CN112107721A - Synthetic dressing with biological effect and preparation method thereof - Google Patents

Abstract

The present invention relates to a synthetic dressing with biological effects and a preparation method thereof. The dressing contains cellulose, plasticizers, film-forming agents, and gamma-ray-treated hyaluronic acid. Compared with collagen dressings of animal origin, such as those extracted from tendons, ligaments, pericardium, etc., the synthetic dressings of the present invention have good biocompatibility, promote fibrous tissue regeneration, anti-inflammatory, short hydration time, mechanical Good performance and other excellent effects.

Description

Synthetic dressing with biological effect and preparation method thereof

technical field

The invention belongs to the technical field of polymer medical biological materials, in particular to a synthetic dressing with biological effects and a preparation method thereof.

Background technique

Surgery, accidents, etc. will cause trauma to the skin tissue. If the wound surface cannot be covered in time, it will cause problems such as loss of tissue fluid, infection, pain, and difficulty in wound healing. In severe cases, scars and even disability may be formed. With the continuous deepening of wound healing research, people gradually realize that the dressing covering the wound surface is not only for physical protection, but also must be able to promote wound healing.

With the development of materials science, there are more and more biological materials that can be used as dressings, which can be divided into natural materials and synthetic materials. Natural materials are usually animal-derived tissues and purified and extracted collagen. However, The genetic characteristics of livestock animals are relatively close to those of humans. If the animals from which collagen is extracted are from infectious disease epidemic areas, the risk of infection may be increased for users. Therefore, in recent years, scholars have shifted their goals to the development of synthetic biological dressings.

Although synthetic dressings do not have the risk of active sources, as dressings, they are only used for passive physical barriers and cannot have the active biological effect of promoting tissue repair. Many scholars have proposed to combine drugs and growth factors with dressings by means of structural loading and chemical cross-linking, so that dressings have the functions of anti-inflammatory and enhanced wound healing. For example, in the patent document CN1083392A, the dressing is used as the matrix for drug release, and the drug is embedded in the structure. In the patent document CN105797193A, the drug is grafted on the skeleton of the dressing by chemical reaction. However, no matter how the drug is loaded into the dressing, the difficulty and time of the manufacturing process will be significantly increased.

Hyaluronic acid is an important core component of extracellular matrix and an important regulator of many physiological and metabolic processes, and has excellent biocompatibility and biodegradability. The molecular weight and concentration of hyaluronic acid directly affect its biological effects, and high-molecular hyaluronic acid is responsible for the hydration, moisturization and lubrication of the tissue surface. Conversely, small molecule hyaluronic acid plays a role in promoting wound mitosis, immune stimulation and promoting angiogenesis.

However, small molecule hyaluronic acid is expensive and difficult to prepare. Therefore, even though small molecule hyaluronic acid has the biological effect of promoting wound healing, scholars and manufacturers still use drug-loading methods to make the dressing have the ability to actively promote wound healing. effect.

SUMMARY OF THE INVENTION

In view of the above situation, the purpose of the present invention is to propose an artificial fully synthetic dressing with biological effects and a preparation method thereof. The dressing has good biocompatibility, can promote fibrous tissue regeneration, has anti-inflammatory properties, and has short hydration time, Good mechanical properties.

In order to solve the above technical problems, the present invention adopts the following technical means.

(1) A synthetic dressing with biological effects, characterized in that the dressing contains cellulose, a plasticizer, a film-forming agent and hyaluronic acid treated with gamma rays.

(2) The synthetic dressing according to (1) above, wherein the hyaluronic acid is hyaluronic acid treated with gamma rays with a cumulative energy of 20 to 40 kiloGy.

(3) The synthetic dressing according to the above (1), wherein the hyaluronic acid is hyaluronic acid treated with gamma rays with a cumulative energy of 20 kGy.

(4) The synthetic dressing according to the above (1), wherein the molecular weight of the gamma-ray-treated hyaluronic acid is 2,000-300,000 Daltons.

(5) The synthetic dressing according to the above (1), wherein the molecular weight of the gamma-ray-treated hyaluronic acid is 150,000-250,000 Daltons.

(6) The synthetic dressing according to any one of the above (1) to (5), wherein the dressing is used as a general surgical wound dressing, a hemostatic cotton, a dental guided bone regeneration membrane, and an anti-gynecological Tissue adhesion barrier, or neurosurgical artificial meninges and anti-tissue adhesion barrier.

(7) a kind of preparation method of the synthetic dressing with biological effect, is characterized in that, comprises the steps:

Gamma-ray treatment of hyaluronic acid;

mixing the gamma-ray-treated hyaluronic acid with cellulose, a plasticizer, and a film-forming agent; and

The mixture is freeze-dried to make a synthetic dressing.

