CN110698581A

CN110698581A - Waterproof easily-stripped wound dressing and preparation method thereof

Info

Publication number: CN110698581A
Application number: CN201911081513.9A
Authority: CN
Inventors: 孙迪; 刘杰
Original assignee: Renmin University of China
Current assignee: Renmin University of China
Priority date: 2019-11-07
Filing date: 2019-11-07
Publication date: 2020-01-17

Abstract

The invention discloses a waterproof easily-stripped wound dressing and a preparation method thereof. The preparation method of the wound dressing comprises the following steps: under the condition of inert atmosphere and the existence of a cross-linking agent and an initiator, the monomer is obtained by free radical polymerization in water; the monomer has the following functional groups of 1) and 2): 1) a carbon-carbon double bond; 2) a carboxyl group or a phenolic hydroxyl group; in the process of forming the waterproof film, the non-adhesive skin surface of the dressing needs to be sprayed or soaked with a saline solution selected from normal saline, a magnesium chloride solution, an iron chloride solution, citric acid and the like. Other additives commonly used in the art, such as sterilizing agents, may also be included in the waterproof peel-off wound dressing of the present invention. The hydrogel dressing prepared by the invention has waterproof surface, and can be well separated when being soaked in too much or a large amount of hydrogel dressing.

Description

Waterproof easily-stripped wound dressing and preparation method thereof

Technical Field

The invention relates to a waterproof easily-stripped wound dressing and a preparation method thereof.

Background

With the aging of population and the wide application of antiplatelet drugs for preventing cardiovascular events, under the condition of trauma or emergency operation, the situation that wounds or wounds are widely exposed is more and more common, the surgical dressing change often meets the challenge that the wounds or the wounds are difficult to peel off, and patients are troubled by scabbing and pain and the like during the postoperative dressing change, including scalds, sprains, bedsores, abrasions, incised wounds, ulcers, operative wounds and the like, which threaten the safety of the patients all the time. It is most desirable to use a waterproof peel-off dressing. The hydrogel can provide a wet environment and has the functions of antibiosis, antioxidation, antivirus and the like. The medical hydrogel dressing has the functions of strongly adhering wounds, relieving pain, stopping bleeding, sealing wounds and accelerating the healing process of the wounds.

In recent years, with respect to the treatment of wounds or incisions, hydrogel wound dressings have been considered to be more advantageous for the healing of wounds or wounds. Firstly, gauze is generally adopted, and the dry materials have the problems that although certain air permeability is realized on the wound surface or the wound, the dry materials can be adhered on the wound surface or the wound, and the dry materials are easy to scab, adhere to the wound, damage newly generated granulation tissues and the like when being peeled off. Secondly, the wound surface or the wound is kept in a wet environment, which is beneficial to preventing crust formation; the non-adhesion of the newly generated granulation tissue is facilitated; is beneficial to fibrin and necrosis; is beneficial to the dissolution of tissues and the like. And a small amount of liquid can seep out of the wound surface or the incision part, drainage and frequent dressing change are needed, and the liquid needs to be absorbed as soon as possible in order to keep the wound surface or the wound clean. Thirdly, the wound surface or the wound and the hydrogel dressing need to be closely adhered to the wound surface, and certain air permeability is also needed, so that the volatilization of liquid exuded from the wound surface or the incision is facilitated, and the healing of the wound surface or the wound is promoted. And after being adhered to the wound surface or the wound, the adhesive is easy to peel off when needing to be peeled off, and can not adhere to newly generated granulation tissues. Fourth, many wound dressings are not waterproof, which causes problems of avoiding wound infection after surgery and not allowing the patient to bathe. Therefore, at present, a new product for wound dressing is urgently needed to be developed to meet the market demand.

Disclosure of Invention

The invention aims to provide a waterproof easily-stripped wound dressing which is obtained by polymerizing a monomer with a specific structure, and the prepared solid wound dressing has the characteristics of waterproofness, skin adhesion, air permeability, easy stripping and the like.

