A dressing for craniocerebral trauma and a method for its production

Abstract

The application discloses a dressing for craniocerebral trauma and a preparation method thereof, and belongs to the field of medicines. The steps include: preparation of a chitosan fiber layer, modified chitosan is dissolved in an acetic acid solution to prepare a modified chitosan solution, cellulose non-woven fabric is immersed in the modified chitosan solution and ultrasonically treated, and then is placed in a hot press for pressure preservation and pressing, so that the chitosan fiber layer is obtained; preparation of an antibacterial fiber layer, cellulose non-woven fabric is immersed in a solution containing an antibacterial agent and ultrasonically treated, and then is placed in a hot press for pressure preservation and pressing, so that the antibacterial fiber layer is obtained; and preparation of the dressing, the chitosan fiber layer and the antibacterial fiber layer are fixed in an outer layer by using a binding thread in sequence, sterilization packaging is carried out, and the dressing for craniocerebral trauma is obtained. The dressing has good water absorption, antibacterial property and in-vitro blood coagulation performance, and has a good healing effect on a wound.

Description

Technical Field

[0001] The invention belongs to the technical field of dressing preparation, and particularly relates to a dressing for craniocerebral trauma and a preparation method thereof. Background Art

[0002] Traumatic brain injury is a common injury caused by traffic accidents and other causes. Most patients in a coma experience impaired consciousness and thinking, are unable to effectively express their wishes, and have diminished or even absent reflexes. Due to decreased sensory sensitivity and a lack of normal protective responses, patients in a coma due to traumatic brain injury are susceptible to burns during physical therapy or winter warming.

[0003] Medical dressings, as coverings for wounds, can replace damaged skin during wound healing, acting as a temporary barrier, preventing or controlling wound infection and providing an environment conducive to wound healing. Currently, the most commonly used dressings in clinical practice are primarily gauze and cotton pads, often made from cotton, soft linen, and linen. These are inert dressings and have no significant effect on wound healing. Prior art, such as publication number CN 109893342 A, discloses a dressing for craniocerebral trauma and its preparation method. The dressing comprises, from the outside to the inside, a fixing layer, a backing layer, a water-absorbing layer spaced apart on the backing layer, and a drug layer. The drug layer contains kaempferol-3-O-rhamnoside, and the drug layer matrix is ​​selected from alginate gel, cellulose gel, chitosan gel, and the like. The dressing promotes wound healing, and the wound healing effect is even better when the drug layer matrix is ​​chitosan gel containing chitosan oligosaccharides. Summary of the Invention

[0004] The object of the present invention is to provide a dressing for craniocerebral trauma with good water absorption, antibacterial and in vitro coagulation properties, which has a good healing effect on wounds.

[0005] The technical solutions adopted by the present invention to achieve the above-mentioned purpose are:

[0006] A dressing for craniocerebral trauma, the dressing structure of which comprises: a fixed outer layer; a chitosan fiber layer as a middle layer; and an antibacterial fiber layer as an inner layer;

[0007] The chitosan fiber layer is prepared by soaking cellulose non-woven fabric in modified chitosan solution;

[0008] The modified chitosan is prepared by modifying chitosan with isomango alcohol acid.

[0009] The modified chitosan is prepared by using isomangiferolic acid to modify chitosan, the chitosan fiber layer is prepared by treating the cellulose non-woven fabric with the modified chitosan, and the water absorption performance of the chitosan fiber layer is improved; the craniocerebral trauma dressing is prepared by combining the chitosan fiber layer with an antibacterial fiber layer and a fixed outer layer, and the air permeability and the in-vitro blood coagulation performance of the craniocerebral trauma dressing are improved; meanwhile, the healing of a wound can be accelerated.

[0010] It should be noted that, in some embodiments of the present application, the fixed outer layer is made of elastic cotton thread, and has a cap-shaped net structure.

[0011] The present application further discloses a preparation method of the craniocerebral trauma dressing.

[0012] S1: Preparation of the chitosan fiber layer: modified chitosan is dissolved in an acetic acid solution to prepare a modified chitosan solution; cellulose non-woven fabric is immersed in the modified chitosan solution and ultrasonically treated, and then is placed in a hot press for pressure preservation and pressing to obtain the chitosan fiber layer.

[0013] S2: Preparation of the antibacterial fiber layer: cellulose non-woven fabric is immersed in a solution containing an antibacterial agent and ultrasonically treated, and then is placed in a hot press for pressure preservation and pressing to obtain the antibacterial fiber layer.