(8) The production method according to the above (7), wherein, in the gamma ray treatment, gamma rays having a cumulative energy of 20 to 40 kGy are irradiated.

The synthetic dressing of the present invention is prepared by using hyaluronic acid treated with gamma rays, thereby utilizing the essential biological effects and biocompatibility of small-molecule hyaluronic acid, and without using drugs, the dressing can actively promote wound tissue repair and improve patient well-being. Compared with collagen dressings extracted from animal sources, the synthetic dressings of the present invention have good biocompatibility, can avoid the potential pathogenic risks of animal-derived materials, and can promote fibrous tissue without the assistance of drugs. Regenerative, anti-inflammatory effect.

Description of drawings

FIG. 1 is a graph showing the L929 fibroblast activity of the excipients of Preparation Examples 1 to 3. FIG.

FIG. 2 is a graph showing the anti-inflammatory activity of the excipients of Formulation Examples 1 to 3. FIG.

Detailed ways

For the method of depolymerizing hyaluronic acid, although there are many methods, such as ultrasonic treatment, microwave treatment, oxidative degradation treatment, high temperature and high pressure treatment and acid hydrolysis treatment, these treatment methods have resource consumption cost, time-consuming and In view of the disadvantages such as chemical residues, the gamma ray treatment method is adopted in the present invention, which has the advantages of saving time, low cost, and no residues of chemical substances, and the treated hyaluronic acid still retains its essential biological effects.

The hyaluronic acid treated with gamma rays in the present invention can be obtained as follows: the high molecular weight hyaluronic acid is properly packaged and placed in a gamma ray processing equipment for irradiation. The conditions of the gamma ray processing are: irradiation accumulated energy It is 20 to 40 kGy, preferably 20 kGy.

The molecular weight of hyaluronic acid is 2,000 to 300,000 Daltons, preferably 150,000 to 250,000 Daltons, after the above-mentioned specific gamma ray treatment.

In addition to hyaluronic acid, the synthetic artificial dressing of the present invention also contains cellulose. The function of cellulose is to provide the skeleton structure of the film, so that the film can maintain a fixed form. The cellulose contained in the dressing of the present invention can be A mixture of one or more of carboxymethyl cellulose, carboxypropyl cellulose, ethyl cellulose, etc.

In addition, the synthetic artificial dressing of the present invention also contains a plasticizer, and the function of the plasticizer is to improve the ductility of the film, and the plasticizer used in the present invention is tributyl citrate, polyethylene glycol, glycerol alcohol, 1,4-butanediol and other mixtures.

The fully synthetic artificial dressing of the present invention also contains a film-forming agent. The function of the film-forming agent is to improve the structural strength of the finished product. The film-forming agent used in the present invention is one of polyvinyl alcohol, polyvinylpyrrolidone, polyurethane, acrylic resin, etc. Various mixtures.

The synthetic dressing with biological effect of the present invention can be used for wound dressings in general surgery, hemostatic cotton, guided bone regeneration membranes in dentistry, anti-tissue adhesion isolation membranes in obstetrics and gynecology, artificial meninges and anti-tissue adhesion isolation membranes in neurosurgery.

In order to reflect the effects of the present invention, specific examples are given below for detailed description, and a brief overview of the preparation examples is shown in the following table.

Table 1

Preparation Example 1

Mix 10 mL of 1.5% carboxymethyl cellulose solution, 10 mL of 0.75% hyaluronic acid solution without gamma ray treatment, and 10 mL of 1.5% sodium alginate solution, and then add 0.375% polyethylene glycol and polyvinyl alcohol solution respectively. , after fully mixing, the mixture was transferred to a dry bath at 56°C for 2 hr for defoaming. After defoaming, pour 20 mL of the mixed solution into a square mold with a bottom area of 30 cm ² , move it to a 56°C oven for dehydration for 2 hours, and then place the film in a -80°C refrigerator for 1 hour. After pre-freezing, move the mold to a Freeze dryer, freeze-drying at a pressure of less than 200 mtorr and a temperature of -45 °C. After freeze-drying, the sample was taken out, and 2% calcium chloride cross-linked ethanol solution was added to the sample for reaction for 12Hr. After the reaction, the sample was placed in 95% EtOH for washing, and then the sample was subjected to secondary freeze-drying to complete the preparation.