The preparation method of the waterproof easily-stripped wound dressing provided by the invention comprises the following steps:

under the condition of inert environment and in the presence of a cross-linking agent and an initiator, carrying out free radical polymerization reaction on a monomer in water to obtain the waterproof easily-stripped wound dressing;

the monomer has the following functional groups of 1) and 2):

1) a carbon-carbon double bond;

2) carboxyl or phenolic hydroxyl.

The monomer in the present invention is preferably a biocompatible monomer such as tannic acid;

the monomer in the invention is preferably chain carboxylic acid, such as carboxylic acid with a structural formula of formula I:

in the formula I, n is an integer between 0 and 5, preferably 0 to 3;

R₁is H, C1-C5 alkyl or aryl;

the aryl group is preferably a phenyl group.

In the above preparation method, the conditions of the radical polymerization reaction are as follows:

the temperature is 50-80 ℃;

the time is 2-4 h.

In the above-mentioned production method, after the completion of the free polymerization reaction, autoclaving treatment may be carried out.

In the preparation method, the mass content of the monomer is 8-20%, the mass content of the crosslinking agent is 0.01-0.5%, and the mass content of the initiator is 0.01-1.0%, based on the total mass of the monomer, the crosslinking agent, the initiator and the water.

The monomer forms hydrogel through free radical polymerization reaction, and the dosage of the monomer is controlled within the range, so that the preparation of the hydrogel wound surface or wound dressing which is easy to attach to the skin is facilitated.

In the above preparation method, the cross-linking agent is methyl methacrylate and/or N, N' -methylene bisacrylamide;

the initiator is at least one of potassium persulfate, sodium persulfate and ammonium persulfate.

In the above preparation method, a reinforcing agent is further added to the system of the radical polymerization reaction;

the reinforcing agent is hydrotalcite and/or laponite;

the mass content of the reinforcing agent is 0.01-3.0% of the total mass of the monomer, the crosslinking agent, the initiator and the reinforcing agent;

the reinforcing agent can play a supporting and reinforcing role, but the content of the reinforcing agent cannot be too high, otherwise, the prepared dressing is hard, the modulus is increased, and the adhesion with a wound surface or a wound is not facilitated.

In the above preparation method, in the process of forming the waterproof film, it is necessary to spray or soak a salt solution selected from a physiological saline solution, a magnesium chloride solution, an iron chloride solution, citric acid, and the like, on the non-adhesive skin surface of the dressing.

The waterproof easily-stripped wound dressing prepared by the method is 0.1-1.0 cm in thickness; when the thickness is too low, such as less than 0.1cm, the formed waterproof film is too thin, cannot continuously prevent water and is quickly separated from a wound surface or a wound; when the thickness is between 0.1cm and 1cm, the buffer device can play a role in buffering slight collision and does not influence normal activities. When the thickness of the hydrogel dressing is more than 1cm, there is a certain influence on normal activities if it is in a joint position.

Other additives commonly used in the art, such as sterilizing agents, may also be included in the waterproof peel-off wound dressing of the present invention.

The non-adhesive skin side of the waterproof easily-peelable wound dressing needs to be treated, such as spraying or soaking with a salt solution at normal temperature.

The hydrogel dressing prepared by the invention has waterproof surface, and can be well separated when being soaked in too much or a large amount of hydrogel dressing.

Drawings

Fig. 1 is a picture showing the adhesive properties of the waterproof easy-peel wound dressing prepared in example 1.

Fig. 2 is a picture showing the water-proof property of the water-proof easily-peelable wound dressing prepared in example 1.

Fig. 3 is a picture of the easy peel performance of the waterproof easy peel wound dressing prepared in example 1.

Fig. 4 is a structural picture showing the air permeability of the waterproof easy-peel wound dressing prepared in example 1.

Fig. 5 is a structural picture showing the waterproof property of the waterproof easy-peel wound dressing prepared in example 1.

Detailed Description

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified.

Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

Examples 1,

1.1g of monomeric acrylic acid (in the formula I, R)₁H, N is 0), 0.02g N, N' -methylenebisacrylamide (crosslinker) and 0.02g hydrotalcite (enhancer) were dissolved in 10ml of water, stirred at 60 ℃ for 1 hour, and nitrogen was introduced in order to remove oxygen from the reactor and water. Meanwhile, 10mg/ml ammonium persulfate solution (initiator) is prepared, the initiator is dripped into a reactor containing monomers dropwise, autoclaving is carried out after 2 hours to obtain hydrogel dressing with good adhesion, the non-adhesive skin surface is treated, normal temperature saline solution is sprayed, the waterproof effect is shown in figure 2, and when water is dripped on the wound dressing, the water droplets stay on the surface of the wound dressing and do not permeate into the wound dressing.

In the above examples, based on the total mass of the monomer acrylic acid, N '-methylenebisacrylamide, ammonium persulfate, and water, the mass content of the monomer acrylic acid was 9.06%, the mass content of the N, N' -methylenebisacrylamide was 0.16%, the mass content of the hydrotalcite was 0.16%, and the mass content of the ammonium persulfate was 0.01%.

The schematic diagram of the hydrogel dressing prepared in this example when adhered to skin (pig skin) is shown in fig. 1, and it can be seen that the hydrogel dressing adhered well to skin and had good adhesion properties.

The hydrogel dressing adhered to the skin was soaked with water, as shown in fig. 3, and was well peeled from the skin.

The scanning electron microscope photos of the hydrogel dressing prepared by the embodiment are as shown in fig. 4 and fig. 5, and it can be seen from fig. 4 that the wound dressing and the skin contact layer have a porous structure, so that the wound and the outside can be well ventilated, and as can be seen from fig. 5, the outermost layer structure of the wound dressing is compact, so that the wound dressing can prevent exogenous moisture or other fine dust or bacteria from entering, and can well play a role in water prevention to avoid secondary infection on the wound.

Examples 2,

1.1g of monomeric acrylic acid (R)₁H, N is 0), 0.02g N, N' -methylenebisacrylamide (crosslinker) and 0.02g hydrotalcite (enhancer) were dissolved in 10ml of water, stirred at 60 ℃ for 1 hour, and nitrogen was introduced in order to remove oxygen from the reactor and water. Meanwhile, 10mg/ml of ammonium persulfate solution (initiator) is prepared, the initiator is dripped into a reactor containing monomers drop by drop, and after 2 hours, autoclaving treatment is carried out to obtain the hydrogel dressing with good adhesion; the prepared hydrogel dressing is treated on the non-adhesive skin surface, and ferric trichloride solution is sprayed at normal temperature, so that the waterproof effect is achieved.

The hydrogel dressing prepared in this example was able to adhere well to the skin.

Examples 3,

1.1g of monomeric cinnamic acid (R)₁N is 0), 0.06g N, N' -methylenebisacrylamide (crosslinker) and 0.02g hydrotalcite (enhancer) in 10ml of water, stirred at 60 ℃ for 1h and purged with nitrogen in order to remove oxygen from the reactor and water. Meanwhile, preparing 10mg/ml potassium persulfate solution (initiator), dropwise adding the initiator into a reactor containing monomers, and carrying out autoclaving treatment after 2 hours to obtain the hydrogel dressing with good adhesion; the prepared hydrogel dressing is treated on the non-adhesive skin surface, and ferric trichloride solution is sprayed at normal temperature, so that the waterproof effect is achieved.

Examples 4,

1.1g of tannic acid (monomer), 0.06g N, N' -methylenebisacrylamide (crosslinker) and 0.02g of hydrotalcite (enhancer) were dissolved in 10ml of water, stirred at 60 ℃ for 1 hour, and nitrogen was introduced so as to remove oxygen from the reactor and water. Meanwhile, 10mg/ml ammonia persulfate solution (initiator) is prepared, the initiator is dripped into a reactor containing monomers drop by drop, and after 2 hours, autoclaving treatment is carried out to obtain the hydrogel dressing with good adhesion; the prepared hydrogel dressing is treated on the non-adhesive skin surface, and ferric trichloride solution is sprayed at normal temperature, so that the waterproof effect is achieved.

Comparative examples 1,

1.1g of oleic acid (formula I, R)₁N-octyl, N is 7), 0.02g N, N' -methylenebisacrylamide (crosslinker) and 0.02g hydrotalcite (reinforcing agent) were dissolved in 10ml of water, stirred at 60 ℃ for 1 hour, and nitrogen was introduced in order to remove oxygen from the reactor and water. Meanwhile, 10mg/ml ammonium persulfate solution (initiator) is prepared, and the initiator is dripped into the reactor containing the monomer dropwise, so that the hydrogel dressing is not easy to form. The method shows that when the carbon chain is too long, the hydrophobic effect is stronger, and the hydrogel is not easy to form under the condition of adopting the same crosslinking agent.

Comparative examples 2,

1.1g of monomeric acrylic acid (R)₁H), 0.1g N, N' -methylenebisacrylamide (crosslinker) and 0.02g hydrotalcite (enhancer) were dissolved in 10ml of water, stirred at 60 ℃ for 1H and nitrogen was introduced in order to remove oxygen from the reactor and water. Meanwhile, 10mg/ml ammonium persulfate solution (initiator) is prepared, the initiator is dripped into a reactor containing monomers drop by drop, and autoclaving is carried out after 2 hours, so that the hydrogel dressing which is easy to attach to the skin is obtained, but the hydrogel dressing is too hard due to too much cross-linking agent and is not beneficial to joint movement. Shows that when the dosage of the cross-linking agent exceeds 0.5 percent, the use performance of the hydrogel dressing is influenced,is not easy to be used as a hydrogel dressing for joint movement.

In the above examples, based on the total mass of the monomer acrylic acid, N '-methylenebisacrylamide, ammonium persulfate, and water, the mass content of the monomer acrylic acid was 9.00%, the mass content of the N, N' -methylenebisacrylamide was 0.81%, the mass content of the hydrotalcite was 0.16%, and the mass content of the ammonium persulfate was 0.01%.

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.

Claims

1. A method of making a wound dressing comprising the steps of:

under the condition of inert environment and in the presence of a cross-linking agent and an initiator, carrying out free radical polymerization reaction on a monomer in water to obtain the modified polyurethane resin;

the monomer has the following functional groups of 1) and 2):

1) a carbon-carbon double bond;

2) carboxyl or phenolic hydroxyl.

2. The method of claim 1, wherein: the monomer is biocompatible.

3. The method of claim 1, wherein: the monomer is chain carboxylic acid, and the structural formula of the monomer is shown as formula I:

in the formula I, n is an integer between 0 and 5;

R₁is H, C1-C5 alkyl or aryl.

4. The production method according to any one of claims 1 to 3, characterized in that: the conditions for the free radical polymerization are as follows:

the temperature is 50-80 ℃;

the time is 2-4 h.

5. The production method according to any one of claims 1 to 4, characterized in that: the mass content of the monomer is 8-20%, the mass content of the cross-linking agent is 0.01-0.5%, and the mass content of the initiator is 0.01-2.5%, based on the total mass of the monomer, the cross-linking agent, the initiator and the water.

6. The production method according to any one of claims 1 to 5, characterized in that: the cross-linking agent is methyl methacrylate and/or N, N' -methylene bisacrylamide;

7. The production method according to any one of claims 1 to 6, characterized in that: a reinforcing agent is also added into the system of the free radical polymerization reaction;

the reinforcing agent is hydrotalcite and/or laponite;

and the mass content of the reinforcing agent is 0.01-2.5% of the total mass of the monomer, the crosslinking agent, the initiator and the reinforcing agent.

8. The production method according to any one of claims 1 to 7, characterized in that: spraying or soaking a saline solution on one surface of the wound dressing.

9. A waterproof peel-off wound dressing prepared by the method of any one of claims 1 to 8.

10. The waterproof peel-off-susceptible wound dressing of claim 9, wherein: the thickness of the waterproof easily-stripped wound dressing is 0.1-1.0 cm.