WO2012092813A1

WO2012092813A1 - Wound dressing with high moisture absorption and capable of being removed as a whole

Info

Publication number: WO2012092813A1
Application number: PCT/CN2011/084376
Authority: WO
Inventors: 王晓东; 吕秋兰; 史福军
Original assignee: 佛山市优特医疗科技有限公司; 南方医科大学珠江医院
Priority date: 2011-01-07
Filing date: 2011-12-21
Publication date: 2012-07-12
Also published as: CN102580136B; CN202590012U; CN102580136A

Abstract

A wound dressing with high moisture absorption and capable of being removed as a whole and a preparation method therefor. The wound dressing with high moisture absorption and capable of being removed as a whole comprises crosslinked carboxymethyl solvent-spun cellulose fiber or fabric, and preferably microcrosslinked carboxymethyl solvent-spun cellulose fiber or fabric. A use of the wound dressing in treatment of chronic wounds.

Description

Highly hygroscopic and whole-piece wound dressing

Technical field

The present invention relates to a wound dressing. More particularly, the present invention relates to a wound dressing comprising a cross-linked carboxymethyl solvent-spun cellulosic fiber, preferably a micro-cross-linked carboxymethyl solvent-spun cellulosic fiber. Background technique

It is well known that wound dressings with low wet strength increase the difficulty of wound care work due to the tendency to break during the removal process. Typically, the wound has approximately 50 ml of exudate within 24 hours. Prior art wound dressings are characterized by absorbing wound exudate and creating a moist environment to provide optimal healing of the wound. Wound dressings, including many new materials, have been developed to absorb more wound exudate than conventional gauze. For example, a wound dressing made of calcium alginate can absorb up to 20 times its own exudate. The most common larger wound dressing (10x20 cm) typically weighs 2-3 g and can be used up to 60 g or more after full absorption. If the wetness of the wound dressing is less than 60g (~0.6 N), the wound dressing may be difficult to replace the dressing due to the low wet strength and damage.

In addition, there are a number of other attempts in the art aimed at increasing the absorptive capacity of wound dressings. EP 0783605 provides a process for obtaining a water-absorbent wound dressing by blend spinning of sodium alginate fibers and carboxymethyl cellulose (CMC). Compared to ordinary sodium alginate fibers, sodium alginate dressings containing CMC can absorb more wound exudate.

EP 0690344 and US Pat. No. 6,075,177 also provide a highly water-absorbent wound dressing, also known as Aquacel®, which is essentially a solvent-spun cellulosic fiber obtained by carboxymethylation with a high salt uptake rate. 15 g / g salt solution.

Aquacel® wound dressings are one of the most commonly used wound dressings for the following reasons: 1) Aquacel® has a strong absorption capacity, a typical Aquacel® wound dressing with a salt solution up to 15g/g; 2) Aquacel® The following solutions were absorbed to form a clear gel: physiological saline (aqueous solution containing 0.9% sodium chloride), Solution A (1L water containing 8.289g sodium chloride and 0.368g anhydrous calcium chloride) and water; 3) Aquacel ® has Lower lateral capillary properties; 4) Aquacel® shrinks after absorbing wound exudate. The latter two are particularly important for chronic wound management. One of the most undesirable conditions in wound treatment is the impregnation of wound exudate. That is, the wound exudate spreads around to the surrounding healthy skin. Frequent impregnation is likely to cause infection or damage to surrounding healthy skin. Most other types of wound dressings cause wound exudate to spread to the surrounding healthy skin due to lateral capillary action, but Aquacel® has very low lateral capillary properties that can reduce this. In addition, Aquacel® shrinks after absorbing water, which reduces the overlap of surrounding skin and wound dressing, further reducing the likelihood of impregnation. Another advantage of Aquacel® in clinical applications is gelation. During wound healing, some of the fibers of the wound dressing sometimes "stick" to the wound and are not easily removed. By using the gel-forming property, it is possible to first wet the dressing with the saline solution to soften or wash the fibers which are "sticky" on the wound, so that the wound removal is no longer a painful process, and the wound care process is improved. The quality of life of patients.

However, due to the characteristics of carboxymethylcellulose, the wound dressing of the above invention can gradually become a colloid during the process of absorbing exudate. Then, the gel portion of the wound dressing becomes the weakest link in the removal of the dressing. Due to the gelation, the wet strength of these dressings can be as low as 0.1 N / cm, which tends to cause inconvenience in wound care due to cracking of the dressing during removal.

WO 2010/061225 discloses a water absorbing material useful for wound dressings, i.e., cellulose sulfonate which is insoluble in water. In order to increase the wet strength, it is also possible to use "reinforcing fibers", a bicomponent fiber or an organic solvent-spun cellulose non-gel fiber. The cross-section of the bicomponent fiber contains two components, a low melting component and a high melting component. However, these "reinforcing fibers" do not gel when they are absorbed by water. Therefore, when the dressing is "sticked" to the wound, it is impossible to gel or wash the fibers "sticking" on the wound with physiological saline, thereby causing some inconvenience in care. .

Therefore, there has been a need to develop a wound dressing that is both absorbent and gel resistant and that provides greater wet strength. Summary of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide a wound dressing which provides absorbent dressings with absorbency and gelation while also having greater wet strength.

