JPS63115562A - Wound cover material - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a dressing for the purpose of treating burns, external injuries, wounds, etc., and particularly to a dressing that prevents the accumulation of exudate (body fluid) between the dressing and the wound surface. The present invention relates to a wound dressing material that has good initial adhesion to the wound surface.

(Prior Art) A variety of dressings have been developed for use in treating a wide range of skin defects caused by burns, trauma, wounds, etc. These dressings can be broadly classified into the following three types: are categorized. That is, (1) tissue pieces such as homogeneous split-thickness skin pieces, heterogeneous skin pieces, and human amniotic membrane; (2) reconstituted biomaterials such as collagen membranes (nonwoven fabrics) and fibrin membranes; (3) silicone membranes and nylon knitted membranes. It is a synthetic polymer material represented by a layered structure.

(Problems to be Solved by the Invention) However, although the tissue pieces (11) are excellent in controlling insensible excretion and preventing leakage of body fluids, they have a strong immunological rejection reaction and can only be covered for a short period of time. In addition, collagen, which can be stably supplied, is mainly used as the reconstituted biomaterial in (2), but even if the antigenicity can be reduced by enzyme treatment, it is quickly degraded and absorbed in the body, so it does not last long. Furthermore, the synthetic polymer material in (3) is non-degradable and absorbable in the living body, so it has low antigenicity and can be stably supplied and sterilized. It has the disadvantage of being low.

In order to improve the drawbacks of these dressings for treating skin defects, the present invention uses polyamino acids with excellent tissue affinity as a microporous membrane to prevent absorption of exudate from the wound surface and penetration into the tissue. In addition, it relates to a wound dressing that has a core material that improves the strength and handleability of the dressing, and that has a biocompatible material attached to it that promotes initial bioadhesion and has the effect of promoting treatment. .

(Means for Solving the Problems) That is, the present invention provides a wound dressing material formed by interposing a core material made of fibers or a metal network within a microporous membrane layer made of polyamino acids. A first invention, wherein a core material made of fibers or a metal network is interposed within a microporous membrane layer made of a polyamino acid, and at least one side of the microporous membrane layer has biocompatibility. The second invention is a wound dressing material formed by adhering materials.

First, the first invention will be explained.

As the polyamino acid used in the present invention, poly-α-amino acids with excellent tissue affinity are preferable, such as polyamino acids.
(γ-benzylene monoglutamate).

Poly (L-leucine), copoly (L-lysine-L-
leucine), copoly (L-lysine-L-glutamic acid), and the like.

This polyamino acid microporous membrane layer is a sheet-like sponge structure with a thickness of about 1 to 10+ U having open pores with a pore diameter of 20 μm to 500 μm at least on the layer side facing the wound side. It is preferable that the diameter decreases toward the other surface. If the pore size is less than 20 μm, tissue penetration and exudate absorption will be impaired, and
Water vapor permeability, oxygen permeability, etc. are also deteriorated, which is undesirable in terms of wound healing.If the thickness is 500 μm or more, adhesion to the wound portion becomes poor, resulting in retention of exudate, which is undesirable.

Further, if the thickness is outside the above range, penetration into tissue, absorption of exudate, etc. will be poor, or handleability will be poor, which is not preferable. Note that the surface portion of the microporous membrane layer that is not a wound portion is preferably several micrometers or less in order to prevent bacterial invasion from the outside.

As the core material made of fiber or metal net, natural or synthetic fiber net or metal net can be used, but when covered with a stretchable material,
It is preferable because it can adapt to the bending of the body and maintains close contact. Examples of such core materials include polyurethane and polyolefin.

Stretchable woven materials such as nets made of synthetic fibers such as polyvinyl chloride, polyvinylidene chloride, polyamide, and polyester, nets of natural cellulose fibers, and metal nets made of ultrafine stainless steel filaments. can give. These core materials have functions such as imparting mechanical strength to the present wound dressing material and providing good handling properties even when peeled off after being covered for a certain period of time.

In the wound dressing according to the present invention, for example, a core material made of cotton is stretched in advance at a predetermined height in a predetermined container, then a polyamino acid solution is injected into the container, and after quenching, , formed by freeze-vacuum drying.

Next, a second invention related to the present invention will be explained. That is, the present invention relates to a wound dressing formed by adhering a biocompatible material to at least the surface of the wound dressing obtained according to the first invention that faces the wound.

Biocompatible materials used in the present invention include fibrinogen, albumin, and γ-globulin.

Serum proteins such as fibronectin and collagen.

