Drug sustained-release medical application

Abstract

The invention discloses a medicine slow release type medical application which comprises a polyurethane film, one side of the polyurethane film is subjected to laser etching treatment, and a medicine carrying groove is etched in the polyurethane film; the drug is loaded on the sustained release skeleton to form a drug-skeleton loading structure, and the drug-skeleton loading structure is loaded in the drug loading groove. The medicine in the medical application is loaded on the sustained-release skeleton, the sustained-release skeleton is prepared through three-dimensional micro-nano printing, the shape of the sustained-release skeleton is customized according to the shape of the medicine carrying groove, the number of the sustained-release skeleton in the medicine carrying groove is maximized, the medicine is loaded on the sustained-release skeleton, and therefore more medicine can be contained in the medicine carrying groove; the drug-loading capacity of the medical application is improved, a drug-skeleton loading structure can play a good slow-release effect, and the medical application still has drug release capacity after being used for 7 days, so that the utilization rate and durability of the medical application are greatly improved, secondary trauma in the dressing change process is avoided, and wound repair is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical fields of biomedical materials and wound care, and particularly relates to a drug sustained-release medical dressing. Background Art

[0002] The skin is the largest organ of the human body. It has various functions such as barrier protection, absorption and metabolism, secretion and excretion, body temperature regulation, and immunity. A medical dressing is a product used for local skin cooling, analgesia, physical therapy, and wound healing. By applying it on the skin surface, the expected purpose of treatment or adjuvant treatment can be achieved. After healthy skin is damaged, the medical dressing covers the wound surface, protecting the wound and preventing the wound from being infected by bacteria and dust, which may aggravate the human body's injury. Some functional medical dressings with excellent performance also have additional effects such as accelerating antibacterial, hemostasis, accelerating wound healing, and reducing scar formation.

[0003] Traditional medical dressings usually consist of a backing layer, a gel layer, and a release liner. In a heat-accumulating environment, the drug release and volatilization are too fast, resulting in a short timeliness of the medical dressing's action efficiency, a short dressing change cycle, poor patient experience, and the inability to meet the requirements of some special scenarios, such as military scenarios.

[0004] To enable the drug to continuously and stably act on the wound surface for a period of time and avoid frequent dressing changes, so as to achieve the purpose of steady and controllable release, modern medical dressings are gradually being developed into a controllable drug delivery system. The present invention is based on this point for research. Summary of the Invention

[0005] The purpose of the present invention is to provide a drug sustained-release medical dressing, which has a large drug loading capacity, can delay the drug release rate, avoid frequent dressing changes, and achieve the purpose of steady and controllable release.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] The present invention provides a drug sustained-release medical dressing, including a polyurethane film. The polyurethane film does not have drug absorption performance, and one side of the polyurethane film is treated by laser etching to etch a drug-loading groove on the polyurethane film;

[0008] The drug is loaded on a sustained-release skeleton to form a drug-skeleton loading structure, and the drug-skeleton loading structure is loaded in the drug-loading groove.

[0009] In the above technical solution, the shape of the drug-loading groove is one of square, trapezoidal, T-shaped, and arc-shaped.

[0010] In the above technical solution, the sustained-release skeleton is a frame structure fabricated by three-dimensional micro-nano printing, with a hollow inner cavity, and the drug is loaded in the inner cavity of the sustained-release skeleton.

[0011] In the above technical solution, the sustained-release skeleton is prepared by three-dimensional micro-nano printing. The shape of the sustained-release skeleton is customized according to the shape of the drug-loading groove to maximize the number of the sustained-release skeletons in the drug-loading groove.

[0012] In the above technical solution, the shape of the drug-loading groove is square, the shape of the sustained-release skeleton is also square, and the side length of the drug-loading groove is an integer multiple of the side length of the corresponding side of the sustained-release skeleton.

