KR100359864B1 - Dressing Having Microporous polyurethane film for Wound Healing - Google Patents

Abstract

The present invention relates to a wound dressing material in which a microporous polyurethane film is formed in direct contact with a wound to heal the wound. More specifically, the microporous polyurethane film having a plurality of pores having a thickness of 1 to 300 µm and having a diameter of 10 µm or less is formed on one or both surfaces of the superabsorbent substrate sheet. It is a complex structure. The microporous polyurethane film is coated with a polyurethane solution prepared by mixing isocyanate, polyether polyol, chain extender and a solvent on a base sheet and then deposited it in a coagulation bath containing water to have a fine pore structure on the base sheet. It solidifies and forms. As the base sheet, a nonwoven fabric or cloth is used, and preferably, one having a high absorbency of 200% or more. The dressing material of the present invention is in contact with the wound to prevent invasion of bacteria from the outside, has excellent air and moisture permeability, and has a wound surface non-adhesive property. And because of its excellent water absorption, it can be applied to various wounds regardless of the degree of exudation, and can be attached for a long time by maintaining a high moisture permeability.

Description

Dressing material for wound coating with microporous polyurethane film {Dressing Having Microporous polyurethane film for Wound Healing}

The present invention relates to a dressing material for wound dressings in direct contact with wounds to heal wounds, and more particularly, a microporous polyurethane film having a plurality of pores having a diameter of 10 μm or less on one or both sides of a base sheet. The present invention relates to a wound dressing material in which a microporous polyurethane film having excellent moisture permeability and water absorption is formed.

Skin is one of the organs that protects the body from external stimuli, prevents loss of moisture, performs vital life protection functions such as controlling body temperature and prevents bacterial invasion. When skin is damaged by burns or various traumas, its protective action is lost. This can lead to functional impairment, which causes various side effects due to water loss and bacterial infections from the outside, making it difficult to treat the affected area or causing additional side effects such as secondary dysfunction or damage. It will also affect. Therefore, in order to quickly heal wounds and to minimize secondary side effects, wound treatment using appropriate dressing materials is essential.

Brief descriptions of the major factors involved in wound healing include a wet environment, infection, foreign body and necrotic tissue, temperature, oxygen concentration, and pH. The ideal dressing material requirement is to maintain adequate moisture in contact with the wound, to absorb exudates, to facilitate attachment and removal of the wound, to transfer gas and water to the outside, to insulate from the outside, and to invade bacteria. Defense, non-toxic to human body, excellent mechanical properties, economics and the like.

Conventional gauze dressings are easy to absorb exudates, but they do not have a protective function against bacterial infections, keep wounds dry and delay treatment, and the dressings adhere to the wound surface and are not easily removed when exchanged. In the early stages of healing, many exudates have the disadvantage of having to change dressings several times a day. Currently, various closed dressing materials have been developed and used to improve the problems of the gauze-type dressing materials. However, due to the high price, the hygroscopicity and the lack of the controllability of moisture permeability, they are not applied to a wide range of wounds and are only applied to specific applications. Types of the closed dressing material which are mainly used include film type, hydrocolloid type, hydrogel type, nonwoven fabric using sodium alginate, polyurethane foam type and the like. In particular, the film type dressing material has a high possibility of being used universally because of its simplicity of use and ease of manufacture.

In US Patent Nos. 4,202,800, 4,367,327, 4,686,137, polyurethane films were prepared using hydrophilic polyols and applied as a dressing material. The film-type dressing material is useful for light wounds, that is, scratches, erosions or skin graft donor sites, but it is not applicable to wounds in which relatively high exudates occur due to lack of moisture permeability and absorption. In addition, U.S. Patent No. 5,437,621 manufactures a closed dressing material by laminating a polyurethane film on a nonwoven fabric, but has a disadvantage in that it is difficult to continuously absorb the exudates due to permeation and drying of the exudates absorbed due to the slow rate of exudates and low moisture permeability. The application to this relatively many wound dressings is unreasonable. The above film type dressing material has ease of manufacture and simplicity of use, but has the disadvantage of lacking a effluent absorption layer and low moisture permeability in terms of properties.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dressing material for wound coating which is excellent in absorbency, air permeability and moisture permeability of exudate, can be widely applied from mild wounds to bedsores, burns, etc., in which a large amount of exudate is generated. . That is, the casting has a form in which a microporous polyurethane film having a large number of pores having a diameter of 10 μm or less is formed on one side or both sides of a superabsorbent base sheet (nonwoven fabric or cloth), and has high moisture permeability and high absorption capacity. The present invention provides a dressing coating material for wound coating having a microporous polyurethane film which can be widely used from a small amount of effusion to many wounds while preventing the invasion of bacteria from the outside.

