Preparation method of multifunctional fiber patch for bone nail fixation postoperative care

Abstract

The invention relates to the technical field of medical materials, and discloses a preparation method of a multifunctional fiber patch for bone nail fixation postoperative care. The fiber patch adopts a three-layer composite structure design, and comprises an anti-allergic silica gel substrate layer, a drug-loaded nanofiber functional layer and a waterproof breathable layer. The preparation method comprises the following steps: (1) preparing the anti-allergic silica gel substrate layer from platinum cured silica gel and a pressure-sensitive adhesive; (2) preparing a medicine-carrying nanofiber functional layer containing phellinus igniarius polysaccharide through electrostatic spinning; (3) mixing waterborne polyurethane with polytetrafluoroethylene to prepare a waterproof breathable layer; and (4) sequentially compounding the substrate layer, the functional layer and the waterproof breathable layer into the multifunctional fiber patch. The fiber patch has the comprehensive effects of resisting bacteria, resisting inflammation, resisting allergy and easing pain, meanwhile has excellent air permeability and comfort, can effectively promote postoperative wound recovery and reduce infection risks, is particularly suitable for wound nursing after orthopedic internal fixation, and has remarkable clinical application value.

Description

Technical Field

[0001] The invention relates to the technical field of medical materials, and in particular to a method for preparing a multifunctional fiber patch for postoperative care after bone screw fixation. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance some understanding of the overall background of the invention and should not be necessarily regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] In orthopedic surgery, bone screws, as key internal fixation devices, are widely used in scenarios such as fracture reduction, joint fusion, and implant fixation, but their postoperative care faces many challenges. Traditional metal bone screws (such as stainless steel and cobalt-chromium alloys) have limited biocompatibility and are prone to infection, inflammation, and allergic reactions. Bacterial biofilms are easily formed on the metal surface, increasing the risk of infection. At the same time, long-term friction between the bone screws and the surrounding soft tissues may cause pain, skin ulcers, and scar hyperplasia, especially in the superficial bone area, which seriously affects the patient's postoperative recovery and quality of life. However, the current postoperative dressings have a single function and are difficult to meet complex clinical needs: ordinary gauze or low-function composite materials have insufficient antibacterial and anti-inflammatory capabilities and cannot effectively resist infection or promote healing; they have poor breathability and comfort, resulting in local moisture and stuffiness in the wound, exacerbating bacterial growth and patient discomfort; in addition, the dressing lacks anti-allergic design, which may induce allergic reactions, and has low compatibility with the bone screws, and cannot effectively reduce the friction between the bone screws and soft tissues. It is particularly noteworthy that existing dressings have obvious defects in drug sustained release. A single drug delivery system is difficult to meet the differentiated treatment needs in different postoperative stages (acute inflammation stage, tissue repair stage), and traditional antibacterial agents such as silver ions may produce cytotoxicity.

[0004] In recent years, electrospinning technology has demonstrated tremendous potential in the development of functional dressings. This technology enables the preparation of nanofibrous membranes with biomimetic extracellular matrix structures, providing an ideal microenvironment for wound healing. Polyvinylpyrrolidone (PVP), due to its excellent solubility, film-forming properties, and biocompatibility, has become a highly valuable carrier material in electrospinning processes. PVP not only significantly improves the processing properties of natural active ingredients, but its unique molecular chain structure also enhances the mechanical strength of the nanofibrous membranes. More importantly, PVP has excellent drug loading capacity, enabling the synergistic loading and controlled release of multiple functional ingredients. However, single polymer systems still struggle to meet the multifunctional integration requirements of orthopedic postoperative care. Therefore, the development of a multilayer composite dressing that integrates advanced spinning technology, innovative material combinations, and rational structural design has become a key approach to breaking through existing technological bottlenecks. This new dressing is expected to provide a more comprehensive solution for postoperative care after bone fixation through the synergistic effects of its various functional layers. Summary of the Invention