[0013] In the above technical solution, the preparation method of the drug-skeleton loading structure includes the following steps:

[0014] S1: Substrate preparation: Spin-coat a PVA solution with a concentration of 1-10 wt% on the entire glass substrate at a spin-coating speed of 1000-3000 r / min and a spin-coating thickness of 1-3 μm, and then perform a drying treatment so that a sacrificial layer exists on the substrate surface;

[0015] S2: Material preparation: The hydrogel material and the drug molecules are premixed by ultrasonic waves and applied on the sacrificial layer;

[0016] S3: Laser printing: The mixed materials are subjected to three-dimensional micro-nano printing by femtosecond laser two-photon polymerization technology to cure the materials into the required three-dimensional micro-nano structure;

[0017] S4: Hydrogel cleaning: The uncured hydrogel is cleaned by soaking in PGMEA, and the residual PGMEA is cleaned by soaking in IPA. Finally, the sacrificial layer and the cured three-dimensional structure are left;

[0018] S5: Sacrificial layer treatment: The sacrificial layer is dissolved by deionized water so that the cured three-dimensional structure can be detached from the substrate;

[0019] S6: Structure transfer: The obtained three-dimensional structure is collected by PBS solution and finally the solution is coated in the drug-loading groove on the polyurethane film.

[0020] In the above technical solution, in S3, the laser parameters are a wavelength of 780 nm, an energy of 30 mW at the laser focus, and a scanning speed of 5 mm / s.

[0021] In the above technical solution, the drug includes drugs for treating wound infection, diabetic foot, and pressure sore.

[0022] In the above technical solution, the inner cavity of the drug-loading groove is filled with hydrogel, and the drug-skeleton loading structure is loaded in the hydrogel.

[0023] The beneficial effects of the present invention are as follows:

[0024] 1. The medical patch of the present invention etches a drug-loading groove on the surface of the polyurethane film through laser etching, which can significantly improve the drug-loading capacity of the medical patch.

[0025] 2. The drug in the medical patch of the present invention is loaded on a sustained-release skeleton, and the sustained-release skeleton is prepared by three-dimensional micro-nano printing. The shape of the sustained-release skeleton is customized according to the shape of the drug-loading groove to maximize the number of sustained-release skeletons in the drug-loading groove. The drug is loaded on the sustained-release skeleton, so that more drugs can be accommodated in the drug-loading groove, improving the drug-loading capacity of the medical patch.

[0026] 3. The drug in the medical patch of the present invention is loaded on a sustained-release skeleton, forming a drug-skeleton loading structure, which can achieve a good sustained-release effect and still have the ability to release drugs after 7 days of use. Thus, the utilization rate and durability of the medical patch are greatly improved, avoiding secondary trauma during the dressing change process and being beneficial to wound repair.

[0027] 4. The inner cavity of the drug-loading groove of the medical patch of the present invention is filled with hydrogel, and the drug-skeleton loading structure is loaded in the hydrogel, thereby further improving the sustained-release ability of the medical patch.

[0028] 5. The medical patch of the present invention abandons drug carriers such as cotton fabrics and yarn strips and selects a polyurethane film. The thickness of the polyurethane film is 0.012 - 0.035 mm, which has the characteristics of being thin, waterproof, breathable, and preventing the intrusion of microorganisms. However, due to its own characteristics, the traditional polyurethane film can carry a limited variety of drugs. In the present invention, a drug-loading groove is etched on the polyurethane film, and then the drug is loaded on the sustained-release skeleton to form a drug-skeleton loading structure, which is loaded in the drug-loading groove and can carry more types of drugs, expanding the application range of the medical patch. Description of the Drawings

[0029] Figure 1 is a schematic structural diagram of the polyurethane film after laser etching in Example 1;

[0030] Figure 2 is a schematic structural diagram of the medical patch in Example 1;

[0031] Figure 3 is Figure 2 an enlarged view of A in

[0032] Figure 4 is a schematic structural diagram of the medical patch in Example 2;

[0033] Figure 5 is Figure 4 an enlarged view of B in

[0034] Figure 6 is a schematic structural diagram of the medical patch in Comparative Example 1;

[0035] Figure 7 is Figure 6 An enlarged view of C therein;

[0036] Figure 8 Is a schematic structural diagram of the medical dressing of Comparative Example 2;

[0037] Figure 9 is Figure 8 An enlarged view of D therein;

[0038] Figure 10 Is a schematic structural diagram of the medical dressing of Comparative Example 3;

[0039] Figure 11 is Figure 10 An enlarged view of E therein;

[0040] Figure 12 Is a schematic structural diagram of the medical dressing of Comparative Example 4;