1 is a schematic cross-sectional view of a dressing material for wound dressings formed with a microporous polyurethane film according to the present invention.

Figure 2 is a scanning electron micrograph of the surface of the microporous polyurethane film according to the present invention. * Explanation of the symbols for the main parts of the drawings * 1: Polyurethane film 2: Base sheet

Hereinafter, the present invention will be described in detail.

The present invention provides a closed dressing material in which a polyurethane film 1 having fine pores having a diameter of 10 μm or less is formed on the superabsorbent base sheet 2. The dressing material of the present invention is a wound dressing material that is in direct contact with a wound to heal the wound, and more specifically, a microporous polyurethane film having a large number of pores having a diameter of 10 μm or less and having a thickness of 1 to 300 μm. (1) has a laminated structure formed on one side or both sides of the superabsorbent base sheet 2. The base sheet 2 is made of synthetic fibers such as polyester, rayon and nylon, or natural fibers such as silk and cotton. Nonwoven fabrics and fabrics (woven fabrics) prepared from the above are preferably those having a high water absorption of 200% or more. The dressing material of the present invention has a high porosity due to the porous structure of the polyurethane film 1 having fine pores. Features such as absorbency, high moisture permeability, prevention of adhesion to window surface (wound surface), prevention of bacterial infection from the outside, long-term wearability, etc. Wound exudate, from the light generated much pressure ulcers, burns, etc., which can be widely applied, and is easy to handle.

Hereinafter will be described in more detail through the manufacturing method of the present invention.

In the polyurethane film 1 according to the present invention, a polyurethane solution is solidified to be formed on the base sheet 2, and the polyurethane solution is solidified and has a fine pore structure. The polyurethane solution is a solution in which a polyurethane resin synthesized from an isocyanate, a polyether polyol, and a chain extender is mixed with a solvent, and optionally, a hydrophilic agent and an antimicrobial agent may be mixed. That is, in the polyurethane solution, a polyether polyol and a chain extender are added to the reactor, and the mixture is sufficiently stirred. After maintaining the temperature in the reactor at 60 to 70 ° C., the viscosity is increased while the isocyanate is added and the solvent is divided. When the reaction viscosity is adjusted and the solid content and viscosity reach the designed target, the reaction is completed by checking the presence or absence of residual NCO. The isocyanate used in the synthesis of the polyurethane resin solution is isophorone diisocyanate, 2. , 4-toluene diisocyanate and isomers thereof, diphenylmethane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, 2,2-bis-4'-propane isocyanate, 6-isopropyl-1, 3-phenyldiisocyanate, bis (2-isocyanateethyl) -fumarate, 3,3 ' Methyl-4,4'-diphenylmethane diisocyanate, 1,6-hexane diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethylphenylene diisocyanate, p-phenylene diisocyanate, m-phenyl Rendiisocyanate, 1,5-naphthalene diisocyanate, 1,4-xylene diisocyanate, 1,3-xylene diisocyanate and the like can be used, and preferably 2,4-toluene diisocyanate and its isomers and p-phenylenedi isocyanate , Isophorone diisocyanate and hexamethylene diisocyanate are used.

Polyether polyols include polyethylene glycol having two or more hydroxyl groups in a molecule and having a molecular weight of 200 to 3,000, an ethylene oxide / propylene oxide random copolymer having two or more hydroxyl groups in a molecule and having a molecular weight of 3,000 to 6,000, and two in a molecule. Polytetramethylene glycol having a hydroxyl group and a molecular weight of 1,000 to 3,000 is used alone or in combination.

Examples of chain extenders include 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentylglycol, propylene glycol, ethylene glycol, and glacese having two or more hydroxyl groups in a molecule. Rolls, trimethylolethane, trimethylolpropane, pentaerythritol, sorbose, sorbitol, and the like may be used alone or in combination. Preferably, 1,3-butanediol, 1,4-butanediol , Ethylene glycol, glycerol, trimethylolpropane may be used.