[0014] S3: Preparation of the dressing: the chitosan fiber layer and the antibacterial fiber layer are fixed on the outer layer by using a binding thread in sequence, and the dressing is sterilized and packaged to obtain the craniocerebral trauma dressing.

[0015] It should be noted that, in some embodiments of the present application, the preparation method of the modified chitosan is as follows: chitosan is dispersed in an acetic acid solution, completely dissolved at room temperature, then isomangiferolic acid and a condensing agent are added, and the reaction is carried out under stirring at room temperature, and the modified chitosan is obtained by washing to neutral.

[0016] It should be further noted that, in some embodiments of the present application, the chitosan is 2.5-5 parts, the acetic acid solution is 20-40 parts, the isomangiferolic acid is 0.5-1.5 parts, and the condensing agent is 0.05-0.1 part by weight.

[0017] It should be noted that, in some embodiments of the present application, in step S1, the concentration of the modified chitosan solution is 20-35 wt%.

[0018] It should be noted that, in some embodiments of the present application, in step S1, the ultrasonic treatment power is 120-200 W, and the ultrasonic treatment time is 15-30 min.

[0019] It should be noted that, in some embodiments of the present application, in step S1, the pressure preservation pressure is 5-10 MPa, and the pressing time is 30-50 min.

[0020] It should be noted that, in some embodiments of the present invention, in step S2, the antibacterial agent is at least one of ampicillin, cefoperazone, levofloxacin, doxycycline, roxithromycin, azithromycin, ciprofloxacin, and lomefloxacin.

[0021] It should be noted that, in some embodiments of the present invention, in step S2, the ultrasonic treatment power is 120-200 W, and the ultrasonic treatment time is 15-30 min.

[0022] The invention also discloses the use of the modified chitosan in improving the air permeability of a dressing for craniocerebral trauma.

[0023] In order to further improve the antibacterial properties of dressings for craniocerebral trauma and accelerate wound healing, the preferred measures taken also include: in the process of preparing the antibacterial fiber layer, the cellulose non-woven fabric is first modified with cedarwood alcohol, and then immersed in an antibacterial agent for surface treatment to obtain a modified antibacterial fiber layer.

[0024] It should be noted that, in some embodiments of the present invention, the steps of modifying the cellulose nonwoven fabric are as follows:

[0025] The cellulose non-woven fabric is soaked in acetone for 2-4 hours, ultrasonically treated for 30-50 minutes, and dried at 100-110° C. to constant weight to obtain a clean cellulose non-woven fabric;

[0026] Dissolve cerium nitrate in deionized water, add the washed cellulose non-woven fabric and a nitric acid solution with a concentration of 0.025-0.05 mol / L, and stir to mix well to obtain system a;

[0027] The cedrene alcohol is dissolved in anhydrous ethanol to obtain system b; the system b is added to the above system a, stirred for reaction, washed, filtered, and dried to a constant weight to obtain a modified cellulose non-woven fabric.

[0028] It should be further noted that in some embodiments of the present invention, by weight, the cerium nitrate is 0.15-0.45 parts, the deionized water is 50-100 parts, the washed cellulose non-woven fabric is 1-3 parts, the nitric acid solution is 0.2-0.5 parts, the cedarwood alcohol is 0.75-1.25 parts, and the anhydrous ethanol is 50-100 parts.

[0029] It should be further noted that, in some embodiments of the present invention, the stirring reaction temperature is 30-40° C., and the reaction time is 5-10 h.

[0030] The application first adopts cembranolide to modify the cellulose non-woven fabric, then soaks in the antibacterial agent to carry out the surface treatment, obtains the modified antibacterial fiber layer, which improves the antibacterial performance of the antibacterial fiber layer, so that it can be used for dressing to reduce the infection of the wound; it is fixed with the chitosan fiber in the outer layer to prepare the dressing for craniocerebral trauma, which further improves the air permeability, the in vitro blood coagulation performance of the dressing and further improves the healing effect of the dressing for craniocerebral trauma on the wound.