[0041] Figure 13 is Figure 12 An enlarged view of F therein;

[0042] Figure 14 Is a schematic structural diagram of the medical dressing of Comparative Example 5;

[0043] Figure 15 Is a schematic structural diagram of the medical dressing of Comparative Example 6;

[0044] Figure 16 Are fluorescence images of the medical dressing prepared in Example 1 at different time points of 0 h, 2 h, 6 h, 12 h, 24 h, 48 h, 3 d, 5 d, and 7 d;

[0045] Figure 17 Are fluorescence images of the medical dressing prepared in Example 2 at different time points of 0 h, 2 h, 6 h, 12 h, 24 h, 48 h, 3 d, 5 d, and 7 d;

[0046] Wherein, 1, polyurethane film; 2, drug-containing groove; 3, skin layer; 4, drug; 5, square sustained-release skeleton; 6, drug-square skeleton loading structure; 7, hydrogel; 8, circular sustained-release skeleton; 9, polyethylene microspheres. Detailed implementation manners

[0047] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. The present invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the present invention to those skilled in the art. The present invention will only be defined by the claims.

[0048] In the following examples, the test methods or testing methods described, unless otherwise specified, are all conventional methods; the reagents and materials, unless otherwise specified, are all obtained from conventional commercial channels or prepared by conventional methods.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0050] The present invention provides a drug - sustained - release medical dressing, which includes a polyurethane film 1. The polyurethane film 1 does not have drug - absorbing properties. One side of the polyurethane film 1 is treated by laser etching, and drug - loading grooves 2 are etched on the polyurethane film 1, as Figure 1 shown.

[0051] The drug 4 is loaded on a sustained - release skeleton to form a drug - skeleton loading structure. The drug - skeleton loading structure is loaded in the drug - loading groove 2. When in use, the skin layer 3 is located below the drug - loading groove 2.

[0052] The thickness of the polyurethane film selected in the present invention is 0.012 - 0.035 mm, the moisture permeability is ≧ 1800 g / ㎡ / 24 h (37℃), and the tensile strength is not less than 5 N / cm 2 .

[0053] Preferably, the laser power is 200 mW - 1 W, and the scanning speed is 0.5 - 5 m / s. The upper and lower diameters of the drug - loading groove are 100 - 5000 nm, the depth is 10 - 1000 μm, and the spacing is 12 - 510 μm.

[0054] It should be noted that the drug - sustained - release medical dressing of the present invention may further include a release - preventing layer and other functional layers in addition to the polyurethane film and the drug. The release - preventing layer needs to be removed during use.

[0055] In the present invention, the shape of the drug - loading groove is one of a square, a trapezoid, a T - shape, and an arc shape.

[0056] In the present invention, the sustained - release skeleton is a frame structure printed by three - dimensional micro - nano printing, with a hollow inner cavity. The drug is loaded in the inner cavity of the sustained - release skeleton. The shape of the sustained - release skeleton can be one of a square, a trapezoid, a T - shape, and an arc shape, or it can be other shapes.

[0057] The sustained - release skeleton is prepared by three - dimensional micro - nano printing. The shape of the sustained - release skeleton is customized according to the shape of the drug - loading groove to maximize the number of sustained - release skeletons in the drug - loading groove. As one of the embodiments, the shape of the drug - loading groove is square, and the shape of the sustained - release skeleton is also square. The side length of the drug - loading groove is an integer multiple of the side length of the corresponding side of the sustained - release skeleton, so that the drug - loading groove can accommodate the maximum number of sustained - release skeletons, and the drug is loaded on the sustained - release skeleton, and thus the maximum amount of drug can be loaded.

[0058] In the present invention, the preparation method of the drug-skeleton loading structure comprises the following steps:

[0059] S1: Substrate preparation: Spin-coat a PVA solution with a concentration of 1-10 wt% on the entire glass substrate at a spin-coating speed of 1000-3000 r / min and a spin-coated thickness of 1-3 μm, and then perform a drying treatment so that a sacrificial layer exists on the substrate surface.

[0060] S2: Material preparation: Ultrasonically premix the hydrogel material and the drug molecules, and apply them on the sacrificial layer.