In addition, the solvent used as a viscosity regulator of the polyurethane solution is excellent in miscibility with water, which is dimethyl acetamide (DMAc), dimethylformamide (DMF), tetrahydrofuran (THF), methyl ethyl ketone (MEK) or Acetone may be used, and dimethylformamide (DMF) and dimethylacetamide (DMAc) are preferable.

Using the polyurethane solution synthesized as described above was used in the following method in order to attach and form a film on the superabsorbent base sheet (2). First, a polyether polyol, a chain extender, and an isocyanate are dissolved in a solvent having excellent miscibility with water to prepare a polyurethane solution, which is coated on the base sheet 2 and then deposited in the water of the coagulation bath. That is, in the coagulation bath containing water, the solvent having excellent compatibility with water escapes from the polyurethane solution into the water and condensation of the polyurethane resin occurs, and at the same time has a fine pore (pore) of the base sheet 2 in the form of a film Is formed on the surface. Polyurethane solution is solidified in a structure having fine pores after about 10-30 minutes of deposition in a coagulation bath. At this time, the coagulation bath may be used by mixing a solvent having excellent miscibility with water in order to control the condensation of the polyurethane resin, and the mixed solvent is dimethyl acetamide (DMAc), dimethylformamide (DMF), tetrahydrofuran (THF ), Methyl ethyl ketone (MEK), acetone (Acetone), methanol (Methanol) or ethanol (Ethanol) can be used.

In addition, a hydrophilic imparting agent may be used in the polyurethane solution in order to promote the absorbent synergistic effect, wherein the hydrophilic imparting agent is L-62, L-64, P-84, P-85, P-105, F-68, F-87, F-88, F-108, F-127 (BASF, Germany) and hyaluronic acid, carboxymethylcellulose (CMC), pectin, guar gum (guar gum), sodium alginate, chitin, chitosan, gelatin, starch, hydroxyethylcellulose, xanthan gum, karaya gum One or more mixtures selected from the group consisting of (karaya gum) can be used. Antimicrobial agents that can be used to promote synergistic effects of silver sulfadiazine, chlorohexidine (chlorohexidine), povidoneiodine, benzalkonium Benzalkonium chloride, furagin, idocaine, idocaine, zino salt, vibriolysin, hexachlorophene, chlorotetracycline, neomycin ), Penicillin, gentamicin or acrilin can be used.

Hereinafter, the present invention will be described by synthesis examples, examples, and comparative examples, but these are merely provided to explain the present invention in detail, and the technical scope of the present invention is not limited thereto.

Synthesis Example 1

The synthesis method of the polyurethane resin solution of this synthesis example is as follows. Into a 3 L flask filled with nitrogen gas, 0.2 mol of polyethylene glycol (molecular weight 2,000), 0.8 mol of polytetramethylene glycol (molecular weight) 2,000, 3 mol of ethylene glycol, methyl ethyl ketone were added and stirred sufficiently, and the temperature in the reactor was maintained at 60 to 70 ° C. The viscosity was raised, dividingly diphenylmethane diisoisate. When the viscosity increased, the solvent was divided and added to adjust the reaction viscosity. When the solid content reached 30%, the presence of residual NCO was confirmed, and the reaction was terminated.

Synthesis Example 2

The synthesis method of the polyurethane resin solution of this synthesis example is as follows. Into a 3 L flask filled with nitrogen gas, 0.2 mol of polyethylene glycol (molecular weight 2,000), 0.8 mol of polytetramethylene glycol (molecular weight) 2,000, 3 mol of ethylene glycol, methyl ethyl ketone were added and stirred sufficiently, and the temperature in the reactor was maintained at 60 to 70 ° C. The viscosity was raised, dividingly diphenylmethane diisoisate. When the viscosity increased, the solvent was divided and added to adjust the reaction viscosity. When the solid content reached 30%, the reaction was terminated after confirming the presence of residual NCO. In addition, 50% by weight of F-127 and 1.0% by weight of silver sulfadiazine were added to the polyurethane solution based on the weight of the polyurethane resin, followed by stirring at room temperature for 30 minutes. To prepare a dispersed polyurethane solution.