In order to enable the wound dressing of the present invention to have the advantageous properties of an Aquacel® dressing, the present invention provides a wound dressing having not only the existing characteristics of the Aquacel® dressing as described in EP 0690344 and US Pat. No. 6,075,177, but also Greater wet strength. This increase in wet strength is achieved by crosslinking of the carboxymethylated solvent spun cellulose fibers. Crosslinking of carboxymethylated solvent spun cellulosic fibers provides greater wet strength to the wound dressing. The wet-intensive wound dressing provided by the present invention allows it to be completely removed in its entirety when applied to chronic wound treatment.

The present invention relates to a wound dressing having hygroscopicity (high hygroscopicity) and whole sheet removal, characterized in that the wound dressing comprises cross-linked carboxymethyl solvent-spun cellulose fibers or fabrics, preferably micro-crosslinked carboxymethyl solvent spinning Cellulose fiber or fabric. In particular, the ratio of the transverse wet strength to the longitudinal wet strength of the wound dressing of the present invention is between 90% and 500%, preferably between 100% and 300%. The solvent-spun cellulosic fiber or fabric of the wound dressing of the present invention is obtained by a carboxymethylation reaction followed by a crosslinking reaction or a micro-crosslinking reaction. The carboxymethylation reaction of the solvent-spun cellulosic fibers or fabric is the reaction of the fibers or fabric with the base and chloroacetate. The solvent-spun cellulosic fiber used in the present invention is a Lyocell fiber having a linear density of from 1 to 5 dtex, preferably from 1.5 to 3 dtex and a solvent-spun cellulosic fiber having a length of from 10 to 125 mm. And wherein the solvent-spun cellulosic fiber fabric is directly subjected to a carboxymethylation reaction and then subjected to a micro-crosslinking reaction, and the fabric may be a woven fabric, or a knitted fabric or a nonwoven fabric. The micro-crosslinked carboxymethyl solvent-spun cellulose fibers are then formed into woven or knitted or nonwoven fabrics, then cut into pieces, packaged in bags, and sterilized via gamma rays or epoxy oxime.

The present invention also relates to a wound dressing characterized in that the wound dressing comprises a cross-linked carboxymethyl solvent-spun cellulosic fiber or fabric containing an antibacterial agent such as nanosilver or PHMB, preferably micro-crosslinked carboxymethyl solvent-spun cellulose Fiber or fabric.

The present invention also relates to a wound dressing comprising a blend of cross-linked carboxymethyl solvent-spun cellulosic fibers and other polysaccharide fibers, such as chitosan and/or alginate fibers, preferably micro-crosslinked carboxymethyl groups. Solvent-spun cellulose fibers are blended with other polysaccharide fibers, such as chitosan and/or alginate fibers.

The present invention also relates to a process for preparing the above micro-crosslinked carboxymethyl cellulose fiber/fabric, characterized in that the micro-crosslinked carboxymethyl cellulose fiber/fabric is obtained by the following method: preparing a non-toxic cross-linking agent, For example, glycerin or polypropylene glycol, the solvent is a crosslinking reaction solution of ethanol; the carboxymethyl cellulose fiber/fabric is fully immersed in the crosslinking reaction solution to obtain a sample; the sample is sandwiched from the crosslinking reaction solution, at 90-180 °C, preferably at a temperature of 120-160 ° C for 3 to 300 minutes, preferably 5 to 90 minutes or leave the sample in the crosslinking reaction solution, at a reaction temperature of 90-180 ° C, preferably 120-160 ° C Heating under reflux for 3-300 minutes, preferably 5-90 minutes; Wash with liquid, add surfactant; dry. DRAWINGS

Figure 1 is a schematic diagram of the reaction of glycerol crosslinking.

Figure 2 is an infrared spectrum of a carboxymethyl solvent-spun cellulose fiber.

Figure 3 is an infrared spectrum of crosslinked carboxymethyl solvent-spun cellulose fibers.

Figure 4 is a schematic view of the use of the wetting device.

Figure 5 is a comparison of the cross-linked sample of the same degree of substitution (right) and the non-crosslinked sample (left) after sufficient soaking in solution A.

Fig. 6 is a bacteriostatic effect of 1% of crosslinked carboxymethyl solvent-spun cellulose fiber-nanosilver (Ag) of Example 11 of the present invention.

Figure 7 is a bacteriostatic effect of 9% of croscarmyl solvent-spun cellulosic fiber -PHMB (Bg) of Example 11 of the present invention. Detailed ways

The solvent-spun cellulose fiber referred to in the present invention means a cellulose fiber obtained by spinning through an organic solvent such as an amine oxide. Lyocell fibers are typical solvent-spun cellulose fibers. The manufacture of such fibers is disclosed in the following patent applications, such as U.S. Patent 4,142,913, U.S. Patent 4,144,080, U.S. Patent 4,211,574, U.S. Patent No. 4,426,622, U.S. Pat.

It is well known that the dry or wet strength of wound dressings is directional, ie longitudinal (MD) and transverse (CD). This longitudinal strength refers to the strength along the direction of movement of the material during production, and the transverse direction is the strength in the direction of 90 degrees from the longitudinal direction. In general, dressings produced by the nonwoven fabric process are less stressed in the longitudinal direction than in the transverse direction. Although wound dressings are difficult to distinguish between longitudinal and transverse directions when they are square or rectangular, any wound dressing has two strength directions, and the strength in one direction is always lower than the other. Therefore, the low-intensity direction must be vertical (MD) and the other direction is horizontal (CD). It is rare that the strength of the wound dressing in one direction is the same as the strength in the other direction. It can be seen that cracking occurs in the weakest direction during the removal of the wound dressing.