[0061] S3: Laser printing: Use the femtosecond laser two-photon polymerization technology to perform three-dimensional micro-nano printing on the mixed material to cure the material into the required three-dimensional micro-nano structure; the laser parameters are a wavelength of 780 nm, an energy at the laser focus of 30 mW, and a scanning speed of 5 mm / s.

[0062] S4: Hydrogel cleaning: Immerse the uncured hydrogel through PGMEA for cleaning, and then immerse the residual PGMEA through IPA for cleaning, and finally leave the sacrificial layer and the cured three-dimensional structure.

[0063] S5: Sacrificial layer treatment: Dissolve the sacrificial layer through deionized water so that the cured three-dimensional structure can be detached from the substrate.

[0064] S6: Structure transfer: Collect the obtained three-dimensional structure through PBS solution, and finally coat the solution in the drug-loading groove on the polyurethane film.

[0065] As one of the embodiments, the inner cavity of the drug-loading groove 2 is filled with the hydrogel 7, and the drug-skeleton loading structure is loaded in the hydrogel 7. The hydrogel 7 can further delay the release of the drug 4.

[0066] In the present invention, the drugs include drugs for treating wound infections, diabetic foot, and pressure sores. For example: hydrophilic drugs for treating wound infections include povidone iodine, chlorhexidine, hydrogen peroxide solution, and various types of antibiotics. Hydrophilic drugs for treating diabetic foot include vitamin B12, various hydrophilic anti-infective drugs mentioned in infected wounds, and Kangfuxin Liquid. Hydrophilic drugs for treating pressure sores include drugs with active ingredients of hyaluronic acid, alginate, hydrogel, honey, aloe vera, and epidermal growth factor. Hydrophobic drugs for treating wound infections include erythromycin ointment, mupirocin ointment, metronidazole gel, neomycin B ointment, ciprofloxacin ointment, clindamycin phosphate gel, and silver sulfadiazine. Hydrophobic drugs for treating pressure sores include drugs with active ingredients of collagen and silver ions.

[0067] As one of the embodiments, a hydrogel layer is provided at the bottom of the inner cavity of the drug-loading groove, and the drug-skeleton loading structure is loaded in the hydrogel layer and above the hydrogel layer in the drug-loading groove.

[0068] The technical solution of the present invention will be described below in conjunction with specific embodiments.

[0069] Embodiment 1

[0070] As Figure 2 and 3 shown, this embodiment provides a drug sustained-release medical dressing, including a polyurethane film 1, one side of the polyurethane film 1 is processed by laser etching, and a drug-loading groove 2 is etched on the polyurethane film 1, and the shape of the drug-loading groove 2 is square.

[0071] The laser power is 300 mW, the scanning speed is 1 m / s, the scanning pitch is 15 μm, the width of the drug-loading groove 2 is 2 μm, and the depth is 50 μm.

[0072] Clindamycin (Drug 4) is loaded on a square sustained-release skeleton 5 to form a clindamycin-square sustained-release skeleton loading structure (drug-square skeleton loading structure 6), and is filled in the drug-loading groove 2.

[0073] The preparation method of the clindamycin-square sustained-release skeleton loading structure (drug-square skeleton loading structure 6) includes the following steps:

[0074] (1) Substrate preparation: By spin-coating a PVA solution (concentration 1-10 wt%) on the entire glass substrate, the spin-coating speed is 2000 r / min, the spin-coating thickness is about 2 μm, and then drying treatment is carried out at 95 °C for 1 min, so that a sacrificial layer exists on the substrate surface.

[0075] (2) Material preparation: The hydrogel material and drug molecules are premixed by ultrasonic for 1 h and applied on the sacrificial layer.

[0076] (3) Laser printing: The mixed material is subjected to three-dimensional micro-nano printing by femtosecond laser two-photon polymerization technology to solidify the material into the required three-dimensional micro-nano structure. Laser parameters: wavelength 780 nm, energy at the laser focus is about 30 mW, scanning speed 5 mm / s.

[0077] (4) Hydrogel cleaning: The uncured hydrogel is cleaned by soaking in PGMEA for 10 min, and the residual PGMEA is cleaned by soaking in IPA for 3 min, and finally the sacrificial layer and the solidified three-dimensional structure are left.

[0078] (5) Sacrificial layer treatment: The sacrificial layer is dissolved by deionized water so that the solidified three-dimensional structure can be detached from the substrate.

