Closed type device for nail path wound and preparation method of dressing filled with closed type device

Abstract

The invention discloses a closed device for a nail path wound and a preparation method of a dressing filled with the closed device, and belongs to the technical field of biological materials and medical dressings. According to the technical scheme, the closed dressing for the hole-shaped wound comprises two sets of shells which are symmetrically arranged, the tail portions of the two sets of shells are hinged through a rotating shaft, a torsional spring is arranged between the tail portions of the two sets of shells, sealing pieces are arranged on the inner sides of the head portions of the two sets of shells, and the two sets of sealing pieces are matched with each other. Semicircular holes which are matched with each other are formed in the inner sides of the tops of the two groups of sealing pieces, skirt edges are arranged on the outer sides of the bottoms of the two groups of sealing pieces, and antibacterial dressings are arranged in the two groups of sealing pieces; according to the preparation method, the internal antibacterial dressing is prepared by alternately immersing the polyurethane sponge matrix into a zinc ion solution and a sodium alginate solution for multiple times of cross-linking for a short time, and performing a freeze drying method. The dressing change is convenient, the operation is simple, the wound can be closed, the infection probability is reduced, and the nursing efficiency and the nursing effect are effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of biomaterials and medical dressings, and in particular relates to a closed device for nail tract wounds and a preparation method of a dressing filled therein. Background Art

[0002] Every year, 180 million new fractures occur worldwide. External fixation of fractures and bone traction surgery are common orthopedic surgeries, which require bone needles to penetrate the bone marrow to form a mechanical fixation point to achieve fracture healing or traction of the fracture ends. This process will form a nail track wound that lasts up to 2-3 months. Because the nail track wound is deep into the bone marrow cavity and remains open, the literature reports that the infection rate of the wound is 30-80%, and severe cases may develop osteomyelitis and lead to disability. In addition, infection may also cause bone screws to loosen, increase the risk of fixation failure, prolong hospitalization, and significantly increase medical costs. Therefore, nail track wound treatment has become a global problem plaguing the field of orthopedics.

[0003] At present, the common method for treating nail tract wounds is to wrap them with gauze after debridement, that is, to wrap the gauze around the nail tract. The existing technology has at least the following problems: first, it is impossible to effectively prevent bacteria from invading the wound, and wound infection cannot be prevented; second, the gauze and the nail tract wound are easily adhered and scabbed, resulting in the inability to effectively discharge the inflammatory exudate deep in the wound, increasing the probability of deep infection; third, it is difficult to change the dressing, the patient is in obvious pain, and it is difficult, time-consuming and labor-intensive for medical staff to deal with it. In addition, the unique pathophysiological characteristics of nail tract wounds make it easy for pathogenic bacteria such as Staphylococcus aureus to form biofilms inside, resulting in persistent and aggravated infections, and triggering severe local and systemic inflammatory reactions. This not only increases the incidence of complications, but can even lead to disability and endanger life.

[0004] Therefore, it is necessary to develop a closed device suitable for nail tract wounds to solve the key problems in nail tract wound care. Summary of the invention

[0005] The present invention provides a closed device for nail tract wounds and a method for preparing its internal dressing, which realizes the synergy of special pathophysiological treatment requirements of nail tract wounds and active and passive synergistic antibacterial enhancement, and can not only effectively prevent and control bacterial invasion of nail tract wounds, but also effectively prevent and control the accumulation of inflammatory exudate deep in the wound. The closed device can also significantly weaken the virulence of pathogens, with high wound treatment efficiency and no secondary damage. It is expected to provide a novel solution for nail tract wound management, significantly improve the treatment effect of patients, and reduce the consumption of medical resources.

[0006] The technical solution of the present invention is:

[0007] In the first aspect, a closed device for nail tract wounds is disclosed, comprising two symmetrically arranged groups of shells, the tails of the two groups of shells are hinged by a rotating shaft, a torsion spring is provided between the tails of the two groups of shells, the inner sides of the heads of the two groups of shells are provided with sealing parts, the two groups of sealing parts cooperate with each other, the inner sides of the tops of the two groups of sealing parts are provided with semicircular holes that cooperate with each other, the outer sides of the bottoms of the two groups of sealing parts are provided with skirts, and the interiors of the two groups of sealing parts are provided with active and passive synergistic antibacterial dressings.

[0008] Preferably, the inner side of the shell head is in a "C" shape, which can form a stable support frame, and press the sealing member when closed to prevent leakage. A plug plate is provided on the inner side of the shell head, and a slot matching the plug plate is provided on the sealing member. By providing the plug plate and the slot, the stability and sealing of the connection between the shell and the sealing member can be ensured.

[0009] Preferably, the skirt edge is tilted downward, which can further improve the fit between the skirt edge and the skin.

[0010] Preferably, a patch is horizontally provided on the inner side of the bottom of the sealing member. By providing the patch, firstly, it can cooperate with the skirt to further improve the fit between the bottom of the sealing member and the skin, reducing the probability of infection caused by bacteria entering the wound; secondly, it can support and fix the antibacterial dressing.

[0011] Preferably, a groove is provided on the inner wall of the sealing member, and by providing the groove, the thickness of the sealing member can be reduced, the softness can be increased, and the skirt can fit the skin. The tails of the two sets of shells are both rotatably provided with a handle, and by providing the handle, it is convenient for medical staff to open the two sets of shells.

[0012] In a second aspect, a method for preparing the antibacterial dressing is disclosed. The antibacterial dressing is prepared by alternately immersing a polyurethane sponge matrix in a zinc ion solution and a sodium alginate solution for short-term multiple cross-linking and then freeze-drying.

[0013] Preferably, the method for preparing the dressing comprises the following steps:

[0014] 1) Immerse the polyurethane sponge in the sodium alginate solution, let it stand, and squeeze out the residual sodium alginate on the surface of the sponge;

[0015] 2) After being immersed in a zinc chloride solution and allowed to stand, it is immersed in a prepared sodium alginate solution and allowed to stand again;

[0016] 3) Repeat step 2), finally put into zinc chloride solution and place in a shaker for reaction, and freeze-dry to obtain an antibacterial dressing.

[0017] Preferably, the standing time in step 1) is 2-5 min.

[0018] Preferably, in step 2), the time for a single immersion in the zinc chloride solution is 10-20 seconds, the time for a single immersion in the sodium alginate solution is 10-20 seconds, and the number of repetitions in step 3) is 3-6 times.

[0019] Preferably, the concentration of sodium alginate is 0.01-0.02 g / mL, the concentration of zinc ions is 8-20 mg / mL, the shaking reaction temperature in step 3) is 37° C., and the reaction time is 2-6 h.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The closed device of the present invention is based on the principle of "sealing above and guiding below". Through the combination of physical barriers and active and passive bactericidal materials, it achieves the blocking of external pathogens and the efficient management of internal inflammatory exudate. The sodium alginate-zinc ion gel layer is passive bactericidal, and the zinc ions are active bactericidal. It is convenient for dressing change and simple to operate, and it can seal the wound and reduce the probability of infection. It effectively improves the nursing efficiency and effect, and significantly solves the treatment problem of nail tract wounds under the complex pathophysiological characteristics.

[0022] 2. The closed device for nail tract wounds of the present invention can form a clamp structure by providing a shell, a rotating shaft and a torsion spring, which is convenient for medical staff to manually open and install. After releasing the hands, under the action of the torsion spring rotating shaft, the two groups of shells can clamp the fracture external fixation needle or drainage tube to prevent it from falling off; by providing a sealing member, it can cooperate with the shell to form a cavity, which can be covered on the hole-shaped wound for protection and fix the antibacterial dressing. The two groups of sealing members can also be opened with the corresponding shells for easy installation, and can form a closed cavity when the two groups of shells are closed; by providing a semicircular hole, it can cooperate with each other to form a complete circular hole, so as to stably clamp the fracture external fixation needle or drainage tube, which can effectively seal the connection and reduce the probability of infection caused by bacteria entering the wound, and will not have adverse effects on the fracture external fixation needle or drainage tube; by providing a skirt, it can cooperate with each other to form a suction cup-like structure, which can fully fit the skin to achieve a closed effect; by providing an antibacterial dressing, it can continuously absorb blood and tissue fluid exuded from the wound, reducing the number of wound immersion and dressing replacement.

[0023] 3. The closed device for nail wounds of the present invention has efficient bacterial barrier and exudate management capabilities: the closed device forms the first physical barrier by designing the shell, effectively blocking the invasion of external pathogens, and at the same time, combined with the internal active sterilization material, further improving the prevention and control capabilities. The dressing uses a hydrophilic material with polyurethane sponge as the base, and through instantaneous multiple coating technology, a more stable three-dimensional network structure is formed, which can more efficiently absorb and discharge the inflammatory exudate of the wound, significantly reduce the inflammatory response, and prevent the spread of infection to the deep bone marrow cavity.

[0024] 4. The closed device for nail tract wounds of the present invention has significant antibacterial and virulence inhibition effects: the closed device has an antibacterial rate of up to 90% against Escherichia coli and Staphylococcus aureus, a bacterial blocking efficiency of more than 95%, and an exudate absorption rate that is several times that of traditional gauze. In in vivo experiments, the closed device significantly reduced local inflammation, reduced bacterial load and Staphylococcus aureus abundance, and increased the diversity and richness of health-related flora.

[0025] 5. The present invention adopts instantaneous multiple cross-linking technology, which is different from the traditional method of curing into a gel after a one-time cross-linking reaction. Instantaneous multiple cross-linking refers to the continuous or multiple introduction of zinc ions during the gel formation process, aiming to enhance the cross-linking density of the gel network, thereby constructing a more stable three-dimensional network structure.

[0026] 6. The closed device for nail tract wounds of the present invention has good clinical transformation and economic efficiency: The design of the closed device fully considers the patient's comfort and clinical ease of use, realizes painless replacement, simple and rapid, and significantly reduces the infection risk and patient pain in medical operations. Its simple and practical design makes the closed device have good clinical transformation potential, and the cost is relatively low, which is expected to be widely used in clinical practice to reduce the consumption of medical resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural diagram of the carrier surface and a schematic diagram of the application of the closed device for treating dry nail channel wound injuries of the present invention.

[0028] Figure 2 The three-dimensional closed device for nail channel wound of the present invention is Figure 1 .

[0029] Figure 3 The three-dimensional closed device for nail channel wound of the present invention is Figure 2 .

[0030] Figure 4 It is a schematic diagram of the shell and the sealing member in the closed device for nail channel wounds of the present invention.

[0031] Figure 5 The figure is an exploded schematic diagram of the shell and the sealing member in the sealed device for nail channel wounds of the present invention.

[0032] Figure 6 These are surface morphologies of the polyurethane (PU) of the present invention, the ZAPU prepared in Example 1, the ZAPU-L prepared in Comparative Example 2, and the SAPU prepared in Comparative Example 1.

[0033] Figure 7 It is the zinc ion release graph of the polyurethane (PU) of the present invention, the ZAPU prepared in Example 1, the ZAPU-L prepared in Comparative Example 2, and the SAPU prepared in Comparative Example 1.

[0034] Figure 8 This is a graph showing the water absorption results of the gauze of the present invention, PU, ​​SAPU prepared in Comparative Example 1, and ZAPU prepared in Example 1.

[0035] Fig. 9 This is a graph showing the porosity results of the PU of the present invention, the SAPU prepared in Comparative Example 1, and the ZAPU prepared in Example 1.

[0036] Fig.10 It is a graph showing the transmittance results of the PU of the present invention, the SAPU prepared in Comparative Example 1, the ZAPU prepared in Example 1 and the blank control group.

[0037] Fig.11 The results of the in vitro antibacterial properties of the PU of the present invention, the SAPU prepared in comparative example 1, the ZAPU prepared in example 1 and the blank control group are shown.

[0038] Fig.12 The graph shows the in vitro antibacterial performance results of the PU of the present invention, the SAPU prepared in comparative example 1, the ZAPU prepared in example 1, and the blank control group.

[0039] Fig.13 This is a graph showing the results of the biosafety test (cytotoxicity a, hemolyticity b) of the ZAPU dressing prepared in Example 1 of the present invention.

[0040] Fig.14 These are pictures of the nail tract wounds of the gauze group and the closed device group of the present invention on the 7th and 14th days of the porcine nail tract infection (PSI) model.

[0041] Fig.15 CT imaging was performed for the nail tract and bone structure of the gauze group and the closed device group in the porcine nail tract infection (PSI) model of the present invention after 14 days.

[0042] Fig.16 Graph showing the soft tissue and medullary cavity of the gauze group and the closed device group in the porcine nail tract infection (PSI) model of the present invention after 14 days.

[0043] Fig.17 Graph showing the levels of systemic inflammatory markers in the gauze group and the closed device group in the porcine nail tract infection (PSI) model of the present invention.

[0044] Fig.18 This is a diagram showing the histological analysis results of gauze and a closed device in the porcine nail tract infection (PSI) model of the present invention.

[0045] Fig.19 This is a diagram showing the results of immunohistochemical staining of IL-1β in the porcine nail infection (PSI) model of the present invention to evaluate the inflammatory response of the nail tract.

[0046] Fig. 20 Representative images of bacterial colonies on agar plates from samples collected from the nail tract wound sites of the gauze group and the closed device group in the porcine nail tract infection (PSI) model of the present invention on the 7th and 14th days.

[0047] Fig.21 The classification composition of the nail tract wound microbiota at the genus level in the gauze group and the closed device group in the porcine nail tract infection (PSI) model of the present invention on the 14th day was analyzed based on 16S rRNA sequencing.

[0048] Fig. 22 The gauze group in the porcine nail infection (PSI) model of the present invention has a microbial composition at the genus level of prominent pathogens.

[0049] Fig.23 The microbial composition at the genus level of the closed device group in the porcine nail infection (PSI) model of the present invention.

[0050] Fig.24 A graph showing the microbial diversity results of the gauze group and the closed device group in the porcine nail infection (PSI) model of the present invention.

[0051] Fig.25 A graph showing the results of Simper analysis of the gauze group and the closed device group in the porcine nail tract infection (PSI) model of the present invention.

[0052] Fig.26 A graph showing the results of T-test analysis of the gauze group and the closed device group in the porcine nail tract infection (PSI) model of the present invention.

[0053] Fig. 27 Surface morphology of the dressing prepared in Comparative Example 3 of the present invention.

[0054] Fig.28 Surface morphology of the dressing prepared in Comparative Example 4 of the present invention.

[0055] In the figure, 1 is a shell; 2 is a rotating shaft; 3 is a sealing part; 4 is a semicircular hole; 5 is a semicircular opening; 6 is a skirt; 7 is a plug-in board; 8 is a slot; 9 is a patch; 10 is a groove; 11 is a handle; and 12 is a torsion spring. DETAILED DESCRIPTION

[0056] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0057] The structure diagram and application diagram of the closed device for dry nail channel wound injury are as follows Figure 1 shown.

[0058] The closed device for nailing wounds has a specific structure as follows Figures 2 to 5 As shown, it includes two groups of shells 1 arranged symmetrically, the shells 1 are made of hard material, the tails of the two groups of shells 1 are hinged by a rotating shaft 2, and the two groups of shells 1 are closed by a compressed torsion spring 12 after the tails of the two groups of shells 1 are hinged together, and the inner sides of the heads of the two groups of shells 1 are provided with sealing parts 3, and the sealing parts 3 are made of soft material. The two groups of sealing parts 3 cooperate with each other, and the inner sides of the tops of the two groups of sealing parts 3 are provided with semicircular holes 4 that cooperate with each other, and the bottoms of the two groups of sealing parts 3 are provided with semicircular openings 5 ​​that cooperate with each other, and the outer sides of the semicircular openings 5 ​​are provided with skirts 6, and the interiors of the two groups of sealing parts 3 are provided with antibacterial dressings.

[0059] By providing the shell 1, the rotating shaft 2 and the torsion spring 12, a clamp structure can be formed, which is convenient for medical staff to manually open for installation. After releasing the hand, under the action of the torsion spring 12, the two groups of shells 1 can clamp the fracture external fixation needle or drainage tube to prevent it from falling off; by providing the sealing member 3, it can cooperate with the shell 1 to form a cavity, which can be covered on the hole-shaped wound for protection and fix the antibacterial dressing. The two groups of sealing members 3 can also be opened with the corresponding shell 1 for easy installation, and can form a closed cavity when the two groups of shells 1 are closed; by providing the semicircular hole 4, it can cooperate with each other to form a complete circular hole, so as to stably clamp the fracture external fixation needle or drainage tube, which can effectively seal the connection and reduce the probability of infection caused by bacteria entering the wound, and will not have adverse effects on the fracture external fixation needle or drainage tube; by providing the skirt 6, it can cooperate with each other to form a suction cup-like structure, which can fully fit the skin to achieve a closed effect; by providing the antibacterial dressing, it can continuously absorb the blood and tissue fluid exuded from the wound, reducing the number of wound immersion and dressing replacement.

[0060] like Figures 2 to 5 As shown, the inner side surface of the head of the housing 1 is in a "C" shape, which can form a stable support frame and press the closure member 3 when closed to prevent leakage.

[0061] like Figure 5 As shown, a plug plate 7 is provided on the inner side of the head of the housing 1, and a slot 8 matching with the plug plate 7 is provided on the sealing member 3. By providing the plug plate 7 and the slot 8, the stability and sealing of the connection between the housing 1 and the sealing member 3 can be ensured.

[0062] like Figures 2 to 5 As shown, the skirt edge 6 is tilted downward, which can further improve the fit between the skirt edge 6 and the skin.

[0063] like Figure 4As shown, a patch 9 is horizontally arranged on the inner side of the bottom of the sealing member 3. The patch 9 can cooperate with the skirt 6 to further improve the adhesion between the bottom of the sealing member 3 and the skin, reducing the probability of infection caused by bacteria entering the wound; and can support and fix the antibacterial dressing.

[0064] like Figure 4 As shown, a groove 10 is provided on the inner side wall of the sealing member 3. By providing the groove 10, the thickness of the sealing member 3 can be reduced, the softness can be increased, and the fitting effect between the skirt 6 and the skin can be improved.

[0065] like Figure 2 and Figure 3 As shown, the tails of the two sets of shells 1 are both rotatably provided with handles 11. By providing the handles 11, it is convenient for medical staff to open the two sets of shells 1.

[0066] When in use, the antibacterial dressing uses the antibacterial dressing ZAPU prepared in Example 1. The medical staff opens the two sets of shells 1 through the handle 11, and the two sets of shells 1 drive the two sets of sealing parts 3 to open. Then, the two sets of antibacterial dressings ZAPU are respectively placed in the two sets of sealing parts 3 and placed above the patch 9, so that the bottom of the antibacterial dressing ZAPU is placed in the groove, and the tops of the two sets of antibacterial dressings ZAPU correspond to each other; then the two sets of sealing parts 3 are located on both sides of the fracture external fixation needle or drainage tube, so that the fracture external fixation needle or drainage tube corresponds to the semicircular hole 4, and then the patch 9 and the skirt 6 are pressed down to fully fit the skin, and the handle 11 is released. Under the action of the torsion spring 12 and the rotating shaft 2, the shell 1 drives the sealing part 3 to merge the two sets of semicircular holes 4. Clamp the fracture external fixation needle or drainage tube, and the tops of the two sets of antibacterial dressings ZAPU surround the fracture external fixation needle or drainage tube, which can continuously absorb the exuded blood and tissue fluid, reduce wound immersion and the number of replacements.

[0067] Example 1

[0068] The preparation method of the antibacterial dressing ZAPU comprises the following steps:

[0069] 1) Immerse a polyurethane sponge (PU, purchased from Silikang Medical Materials (Tianchang) Co., Ltd.) in a dissolved sodium alginate (SA, purchased from Qingdao Juda Seaweed Industry Group Co., Ltd.) solution (viscosity 80 mPas, 0.01 g / mL), let it stand for 5 minutes, and gently squeeze out the sodium alginate remaining on the surface of the sponge;

[0070] 2) The polyurethane sponge with sodium alginate was immersed in a zinc chloride (Sigma-Aldrich, USA) solution (12 mg / mL) for 10 seconds, and then immersed in a prepared sodium alginate solution (viscosity 80 mPas, 0.01 g / mL) and allowed to stand for 10 seconds;

[0071] 3) After repeating step 2) three times, the mixture was finally placed in a zinc chloride solution (12 mg / mL) and placed in a shaker at 37° C. to react for 2 hours. The antibacterial dressing ZAPU was obtained after freeze-drying.

[0072] