: 1.

(3) 0.2g of chitosan with high deacetylation degree is weighed and dissolved in 0.1 wt% of glacial acetic acid, and stirred overnight at normal temperature to completely dissolve all the chitosan, so as to form a chitosan solution with the mass percentage of 0.1%.

(4) Taking a proper amount of the dissolved mixed solution of the polyvinylpyrrolidone and the sodium carboxymethyl cellulose, and adding a proper amount of the chitosan solution into the mixed solution to ensure that the mass ratio of the polyvinylpyrrolidone to the sodium carboxymethyl cellulose to the chitosan is 45:45: 10;

(5) and (3) putting the mixed solution into a constant-temperature oven, heating at 100 ℃, drying until the residual solution is 20% of the volume of the initial solution to form a gel matrix, and naturally cooling to room temperature.

FIG. 2 is a scanning electron micrograph of the gel matrices prepared in examples 2 and 3, from which it can be seen that the pore size of the gel matrix prepared in the presence of chitosan is smaller, illustrating that chitosan has some effect of adjusting the pore size of the gel matrix.

Example 4:

(1) 0.5g of polyvinylpyrrolidone is added into 100mL of ultrapure water, and stirred at normal temperature until the polyvinylpyrrolidone is completely dissolved to form a polyvinylpyrrolidone solution with the mass percent of 0.5%.

(2) Weighing 800mg of Methylcellulose (MC), dissolving in ultrapure water, and stirring at room temperature to dissolve completely to obtain 5% methylcellulose solution.

(3) Taking a proper amount of the dissolved polyvinylpyrrolidone solution, adding a proper volume of the methylcellulose solution dissolved by the method into the polyvinylpyrrolidone solution to ensure that the mass fraction ratio of the polyvinylpyrrolidone to the methylcellulose is 80: 20;

(4) and (3) adding the mixed solution into a constant-temperature oven, heating at 50 ℃ for half an hour to form a gel matrix, and naturally cooling to room temperature.

Example 5

The gel matrix of chitosan prepared in example 1 with different mass percentages is subjected to an antibacterial effect test, and the specific test method is as follows:

100 microliters of staphylococcus aureus (OD) solution was uniformly coated on a broth (LB) agar plate with a triangular coating bar₆₀₀Approximately equal to 0.1-2), respectively fully wetting 3 round paper sheets with the diameter of 5mm in PVP/PVA gel matrixes with different chitosan contents, and then uniformly placing on an LB agar plate coated with bacterial liquid. The agar plates were then incubated in a 37 ℃ incubator for 24 hours to observe the size of the zone of inhibition formed. As shown in FIG. 3, the bacteriostatic effect of the gel matrix is remarkably increased with the increase of the chitosan content in the gel matrix. This indicates that the antibacterial effect of chitosan is positively correlated with its own concentration.

Example 6

The gel matrices of chitosan prepared in example 1 with different mass percentages were subjected to cytotoxicity tests, which were carried out as follows:

african green monkey kidney fibroblast (COS-7) and mouse fibroblast (L929) were seeded at a density of 500. mu.l 20000cells/well in 24-well plates at 37 ℃ with 20% CO₂And (5) carrying out aseptic culture at constant temperature for 24 hours. Subsequently, a 24-well transwell chamber (filter diameter: 6.5mm, filter pore size: 0.4 μm) was placed on the above COS-7 and L929 cell-seeded 24-well plate, and 100. mu.l of a PVP/PVA/CHI gel matrix of different chitosan contents was added to each well, with three duplicate wells per chitosan-content gel matrix. All cells were incubated at 37 ℃ with 20% CO₂The contents were incubated for 24 hours in the dark. The transwell chamber was then removed, 50. mu.l of 5mg/mL MTT was added to each well, and after 4 hours of incubation, the medium was aspirated, 375. mu.l dimethyl sulfoxide (DMSO) was added to each well, and the well-blown transfer was performed to a 96-well plate, 150. mu.l per well. The microplate reader measures the absorbance of all wells at 570nm and calculates the corresponding cell viability. Thereby achieving the toxicity of the gel matrix to normal COS-7 and L929 cells. The result is shown in fig. 4, from which it can be seen that the gel matrix prepared in example 1 is non-toxic and non-irritating to COS-7 and L929, safe and reliable, and can be used in the medical field.