[0079] (6) Structure transfer: The obtained three-dimensional structure was collected using PBS solution and finally coated in the drug-loading groove on the polyurethane film.

[0080] Example 2

[0081] As Figure 4 and 5 shown, on the basis of Example 1, a hydrogel 7 is provided in the drug-loading groove 2, and the clindamycin-square sustained-release skeleton loading structure (drug-square skeleton loading structure 6) is loaded in the hydrogel 7.

[0082] Comparative Example 1

[0083] As Figure 6 and 7 shown, on the basis of Example 1, the sustained-release skeleton is circular, i.e., the circular sustained-release skeleton 8.

[0084] Comparative Example 2

[0085] As Figure 8 and 9 shown, on the basis of Comparative Example 1, a hydrogel 7 is provided in the drug-loading groove 2, and the clindamycin-circular skeleton loading structure is loaded in the hydrogel 7.

[0086] Comparative Example 3

[0087] As Figure 10 and 11 shown, on the basis of Example 1, the sustained-release skeleton is selected as polyethylene microspheres 9, and the preparation process of loading clindamycin in the polyethylene microspheres 9 includes the following steps:

[0088] Step 1: Preparation of polyethylene microspheres

[0089] Dissolution of polyethylene: 5 grams of polyethylene was dissolved in 50 milliliters of ethanol, heated and stirred on a magnetic stirrer until completely dissolved. The temperature was controlled at about 60 °C, and the stirring speed was maintained at 600 revolutions per minute.

[0090] Addition of emulsifier: 1 gram of polysorbate-80 was added to the polyethylene solution and stirring was continued.

[0091] Dropwise addition of water: 100 milliliters of deionized water was slowly added dropwise to the polyethylene solution to form an emulsion. The emulsion was treated with an ultrasonic disperser to ensure uniform and stable emulsion. The ultrasonic treatment time was set to 5 minutes and the power was set to 30%.

[0092] Solidification of microspheres: The emulsion was poured into a large amount of deionized water, and the microspheres were collected by precipitation. The microspheres were washed to remove unreacted organic matter and emulsifier. The washing conditions were washing 3 times with deionized water, 500 milliliters each time, and each washing time was 10 minutes.

[0093] Step 2: Loading of Clindamycin

[0094] Dissolve clindamycin: Dissolve 2 grams of clindamycin in 20 milliliters of ethanol, ensuring complete dissolution of clindamycin and avoiding undissolved particles.

[0095] Soak the microspheres: Soak the prepared polyethylene microspheres in the clindamycin solution to allow the drug to be fully adsorbed into the interior of the microspheres. The soaking time is 24 hours to ensure sufficient drug adsorption. Maintain the stirring speed at 400 revolutions per minute during the soaking process.

[0096] Remove the unloaded drug: Remove the unloaded drug and solvent from the drug-loaded microspheres by centrifugation or filtration. The centrifugation conditions are 4000 revolutions per minute for 15 minutes. Wash the microspheres to remove the residual solvent and unadsorbed drug. The washing conditions are to wash 3 times with deionized water, 500 milliliters each time, and each washing time is 10 minutes.

[0097] Comparative Example 4

[0098] As Figure 12 and 13 shown, on the basis of Comparative Example 3, a hydrogel 7 is provided in the drug-loading groove 2, and the clindamycin-polyethylene microsphere loading structure is loaded in the hydrogel 7.

[0099] Comparative Example 5

[0100] As Figure 14 shown, this comparative example provides a drug sustained-release medical dressing, including a polyurethane film 1, one side of which is treated by laser etching to etch a drug-loading groove 2 on the polyurethane film, and the shape of the drug-loading groove 2 is square. Clindamycin is filled in the drug-loading groove 2. The laser etching parameters are the same as those in Example 1.

[0101] Comparative Example 6

[0102] As Figure 15 shown, on the basis of Comparative Example 5, a hydrogel 7 is provided in the drug-loading groove 2, and clindamycin is loaded in the hydrogel 7.