Preparation example 2

10 mL of 1.5% carboxymethyl cellulose solution, 10 mL of 0.75% hyaluronic acid (weight average molecular weight: 141864 Daltons) solution treated with gamma rays (cumulative energy 40 kGy), and 10 mL of 1.5% sodium alginate solution After mixing, 0.375% polyethylene glycol and polyvinyl alcohol solutions were added respectively, and after thorough mixing, the mixed solution was transferred to a dry bath at 56° C. and allowed to stand for 2 hr for defoaming. After defoaming, pour 20 mL of the mixed solution into a square mold with a bottom area of 30 cm ² , move it to a 56°C oven for dehydration for 2 hours, and then place the film in a -80°C refrigerator for 1 hour. After pre-freezing, move the mold to a Freeze dryer, freeze-drying at a pressure of less than 200 mtorr and a temperature of -45 °C. After freeze-drying, the sample was taken out, and 2% calcium chloride cross-linked ethanol solution was added to the sample for reaction for 12Hr. After the reaction, the sample was placed in 95% EtOH for washing, and then the sample was subjected to secondary freeze-drying to complete the preparation.

Preparation example 3

10 mL of 1.5% carboxymethyl cellulose solution, 10 mL of 0.75% hyaluronic acid (weight average molecular weight: 232443 Daltons) solution treated with gamma rays (cumulative energy 20 kGy), and 10 mL of 1.5% sodium alginate solution Mixing, adding 0.375% polyethylene glycol and polyvinyl alcohol solution respectively after mixing, fully mixing and then transferring the mixed solution to a dry bath at 56° C. and standing for 2 hr for defoaming. After defoaming, pour 20 mL of the mixed solution into a square mold with a bottom area of 30 cm ² , move it to a 56°C oven for dehydration for 2 hours, and then place the film in a -80°C refrigerator for 1 hour. After pre-freezing, move the mold to a Freeze dryer, freeze-drying at a pressure of less than 200 mtorr and a temperature of -45 °C. After freeze-drying, the sample was taken out, and 2% calcium chloride cross-linked ethanol solution was added to the sample for reaction for 12Hr. After the reaction, the sample was placed in 95% EtOH for washing, and then the sample was subjected to secondary freeze-drying to complete the preparation.

The products finally obtained by the above formulation examples 1 to 3 are tested as follows:

Thickness test: soak the sample in phosphate buffer solution, after reaching the liquid absorption balance, take out the sample and measure the thickness of the sample with a vernier caliper.

Hydration time test: The sample was cut to 10 x 10 mm, then the sample was soaked in phosphate buffered solution and the time required for complete darkening due to wetting was measured.

The results are shown in Table 2 below.

Table 2

It can be seen from Table 2 that, compared with the dressing of Formulation Example 1 containing hyaluronic acid not treated with gamma rays, the dressings of Formulation Example 2 and Formulation Example 3 have smaller thicknesses and are closer to the thickness of the human body's native tissue. In addition, as for the hydration time, regardless of whether the hyaluronic acid used is treated with gamma rays or not, it does not affect the hydration time of the prepared dressing, nor does it affect the operation time of the physician's operation in clinical use.

Maximum tensile stress test: Cut the sample into 5 × 50 mm, then soak the sample in phosphate buffer solution, take it out and pat it dry and fix it on the fixture of the test machine, at a rate of 30 cm per minute Stretch and record. The results are shown in Table 3 below.

table 3

Compared with the dressing of Formulation Example 1 containing hyaluronic acid without gamma ray treatment, the dressings of Formulation Example 2 and Formulation Example 3 have higher tensile stress than Formulation Example 1, and the dressings containing gamma ray treated and In the preparation example 3 of hyaluronic acid with a cumulative energy of 20 kGy, the mechanical properties of the dressing are higher, about 2.45 times that of the preparation example 1, which not only makes the doctor better in clinical use, but also can withstand the application. Greater pressure without breakage.

Next, in order to confirm that the gamma-ray-treated hyaluronic acid-containing dressing of the present invention has a biological effect of promoting fibroblast proliferation, the inventors of the present application conducted a cell test of biocompatibility as follows.

The cell line selected in this experiment was L929 fibroblasts. First, the cells were cultured in a 24-well plate at a concentration of 10,000 cells/well. After 24 hours of cell attachment, the culture medium was replaced with those of Preparation Example 1 and Preparation Example 2. The dressing medium prepared in Example 3 was formulated, and the MTT cell activity test was carried out every 24 hours after the medium was replaced, and the test was continued for 48 hours. The results are shown in FIG. 1 .