[0005] This invention addresses the problems of infection, inflammation, allergies, and soft tissue friction damage that exist in postoperative care after bone screw fixation. It proposes a method for preparing a multifunctional fiber patch based on electrospinning technology. This patch combines an anti-allergic silicone base layer with a waterproof and breathable layer to achieve multifunctional synergistic effects of antibacterial, anti-inflammatory, anti-allergic, analgesic, and healing promotion. The patch is compatible with bone screws and significantly improves postoperative care. The specific technical solution is as follows:

[0006] In a first aspect of the present invention, a method for preparing a multifunctional fiber patch for postoperative care after bone screw fixation is provided, comprising the following steps:

[0007] (1) Preparation of the base layer: Platinum-cured silicone is injected into a microporous mold and cured to form a breathable and anti-allergic silicone base layer; then, a thin layer of pressure-sensitive adhesive is coated on the surface of the silicone base layer and evenly applied with a scraper. After drying, a composite base layer with anti-allergic, breathable and strong adhesion is obtained.

[0008] (2) Preparation of functional layer: Phellinus igniarius polysaccharide and polyvinyl pyrrolidone (PVP) were dissolved in deionized water, and lidocaine hydrochloride (LH) and dipotassium glycyrrhizate (DPG) were added to prepare a uniform spinning solution, and the nanofiber membrane was obtained by electrospinning technology.

[0009] (3) Preparation of waterproof and breathable layer: Add waterborne polyurethane (WPU) and polytetrafluoroethylene (PTFE) to dimethylformamide (DMF) solvent and stir evenly. Pour the blended solution into a flat mold and apply it evenly with a scraper. Place the coated film in an oven for curing and perform surface plasma treatment on the cured film.

[0010] (4) Composite process: The base layer, functional layer and waterproof breathable layer are composited in sequence by hot pressing, and the edges are sealed by ultrasonic welding; then a hole is punched in the middle of the composite fiber patch, the shape of the hole is a square hole or a round hole, and the size of the hole is consistent with the outer diameter of the bone screw; one or more oblique openings are cut out from the edge of the fiber patch to the hole in the middle with serrated scissors, and the angle between the oblique opening and the plane of the fiber patch is less than 30°, and the blade of the serrated scissors is a continuous S-shape in the thickness direction.

[0011] In one or some embodiments of the present invention, in step (1), the pore size of the microporous mold is in the range of 10-50 μm, the curing temperature is 60° C., and the curing time is 2 h.

[0012] In one or some embodiments of the present invention, in step (1), the pressure-sensitive adhesive is an acrylic adhesive, and the thickness is controlled to be ≤50 μm to avoid affecting the air permeability.

[0013] In one or some embodiments of the present invention, in step (2), mulberry ignia polysaccharide is prepared by water extraction and alcohol precipitation, the concentration of mulberry ignia polysaccharide is 0.5-3% (w / v), the concentration of PVP is 15-20% (w / v), the LH loading amount is 2-5% (w / v), and the DPG loading amount is 1-3% (w / v).

[0014] In one or some embodiments of the present invention, in step (2), the electrospinning parameters are: needle 19# or 21#, negative pressure 6-8kV, positive pressure 12-16kV, receiving distance 12-18cm, flow rate 0.4-0.8mL / h, drum speed 300rpm, and ambient temperature and humidity are 20-25°C and 25-30%, respectively.

[0015] In one or some embodiments of the present invention, in step (3), WPU accounts for 60-80% (w / w), and PTFE accounts for 20-40% (w / w).

[0016] In one or some embodiments of the present invention, in step (3), the concentration of the solvent DMF is 10-20% (w / v).

[0017] In one or some embodiments of the present invention, in step (3), the stirring treatment is carried out at 60° C. for 2 h until the solution is completely dissolved.

[0018] In one or some embodiments of the present invention, in step (3), the film thickness is controlled to be 20-50 μm during blade coating, and the coated film is placed in an oven, pre-dried at 80° C. for 30 minutes, and then cured at 120° C. for 1 hour to form a dense film with a microporous structure.

[0019] In one or some embodiments of the present invention, in step (3), the plasma treatment conditions are: power 50 W, time 5 min.