[0031] The application adopts isomangiferolic acid to modify chitosan to prepare modified chitosan, which is used to treat the cellulose non-woven fabric to prepare the chitosan fiber layer, which improves the water absorption performance of the chitosan fiber layer; the chitosan fiber layer is combined with the antibacterial fiber layer and the fixed outer layer to prepare the dressing for craniocerebral trauma, which improves the air permeability and the in vitro blood coagulation performance of the dressing for craniocerebral trauma; and can accelerate the healing of the wound. Therefore, the application is a dressing for craniocerebral trauma with good water absorption, antibacterial property and in vitro blood coagulation performance, which has good healing effect on the wound. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is the infrared spectrum of chitosan before and after modification in Example 1;

[0033] Figure 2 It is the infrared spectrum of cellulose non-woven fabric before and after modification in Example 5;

[0034] Figure 3 It is the moisture absorption rate of the chitosan fiber layer;

[0035] Figure 4 It is the air permeation amount of the dressing for craniocerebral trauma;

[0036] Figure 5 It is the in vitro blood coagulation index (BCI) of the dressing for craniocerebral trauma;

[0037] Figure 6 It is the wound healing rate of the dressing for craniocerebral trauma. DETAILED DESCRIPTION

[0038] The technical solutions of the application are further described in detail in combination with the specific embodiments and the drawings; however, it should be understood that these embodiments are implemented on the premise of the technical solutions of the application, detailed implementation manners and specific operation processes are given, which are only for further illustrating the features and beneficial effects of the application, and are not limited to the claims of the application, and the protection scope of the application is not limited to the following embodiments. If not otherwise specified, the raw materials used in the application are commercially available.

[0039] Furthermore, it should be noted that the preparation method of the modified chitosan is as follows: 2.5-5 parts of chitosan are dispersed in 20-40 parts of acetic acid solution with a concentration of 2-4wt%, and completely dissolved at room temperature, and then 0.5-1.5 parts of isomangoic acid and 0.05-0.1 parts of a condensing agent are added, and the mixture is stirred and reacted at room temperature for 3-6 hours, and washed with distilled water until neutral to obtain modified chitosan.

[0040] It should be further noted that, in some embodiments of the present invention, the condensing agent used to modify chitosan is at least one of DIC, EDC, HOAt, and HOBt.

[0041] Furthermore, it should be noted that a method for preparing a dressing for craniocerebral trauma comprises the following steps:

[0042] S1: Preparation of chitosan fiber layer: The modified chitosan is dissolved in a 2-4 wt% acetic acid solution to prepare a 20-35 wt% modified chitosan solution; a cellulose non-woven fabric is immersed in the modified chitosan solution and ultrasonically treated at a power of 120-200 W for 15-30 minutes, and then placed in a hot press and pressed at room temperature under a pressure of 5-10 MPa for 30-50 minutes to obtain a chitosan fiber layer;

[0043] S2: Preparation of the antibacterial fiber layer: immersing the cellulose nonwoven fabric in a solution containing an antibacterial agent at a concentration of 5-10 wt %, ultrasonically treating the solution at a power of 120-200 W for 15-30 min, and then placing the solution in a hot press and pressing the solution at room temperature at a pressure of 5-10 MPa for 30-50 min to obtain the antibacterial fiber layer;

[0044] S3: Preparation of dressing: fix the chitosan fiber layer and the antibacterial fiber layer to the outer layer in sequence by tying wire, sterilize and package, and obtain a dressing for craniocerebral trauma.

[0045] The specific implementation is as follows:

[0046] Example 1:

[0047] A method for preparing a dressing for craniocerebral trauma comprises the following steps:

[0048] S1: Preparation of chitosan fiber layer: Modified chitosan was dissolved in 2.5 wt% acetic acid solution to prepare a 30 wt% modified chitosan solution; a cellulose nonwoven fabric was immersed in the modified chitosan solution and ultrasonically treated at 180 W for 20 min. The fabric was then placed in a hot press and pressed at 8 MPa at room temperature for 30 min to obtain a chitosan fiber layer;

[0049] S2: Preparation of the antibacterial fiber layer: The cellulose nonwoven fabric was immersed in a solution containing ampicillin at a concentration of 7.5 wt %, ultrasonically treated at 180 W for 20 min, and then placed in a hot press and pressed at 8 MPa at room temperature for 35 min to obtain the antibacterial fiber layer.

[0050] S3: Preparation of dressing: The chitosan fiber layer and the antibacterial fiber layer are fixed to the outer layer of the cap-shaped mesh structure made of elastic cotton thread in the required size by tying wire in sequence, and sterilized and packaged to obtain a dressing for craniocerebral trauma.

[0051] Specifically, in this embodiment, the modified chitosan is prepared as follows: 4.5 parts of chitosan (with a degree of deacetylation of 90% and a molecular weight of 2500 Da) are dispersed in 30 parts of a 2.5 wt% acetic acid solution and completely dissolved at room temperature; then, 1.2 parts of isomangoic acid and 0.075 parts of a condensing agent are added, the mixture is stirred and reacted at room temperature for 4 hours, and the mixture is washed with distilled water until neutral to obtain the modified chitosan.