Based on the results, it can be seen that the cell viability at the initial 0 hour was comparable in each group, but after the 24th hour and the 48th hour, the cell viability of the dressings of Formulation Example 2 and Formulation Example 3 were both better than those of Formulation Example 1 (using untreated gamma-ray treated hyaluronic acid). Thus, it was confirmed that the dressing containing the gamma-ray-treated hyaluronic acid had the effect of enhancing the activity of fibroblasts. In addition, the cell activity of Formulation Example 3 was more excellent than that of Formulation Example 2, indicating that hyaluronic acid treated with gamma rays (cumulative energy of 20 kGy) had more biological effects than hyaluronic acid of cumulative energy of 40 kGy. Excellent, the better the effect of promoting the proliferation of fibroblasts, indicating that the ability to promote the healing of wound tissue is stronger during application.

In addition, in order to confirm that the gamma-ray-treated hyaluronic acid-containing dressing of the present invention has a biological effect of regulating the inflammatory response, the inventors of the present application conducted an anti-inflammatory cell test as follows.

In this experiment, the mouse macrophage cell line RAW264.7 was seeded into a 96-well plate at a concentration of 40,000 cells/well. After 24 hours of cell attachment, the cell culture medium was replaced with a medium containing endotoxin at a concentration of 1 μg/mL to stimulate the cells to carry out an inflammatory response, which was used as a negative control group. In addition to investigating the anti-inflammatory activity of Formulation Example 1, Formulation Example 2 and Formulation Example 3, an inflammatory response inhibitor was also used as a positive control group. The results are shown in Figure 2.

It can be seen from the results that the inflammatory reaction of endotoxin-treated cells is quite significant. The dressings of preparation example 2 and preparation example 3 of the present invention containing hyaluronic acid treated with gamma rays have an anti-inflammatory effect. The anti-inflammatory effect is particularly pronounced. On the other hand, Formulation Example 1 containing hyaluronic acid not treated with gamma rays had no anti-inflammatory biological effect at all.

Therefore, the above results confirm that the gamma-ray-treated hyaluronic acid-containing dressing of the present invention has an anti-inflammatory biological effect, and the anti-inflammatory biological effects of the gamma-ray-treated hyaluronic acid-containing dressing with a cumulative energy of 20 kGy effect is more pronounced.

In addition, in the research process, in addition to the above formulation examples, the inventors of the present invention also performed gamma ray treatment with a cumulative energy of 60 kGy on hyaluronic acid. As a result, it was found that the treated hyaluronic acid The weight average molecular weight was 59,565 Daltons, a significant reduction in molecular weight compared to hyaluronic acid treated with gamma rays with a cumulative energy of 40 kGy. Based on the above test results, it can be seen that the biological effect of the dressing of Formulation Example 2 (treated with gamma rays with a cumulative energy of 40 kGy, and the weight-average molecular weight of hyaluronic acid is 141864 Daltons) is not as good as that of Formulation Example 3 (with cumulative energy of 40 kGy). The dressing was treated with gamma rays with an energy of 20 kGy, and the weight-average molecular weight of hyaluronic acid was 232,443 Daltons). Therefore, the inventors determined that the transparent The dressing prepared with uric acid could not obtain good biological effect.

It can be seen from the above results that the synthetic dressing of the present invention has excellent effects such as good biocompatibility, promotion of fibrous tissue regeneration, anti-inflammatory, short hydration time, and good mechanical properties.

Claims (8)

1. A synthetic dressing having a biological effect, characterized in that,

the dressing contains cellulose, a plasticizer, a film-forming agent and hyaluronic acid treated by gamma rays.

2. The synthetic dressing of claim 1,

the hyaluronic acid is treated by gamma rays with the accumulated energy of 20-40 kilogray.

3. The synthetic dressing of claim 1,

the hyaluronic acid is treated by gamma rays with the accumulated energy of 20 kilogray.

4. The synthetic dressing of claim 1,

the molecular weight of the hyaluronic acid treated by the gamma ray is 2,000-300,000 daltons.

5. The synthetic dressing of claim 1,

the molecular weight of the hyaluronic acid treated by the gamma ray is 150,000-250,000 daltons.

6. The synthetic dressing of any of claims 1-5, wherein said dressing is used as a general surgical wound dressing, a hemostatic cotton, a dental guided bone regeneration membrane, a gynecological anti-tissue adhesion barrier membrane, or a neurosurgical artificial meninges and anti-tissue adhesion barrier membrane.

7. A method of making a synthetic dressing having a biological effect, comprising the steps of:

performing gamma ray treatment on hyaluronic acid;

mixing hyaluronic acid treated by gamma rays with cellulose, a plasticizer and a film-forming agent; and

the mixture was freeze-dried to produce a synthetic dressing.

8. The production method according to claim 7,

in the gamma ray treatment, gamma rays with the accumulated energy of 20-40 kilogray are irradiated.

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