Example 1

The polyurethane resin solution prepared in Synthesis Example 1 was coated on a non-woven fabric with a thickness of 400 μm and obtained in a coagulation bath. At this time, the conditions of the coagulation bath were made into 20% methyl ethyl ketone (MEK) concentration and the coagulation time was 20 minutes. The polyurethane resin solution immediately solidified to form a white microporous membrane. The coagulated specimen was taken out, transferred to water, taken out after 10 minutes, fixed to a drying stand, and completely dried in a drier at 100 ° C. The physical properties were measured by the following exemplified method, and the results of the above experiments are shown in Table 1 below.

That is, the closed dressing material in which the microporous polyurethane film was formed on the obtained superabsorbent nonwoven fabric was measured for physical properties by the following method.

① Mechanical Properties (tensile strength, elongation, modulus)

It measured by the tensile tester (Universal Test Machine, USA, Instron) based on JIS-K-6401.

② Absorbance%

Taking the closed dressing agent of the present invention in the size of 3Cm × 3Cm and drying for 24 hours in an oven (70 ℃) after measuring the initial weight (A) and impregnated in 25 ℃ distilled water for 48 hours and then taken out Wipe dry the surface with a dust-free tissue and measure the weight (B). Finally, the following equation is used.

Absorbance% = (B-A) / A × 100

③ moisture permeability

It was measured according to the test method of KS M 6886 using a constant temperature and humidity device. At this time, the temperature was 40 ° C and the relative humidity was 90%, and the moisture permeability was calculated according to the following equation.

P = A / S

A = ((a ₁ -a ₀ ) + (a ₂ -a ₁ ) + (a ₃ -a ₂ )) / 3

Where P: breathability (g / m ² / 24hr)

A: average amount of increase per hour (g)

S: moisture permeation area of the test piece (m ² )

④ Morphology

Scanning electron microscope was used to measure the cell shape and size of the surface and cross-section of the closed dressing agent of the present invention.

⑤ Toxicity test on cells

ISO 10993-5 was used to evaluate the toxicity of the occlusive dressing agents of the invention to the cells. Cells were used 3T3 cells, mouse fibroblasts provided by the National Institute of Sanitation. Rootswell Park Memorial Institute-1640 (RPS-1640) containing 10% FCS (Fetal Calf Serum) in a 12 well plastic culture dish was used to seed 3T3 cells at 2 × 10 ⁴ / cm 2, 37 ° C, 5%. Secondary incubation for 4 days under CO ₂ . The hydrophilic polyurethane foam dressing material was directly contacted and incubated for 1 day and 3 days, respectively, harvested using trypsin / EDTA (Ethylene Diamine Tetraacetic Acid) solution, and stained with 0.4% trypan blue solution. The number was measured with a hemasitometer.

⑥ Animal experiment

In order to observe the wound healing effect of non-woven dressing material, the average age was 6-8 weeks and the weight was 250-300g rats. Rats were intraperitoneally anesthetized with rembutal, and a square skin defect of 4 × 4 cm in diameter was made on the back and dressing was performed. Wound healing effects were measured by the size change of skin defects and the dissociation of tissue cells during histological examination, histological examination, and the like.

Example 2

The polyurethane resin solution prepared in Synthesis Example 1 was coated with a non-woven fabric (ED-8423) in a thickness of 400 μm and obtained in a coagulation bath. At this time, the conditions of the coagulation bath were the concentration of methyl ethyl ketone (MEK) was 20% and the coagulation time was 20 minutes. The polyurethane resin solution immediately solidified to form a white microporous membrane. Then, the coagulation specimens were taken out, transferred to water, taken out after 10 minutes, fixed to a drying stand, and completely dried in a dryer at 100 ° C. Physical properties were measured by the method exemplified in Example 1, and the experimental results are shown in Table 1 below.

Example 3

The polyurethane resin solution prepared in Synthesis Example 2 was coated with a non-woven fabric (ED-8423) in a thickness of 400 μm and obtained in a coagulation bath. At this time, the conditions of the coagulation bath were the concentration of methyl ethyl ketone (MEK) was 20% and the coagulation time was 20 minutes. The polyurethane resin solution immediately solidified to form a white microporous membrane. Then, the coagulation specimens were taken out, transferred to water, taken out after 10 minutes, fixed to a drying stand, and completely dried in a dryer at 100 ° C. Physical properties were measured by the method exemplified in Example 1, and the experimental results are shown in Table 1 below.