In general, most people give the average intensity in both directions as the dry or wet strength of the wound dressing, ie the average of the longitudinal and transverse directions, rather than two values (MD and CD). Doing so may simplify the discussion, but does not solve the real problem that the wound dressing will rupture in the direction of the weakest force. Then, the intensity of MD is more important than the average intensity. For example, an average dressing wetness of 0.6 N/cm may mean 1.0 N/cm on CD and 0.2 N/cm on MD.

The present invention relates to a wound dressing comprising crosslinked carboxymethyl solvent spun cellulose fibers. In a specific embodiment, in the wet strength of the wound dressing of the present invention, the ratio of the transverse wet strength to the longitudinal wet strength may be between 90% and 500%, preferably between 100% and 300%. The longitudinal wet strength is greater than 0.3 N/cm, preferably 0.4 N/cm.

Carboxymethyl solvent-spun cellulose fibers have certain advantages over natural cellulose fibers or ordinary viscose fibers. The solvent-spun cellulose fibers have a high degree of crystallinity, which allows the carboxymethyl solvent-spun cellulose fibers to maintain a stable structure after contact with water, and remains insoluble and non-tacky after being gelled.

The degree of substitution (DS) is generally used in the art to describe the degree of carboxymethylation of cellulose fibers. By controlling the process parameters, the carboxymethylated DS can be controlled to a narrow range. In particular, the DS of carboxymethyl solvent-spun cellulosic fibers used in wound dressings should be less than 0.4. Ideally, the carboxymethyl solvent-spun cellulose fibers achieve maximum absorption and gelation, but are still insoluble in water.

The carboxymethylation reaction is the replacement of a partial hydroxyl group with a carboxymethyl group (-CH ₂ -COOH) on a macromolecular chain. The carboxyl group enlarges the space between adjacent molecular chains, thereby weakening the hydrogen bonds between the molecules. These structural changes allow the material to have greater absorption capacity and form a clear gel while in contact with water.

By appropriate cross-linking reactions (appropriate cross-linking agents and choice of process conditions), intermolecular linkages can be increased and DS can be reduced during cross-linking.

In order to maintain its water absorption and gelation properties, the crosslinking process must be carefully controlled to ensure that only a small portion of the glucose units are crosslinked for microcrosslinking, otherwise excessive crosslinking will lose the above properties of carboxymethylation.

Compared to the carboxymethyl solvent-spun cellulosic fiber wound dressing, the micro-crosslinked carboxymethyl solvent-spun cellulosic fiber wound dressing has the same DS of the wound dressing formed by the two materials, but has different characteristics. The former produces a clear gel and greater wet strength, while the latter gel is opaque. The carboxymethyl solvent-spun cellulosic fibers of the present invention are micro-crosslinked such that the ratio of their transverse wet strength to longitudinal wet strength is between 90% and 500%. Crosslinking is a common technique used to treat textile fibers, especially in fabric finishing. However, most crosslinkers (such as glyoxal, epichlorohydrin, etc.) or its catalysts are too toxic to limit the application of the cross-linking process to some extent. Micro-crosslinking means that in the presence of a specific catalyst such as a protonic acid, cross-linking occurs between the macromolecular chains of the carboxymethyl solvent-spun cellulose fibers under the action of a crosslinking agent, wherein only a small portion of the glucose units are cross-linked. reaction. The degree of microcrosslinking usually depends on the degree of carboxymethylation prior to the microcrosslinking reaction. If the degree of carboxymethylation is high, the degree of crosslinking is high, and if the degree of carboxymethylation is low, the degree of crosslinking low.

The inventors of the present invention were pleasantly surprised to find non-toxic cross-linking agents such as glycerin and/or polypropylene glycol. This cross-linking agent enables the micro-crosslinking of adjacent glucose units on the carboxymethyl solvent-spun cellulosic fibers in the presence of a specific catalyst such as a protonic acid, and the cross-linking reaction with glycerol is shown in Fig. 1.

The carboxymethyl solvent-spun cellulosic fiber wound dressing after the micro-crosslinking reaction still has high hygroscopicity and gel-forming properties, but also has good wet strength.

The wound dressing of the present invention is an aseptically packaged nonwoven fabric comprising crosslinked carboxymethyl solvent spun cellulose fibers. Usually, in the crosslinking of carboxymethyl solvent-spun cellulose fibers, glycerin is used as a crosslinking agent and protonic acid is used as a catalyst.

The carboxymethyl solvent-spun cellulosic fibers of the present invention are subjected to a micro-crosslinking reaction as follows: After the carboxymethylation reaction disclosed in the conventional ones as disclosed in EP 0 690 344 and US Pat. No. 6,075,177, the obtained carboxymethyl solvent-spun cellulose fibers are placed. In a crosslinking reaction solution, it is then heated to 90-180 ° C, preferably 120-160 ° C, for 3-300 minutes, preferably 5-90 minutes. The above reaction is temperature sensitive, and if the temperature is lower than 80 ° C, the reaction rate becomes slow. Further, the above reaction is reversible, so the reaction time should not be too long and the reaction time should be less than 300.