Examples include gelatin and mucopolysaccharides. Attaching these biocompatible materials has the effect of promoting initial bioadhesion, preventing accumulation of exudate (body fluid, etc.) between the dressing and the wound surface, and promoting treatment.

Further, as a method of attachment, for example, a solution of the biocompatible material is applied to at least the surface of the wound dressing obtained in the first invention that will be on the wound side, and the solution is freeze-vacuum-dried to make it adhere. It will be done.

(Example) The present invention will be further explained below based on Examples.

Example 1 Benzene solution of poly (L-leucine) (concentration 0, 25
A homogeneous polymer solution of 50 m/g/d was poured at 70° C. into a 10×15c+n container in which a nylon net was stretched in advance at a height of about 1 crane from the bottom. After gelation at room temperature, the surface was dried with warm air at about 50°C, and then heated at 130°C.
The wound dressing material according to the present invention was obtained by rapidly cooling to °C and freeze-vacuum drying.

The wound dressing material was sterilized with ethylene oxide gas and stored protected from light. The pore diameter on the wound side of this wound dressing is 100-2
00 μm, and the thickness was 21 m.

Example 2゜On the wound side of the wound dressing obtained in Example 1,
Human fibrinogen aqueous solution (concentration 1 g/a) 10 mA
was applied, rapidly cooled at -20°C, freeze-vacuum dried, and irradiated with ultraviolet rays in a sterile room to form a wound dressing according to the present invention.

The evaluation of the present wound dressings obtained in Examples 1 and 2 was as follows: 6-
The experiment was conducted using 8-week-old rats. A full-thickness cortical lesion (3 cm x 2.5 c!Il) was surgically created on one side of the rat's back, this wound dressing was sutured, gentamicin ointment was applied to the surrounding area, Telefa Pasoto was sutured, and an elastic band was applied. It was bandaged. The present wound dressing was applied to a full-thickness defective lesion in the back cortex of a rat. In particular, the dressing obtained in Example 2 adhered with appropriate strength after being lightly compressed for about 1 minute, and the present dressing moved during suturing. There was no such thing. This is thought to be because fibrinogen present in the lower layer of the sponge changed to fibrin on the wound surface and acted as an adhesive. The covering material obtained in Example 1 also adhered under pressure for several minutes and did not move even when sutured. In addition, a sufficient hemostatic effect was obtained even against bleeding at the level of oozing on the wound surface. Such early adhesion and hemostasis are thought to be effective in preventing blood from forming under the dressing.

When the state of the tissue was observed after 4 weeks, new tissue rich in capillaries was observed at the bottom of both the 100 wound dressings of Examples 1 and 2.

This wound dressing is used directly by applying it to the wound surface. Among wounds, when treating superficial first-degree burns, the dressing is removed when the epidermis formation is completed, while when treating deep first-degree burns and second-degree burns, the covering is protected for a certain period of time and then the dressing is removed. When skin grafting is performed, some of the base material of the wound dressing remains within the new tissue, but since it is made of poly-α-amino acids, fibrinogen, collagen, etc., it is decomposed and absorbed within the tissue.

Furthermore, fibrinogen is a blood coagulation protein, and fibrin is formed by the action of thrombin.

Fibrin exhibits excellent adhesion and proliferation properties for fibroblasts. Therefore, by impregnating or applying fibrinogen to the adhesive layer on the wound surface of the dressing, it exhibits a hemostatic effect and at the same time exhibits excellent bioadhesion and wound treatment effects.

(Effects of the Invention) As explained above, the wound dressing according to the present invention has the following characteristics.

■ A special structured membrane with continuously changing pore size controls insensible excretion through the permeation of water vapor and blocks the invasion of bacteria from the outside.

■ By making the layer in contact with the wound surface porous, it enables strong biological contact and prevents exudate from accumulating.

■ Promote wound healing by using materials with excellent compatibility with living organisms, such as fibrinogen.

■ By incorporating a core material, the wound surface is covered and protected for a certain period of time, and then peeled off easily. Upon exfoliation, the base material remaining within the regenerated tissue is biodegraded and absorbed.

Claims (2)

[Claims] (1) A wound dressing characterized in that it is formed by interposing a core material made of fibers or a metal network within a microporous membrane layer made of polyamino acids. (2) A core material made of fiber or metal network is interposed within the microporous membrane layer made of polyamino acids, and at least the surface of the microporous membrane layer facing the wound side has biocompatibility. A wound dressing characterized by being formed by adhering materials.