[0052] Example 2:

[0053] A method for preparing a dressing for craniocerebral trauma, which differs from Example 1 in that:

[0054] Step S1: Preparation of chitosan fiber layer: Modified chitosan is dissolved in acetic acid solution with a concentration of 2.5 wt% to prepare a modified chitosan solution with a concentration of 35 wt%; a cellulose non-woven fabric is immersed in the modified chitosan solution, ultrasonically treated at a power of 150 W for 30 minutes, and then placed in a hot press and pressed at room temperature under a pressure of 6 MPa for 40 minutes to obtain a chitosan fiber layer.

[0055] The preparation method of the modified chitosan is the same as that in Example 1.

[0056] Example 3:

[0057] A method for preparing a dressing for craniocerebral trauma, which differs from Example 1 in that:

[0058] Step S2: Preparation of the antibacterial fiber layer: The cellulose non-woven fabric was immersed in a solution containing ampicillin, wherein the concentration of ampicillin was 8.5 wt %, and ultrasonically treated at a power of 200 W for 20 min. The fabric was then placed in a hot press and pressed at room temperature under a pressure of 8 MPa for 40 min to obtain the antibacterial fiber layer.

[0059] Example 4:

[0060] A method for preparing a dressing for craniocerebral trauma, which differs from Example 1 in that:

[0061] Step S1: Preparation of chitosan fiber layer: Chitosan (90% deacetylation degree, 2500Da molecular weight) was dissolved in 2.5wt% acetic acid solution to prepare a 30wt% chitosan solution; a cellulose nonwoven fabric was immersed in the chitosan solution and ultrasonically treated at 180W power for 20 minutes, then placed in a hot press and pressed at room temperature under a pressure of 8MPa for 30 minutes to obtain a chitosan fiber layer.

[0062] Example 5:

[0063] A method for preparing a dressing for craniocerebral trauma, which differs from Example 1 in that:

[0064] Step S2: first modifying the cellulose non-woven fabric; wherein, the steps of modifying the cellulose non-woven fabric are as follows:

[0065] The cellulose nonwoven fabric was immersed in acetone for 3 h, ultrasonically treated for 30 min, and dried at 105 °C to constant weight to obtain a cleaned cellulose nonwoven fabric;

[0066] 0.25 parts by weight of cerium nitrate was dissolved in 70 parts by weight of deionized water, 1.5 parts by weight of the washed cellulose non-woven fabric and 0.3 parts by weight of a 0.045 mol / L nitric acid solution were added, and the mixture was stirred and mixed at room temperature to obtain system a;

[0067] 1.05 parts by weight of cedarene alcohol was dissolved in 80 parts by weight of anhydrous ethanol to obtain system b; system b was added to the above system a, stirred and reacted at 35°C for 8 hours, washed with ethanol and filtered three times, then washed with distilled water and filtered three times, and placed in a drying oven to dry to constant weight to obtain a modified cellulose non-woven fabric.

[0068] The modified cellulose non-woven fabric was immersed in a solution containing ampicillin, wherein the concentration of ampicillin was 7.5 wt%, and ultrasonically treated at a power of 180 W for 20 min. Then, the fabric was placed in a hot press and pressed at room temperature for 35 min under a pressure of 8 MPa to obtain an antibacterial fiber layer.

[0069] Example 6:

[0070] A method for preparing a dressing for craniocerebral trauma, which differs from Example 5 in that:

[0071] The steps of modification of cellulose nonwoven fabrics are as follows:

[0072] The cellulose nonwoven fabric was immersed in acetone for 3 h, ultrasonically treated for 30 min, and dried at 105 °C to constant weight to obtain a cleaned cellulose nonwoven fabric;

[0073] 0.45 parts by weight of cerium nitrate was dissolved in 100 parts by weight of deionized water, 2 parts by weight of the washed cellulose non-woven fabric and 0.4 parts by weight of a 0.045 mol / L nitric acid solution were added, and the mixture was stirred and mixed at room temperature to obtain system a;

[0074] 1.25 parts by weight of cedarene alcohol was dissolved in 80 parts by weight of anhydrous ethanol to obtain system b; system b was added to the above system a, stirred and reacted at 35°C for 8 hours, washed with ethanol and filtered three times, then washed with distilled water and filtered three times, and placed in a drying oven to dry to constant weight to obtain a modified cellulose non-woven fabric.

