JPH04263854A - Wound coating material - Google Patents

Abstract

PURPOSE:To provide the wound coating material which has good adhesion to a wound surface, does not easily separate and detach in spite of contact with the wound part and accelerates the treatment, particularly the epithelial regeneration of the wound part by consisting this material of a porous polyolefinic film and/or porous halogenated polyolefinic film having specific porosity and steam permeation rate. CONSTITUTION:This material consists of the porous polyolefinic film and/or porous halogenated polyolefinic film having <50% porosity and 500 to 10000g/m<2> 24hr steam permeation rate. For example, polyethylene, polypropylene, polyvinylidene fluoride, polyvinylidene chloride, chlorinated polyethylene, or the copolymers thereof are preferable. Hydrophilic polymers are preferably chemically bonded with these porous films and/or acrylate is graft-polymerized therewith to impart elasticity thereof.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to wound dressings. More specifically, the present invention relates to a wound dressing that is applied to a skin defect site due to a wound, burn, etc., and promotes epidermal regeneration by bringing the surface in contact with the skin defect into a hydrated state.

0002

BACKGROUND OF THE INVENTION Methods and materials for protecting wounds such as traumatic skin wounds and skin harvest wounds, as well as wounds associated with diseases, can be roughly divided into two methods: keeping the wound dry and healing it by forming an eschar; So-called dry dress
g, and wet dressing, which creates a moderately moist environment and allows rapid migration of epidermal cells, is known.The latter allows for rapid wound healing, less dry necrosis on the wound surface, and protects the wound surface. It is also known to have beneficial effects.

[0003] However, in the method of using a surgical drape, which is one method of wet dressing, a large amount of exudate accumulates and there is a risk that it will be reabsorbed into the wound surface, and there is also a high risk of infection, and because the adhesive comes into direct contact with the wound surface,
It has been pointed out that there are problems that may be detrimental to wound healing. In addition, they tend to peel off from the wound surface, so some products have small protrusions attached to the part that comes into contact with the wound surface, but they have the disadvantage of being difficult to remove.

[0004] In order to solve these problems, in recent years, biopolymers such as collagen, chitin, and fibrin are used in areas that can come into contact with the wound, or moisturizing ingredients are dispersed in rubber-based materials to provide adhesive and non-adhesive materials. A biocompatible hydrogel-forming support layer that is designed to ensure adhesion and maintain a high water content state, as well as a biocompatible hydrogel-forming support layer in which at least a portion of the area that can come into contact with the wound area is coated with a water-repellent material, as previously proposed by the applicant. (for example, carboxymethylcellulose, alginate-based, hyaluronate-based, poly(meth)acrylate-based), and a moisture permeation regulating layer formed on the opposite side of the support layer from the part that can come into contact with the wound area. There are wound dressing materials (Japanese Unexamined Patent Application Publication No. 183760/1983) made of these materials, which have achieved a certain degree of success.

On the other hand, porous polymer membranes are available as dry dressings, but in this case the dressings stick to the wound surface and cause bleeding when removed, so recently non-adhesive porous films ( Me
lolinR, Smith & Nephew Limi
ted) is commercially available.

[0006] Furthermore, as seen in JP-A-58-155854, there is a wound dressing made of a porous film, but since the porosity is 50% or more, it cannot be applied to wound surfaces such as joints. In this case, cracks occur in the covering material and the strength is not sufficient.

[0007]

[Problems to be Solved by the Invention] Although the above-mentioned conventional dressings have some effects, the materials used to form the biocompatible base layer in the part that comes into contact with the wound are It easily decomposes and falls off, and there are problems with its physical properties when used as a wound dressing.Furthermore, the decomposed and separated substances are sometimes recognized as foreign substances, and there is a 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 come off when it comes into contact with the wound, promotes healing of the wound, especially epidermal regeneration, and improves the wound area. The purpose of the present invention is to provide a wound dressing material that can perform early healing of the wound and in which the porous polyolefin membrane or the porous halogenated polyolefin membrane has water vapor permeability.

[0009]

The above objects are achieved by a wound dressing having the following structure. 1) Porosity less than 50%, water vapor permeability 500-10.0
A wound dressing made of a porous polyolefin membrane or a porous halogenated polyolefin membrane with a weight of 00g/m2/24hr. 2) The wound dressing according to item 1, wherein a hydrophilic polymer is chemically bonded to at least one surface of a porous polyolefin membrane or a porous halogenated polyolefin membrane. 3) The wound dressing material according to item 1, which is obtained by graft polymerizing an acrylic acid ester to a porous polyolefin membrane or a porous halogenated polyolefin membrane to impart elasticity.

