JPH0490764A - Covering material for wound - Google Patents

Abstract

PURPOSE:To promote a regeneration of skins by bonding a hydrophilic polymer chemically onto one surface of a porous polyolefin film to make a surface contacting a skin missing part lubricate by hydration. CONSTITUTION:A wound cover material is a porous polyolefin film or a porous polyolefin halide film bonded to a hydrophilic polymer chemically. In the cover material thus obtained, a pore diameter is preferably in a range of 0.01-1.0mum and a steam permeability in a range of 200-5000mg/m<2> per 24 hours. An antibacterial metal is evaporated and held on a surface where the hydrophilic polymer is bonded, thereby enabling the prevention of infection to wounds.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to wound dressings. Specifically, the present invention provides treatment for skin defects caused by wounds, burns, etc.
The present invention relates to a wound dressing that is applied to the skin defect site and promotes epidermal regeneration by bringing the surface in contact with the skin defect site into a hydrated and lubricated state.

[Conventional technology]

Wound treatment methods for wounds such as traumatic skin wounds and skin harvest wounds, as well as wounds associated with diseases, can be broadly divided into dry dressing, which keeps the wound dry and forms epidermis, and heals. Wet dress creates a moist environment for rapid migration of epidermal cells.
The latter is known to have rapid wound healing, less dry necrosis on the surface of the wound, and a protective effect on the wound surface.

However, with the method of using a surgical drape, which is one method of yet dressing, a large amount of exudate accumulates and there is a risk of reabsorption into the wound surface, and there is also a high risk of infection, and the adhesive comes into direct contact with the wound surface, making it difficult for wound healing to occur. It has been pointed out that there are problems that seem to be harmful. Also,
Because they tend to peel off from the wound surface, some have small protrusions attached to the part that comes in contact with the wound surface, but they have the disadvantage of being difficult to remove.

In order to solve these problems, in recent years, dressings that use biopolymers such as collagen, chitin, and fibrin in the part of the dressing that comes into contact with the wound, or that have moisturizing ingredients dispersed in rubber-based materials, have been developed to provide better adhesion and non-adhesion.・Those designed to maintain a high water content state, and furthermore, a biocompatible hydrogel-forming support layer in which at least a portion of the part that contacts the wound area is coated with a water-repellent substance, as previously proposed by the present inventors. (For example, carboxymethylcellulose, alginate-based,
hyaluronate-based, poly(meth)acrylate-based),
A wound dressing comprising a moisture permeation regulating layer formed on the side of the supporting layer opposite to the part that contacts the wound (Japanese Patent Application Laid-open No. 1982-
183780), and has achieved a certain degree of success.

On the other hand, porous polymer membranes are available as dry dressings, but in this case dress+ng sticks to the wound surface and causes bleeding when removed, so recently non-adhesive porous films (Melol in@ )
Sfflith & Nephew Lia+jted
) is commercially available.

In addition, infection is likely to occur on the wound surface and the sutured part of the wound.
A cream base containing antibacterial agents is used to prevent infection. However, when antibacterial agents are kneaded into gauze,
About 57% of the exudate soaks into the gauze bandage, and only about 21% reaches the wound surface. In addition, cream-based products are cumbersome to use, as they have to be applied to the wound surface every day.

[Problem to be solved by the invention]

Although the conventional dressings mentioned above are effective to some extent, the material used to form the biocompatible base layer in the part that comes into contact with the wound easily decomposes and falls off. There are problems with the physical properties when used as a wound, and furthermore, the decomposition and detachment may be recognized as foreign matter, posing the risk of delaying the healing of the wound. In addition, the moisture permeation regulating layer formed on the side of the support layer opposite to the part that contacts the wound area is required to have appropriate moisture permeability and bacterial invasion prevention ability; Materials that satisfy these properties are quite limited.

Therefore, the present invention has good adhesion to the wound surface, does not easily decompose or detach even if it comes into contact with the wound, promotes healing of the wound, especially epidermal regeneration, and promotes early recovery of the wound. The object of the present invention is to provide a wound dressing that is capable of healing and whose porous polyolefin membrane is water vapor permeable.

In addition, extensive burns and second-degree burns are susceptible to infection, so
A cream base containing antibacterial agents is used to prevent infection. However, about 57% of the exudate soaks into the gauze bandage, and only about 21% reaches the wound surface. In addition, cream-based products are cumbersome to use, as they have to be applied to the wound surface every day. By depositing an antibacterial metal on this membrane, it can not only prevent infection from the outside, but also be used when the wound surface is contaminated with bacteria.

[Means to solve the problem]

The above object is achieved by a wound dressing having the following structure.

(1) A wound dressing material characterized by having a hydrophilic polymer chemically bonded to one surface of a porous polyolefin membrane or a porous halogenated polyolefin membrane.

(2) The average pore diameter of the porous polyolefin membrane is 0.01~
The wound dressing according to item 1, which is 1.0-.

(3) Water vapor permeability of porous polyolefin membrane is 200
The wound dressing according to item 1 or 2, which has a dosage of ~5000 mg/rn"/24 hr.

(4) The wound dressing material according to any one of items 1 to 3, comprising a porous polyolefin membrane or a porous halogenated polyolefin membrane, on which a hydrophilic polymer-bonded surface is coated with a metal having antibacterial properties.

The wound dressing of the present invention is made of a porous polyolefin crotch or a porous halogenated polyolefin membrane with a hydrophilic polymer chemically bonded to it, as described above, and keeps the surface in contact with the skin defect site in a hydrated and lubricated state. 1. It can promote epidermal regeneration.

The membrane used in the present invention is a porous polyolefin membrane or a porous halogenated polyolefin membrane, and polyethylene, polypropylene, polyvinylidene fluoride, polyvinylidene chloride, chlorinated polyethylene, etc. are preferable in view of general use and low cost. Hydrophilic polymers to be bonded to the porous polyolefin membrane or porous halogenated polyolefin membrane include methoxyethyl acrylate or N-dimethylacrylamide, and polymethoxyethyl acrylate and N-dimethylacrylamide are chemically bonded to the polyolefin membrane by graft polymerization. Acrylate has excellent biocompatibility and has the advantage of less foreign body reaction when it comes into contact with living tissue. The obtained coating material has a pore size of 0.01 to 1.0 μm and a water vapor permeability of 200 to 5.
000mg/m”・24hr is preferable.

The metal used as the antifungal agent in the present invention is silver, copper, zinc, etc., and silver is preferred from the viewpoint of antibacterial properties. Further, two or more types of metals may be present on the film surface, or they may be in the form of a single metal, an oxide, or a salt. The amount of metal present in the porous membrane is not particularly limited, but due to cost and secondary contamination due to eluted metals, the amount of metal present on the membrane surface is determined by the X-ray photoelectron spectrum of the membrane surface. The abundance ratio is 0.02~
A value within the range of 5.0 is good. When the metal atom/carbon atom ratio exceeds 5.0, the metal abundance ratio on the membrane surface becomes excessive, and although it has antibacterial properties, the pore size is reduced by the attached metal and the membrane loses its original water vapor permeability. Put it away.

Furthermore, if an excessive amount of metal adheres and the metal becomes thin, the pores may become clogged, the metal layer may peel off due to impact, etc., and this is uneconomical. Conversely, the metal atom/carbon atomic ratio is 0
．． If it is less than 02, stable antibacterial properties may be lost.

[For production]

The wound dressing of the present invention is manufactured, for example, as follows. First, a predetermined amount of liquid paraffin and a crystal nucleating agent are added to polypropylene powder and melt-kneaded to form pellets.

This pellet is melted at 150 to 200°C, extruded using an extruder equipped with a T-die, introduced into a cooling fixation liquid, cooled and fixed, and made into a film, and the liquid paraffin in the film is extracted. A heat treatment is performed for about 2 minutes in a polypropylene film to obtain a porous polypropylene film. Plasma-initiated surface graft polymerization of methoxyethyl acrylate is performed on the membrane to obtain a porous polypropylene membrane subjected to hydrophilic treatment. Table 1 shows the surface lubricity of this film under wet conditions.

Table 1 Surface Lubricity of Wound Dressing Material The degree of surface lubricity of the surface of a material under wet conditions can be determined from the average coefficient of friction (frictional resistance) and the variation in the coefficient of friction (so-called dry feeling).

While the untreated polypropylene film shows high values of average friction coefficient and friction coefficient variation, the hydrophilic treatment with methoxyethyl acrylate shows low values, with very low roughness under wet conditions. It becomes a slimy hydrated state.

Next, this porous membrane is placed in a Pel jar for vacuum deposition, the pressure inside the Pel jar is reduced, and silver is vacuum deposited for a predetermined period of time.

Note that the method for making metal present on the film surface is not particularly limited, and there are other methods such as sputtering method and ion beam method.

The wound dressing of the present invention is prepared by applying an acrylic adhesive using a precision coating tool (applicator) onto the porous membrane on which the metal obtained above is vapor-deposited.

Since the wound dressing of the present invention has metal present on the membrane surface, the antibacterial action of this metal suppresses the growth of bacteria.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Polypropylene mixture with melt flow index of 30 and 0.3 (mixing weight ratio 1 (10:40) 100
Per part by weight, 400 parts by weight of liquid paraffin (average molecular weight 324) and 0.3 parts by weight of 1 as a crystal nucleating agent.
．． 3,2.4-bis(p-ethylbenzylidene) sorbitol was melt-kneaded using a twin-screw extruder and pelletized. This pellet was processed using the above two-wheeled extruder to
It was melted at 200°C and extruded into a film through a T-die with a slit of 0.6W into the air, and this film-like material was placed directly under the T-die and was guided into a cooling fixing liquid by an idle roller and cooled and fixed. Wind it up. Cut this rolled-up film-like material into a certain size, fix it both vertically and horizontally, and 1.1
．． The liquid paraffin in the film-like material is extracted by immersing it in 2-trichloro-L2,2-trifluoroethane for a total of 4 1O minutes. Next, heat treatment was performed in air at 135° C. for 2 minutes to obtain a polypropylene porous membrane having a pore size of 0.6 and a thickness of 140 μm.

This membrane was subjected to plasma-initiated surface graft polymerization of N,N-dimethylacrylamide to obtain a hydrophilic polypropylene membrane.

Example 2 Polyvinylidene fluoride powder (Kynar manufactured by Mitsubishi Yuka)
A solution of 18 parts by weight of K2O2) dissolved in 73.8 parts by weight of acetone and 8.2 parts of dimethylformamide was cast onto a polyethylene terephthalate film, and then 1.1.
Soak for minutes, dry, average pore size 0.45 um, film thickness 13
A five-node polyvinylidene fluoride porous membrane was obtained.

This membrane was subjected to plasma-initiated surface graft polymerization of N,N-dimethylacrylamide to obtain a hydrophilic polyvinylidene fluoride membrane.

Example 3 Silver is deposited on the porous membrane obtained in Example 1 by sputtering. In this sputtering deposition, the porous film was first placed in a Pel jar for vacuum deposition, the pressure was first reduced to 10' Torr, the shutter was opened, and silver was deposited on the porous film by sputtering for a predetermined period of time.

Test Example 1 [Antibacterial evaluation method Hut lcr - Hilton Agar (Difc
(manufactured by company o) was autoclaved and kept at 50℃,
0ml each was dispensed into petri dishes and left to solidify at room temperature for 1 hour. After culturing the bacteria on a flat plate, each type of bacteria was suspended in Tris buffer to obtain a bacterial solution, which was applied to the entire surface of the medium three times using a cotton swab. The sample prepared by the method of Example 3 was cut into 8 diameter pieces, placed on a culture medium coated with bacteria, and cultured at 37°C for 18 hours. The results are shown in Table 1.

Test Example 2 Antibacterial properties were tested in the same manner as in Test Example 1 for the wound dressing of the present invention prepared by the method of Example 3 and the wound dressing without a hydrophilic polymer in which silver was vapor-deposited on a porous polypropylene membrane. We conducted an evaluation.

The results are shown in Table 2.

〔Effect of the invention〕

The wound dressing of the present invention can be applied to burns, skin harvest wounds and dermabrasion wounds,
When applied to areas affected by diseases such as traumatic skin defects or wounds, it provides appropriate water vapor permeability and hydrates and lubricates the contact surface with the wound surface, allowing it to adhere closely to the wound surface and promote epidermal regeneration. In particular, by retaining metals that have antibacterial properties, infection of wounds can be prevented.

When a hydrophilic polymer and an antibacterial metal coexist on the surface of a coating material, the bactericidal ability is improved compared to when a hydrophilic polymer is not coexisting. This is thought to be because the hydrophilic polymer introduced onto the surface of the coating material swells with moisture and becomes loose in structure, promoting the desorption and diffusion of metal ions, thereby improving antibacterial properties. Ru.

Claims (4)

[Claims] (1) A wound dressing material characterized by having a hydrophilic polymer chemically bonded to one surface of a porous polyolefin membrane or a porous halogenated polyolefin membrane. (2) The average pore diameter of the porous polyolefin membrane is 0.01~
The wound dressing according to claim 1, which has a diameter of 1.0 μm. (3) Water vapor permeability of porous polyolefin membrane is 200
The wound dressing according to claim 1 or 2, which has a content of ~5000 mg/m^2.24 hr. (4) The wound dressing material according to any one of claims 1 to 3, wherein a metal having antibacterial properties is vapor-deposited on the surface to which a hydrophilic polymer is bonded to a porous polyolefin membrane or a porous halogenated polyolefin membrane. .