The crosslinking reaction solution contains 0.01 to 40% by weight of glycerin or polypropylene glycol, preferably 0.05 to 10% by weight, based on the weight of the crosslinking reaction solution, and ethanol is a solvent. The catalyst may be a single protonic acid such as citric acid, p-toluenesulfonic acid, sulfuric acid, malic acid, maleic acid, etc., and the content is 0.01-10%, preferably 0.01-5%. The catalyst may also be a composite catalyst composed of a protic acid and an alkaline earth metal compound (e.g., magnesium chloride, magnesium sulfate, calcium chloride, calcium sulfate, etc.) in an amount of 0.01 to 10% by weight.

The carboxymethyl solvent-spun cellulose fibers may be placed in the crosslinking reaction solution at a temperature of 90 to 180 ° C, preferably 120 to 160 ° C, for 3 to 300 minutes, preferably 5 to 90 minutes, and dried. Carboxymethyl The spun-spun cellulose fibers may also be dried after being soaked in a solution, and placed in an oven at 90-180 ° C, preferably 120-160 ° C for 3 to 300 minutes, preferably 5 to 90 minutes, and dried.

The carboxymethyl solvent-spun cellulose fibers after drying (cross-linking) must be thoroughly washed with ethanol. It is preferred to add some surfactant such as Tween 20 to the washing liquid as a surface oil for subsequent production.

Essentially, the crosslinking reaction of the present invention is an esterification reaction. The formation of the ester carbonyl group (-^-) confirmed the presence of the esterification reaction. Infrared spectroscopy is typically used to detect the presence of ester groups. Figure 2 is an infrared spectrum of a carboxymethyl solvent-spun cellulose fiber, and Figure 3 is an infrared spectrum of a cross-linked carboxymethyl solvent-spun cellulose fiber. As shown, there are 2 -OH stretching vibration at 3300 cm; "antisymmetric stretching vibration at ^1, CH; In 1407 cm" -COONa appears in the vicinity of 2946 cm ^{^1,} 1562 cm ^"1 The characteristic absorption peak. As shown in Fig. 3, characteristic peaks appear at 1323 cm " ¹ and 1704 cm" ¹ indicating the presence of an ester carbonyl group (-^-) in croscarmellose.

In a specific embodiment, the present invention relates to a croscarmyl solvent-spun cellulosic fiber made into a woven fabric or a non-woven fabric, and after being cut into various sizes/shapes, a wound dressing is formed through a process such as packaging, and finally, The packaged wound dressing is sterilized by gamma rays or epoxy.

In the present invention, the wound dressing may be in the form of a nonwoven fabric, but is also suitable for woven and knitted fabrics. Needle punching technology or spunbonding technology can be used in the nonwoven fabric process.

Cross-linked carboxymethyl solvent spun cellulose fibers can be crimped and cut into fibers of appropriate length prior to the nonwoven manufacturing process. The length of the cross-linked carboxymethyl solvent-spun cellulose fiber should be between 10 mm and 125 mm. The linear density of the cross-linked carboxymethyl solvent-spun cellulose fibers should be about ldtex to 5 dtex.

In another embodiment, the invention relates to the direct treatment of fabrics made from solvent spun cellulosic fibers. Such fabrics may be in the form of woven, knitted or non-woven fabrics. Then, the fabric is subjected to carboxymethyl treatment and then subjected to a microcrosslinking reaction.

In a specific embodiment of the present invention, an antibacterial agent such as a nanosilver solution or an antibacterial agent of a PHMB solution may be sprayed on the croscarmyl solvent-spun cellulosic fiber or fabric of the present invention, and the obtained wound dressing has antibacterial property. At the same time, it can absorb wound exudate and can be completely removed.

In a specific embodiment of the present invention, croscarmyl solvent-spun fibers can be used. The fiber, preferably the micro-cross-linked carboxymethyl solvent-spun cellulosic fiber, is blended with other polysaccharide fibers to improve the performance of the dressing, such as chitosan and/or alginate fibers.

The invention also relates to a method of testing the wet strength of a wound dressing. Since such a wound dressing forms a gel during water absorption, when it sufficiently absorbs water or A solution or physiological saline, the material becomes a gel and becomes quite fragile and heavy. This may cause some difficulties in testing wet strength. That is, the wound dressing may be damaged by the clamp of the tensile testing machine (because the dressing becomes a gel), often resulting in erroneous readings. If the force of the clamp to grip the wound dressing is too great, the wound dressing will tend to be shredded by the clamp. If the force of the clamp to grasp the wound dressing is too small, the wound dressing will often slip in the fixture. All of the above will affect the accuracy of this type of test.

In order to improve the accuracy of the wet strength test of a wound dressing, the present invention also relates to a sample wetting device for the purpose of wetting only the middle portion of the sample while keeping the ends of the sample dry and clamping the dried portion by the tester. The sample wetting device 4 of the present invention comprises a container 2 of the solution and a test solution 3. Figure 4 illustrates the use of such a device in which sample 1 is placed in test solution 3 of container 2 of the solution of wetting device 4.

In order to improve the accuracy of the wet strength test, in particular to be able to more accurately compare the wet strength of the same product, the test procedure for the wound dressing is as follows:

1) Cut the wound dressing sample into strips of 2 cm width and at least 7 cm in length. Preferably, a second sample is cut in a lO X lOcm wound dressing in a 90 degree angle to the first sample to ensure simultaneous MD and CD orientation.

2) A double-folded sample was placed in the container 2 of the above-mentioned solution in which the test liquid 3 was prepared, and the A solution specified in BP1995 was used as the test liquid 3. The solution in the container has a height of 2 +/- 0.5 cm.