[0103] Experimental process

[0104] 1. Detection experiment of the total drug loading of the medical dressing

[0105] (1) Experimental process

[0106] This solution uses high performance liquid chromatography to detect the concentration of drugs in the eluate of medical dressings. First, prepare the standard solution and the sample. The reagents used are required to be of chromatographic purity or above. The concentration gradients of the standard drug (clindamycin) are designed as follows: 1.0 mg / mL, 0.8 mg / mL, 0.6 mg / mL, 0.4 mg / mL, 0.2 mg / mL, 0.1 mg / mL, 0.05 mg / mL. The solvents used include methanol, acetonitrile and dichloromethane, and p-aminobenzoic acid is used as the internal standard.

[0107] In the sample pretreatment process, first combine the medical dressing with 200 μL of deionized water and incubate for 7 days. After incubation, mix the eluate with an equal volume of internal standard solution, then add an appropriate amount of acetonitrile and shake, and then obtain the supernatant by centrifugation. Next, add dichloromethane for shaking and centrifugation again, and finally extract the organic phase solution for analysis.

[0108] The conditions for liquid chromatography analysis include using a C18 chromatographic column, and using 0.01 mol / L sodium dihydrogen phosphate buffer solution and acetonitrile as the mobile phase, and adjusting the ratio to ensure the best separation effect. The detection wavelength is in the range of 215 nm, 240 nm or 308 nm, and the specific wavelength is determined according to the experimental requirements. The analysis process uses isocratic elution, the flow rate is 1 mL per minute, the injection volume is 20 μL, and the column temperature is maintained at 35 °C. In order to ensure the accuracy and reliability of the method, it is necessary to measure samples with different concentrations through a standard curve, and then determine the concentration range of the drug. Through the above steps and verification, it can be ensured that this high performance liquid chromatography method has high reliability and applicability in the accurate detection of the drug concentration in the eluate of drug dressings.

[0109] (2) Experimental results

[0110] The total drug loading of the medical dressings prepared in Examples 1-2 and Comparative Examples 1-6 was detected by the above experimental method, and the experimental results are shown in Table 1 below.

[0111] 2. Cumulative drug release detection experiment of medical dressings

[0112] (1) Experimental process

[0113] 1) Cleaning the samples: The samples after internal etching (Examples 1-2 and Comparative Examples 1-6) were placed in 100 ml of deionized water and soaked at room temperature. The samples were placed under a Zeiss LSM980 confocal fluorescence microscope for photography at different time points of 0 h, 2 h, 6 h, 12 h, 24 h, 48 h, 3 d, 5 d, and 7 d. The z-axis scanning function of the microscope was started. Starting from the bottom of the sample, the z-axis was gradually moved upward by 1 μm at intervals, and the image was acquired while staying at each z-axis height. Continuous shooting was carried out until the entire thickness range of the sample was covered, thereby obtaining a series of two-dimensional fluorescence images at different z-axis heights, and these images together constituted a three-dimensional stack group.

[0114] 2) Three-dimensional reconstruction of the image data of the obtained three-dimensional stack group. Based on the three-dimensional reconstruction, the ImageJ software will perform intensity analysis on the fluorescence signal of the entire sample. By setting a specific region of interest (ROI), the total fluorescence intensity within this region is calculated.

[0115] 3) Obtaining the total fluorescence intensity

[0116] After measuring the total fluorescence intensity of the medical patches prepared in Examples 1-2 and Comparative Examples 1-6 at different time points of 0 h, 2 h, 6 h, 12 h, 24 h, 48 h, 3 d, 5 d, and 7 d using the above method, the cumulative residual drug amount at 0 h was defined as 100%, corresponding to the value of the total drug loading amount of the medical patch obtained in the total drug loading amount detection experiment of the above medical patch. In the subsequent different time periods after drug release, according to the decay ratio of the total fluorescence intensity, the cumulative residual drug amount in each time period was calculated.

[0117] (2) Experimental results

[0118] The experimental results are shown in Table 1 below.