[0020] In one or some embodiments of the present invention, in step (4), the hot pressing conditions are: 120° C., 0.5 MPa, 30 s.

[0021] In a second aspect of the present invention, a multifunctional fiber patch prepared by the above method for postoperative care after bone screw fixation is provided.

[0022] Preferably, it is used for postoperative care of bone nail surgery.

[0023] In a third aspect of the present invention, there is provided use of the multifunctional fiber patch in the preparation of medical supplies.

[0024] Preferably, the multifunctional fiber patch is used in the preparation of a postoperative care product for bone screw fixation. Compared with the related technologies known to the inventors, the technical solution of the present invention has the following beneficial effects:

[0025] The present invention comprehensively utilizes the composite method of anti-allergic silica gel base layer, drug-loaded nanofiber functional layer and waterproof breathable layer to develop a multifunctional fiber patch for postoperative care after bone screw fixation.

[0026] The present invention comprehensively utilizes the biocompatibility of anti-allergic silica gel, the antibacterial and anti-inflammatory properties of mulberry ignia polysaccharide, the anti-allergic effect of dipotassium glycyrrhizate (DPG), the analgesic effect of lidocaine hydrochloride (LH) and the protective function of a waterproof and breathable layer to develop a multifunctional fiber patch for postoperative care after bone screw fixation. Through the multifunctional synergistic effects of antibacterial, anti-inflammatory, anti-allergic, analgesic and healing-promoting effects, the postoperative care effect of bone screw fixation is significantly improved.

[0027] The present invention not only achieves antibacterial effects through mulberry ignia polysaccharide, but also inhibits allergic reactions and relieves postoperative pain through the sustained-release mechanism of dipotassium glycyrrhizate (DPG) and lidocaine hydrochloride (LH). In addition, the low surface energy characteristics of the anti-allergic silicone base layer can reduce tissue adhesion, and the microporous structure of the waterproof and breathable layer ensures that the wound is dry and prevents infection. The nanofiber membrane biomimetic extracellular matrix prepared by electrospinning technology provides a suitable microenvironment for cell migration and proliferation, and promotes tissue regeneration. In addition to postoperative care for bone screws, it can also be used in scenarios such as chronic wound repair, sports medicine, and internal tissue repair.

[0028] The multifunctional fiber patch of the present invention has one or more openings, making it easier to adhere the multifunctional fiber patch around the bone screw; the opening of the multifunctional fiber patch is inclined, which significantly increases the contact area and makes the two multifunctional fiber patches on both sides of the opening fit more tightly; the opening inclined surface of the multifunctional fiber patch has serrated scissor-shaped corrugations, which can increase the sliding friction between the two multifunctional fiber patches and make them more firmly fixed.

[0029] The multifunctional fiber patch for postoperative care after bone screw fixation of the present invention has the following functions: 1) the anti-allergic silicone base layer adapts to the dynamic stress of the bone screw implantation site, reducing soft tissue friction damage; 2) the mulberry linterinary polysaccharide nanofiber membrane of the functional layer mimics the extracellular matrix, promotes angiogenesis and epithelial regeneration, shortens the healing cycle, and the sustained release of dipotassium glycyrrhizate (DPG) inhibits skin allergic reactions, and lidocaine hydrochloride (LH) quickly relieves pain, thereby improving patient comfort; 3) the waterproof and breathable layer allows water vapor and small molecule drugs to pass through, preventing the invasion of external liquids and bacteria. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which constitute a part of the specification of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0031] Figure 1Schematic diagrams of the multifunctional fiber patch of the present invention. (a) shows the three-layer structure and shape design of the multifunctional fiber patch, and (b) shows the composite effect of the multifunctional fiber patch (the fiber patch has a hole in the middle and the lines are zigzag side cuts).

[0032] Figure 2 These are the scanning electron microscope (SEM) images and diameter distribution diagrams of the mulberry linterinary polysaccharide / PVP nanofibers in the examples of the present invention (without LH and DPG loading), (a) Example 1, (b) Example 2.