3) Place the folded portion of the specimen on the bottom of the device and let it stand for 30 seconds.

4) Clamp the sample out of the container and place the ends of the tensile tester clamp at the top and bottom.

5) The distance between the two jaws of the tester is 50 mm. The top jaw is operated at a speed of 100 mm/min.

6) Record the maximum force (N) of the damaged sample. It is recommended to test two samples from the same dressing (10×10 cm) at the same time, so that the higher intensity value tested is CD and the lower intensity value is MD. 7) Repeat the above experiment at least 5 times for the same wound dressing to obtain 5 MD and 5 CD wet strengths, and calculate the average value.

Table 1 Tests the wet strength of samples 1-5 of 10 X 10 cm Aquacel® (Lot 0H00332) wound dressing according to the above method.

The Applicant further clarifies the invention by the following non-limiting examples in conjunction with the invention hereinbelow.

The ratios in the following examples are, for example, unless otherwise specified, and are all by weight. The amount of liquid absorbed is measured by cutting the fiber into a length of 10 cm. Weigh 0.1 g completely into 100 ml of solution A or 0.9% sodium chloride solution for 30 seconds, pick up the fiber for 30 seconds, then weigh it, subtract the fiber. Dry weight to absorb liquid. The dry strength test method is to cut 10 cm, 0.01 g of fiber and place it in a tensile machine to measure its tensile strength. The wet strength test method is to cut 10 cm, 0.01 g of fiber, the fiber is folded in half, and the middle part is placed in solution A for 30 seconds, and placed in a tensile machine to measure the tensile strength. The test method of DS is to wash the sample with ethanol to remove soluble salt, dry and burn at high temperature, the residue is sodium oxide, add water to dissolve sodium hydroxide, add excess sulfuric acid standard titration solution, titrate excess sulfuric acid with sodium hydroxide standard titration solution, The average value of the carboxymethyl group in each anhydrous glucose unit is calculated by calculation, which is the degree of substitution. Example 1

The solvent-spun cellulose fiber purchased from Lanjing Fiber Co., Ltd. (Nanjing, China) was heated at 80 ° C for 90 minutes in a reaction solution of sodium hydroxide: sodium chloroacetate:ethanol:water = 1:2.9:2.7:93.4. Carboxymethylation to obtain carboxymethyl solvent-spun cellulose fibers (DS = 0.39), followed by crosslinking as follows: The sample is the carboxymethyl solvent-spun cellulose fiber obtained as above, and the crosslinking reaction solution is ethanol as a solvent, 1% glycerin as a crosslinking agent and 0.8% sulfuric acid as a catalyst;

The sample was placed in a crosslinking reaction solution and heated under reflux at a temperature of 180 ° C for 20 minutes; the sample was washed with ethanol, and then dried in an oven to obtain a crosslinked carboxymethyl solvent-spun cellulose fiber, DS = 0.25 . Comparative Example 1

The samples were sampled in the same batch of solvent-spun cellulose fibers and subjected to carboxymethylation to give carboxymethyl solvent-spun cellulose fibers, but were not treated with a crosslinking reaction solution, DS = 0.25.

The above two fiber samples were placed in the A solution, as shown in Fig. 5, the crosslinked sample (right) and the non-crosslinked sample (left) were fully immersed in the solution A, and the non-crosslinked sample was observed in the absorption solution. After A, it can be gelatinized but opaque, but the crosslinked sample becomes a transparent colloid after absorbing the A solution and has a distinctly high strength. Example 2

As in the method of Example 1, the solvent-spun cellulose fiber was heated by a carboxymethylation reaction at 80 ° C in a reaction solution of sodium hydroxide: sodium chloroacetate:ethanol:water = 1:2.9:2.7:93.4. The carboxymethyl solvent-spun cellulose fiber (DS=0.36) was prepared in minutes, and then the crosslinking time was reduced as follows:

The sample is a carboxymethyl solvent-spun cellulose fiber obtained as above, and the crosslinking reaction solution is ethanol as a solvent, 0.8% of polypropylene glycol as a crosslinking agent, and 0.1% DL-malic acid as a catalyst;

The sample was placed in a crosslinking reaction solution and heated to reflux at 180 ° C for 15 minutes;

The sample was washed with ethanol, and then the sample was dried in an oven to obtain a crosslinked carboxymethyl solvent-spun cellulose fiber, DS = 0.34. Example 3

The method of Example 1 was carried out by a carboxymethylation reaction from a solvent-spun cellulose fiber by heating at 80 ° C in a reaction solution of sodium hydroxide: sodium chloroacetate:ethanol:water = 1:2.9:2.7:93.4. The carboxymethyl solvent-spun cellulose fiber (DS=0.52) was prepared in minutes, and then the obtained carboxymethyl solvent-spun cellulose fiber was immersed in the crosslinking reaction solution (0.1% DL-malic acid, 1% glycerin, 1% water). , 97.9% ethanol), the temperature is maintained at 90 ° C, the reaction is 28 minutes; The sample was washed with 70% ethanol/water, and then the sample was placed in an oven at a low temperature (40 ° C); a cross-linked carboxymethyl solvent-spun cellulose fiber was obtained with a DS of 0.32.

The solution A of the obtained croscarmyl solvent-spun cellulose fiber has a liquid absorption of 15.90 g/g.