[0075] Other steps are the same as in Example 5.

[0076] Example 7:

[0077] A method for preparing a dressing for craniocerebral trauma, which differs from Example 4 in that:

[0078] Step S2: first modifying the cellulose non-woven fabric; wherein, the steps of modifying the cellulose non-woven fabric are as follows:

[0079] The cellulose nonwoven fabric was immersed in acetone for 3 h, ultrasonically treated for 30 min, and dried at 105 °C to constant weight to obtain a cleaned cellulose nonwoven fabric;

[0080] 0.25 parts by weight of cerium nitrate was dissolved in deionized water, and 1.5 parts by weight of the washed cellulose non-woven fabric and 0.3 parts by weight of a 0.045 mol / L nitric acid solution were added, and the mixture was stirred and mixed at room temperature to obtain system a;

[0081] 1.05 parts by weight of cedarene alcohol was dissolved in 80 parts by weight of anhydrous ethanol to obtain system b; system b was added to the above system a, stirred and reacted at 35°C for 8 hours, washed with ethanol and filtered three times, then washed with distilled water and filtered three times, and placed in a drying oven to dry to constant weight to obtain a modified cellulose non-woven fabric.

[0082] The modified cellulose non-woven fabric was immersed in a solution containing ampicillin, wherein the concentration of ampicillin was 7.5 wt%, and ultrasonically treated at a power of 180 W for 20 min. Then, the fabric was placed in a hot press and pressed at room temperature for 35 min under a pressure of 8 MPa to obtain an antibacterial fiber layer.

[0083] Example 8:

[0084] 1. Infrared structural characterization

[0085] Fourier transform infrared spectrometer (Nicolet-6700) was used to characterize the chitosan before and after modification and the cellulose nonwoven fabric before and after modification.

[0086] Figure 1 is the infrared spectra of chitosan before and after modification in Example 1; curves a and b are the infrared spectra of chitosan and modified chitosan respectively; Figure 1 It can be seen that in the infrared spectrum of chitosan, 1025cm -1 The characteristic absorption peak appearing near 870cm is the stretching vibration of COC; -1 The characteristic absorption peaks appearing near the stretching vibration of primary amine -NH2; at 1700cm -1 The characteristic absorption peaks appearing near the C=O stretching vibration are at 1650cm -1 , 1550cm -1 The characteristic absorption peaks appearing near the amide band are the stretching vibrations of C=O in the amide band I and NH in the amide band II. Therefore, chitosan was modified by isomango alcohol acid to obtain modified chitosan.

[0087] Figure 2 is the infrared spectra of the cellulose nonwoven fabric before and after modification in Example 5; curves c and d are the infrared spectra of the cellulose nonwoven fabric and the modified cellulose nonwoven fabric, respectively; Figure 2 It can be seen that compared with the unmodified cellulose nonwoven fabric, the modified cellulose nonwoven fabric has a -1 The CH symmetric characteristic absorption peak near 1450cm -1 The CH bending vibration absorption peak appearing nearby is enhanced, indicating that the modified fiber non-woven fabric is prepared by graft copolymerization of cedarwood ene alcohol and cellulose non-woven fabric.

[0088] 2. Water absorption performance test

[0089] The water absorption performance of the chitosan fiber layer was determined by weighing method. First, the chitosan fiber layer was cut into a size of 15 mm × 15 mm, placed in a drying oven and dried to constant weight, and then weighed and recorded as W0. Then, it was immersed in PBS buffer solution with a pH of 7.4 for 24 hours, and the chitosan fiber layer was taken out and weighed and recorded as W1. The moisture absorption rate was calculated as follows:

[0090] Moisture absorption rate (%) = (weight after absorption - weight before absorption) / weight before absorption × 100%

[0091] Test samples: untreated cellulose nonwoven fabric, the chitosan fiber layer in Example 1, the chitosan fiber layer in Example 2, and the chitosan fiber layer in Example 4, which are respectively denoted as M1, M2, M3, and M4.

[0092] Figure 3 is the moisture absorption rate of the chitosan fiber layer; Figure 3It can be seen that the moisture absorption rate of the chitosan fiber layer in Examples 1-2 is higher than 980%. Comparing Example 1 with Example 4 and the untreated cellulose non-woven fabric, the moisture absorption rate of the chitosan fiber layer in Example 1 is higher than that in Example 4 and the untreated cellulose non-woven fabric, indicating that the chitosan modified with isomango alcohol acid is used to prepare the modified chitosan, which is used to treat the cellulose non-woven fabric to prepare the chitosan fiber layer, which improves the water absorption performance of the chitosan fiber layer.