[0119] Table 1 Experimental results

[0120]

[0121]

[0122] As can be seen from the above, in Examples 1 and 2, the shapes of the drug-loading groove and the sustained-release matrix are both square, enabling the drug-loading groove to accommodate more sustained-release matrix. The drug is loaded on the sustained-release matrix, thus greatly enhancing the drug-loading capacity. Moreover, the drug-sustained-release matrix loading structure can play a role in delaying drug release. In Example 2, the drug-loading groove is filled with hydrogel, which can further enhance the drug release rate, thereby greatly improving the utilization rate and durability of the medical dressing, avoiding secondary trauma during the dressing change process, and being beneficial to wound repair. In Comparative Examples 1 and 2, the drug-loading groove is square and the shape of the sustained-release matrix is circular. Compared with Examples 1 and 2, the drug-loading capacity is reduced. In Comparative Examples 3 and 4, the sustained-release matrix is polyethylene microspheres. Compared with the hollow-structured sustained-release matrix printed by three-dimensional micro-nano technology in Examples 1 and 2 and Comparative Examples 1 and 2, the polyethylene microspheres are a loose and porous structure composed of a large number of microsphere monomers, and the drug only exists in the pores, so the drug-loading capacity is limited. In Comparative Examples 5 and 6, there is no skeleton structure carrying the drug, and the number of drugs entering the drug-loading groove is limited, with even less drug-loading capacity.

[0123] Obviously, the above examples are merely illustrations given for clear explanation and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or alterations can be made based on the above description. It is not necessary and impossible to list all implementation manners here. And the obvious changes or alterations derived therefrom still fall within the protection scope of this invention.

Claims

1. A drug sustained-release medical dressing, comprising a polyurethane film, characterized in that: The polyurethane film does not have drug absorption performance. One side of the polyurethane film is treated by laser etching, and drug-loading grooves are etched on the polyurethane film. The drug is loaded on a sustained-release skeleton to form a drug-skeleton loading structure, and the drug-skeleton loading structure is loaded in the drug-loading groove.

2. The drug sustained-release medical dressing according to claim 1, wherein: The shape of the drug-loading groove is one of square, trapezoidal, T-shaped, and arc-shaped.

3. The drug sustained-release medical dressing according to claim 1, wherein: The sustained-release skeleton is a frame structure fabricated by three-dimensional micro-nano printing, with a hollow inner cavity, and the drug is loaded in the inner cavity of the sustained-release skeleton.

4. The medicated sustained-release medical dressing according to claim 1, wherein: The sustained-release skeleton is prepared by three-dimensional micro-nano printing, and the shape of the sustained-release skeleton is customized according to the shape of the drug-loading groove to maximize the number of the sustained-release skeletons in the drug-loading groove.

5. The drug sustained-release medical dressing according to claim 4, characterized in that: The shape of the drug-loading groove is square, and the shape of the sustained-release skeleton is also square. The side length of the drug-loading groove is an integer multiple of the side length of the corresponding side of the sustained-release skeleton.

6. The drug-sustained release medical dressing according to claim 1, wherein: The preparation method of the drug-skeleton loading structure comprises the following steps: S1: Substrate preparation: A PVA solution with a concentration of 1-10 wt% is spin-coated on the entire glass substrate at a spin-coating speed of 1000-3000 r / min and a spin-coated thickness of 1-3 μm, and then dried to form a sacrificial layer on the substrate surface. S2: Material preparation: The hydrogel material and drug molecules are premixed by ultrasonic treatment and applied on the sacrificial layer. S3: Laser printing: The mixed material is subjected to three-dimensional micro-nano printing by femtosecond laser two-photon polymerization technology to cure the material into the required three-dimensional micro-nano structure. S4: Hydrogel cleaning: The uncured hydrogel is cleaned by soaking in PGMEA, and the residual PGMEA is cleaned by soaking in IPA, and finally the sacrificial layer and the cured three-dimensional structure are left. S5: Sacrificial layer treatment: The sacrificial layer is dissolved by deionized water so that the cured three-dimensional structure can be detached from the substrate. S6: Structure transfer: The obtained three-dimensional structure is collected by PBS solution and finally coated in the drug-loading groove on the polyurethane film.

7. The medicament sustained-release medical dressing according to claim 6, wherein: In S3, the laser parameters are a wavelength of 780 nm, an energy of 30 mW at the laser focus, and a scanning speed of 5 mm / s.

8. The drug sustained-release medical dressing according to claim 1, wherein: The drug includes drugs for treating wound infection, diabetic foot, and pressure sore.

9. The drug sustained-release medical dressing according to claim 1, characterized in that: The inner cavity of the drug-loading groove is filled with hydrogel, and the drug-skeleton loading structure is loaded in the hydrogel.

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