The 0.9% sodium chloride solution has a liquid absorption of 15.11 g/g, a dry strength of 1.97 cN/dtex, and a wet strength of

0.50 cN/dtexo Example 4

The method of Example 1 was carried out by a carboxymethylation reaction from a solvent-spun cellulose fiber by heating at 80 ° C in a reaction solution of sodium hydroxide: sodium chloroacetate:ethanol:water = 1:2.9:2.7:93.4. The carboxymethyl solvent-spun cellulose fiber (DS=0.38) was prepared in minutes, and then the obtained carboxymethyl solvent-spun cellulose fiber was immersed in the crosslinking reaction solution (1% DL-malic acid, 1% glycerin, 1% water). , 97.9% ethanol), the temperature is maintained at 90 ° C, the reaction is 8 minutes;

The sample was washed with 70% ethanol/water, and then the sample was placed in an oven at a low temperature (40 ° C); a cross-linked carboxymethyl solvent-spun cellulose fiber was obtained with a DS of 0.32.

The solution A of the obtained croscarmyl solvent-spun cellulose fiber has a liquid absorption of 14.87 g/g, the 0.9% sodium chloride solution has a liquid absorption of 14.05 g/g, the dry strength is 1.88 cN/dtex, and the wet strength is 0.67 cN/dtexo Example 5

The method of Example 1 was carried out by a carboxymethylation reaction from a solvent-spun cellulose fiber by heating at 80 ° C in a reaction solution of sodium hydroxide: sodium chloroacetate:ethanol:water = 1:2.9:2.7:93.4. The carboxymethyl solvent-spun cellulose fiber (DS=0.52) was prepared in minutes, and then immersed in the crosslinking reaction solution (0.1% DL-malic acid, 1% glycerol, 1% water, 97.9% ethanol), and the temperature was maintained at 90°. C, the reaction is 100 minutes;

The sample was washed with 70% ethanol/water, and then the sample was placed in an oven at a low temperature (40 ° C) to obtain a cross-linked carboxymethyl solvent-spun cellulose fiber with a DS of 0.17.

The solution A of the obtained croscarmyl solvent-spun cellulose fiber has a liquid absorption of 9.40 g/g.

The 0.9% sodium chloride solution has a liquid absorption of 9.23 g/g, a dry strength of 2.11 cN/dtex, and a wet strength of

2.03cN/dtex o Example 6 The method of Example 1 was carried out by a carboxymethylation reaction from a solvent-spun cellulose fiber by heating at 80 ° C in a reaction solution of sodium hydroxide: sodium chloroacetate:ethanol:water = 1:2.9:2.7:93.4. The carboxymethyl solvent-spun cellulose fiber (DS=0.52) was prepared in a minute, and then immersed in a crosslinking reaction solution (0.5% p-toluenesulfonic acid, 1% glycerin, 1% water, 97.9% ethanol) for 5 minutes, and the mixture was squeezed. Dry solvent, then the sample was baked at 120 ° C, and reacted for 28 minutes;

The sample was washed with 70% ethanol/water, and then the sample was placed in an oven at a low temperature (40 ° C); crosslinked CMC was obtained with a DS of 0.40.

The solution A of the obtained croscarmyl solvent-spun cellulose fiber had a liquid absorption of 22.84 g/g, the 0.9% sodium chloride solution had a liquid absorption of 22.10 g/g, the dry strength was 1.78 cN/dtex, and the wet strength was 0.57 cN/dtex o Example 7

The method of Example 1 was carried out by a carboxymethylation reaction from a solvent-spun cellulose fiber by heating at 80 ° C in a reaction solution of sodium hydroxide: sodium chloroacetate:ethanol:water = 1:2.9:2.7:93.4. The carboxymethyl solvent-spun cellulose fiber (DS=0.28) was prepared in minutes, and then immersed in the crosslinking reaction solution (0.5% concentrated sulfuric acid, 1% glycerol, 1% water, 97.9% ethanol) for 5 minutes, and the squeezed dry solution was sandwiched. Then, the obtained sample is baked at 90 ° C for 3 minutes;

The sample was washed with 70% ethanol/water, and then the sample was placed in an oven at a low temperature (40 ° C); a cross-linked carboxymethyl solvent-spun cellulose fiber was obtained with a DS of 0.18.

The solution A of the obtained cross-linked carboxymethyl solvent-spun cellulose fiber has a liquid absorption of 5.23 g/g, the 0.9% sodium chloride solution has a liquid absorption of 5.16 g/g, the dry strength is 2.52 cN/dtex, and the wet strength is 2.17cN/dtex o Example 8

The method of Example 1 was carried out by a carboxymethylation reaction from a solvent-spun cellulose fiber by heating at 80 ° C in a reaction solution of sodium hydroxide: sodium chloroacetate:ethanol:water = 1:2.9:2.7:93.4. The carboxymethyl solvent-spun cellulose fiber (DS=0.37) was obtained in 80 minutes, and then immersed in the crosslinking reaction solution (40% glycerol, 0.5% citric acid, 0.5% magnesium chloride, 2% water, 58% ethanol), and the temperature was maintained at Reaction at 160 ° C for 40 minutes;

The sample was washed with 70% ethanol/water, and then the sample was placed in an oven at a low temperature (40 ° C); a cross-linked carboxymethyl solvent-spun cellulose fiber was obtained with a DS of 0.19. The solution A of the obtained cross-linked carboxymethyl solvent-spun cellulose fiber has a liquid absorption of 9.82 g/g, the 0.9% sodium chloride solution has a liquid absorption of 8.49 g/g, the dry strength is 1.99 cN/dtex, and the wet strength is 1.85cN/dtex o Example 9

As in the method of Example 1, the solvent-spun cellulose fiber was heated by a carboxymethylation reaction at 80 ° C in a reaction solution of sodium hydroxide: sodium chloroacetate:ethanol:water = 1:2.9:2.7:93.4. The carboxymethyl solvent-spun cellulose fiber (DS=0.48) was prepared in a minute, and then immersed in a crosslinking reaction solution (1% tartaric acid, 1% glycerol, 4% water, 94% ethanol), and the temperature was maintained at 90 ° C. 30 minutes.