[0093] 3. Antibacterial performance test

[0094] Take 60mL of PBS buffer and 1 / 400 of nutrient broth mixture and place it in a conical flask, add appropriate amount of glass beads, sterilize it at high temperature, inoculate Escherichia coli and Staphylococcus aureus respectively, shake and mix thoroughly to make the bacterial suspension concentration be 10 6 CFU / mL;

[0095] Test samples: The experiment without sample was used as the blank control group; the experiment with unmodified cellulose non-woven fabric was used as the negative control group; the experiment with antibacterial fiber layer (the antibacterial fiber layer in Example 1, the antibacterial fiber layer in Example 3, and the antibacterial fiber layer in Example 5) was used as the experimental group. The test samples were cut into samples with a size of 4 mm × 4 mm, and 0.25 g was weighed as the test sample.

[0096] Oscillation antibacterial test: Add 30mL of physiological saline and 1 / 400 nutrient broth mixture to a conical flask, sterilize it as a negative control group or add 0.25g of sample, then use a pipette to add 0.15mL of bacterial solution to the conical flask and seal it; oscillate at a rate of 180r / min for 20min at 25℃; use a 10-fold dilution method to serially dilute the remaining bacterial suspension in the flask to the appropriate dilution multiple. Take 0.15mL of the original bacterial suspension and the appropriate dilution multiples of the plate, pour 15mL of nutrient agar medium, and mix evenly. After solidification, invert the plate and place it in a constant temperature incubator at (37±2)℃. Count the colonies after incubation for 24 hours. The antibacterial rate calculation formula is as follows:

[0097] R (%) = (AB) / A × 100%

[0098] Where: R is the antibacterial rate, %; A is the average number of recovered colonies in the negative control group, CFU / mL; B is the average number of recovered colonies in the experimental group, CFU / mL.

[0099] Table 1 Antibacterial properties of antibacterial fiber layer

[0100]

[0101] As can be seen from Table 1, the antibacterial rate of the antibacterial fiber layer in Example 1, Example 3 and Example 5 against Escherichia coli is higher than 95.5%, and the antibacterial rate against Staphylococcus aureus is higher than 96.5%. Compared with the negative control group, Example 1 and Example 5, the antibacterial rates of Escherichia coli and Staphylococcus aureus in Example 5 are higher than those of the negative control group and Example 1, indicating that the cellulose non-woven fabric is first modified with cedarwood alcohol and then immersed in an antibacterial agent for surface treatment to obtain a modified antibacterial fiber layer, which improves the antibacterial performance of the antibacterial fiber layer, so that its use in dressings can reduce wound infection.

[0102] 4. Air permeability test

[0103] According to GB / T 5453-1997, the test sample was cut into a size of 6cm×6cm, and the nozzle size was selected as φ8; then the air permeability of the dressing sample was tested using a YG461E computerized air permeability tester.

[0104] Test samples: the dressings for craniocerebral trauma in Examples 1-7; respectively denoted as N1, N2, N3, N4, N5, N6, and N7.

[0105] Figure 4 Is the air permeability of the dressing for craniocerebral trauma; Figure 4 It can be seen that the air permeability of the craniocerebral trauma dressing in Examples 1-3 is not less than 1875 mm / s. Comparing Example 1 with Example 4, the air permeability of the craniocerebral trauma dressing in Example 1 is higher than that in Example 4, indicating that the modified chitosan prepared by using isomango alcohol acid modified chitosan is used to treat the cellulose non-woven fabric to obtain the modified chitosan fiber layer, which is combined with the antibacterial fiber layer and the fixed outer layer to prepare the craniocerebral trauma dressing, which improves the air permeability of the dressing; the air permeability of the craniocerebral trauma dressing in Examples 5-6 is not less than 1875 mm / s. The air permeability of the dressing for craniocerebral trauma in Example 5 is higher than 2158 mm / s. Comparing Example 1 with Example 5, and Example 4 with Example 7, the air permeability of the dressing for craniocerebral trauma in Example 5 is higher than that in Example 1, and the air permeability of the dressing for craniocerebral trauma in Example 7 is higher than that in Example 4, indicating that the cellulose non-woven fabric is first modified with cedarwood alcohol and then immersed in an antibacterial agent for surface treatment to obtain a modified antibacterial fiber layer, which is then composited with chitosan fiber and fixed on the outer layer to prepare a dressing for craniocerebral trauma, which further improves the air permeability of the dressing.