[0033] Icon: 1- waterproof and breathable layer; 2- functional layer; 3- basal layer; 4- part of the bone screw; 5- serrated incision on the outside of the fiber patch; 6- serrated incision on the side of the fiber patch; 7- serrated incision on the inside of the fiber patch. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0035] Example 1 Preparation method of a multifunctional fiber patch for postoperative care of bone screw fixation

[0036] (1) Preparation of the base layer: Platinum-cured silicone was injected into a microporous mold with a pore size of 20 μm and cured at 60°C for 2 h to form a breathable and anti-allergic silicone base layer. Subsequently, an acrylic pressure-sensitive adhesive with a thickness of ≤50 μm was evenly coated on the surface of the base layer and dried at room temperature for 24 h to obtain a composite base layer.

[0037] (2) Preparation of the functional layer: 2% (w / v) phellin polysaccharide and 18% (w / v) PVP were dissolved in deionized water, and 3% (w / v) LH and 2% (w / v) DPG were added and stirred until completely dissolved. Electrospinning was performed using a 19# needle at a negative pressure of 6 kV, a positive pressure of 12 kV, a receiving distance of 18 cm, a flow rate of 0.6 mL / h, and a drum speed of 300 rpm. The ambient temperature was 22 ± 2°C and the relative humidity was 28 ± 2%.

[0038] (3) Preparation of the waterproof and breathable layer: 70% (w / w) WPU and 30% (w / w) PTFE were dissolved in 15% (w / v) DMF solvent and stirred at 60°C for 2 h. A 30 μm film was then coated using a doctor blade, pre-dried at 80°C for 30 min, and cured at 120°C for 1 h. After curing, the film was treated with 50W plasma for 5 min.

[0039] (4) Composite process: Figure 1As shown, the base layer, functional layer and waterproof breathable layer are aligned, hot pressed at 120°C and 0.5 MPa for 30 seconds, and the edges are ultrasonically welded and sealed. Next, a hole is punched in the middle of the composite fiber patch. The hole is square or round and the size of the hole is consistent with the bone screw. One or more oblique openings are cut out from the edge of the fiber patch to the middle hole using serrated scissors. The angle between the oblique opening and the plane of the fiber patch is less than 30°.

[0040] Example 2 Preparation method of a multifunctional fiber patch for postoperative care of bone screw fixation

[0041] (1) Preparation of base layer: same as in Example 1.

[0042] (2) Preparation of the Functional Layer: 2% (w / v) phellin polysaccharide and 18% (w / v) PVP were dissolved in deionized water, and 4% (w / v) LH and 1.5% (w / v) DPG were added. Electrospinning was performed using a 19# needle at a negative pressure of 7 kV, a positive pressure of 14 kV, a receiving distance of 15 cm, a flow rate of 0.5 mL / h, and a drum speed of 300 rpm. The ambient temperature and humidity were the same as in Example 1.

[0043] (3) Preparation of waterproof and breathable layer: 65% (w / w) WPU and 35% (w / w) PTFE were blended, and the rest was the same as in Example 1.

[0044] (4) Composite process: same as in Example 1.

[0045] Example 3 Preparation method of a multifunctional fiber patch for postoperative care of bone screw fixation

[0046] (1) Preparation of base layer: same as in Example 1.

[0047] (2) Preparation of the Functional Layer: 3% (w / v) phellin polysaccharide and 15% (w / v) PVP were dissolved in deionized water, and 2% (w / v) LH and 3% (w / v) DPG were added. Electrospinning was performed using a 21# needle at a negative pressure of 8 kV, a positive pressure of 12 kV, a receiving distance of 12 cm, a flow rate of 0.4 mL / h, and a drum speed of 300 rpm. The ambient temperature and humidity were the same as in Example 1.

[0048] (3) Preparation of waterproof and breathable layer: 5% (w / w) WPU and 25% (w / w) PTFE were blended, and the rest was the same as in Example 1.

[0049] (4) Composite process: same as in Example 1.