[0010] The membrane used in the present invention is a porous polyolefin membrane or a porous halogenated polyolefin membrane, and considering its general purpose and low cost, polyethylene, polypropylene, polyvinylidene fluoride, polyvinylidene chloride, chlorinated polyethylene, Or copolymers thereof are preferred. The resulting coating material has a porosity of less than 50%,
More preferably 40-48%, water vapor transmission rate 500-1
0,000g/m2・24hr, more preferably 200
It is preferable that it be within the range of 0 to 5000g/m2・24hr.

The wound dressing of the present invention is made of a porous polyolefin membrane or a porous halogenated polyolefin membrane chemically bound to a hydrophilic polymer as described above, and hydrates the surface in contact with the skin defect site. It is possible to promote epidermal regeneration by providing a lubricated state. The hydrophilic polymer to be bonded to the porous polyolefin membrane or the porous halogenated polyolefin membrane is N- such as methoxyethyl acrylate or N-dimethylacrylamide.
Substituted acrylamide polymers are mentioned, and polymethoxyethyl acrylate, which is chemically bonded by graft polymerization to the above-mentioned polyolefin membrane, has excellent biocompatibility and has the advantage that there is little foreign body reaction when it comes in contact with living tissues. has.

Although the wound dressing of the present invention is excellent in terms of strength as it is, it is also possible to graft-polymerize an acrylic ester in order to further improve the physical properties. Acrylic ester is methyl acrylate,
Examples include ethyl, n-propyl, iso-propyl, n-butyl or iso-butyl, without particular limitation.

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 a random copolymer of propylene and ethylene, and the mixture is melt-kneaded and pelletized. 15 of these pellets
Melt at 0 to 200°C and extrude using an extruder with a T die,
After cooling and fixation, liquid paraffin is extracted to obtain a porous membrane made of polyolefin. The porosity of the membrane thus obtained can be measured as follows.

The thickness and dry weight of the porous membrane are measured, and after immersing it in methanol, the methanol is replaced with water, the membrane is taken out, and the water on the surface is wiped to measure the wet weight of the membrane. Determine the dry porosity from the film thickness, dry weight, and specific gravity of the raw material. In addition, the wet porosity is determined from the dry weight and wet weight. The porosity used in the present invention is dry porosity.

On the other hand, in order to obtain a porous membrane made of elastic polyolefin, ethyl acrylate is subjected to plasma-initiated surface graft polymerization onto the porous membrane made of polyolefin. The strength of this membrane was 1.5 times higher and the elongation was 1.8 times higher than that of the polyolefin porous membrane before treatment.

[0016] Furthermore, plasma-initiated surface graft polymerization of N-substituted acrylamide such as methoxyethyl acrylate or N-dimethylacrylamide is performed on a polyolefin membrane to obtain a hydrophilic porous membrane made of polyolefin. When wet, this film has a very low roughness and becomes slimy and hydrated.

The wound dressing of the present invention can be applied to bending and stretching wound surfaces such as the joints of hands and feet, and allows air and water vapor to pass therethrough, but prevents moisture and bacteria from entering.

[0018]

EXAMPLES The present invention will be explained in more detail below with reference to Examples.

Example 1 Per 100 parts by weight of a random copolymer of propylene and ethylene (manufactured by Mitsui Toatsu Chemical Co., Ltd.), 300 parts by weight of liquid paraffin (average molecular weight 324) and 0.3 parts by weight as a crystal nucleating agent were added. 1,3,2,4-bis(p-ethylbenzylidene) sorbitol was melt-kneaded using a twin-screw extruder and pelletized. The pellets were melted at 150 to 200°C using the above-mentioned twin screw extruder, and the slits were 0.
It is extruded into a film through a 6 mm T-die in the air, guided into a cooling fixation liquid by a guide roller placed directly below the T-die, cooled and fixed, and then wound up. This rolled-up film-like material was cut into a certain size, fixed both vertically and horizontally, and 1,1,2-trichloro-1,2,
Immersed in 2-trifluoroethane for 10 minutes 4 times in total,
The liquid paraffin in the film was extracted to obtain a polyolefin porous membrane having a porosity of 45% and a pore diameter of 0.07 μm.

Comparative Example 1 Polypropylene powder (manufactured by Mitsui Toatsu Chemical Co., Ltd.) 100
Per part by weight, 300 parts by weight of liquid paraffin (average molecular weight 324) and 0.3 parts by weight of 1,3,2,4-bis(p-ethylbenzylidene) sorbitol as a crystal nucleating agent were added in a twin-screw extruder. The mixture was melt-kneaded and pelletized. The pellets were processed using the above twin-screw extruder for 150
It is melted at ~200°C and extruded into a film through a T-die with a slit of 0.6 mm into a film.
It is guided into a cooling fixation liquid by a guide roller placed directly under the die, cooled and fixed, and then wound up. This rolled-up film-like material is cut into a certain size, fixed in both vertical and horizontal directions, and
, 1,2-trichloro-1,2,2-trifluoroethane for a total of 4 times for 10 minutes to extract the liquid paraffin in the film. Then, in air at 135°C,
A heat treatment was performed for a minute to obtain a polypropylene porous membrane with a porosity of 60% and a pore diameter of 0.1 μm.

Example 2 Ethyl acrylate was subjected to plasma-initiated surface graft polymerization to the membrane obtained in Example 1 to obtain a polyolefin porous membrane imparted with elasticity. That is, the porous membrane was heated to 0.1 Torr, 1
After irradiating with argon plasma for 5 seconds, graft polymerization was carried out for 30 minutes in an ethyl acrylate atmosphere (25° C., 4 Torr). The resulting ethyl acrylate grafted porous membrane had a porosity of 42%.

Example 3 The methoxyethyl acrylate obtained in Example 1 was subjected to plasma-initiated surface graft polymerization in the same manner as in Example 2 to obtain a hydrophilic porous membrane.

Test 1 <Physical property test of various wound dressing materials> The tensile strength (Strograph T type, Toyo Seiki Seisakusho) of the porous membranes obtained in Examples 1, 2, and 3 and Comparative Example 1 was measured. The results are shown in Table 1.

[0024]

[Table 1]

Examples 1 to 3 were superior in breaking strength and breaking elongation as compared to comparative examples.

Test 2 <Water permeation test> After sufficiently soaking a sponge in a Petri dish with distilled water, the porous membranes of Example 3 and Comparative Example 1 were placed on its surface, and 8 sheets of gauze were placed on top of it. . Then, after pressing with a Petri dish lid and a weight (approximately 5 g), this was left at room temperature. The weight of the gauze was accurately measured over time. The results are shown in Figure 1. In Figure 1, ○-○ is Example 3, ●-
● indicates the water content of the gauze in Comparative Example 1. Figure 1
From the results, it was found that Example 3 had very high moisture permeability.

Test 3 <Water vapor permeation test> The water vapor permeation test is based on the JIS standard (Z
0208). The results are shown in Table 2.

[0028]

[Table 2]

[0029]

[Effects of the Invention] The wound dressing of the present invention can be applied to diseases such as burns, skin harvest wounds, skin abrasion wounds, traumatic skin loss wounds, and affected areas caused by wounds, especially wound surfaces that bend and stretch such as the joints of hands and feet. In addition, by hydrophilic treatment, the surface in contact with the wound surface can be made into a hydrated and lubricated state with appropriate water permeability, allowing it to adhere closely to the wound surface and promote epidermal regeneration.

[Brief explanation of the drawing]

FIG. 1 is a graph showing changes over time in the water content of gauze layered on a porous membrane.

[Explanation of symbols]

○−○ Example 3 ●−● Change in water content of gauze over time in Comparative Example 1

Claims (3)

[Claims] [Claim 1] Porosity less than 50%, water vapor permeability 50
A wound dressing consisting of a porous polyolefin membrane and/or a porous halogenated polyolefin membrane having a weight of 0 to 10,000 g/m2/24 hr. 2. The wound dressing according to claim 1, wherein a hydrophilic polymer is chemically bonded to one surface of a porous polyolefin membrane and/or a porous halogenated polyolefin membrane. 3. The wound dressing material according to claim 1, wherein elasticity is imparted to the porous polyolefin membrane and/or the porous halogenated polyolefin membrane by graft polymerization of an acrylic acid ester.