[0106] 5. In vitro coagulation performance test

[0107] Test samples: the dressings for craniocerebral trauma in Examples 1-7, and commercially available medical gauze (purchased from Guangzhou Luohua Medical Instrument Industry Co., Ltd.); respectively denoted as K1, K2, K3, K4, K5, K6, K7, and K8.

[0108] The test sample was cut into a 0.5 cm × 0.5 cm square and placed in a beaker. The sample was placed in a water bath at 37°C for 8 min, 60 μL of fresh anticoagulated rabbit blood was added, and then 25 μL of 0.25 mol / L calcium chloride solution was added. The sample was incubated at 37°C for 10 min. 30 mL of deionized water was added and the sample was shaken in a constant temperature shaker at 37°C and 50 rpm for 5 min. The supernatant was collected and the absorbance at 540 nm was measured. For the blank group, 60 μL of fresh anticoagulated rabbit blood was added to 30 mL of deionized water, and the absorbance at 540 nm was measured. The in vitro coagulation index (BCI) was calculated. The lower the BCI value, the better the coagulation effect. The calculation formula is as follows:

[0109] BCI (%) = A 样品 / A 空白 ×100%

[0110] Figure 5 In vitro coagulation index (BCI) of dressing for craniocerebral trauma; Figure 5 It can be seen that the in vitro coagulation index (BCI) of the craniocerebral trauma dressings in Examples 1-3 is lower than 31%, which is much lower than that of commercially available medical gauze. Comparing Example 1 with Example 4, the in vitro coagulation index (BCI) of the craniocerebral trauma dressing in Example 1 is lower than that of Example 4, indicating that the modified chitosan prepared by using isomango alcohol modified chitosan is used to treat a cellulose non-woven fabric to obtain a chitosan fiber layer, which is then combined with an antibacterial fiber layer and a fixed outer layer to prepare a craniocerebral trauma dressing, which improves the in vitro coagulation effect of the dressing to achieve a better hemostatic effect; the craniocerebral trauma dressings in Examples 5-6 The in vitro coagulation index (BCI) of the dressing is lower than 27%. Comparing Example 1 with Example 5, and Example 4 with Example 7, the in vitro coagulation index (BCI) of the dressing for craniocerebral trauma in Example 5 is lower than that in Example 1, and the in vitro coagulation index (BCI) of the dressing for craniocerebral trauma in Example 7 is lower than that in Example 4, indicating that the cellulose non-woven fabric is first modified with cedarwood alcohol and then immersed in an antibacterial agent for surface treatment to obtain a modified antibacterial fiber layer, which is then composited with chitosan fiber and fixed on the outer layer to prepare a dressing for craniocerebral trauma, which further improves the hemostatic performance of the dressing for craniocerebral trauma.

[0111] 6. Wound healing performance test

[0112] Eight healthy male Sprague-Dawley rats were randomly divided into four groups: 4, 6, 8, and 10 days after surgery, with two rats in each group. Rats were anesthetized with 3% sodium pentobarbital solution (1.5 μL / g) intraperitoneally. After anesthesia, the backs of the rats were hairless and disinfected with iodine and 80% alcohol. Three circular wounds, each 10 mm in diameter, were created on the backs of the rats using a 10 mm diameter punch, extending to the fascia. One wound per rat was covered with a craniocerebral trauma dressing, and the other with commercially available medical gauze (purchased from Guangzhou Luohua Medical Device Industry Co., Ltd.). The dressings were covered with a PU film and secured with medical tape. Rats were housed individually, and the wounds were disinfected and the dressings changed on days 4, 6, 8, and 10.

[0113] Rats in the corresponding groups were anesthetized on the 4th, 6th, 8th, and 10th day after surgery. The wound size was photographed with a camera, and the wound healing status of each group of animals was observed. The wound area was measured using Image software, and the wound healing rate was calculated using the following formula:

[0114] Healing rate (%) = [(A0-A t ) / A0]×100%

[0115] Where: A0 is the original wound area; A t The area of ​​unhealed wound.

[0116] Test samples: the dressings for craniocerebral trauma in Examples 1, 4, 5, and 7, and commercially available medical gauze as a control group, respectively designated as Y1, Y2, Y3, Y4, and Y5.

[0117] Figure 6 The wound healing rate of the dressing used for craniocerebral trauma; Figure 6It can be seen that with the increase of time, the wound healing rate gradually increases; and the wound healing rates of the craniocerebral trauma dressings in Example 1, Example 4, Example 5, and Example 7 are all higher than those of the commercially available medical gauze, indicating that the craniocerebral trauma dressing prepared by the present invention has a higher wound healing rate and can accelerate wound healing; Comparing Example 1 with Example 4, the wound healing rate of the craniocerebral trauma dressing in Example 1 is higher than that in Example 4, indicating that the modified chitosan is prepared by modifying chitosan with isomango alcohol acid, treating the cellulose non-woven fabric with the chitosan fiber layer, and combining the chitosan fiber layer with the antibacterial fiber layer and the fixed outer layer to prepare the craniocerebral trauma dressing. The dressing for brain trauma improves the wound healing rate of the dressing and can better promote wound healing. Comparing Example 1 with Example 5, and Example 4 with Example 7, the wound healing rate of the dressing for brain trauma in Example 5 is higher than that in Example 1, and the wound healing rate of the dressing for brain trauma in Example 7 is higher than that in Example 4, indicating that the cellulose non-woven fabric is first modified with cedarwood alcohol and then immersed in an antibacterial agent for surface treatment to obtain a modified antibacterial fiber layer, which is then composited with chitosan fiber and fixed on the outer layer to prepare a dressing for brain trauma, which further improves the healing effect of the dressing for brain trauma on the wound.

[0118] The conventional operations in the operating steps of the present invention are well known to those skilled in the art and will not be described in detail here.

[0119] The above embodiments are intended to illustrate the present invention only and are not intended to limit the present invention. Persons skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the present invention, and the scope of patent protection of the present invention shall be defined by the claims.

Claims

1. A method for preparing a dressing for craniocerebral trauma, comprising the following steps: S1: Preparation of chitosan fiber layer: dissolving modified chitosan in acetic acid solution to prepare modified chitosan solution; impregnating cellulose non-woven fabric in the modified chitosan solution and ultrasonically treating the chitosan solution, and then placing the non-woven fabric in a hot press and pressing the chitosan fiber layer; the preparation method of the modified chitosan is as follows: dispersing chitosan in acetic acid solution and completely dissolving it at room temperature, then adding isomangoic acid and a condensing agent, stirring and reacting at room temperature, and washing until neutral to obtain modified chitosan, wherein, by weight, the chitosan is 2.5-5 parts, the acetic acid solution is 20-40 parts, the isomangoic acid is 0.5-1.5 parts, and the condensing agent is 0.05-0.1 parts; the concentration of the modified chitosan solution is 20-35wt%; S2: Preparation of antibacterial fiber layer: cellulose non-woven fabric is immersed in a solution containing an antibacterial agent and ultrasonically treated, and then placed in a hot press to maintain pressure and press to obtain an antibacterial fiber layer; in the preparation of the antibacterial fiber layer, the cellulose non-woven fabric is first modified with cedarene alcohol, and the steps of the cellulose non-woven fabric modification are as follows: the cellulose non-woven fabric is soaked in acetone for 2-4 hours, and ultrasonically treated for 30-50 minutes, and dried at 100-110°C to constant weight to obtain a cleaned cellulose non-woven fabric; cerium nitrate is dissolved in deionized water, and the cleaned cellulose non-woven fabric and the concentration of cerium nitrate are added. A 0.025-0.05 mol / L nitric acid solution is stirred and mixed to obtain system a; cedrene alcohol is dissolved in anhydrous ethanol to obtain system b; system b is added to the above system a, stirred for reaction, washed, filtered, and dried to constant weight to obtain a modified cellulose non-woven fabric; by weight, cerium nitrate is 0.15-0.45 parts, deionized water is 50-100 parts, washed cellulose non-woven fabric is 1-3 parts, nitric acid solution is 0.2-0.5 parts, cedrene alcohol is 0.75-1.25 parts, and anhydrous ethanol is 50-100 parts; In step S2, the antibacterial agent is at least one of ampicillin, cefoperazone, levofloxacin, doxycycline, roxithromycin, azithromycin, ciprofloxacin, and lomefloxacin; The ultrasonic treatment power is 120-200W, and the ultrasonic treatment time is 15-30min; S3: Preparation of dressing: fixing the chitosan fiber layer and the antibacterial fiber layer to the outer layer with tying wires in sequence, sterilizing and packaging, and obtaining a dressing for craniocerebral trauma.

2. The method for preparing a craniocerebral trauma dressing according to claim 1, wherein: The outer layer is made of elastic cotton thread and has a cap-shaped mesh structure.

3. A dressing for craniocerebral trauma prepared according to any one of claims 1-2.

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