[0050] The above embodiments are merely illustrative of the specific implementation methods of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, or variations made within the technical concept and spirit of the present invention, including but not limited to equivalent substitutions of material components, reasonable adjustment of process parameters, adaptive changes in structural composition, and expanded implementation of application scenarios, shall be deemed to fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing a multifunctional fiber patch for postoperative care of bone screw fixation, characterized in that: The method comprises the following steps: (1) Preparation of the base layer: Platinum-cured silicone is injected into a microporous mold and cured to form a breathable and anti-allergic silicone base layer; then, a thin layer of pressure-sensitive adhesive is coated on the surface of the silicone base layer and evenly applied with a spatula. After drying, a composite base layer with anti-allergic, breathable and strong adhesion is obtained; (2) Preparation of functional layer: Phellinus igniarius polysaccharide and polyvinylpyrrolidone (PVP) were dissolved in deionized water, lidocaine hydrochloride (LH) and dipotassium glycyrrhizate (DPG) were added to prepare a uniform spinning solution, and the nanofiber membrane was obtained by electrospinning technology; (3) Preparation of waterproof and breathable layer: waterborne polyurethane (WPU) and polytetrafluoroethylene (PTFE) were added to dimethylformamide (DMF) solvent and stirred evenly, the blended solution was poured into a flat mold, and evenly coated with a scraper, and the coated film was placed in an oven for curing, and the cured film was subjected to surface plasma treatment; (4) Composite process: The base layer, functional layer and waterproof breathable layer are composited in sequence by hot pressing, and the edges are sealed by ultrasonic welding; then a hole is punched in the middle of the composite fiber patch, the shape of the hole is a square hole or a round hole, and the size of the hole is consistent with the outer diameter of the bone screw; one or more oblique openings are cut out from the edge of the fiber patch to the hole in the middle with serrated scissors, and the angle between the oblique opening and the plane of the fiber patch is less than 30°, and the blade of the serrated scissors is a continuous S-shape in the thickness direction.

2. The method for preparing a multifunctional fiber patch for postoperative care of bone screw fixation according to claim 1, wherein: In step (1), the pore size of the microporous mold is in the range of 10-50 μm, the curing temperature is 60° C., and the curing time is 2 h.

3. The method for preparing a multifunctional fiber patch for postoperative care of bone screw fixation according to claim 1, wherein: In step (1), the pressure-sensitive adhesive is an acrylic adhesive, and the thickness is controlled to be ≤50 μm.

4. The method for preparing a multifunctional fiber patch for postoperative care of bone screw fixation according to claim 1, wherein: In step (2), mulberry ignia polysaccharide is prepared by water extraction and alcohol precipitation, the mulberry ignia polysaccharide concentration is 0.5-3% (w / v), the PVP concentration is 15-20% (w / v), the LH loading amount is 2-5% (w / v), and the DPG loading amount is 1-3% (w / v).

5. The method for preparing a multifunctional fiber patch for postoperative care of bone screw fixation according to claim 1, wherein: In step (2), the electrospinning parameters are: needle 19# or 21#, negative pressure 6-8kV, positive pressure 12-16kV, receiving distance 12-18cm, flow rate 0.4-0.8mL / h, drum speed 300rpm, ambient temperature and humidity 20-25°C and 25-30%, respectively.

6. The method for preparing a multifunctional fiber patch for postoperative care of bone screw fixation according to claim 1, wherein: In step (3), WPU accounts for 60-80% (w / w), PTFE accounts for 20-40% (w / w), the concentration of the solvent DMF is 10-20% (w / v), and the stirring condition is stirring at 60° C. for 2 hours until completely dissolved.

7. The method for preparing a multifunctional fiber patch for postoperative care of bone screw fixation according to claim 1, wherein: In step (3), the film thickness is controlled to be 20-50 μm during blade coating. The coated film is placed in an oven and pre-dried at 80° C. for 30 minutes, and then cured at 120° C. for 1 hour. The plasma treatment conditions are power 50 W and time 5 minutes.

8. The method for preparing a multifunctional fiber patch for postoperative care of bone screw fixation according to claim 1, wherein: In step (4), the hot pressing conditions are: 120° C., 0.5 MPa, 30 s.

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