Example 7

A cold compress gel is prepared by taking a gel matrix with the mass fraction ratio of polyvinylpyrrolidone to polyethylene to chitosan of 80:20 in example 1, and specifically, menthol and tacrolimus dissolved by a small amount of ethanol and sodium hyaluronate dissolved by ultrapure water are added into the gel matrix prepared in the above way, so that the weight fractions of the menthol, the tacrolimus and the sodium hyaluronate in the whole are respectively 0.2%, 0.03% and 0.5%.

The therapeutic effect of the cold compress gel on the DNCB-induced eczema model mouse is tested by the specific method:

after depilating the back of a white mouse (BALB/c) for 6-8 weeks, the mouse was coated with a 0.5-5% DNCB acetone solution on the back 2 x 2cm²Skin, after an eczema model is successfully established, the eczema is smeared on the skin of the back of the mouse every dayGel, apply once every other day for two weeks. The size of the eczematous area of the back of the mice was observed every day and data analysis was performed. The results are shown in fig. 5, and compared with the untreated group, the area of eczema on the back of the mice coated with the cold compress gel is obviously reduced, and the eczema symptom is obviously relieved and cured.

After the back of the eczema model mouse is smeared with the cold compress gel for 14 days, the skin of the eczema part of the mouse is taken for pathological analysis. The results are shown in figure 6, relative to the untreated eczema group. The mice treated with the cold compress gel had a significant reduction in skin inflammatory cells and a thinning of the epidermal layer. In the untreated group, a large number of inflammatory cells were found in the skin and the epidermal layer was abnormally thickened, compared to the healthy group of mice. It is also shown that the cold compress gel has significant alleviating and treating effects on eczema in mice.

While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. A preparation method of medical slow-release gel with a micropore structure is characterized by comprising the following steps: mixing a certain amount of solution A prepared by a synthetic biomedical polymer material and a certain amount of solution B prepared by a natural polymer material or a natural polymer modified material according to a certain proportion, uniformly mixing, and drying at 50-100 ℃ until the volume of the residual solution is 20-50% of the volume of the initial solution to form gel, thus obtaining the medical slow-release gel with the microporous structure; the synthetic biomedical polymer material, the natural polymer material or the natural polymer modified material are polymer materials containing polyhydroxy or polyamino structures; the synthetic biomedical polymer material is one or two of polyvinylpyrrolidone and polyvinyl alcohol; the natural polymer material or the natural polymer modified material is at least one of methylcellulose, sodium carboxymethylcellulose and chitosan; the weight ratio of the synthetic biomedical polymer material to the natural polymer material or the natural polymer modified material in the mixed solution is 45:55-95: 5.

2. The method for preparing a medical sustained-release gel having a microporous structure according to claim 1, wherein: the concentration of the synthesized biomedical polymer material in the solution A is 0.5 to 2 weight percent; the concentration of the natural polymer material or the natural polymer modified material in the solution B is 0.1 to 5 weight percent.

3. A cold compress gel for treating dermatitis and eczema is characterized in that: comprises the medical slow release gel with the micropore structure prepared by the preparation method of claim 1 or 2 and auxiliary materials; the auxiliary materials at least comprise the following components: natural plant extract, anti-inflammatory immunosuppressant and humectant.

4. A cold compress gel for the treatment of dermatitis and eczema according to claim 3, wherein: in the cold compress gel for treating dermatitis and eczema, the mass percent of the natural plant extract is 0.2-2%; the mass percentage of the anti-inflammatory immunosuppressant is 0.01-1%; the mass percentage of the humectant is 0.1-1%.

5. The cold compress gel for the treatment of dermatitis and eczema of claim 3, wherein: the natural plant extract is from herbal plant mint, and is one or two of menthol, peppermint oil, menthyl ester and menthone; the anti-inflammatory immunosuppressant is any one of tacrolimus, sirolimus, erythromycin and derivatives thereof, amphotericin B and pentamycin; the humectant is at least one of polyethylene glycol, glycerol, propylene glycol, sorbitol, sodium hyaluronate and 1, 2-hexanediol.