Example 4

The polyurethane resin solution prepared in Synthesis Example 2 was coated on a non-woven fabric (SPT-120) with a thickness of 400 μm and obtained in a coagulation bath. At this time, the conditions of the coagulation bath were the concentration of methyl ethyl ketone (MEK) was 20% and the coagulation time was 20 minutes. The polyurethane resin solution immediately solidified to form a white microporous membrane. Then, the coagulated specimen was taken out, transferred to water, taken out after 10 minutes, fixed to a drying stand, and completely dried in a dryer at 100 ° C. Physical properties were measured by the method exemplified in Example 1, and the experimental results are shown in Table 1 below.

Comparative Example 1

Commercially available S company's product (trade name: Opsite, a non-porous polyurethane film form) was applied, and the physical properties were measured by the method exemplified in Example 1, and the above experimental results are shown in Table 1 below.

As can be seen in Example 1 and Comparative Example 1 of Table 1, the dressing material in which the microporous polyurethane film is formed on the nonwoven fabric according to the present invention has lower mechanical properties than the non-porous polyurethane film type dressing material, but has excellent moisture permeability. And in Examples 2, 3, and 4, a water absorption is large by using a super absorbent nonwoven fabric. Accordingly, it can be used for bedsores, burns, etc., in which a large amount of exudate is generated. The polyurethane film from Example 1 to Example 4 is a microporous film having a fine pore of 10 μm or less. The results of the toxicology test of Example showed that the number of living cells decreased by 40% and 10% for control cells after 1 day and 3 days, respectively, and Comparative Example 1 showed similar results. In addition, as a result of the animal experiment, the control group and the Example 1 and the existing product had insufficient absorption of the wound secretion, so that the wound healing progressed by contraction and crust was formed. In the case of Example 4, wound healing progressed due to re-epithelialization, no crust was formed, and showed a fast healing effect of 50% or more compared to Comparative Example 1.

The dressing material in which the microporous polyurethane film of the present invention is formed is a dressing material that dramatically improves low moisture permeability and low water absorption, which is a disadvantage of the conventional film dressing material, and a polyurethane film having a fine pore of 10 μm or less in structure. It is formed on one side or both sides of this nonwoven fabric (base sheet), and from these structural features, it prevents the invasion of external bacteria and prevents adhesion of the window, and the moisture permeability is more than two times higher than that of the existing products, It is a dressing material with excellent efficiency that can be applied to wounds where a large amount of exudates are generated for a relatively long period of time due to continuous absorption of exudates.

Claims (7)

In the dressing material for wound dressing which touches a wound and heals a wound, A dressing material for wound coating, characterized in that a polyurethane film (1) having a pore of 10 µm or less in diameter is formed on one or both surfaces of the base sheet 2 made of a nonwoven fabric or cloth. 2. The window according to claim 1, wherein the polyurethane film (1) is formed by coating a base sheet (2) with a polyurethane resin solution synthesized from a polyether polyol, a chain extender, and an isocyanate and then depositing it in a coagulation bath. Epithelial dressings. 3. The dressing material for wound dressing according to claim 1 or 2, wherein the base sheet (2) is a nonwoven fabric or fabric made from polyester, nylon, rayon, silk, cotton. The method of claim 2, wherein the polyurethane solution is ethylene oxide-propylene oxide block copolymer L-62, L-64, P-84, P-85, P-105, F-68, F-87, F-88 , F-108, F-127, hyaluronic acid, carboxymethylcellulose (CMC), pectin, guar gum, sodium alginate, chitin, chitosan Hydrophilic emollients, one or more mixtures selected from the group consisting of gelatin, starch, hydroxyethylcellulose, xanthan gum, and karaya gum. Wound dressing material, characterized in that included. The method of claim 2 or 4, wherein the polyurethane solution is silver sulfadiazine, chlorohexidine, povidone iodine, benzalkonium chloride , Furagin, idocaine, zino salt, zino salt, vibriolysin, hexachlorophene, chlorotetracycline, neomycin, penicillin Wound dressing material, characterized in that it further comprises an antibacterial agent of gentamicin or acrinoline. delete delete