The sample was washed with 70% ethanol/water, and then the sample was placed in an oven at a low temperature (40 ° C); a cross-linked carboxymethyl solvent-spun cellulose fiber was obtained with a DS of 0.38.

The solution A of the obtained cross-linked carboxymethyl solvent-spun cellulose fiber has a liquid absorption of 17.74 g/g.

The 0.9% sodium chloride solution has a liquid absorption of 17.85 g/g, a dry strength of 1.02 cN/dtex, and a wet strength of

0.42cN/dtex o Comparative Example 10

In Table 1, No. 1 is a solvent-spun tencel fiber, and Nos. 2-7 are CMCs of different degrees of substitution (DS) obtained by carboxymethylation of uncrosslinked tencel fibers, and the DS obtained by the present invention is 0.52. The CMC was prepared by heating at 80 ° C for 100 minutes in a reaction solution of sodium hydroxide: sodium chloroacetate:ethanol:water = 1:2.9:2.7:93.4, except that the crosslinking time was changed to obtain a crosslinked CMC of different DS. Except for changing the crosslinking time, the rest of the conditions are as described in Example 3. The specific preparation conditions are as follows:

No. 1: Solvent-spun Tencel fiber (purchased from Lanjing Fiber Co., Ltd. (Nanjing, China)); No. 2: Uncrosslinked sample (Preparation conditions: In sodium hydroxide: sodium chloroacetate: ethanol: water = 1: 2.9: 2.7: 93.4 in a reaction solution heated at 80 ° C for 3 minutes, DS = 0.17); cross-linked sample (cross-linking time 100 minutes, DS = 0.17)

No. 3 : Uncrosslinked sample (preparation conditions: heating in a reaction solution of sodium hydroxide: sodium chloroacetate: ethanol: water = 1:2.9:2.7:93.4 at 80 ° C for 10 minutes, DS = 0.20); cross-linked sample (cross-linking time 80 minutes, DS=0.20)

No. 4: Uncrosslinked sample (preparation conditions: in sodium hydroxide: sodium chloroacetate: ethanol: water =1: 2.9: 2.7: 93.4 in a reaction solution heated at 80 ° C for 15 minutes, DS = 0.23); cross-linked sample (cross-linking time 70 minutes, DS = 0.23)

No. 5: Uncrosslinked sample (preparation conditions: heating in a reaction solution of sodium hydroxide: sodium chloroacetate: ethanol: water = 1:2.9:2.7:93.4 at 80 ° C for 20 minutes, DS = 0.26); cross-linked sample (45 minutes of cross-linking time, DS=0.26)

No. 6: Uncrosslinked sample (preparation conditions: heating in a reaction solution of sodium hydroxide: sodium chloroacetate: ethanol: water = 1:2.9:2.7:93.4 at 80 ° C for 30 minutes, DS = 0.29); cross-linked sample (cross-linking time 35 minutes, DS=0.29)

No. 7 : Uncrosslinked sample (preparation conditions: heating in sodium hydroxide: sodium chloroacetate: ethanol: water = 1:2.9:2.7:93.4 in a reaction solution at 80 ° C for 55 minutes, DS = 0.31); cross-linked sample (cross-linking time 27 minutes, DS=0.31)

Cutting the above three fibers into a length of 10 cm;

The samples were completely immersed in solution A or 0.9% sodium chloride solution for 30 seconds, the fiber was dripped for 30 seconds, and then weighed to compare the difference between the fluid intake and the wet and dry strength of the above three samples.

The data obtained are shown in Table 1. The liquid absorption, dry strength and wet strength of the above three samples were recorded. The results showed that:

Solution A liquid absorption (g/g): Tencel fiber <crosslinked CMC CMC;

Aspirate of 0.9% sodium chloride solution (; g/g tencel fiber < crosslinked CMC CMC;

And the amount of liquid absorbed by the three fibers to the solution A is similar to that of the 0.9% sodium chloride solution.

Dry strength (cN/dtex) : cross-linking CMC CMC<tencel fiber;

Wet strength (cN/dtex): CMC<crosslinking CMC<tencel fiber. Table 1: Sample Aspiration, Dry Strength, Wet Strength Control Aspiration (Solution Α) Aspiration (0.9% Chlorine Dry Strength)

/(s/s) sodium solution) /(g/g) (cN/dtex) wet strength (cN/dtex) degree of substitution without cross-linking after cross-linking without cross-linking after cross-linking without cross-linking After the cross-linking

0 4.95 - 5.01 - 3.16 - 2.04 -

0.17 10.42 9.40 10.50 10.11 1.82 2.11 1.05 2.51

0.20 12.03 12.06 11.49 12.92 1.72 1.87 0.87 1.97

0.23 11.26 10.42 12.78 11.65 1.47 1.99 0.74 1.37

0.26 13.30 11.18 13.44 12.96 1.35 1.67 0.63 0.89

0.29 15.49 15.01 15.65 14.97 1.02 2.05 0.53 0.77

0.31 16.09 15.22 16.12 15.30 1.11 1.87 0.16 0.52 Example 11

The nano-silver and polyhexamethylene biguanide (PHMB) were sprayed on the cross-linked CMC respectively. According to GB/T 20944-1-2007, the sample was qualitatively evaluated according to the degree of bacterial growth at the contact between the medium and the sample. Bacteriostatic performance.

The test procedure is as follows:

(1) Sample preparation: The crosslinked fiber short fibers (length about 1 mm) of Example 1 were sprayed with a solution containing nano silver and PHMB antibacterial ingredients, respectively, to obtain nano silver crosslinked fibers containing 1% of silver, PHMB crosslinked. Fiber content 9%, by mass;

(2) After preparing an appropriate amount of agar medium for sterilization, inject 10 mL into a sterile plate and condense into a flat plate;

(3) Prepare the bacterial suspension (10 ⁶ cfu/mL) in the concentration of the test bacteria (diluted to 2 mL of sterile water in the inoculation loop), and inject 200 μΙ^~250 μΙ into the surface of the plate and apply aseptic coating. Spread the stick evenly and let stand for 5 minutes;

(4) Press the fiber sample 0.3g~0.5g evenly on the surface of the plate with sterile forceps

(central part), try to ensure good contact (we can be moistened with a small amount of sterile water or sterile saline);

(5) Place the plate with the sample in the incubator at 37 °C ± 2 °C for 9 hours or more. Figure 7 shows the test results after three days of testing two crosslinked fibers containing nanosilver and PHMB antibacterial components, respectively, B. Bacillus subtilis; E. Escherichia coli; R. aeruginosa; S. Staphylococcus aureus.

Test results: The cross-linked fibers after antibacterial spray have antibacterial effects on the four test bacteria, and the inhibitory effect on Staphylococcus aureus is most obvious.

Claims

Claim

A wound dressing having a high moisture absorption and overall removal, characterized in that the wound dressing comprises croscarmyl solvent-spun cellulosic fibers or fabrics, preferably micro-crosslinked carboxymethyl solvent-spun cellulose fibers or fabrics.

2. A wound dressing according to claim 1 wherein the wound dressing has a ratio of transverse wet strength to longitudinal wet strength of between 90% and 500%, preferably between 100% and 300%.

A wound dressing according to any of the preceding claims, wherein the solvent-spun cellulosic fiber or fabric is obtained by a carboxymethylation reaction followed by a crosslinking reaction or a micro-crosslinking reaction.

A wound dressing according to any of the preceding claims, wherein the carboxymethylation reaction of the solvent-spun cellulosic fiber or fabric is a reaction of the fiber or fabric with a base and a chloroacetate.

The wound dressing according to any of the preceding claims, wherein the solvent-spun cellulosic fiber is a Lyocell fiber, and the solvent-spun cellulosic fiber has a linear density of from 1 to 5 dtex, preferably from 1.5 to 3 dtex, and a solvent-spun cellulosic fiber. The length is 10-125mm.

6. A wound dressing according to any of the preceding claims, wherein the solvent-spun cellulosic fiber fabric is directly subjected to a carboxymethylation reaction followed by a micro-crosslinking reaction, and the fabric may be a woven fabric, or a knitted fabric or Non-woven fabric.

The wound dressing according to any of the preceding claims, wherein the micro-cross-linked carboxymethyl solvent-spun cellulose fibers are made into woven or knitted fabric or non-woven fabric, then cut into pieces and packaged in bags. Sterilized by gamma rays or epoxy oxime.

8. A wound dressing, characterized in that the wound dressing comprises a cross-linked carboxymethyl solvent-spun cellulosic fiber or fabric containing an antibacterial agent, such as nanosilver or PHMB, preferably micro-crosslinked carboxymethyl solvent-spun cellulosic fiber Or fabric.

9. A wound dressing characterized in that the wound dressing comprises a crosslinked carboxymethyl solvent-spun cellulosic fiber mixed with other polysaccharide fibers, such as chitosan and/or alginate fibers, preferably micro-crosslinked carboxylate The methyl solvent-spun cellulose fibers are blended with other polysaccharide fibers, such as chitosan and/or alginate fibers.

10. A process for the preparation of a micro-cross-linked carboxymethyl cellulose fiber/fabric according to any of the preceding claims, characterized in that the micro-cross-linked carboxymethylcellulose fiber/fabric is obtained by the following method:

Preparing a non-toxic cross-linking agent, preferably glycerin or polypropylene glycol, the solvent is a cross-linking reaction liquid of ethanol; fully immersing the carboxymethyl cellulose fiber/fabric in the cross-linking reaction liquid to obtain a sample; and taking the sample from the cross-linking reaction liquid Pinch, heated at a temperature of 90-180 ° C, preferably 120-160 ° C for 3 to 300 minutes, preferably 5 to 90 minutes or leave the sample in the crosslinking reaction solution, at 90-180 ° C, preferably 120- Heating at a reaction temperature of 160 ° C for 3 to 300 minutes, preferably 5 to 90 minutes; washing with a washing liquid, adding a surfactant; drying.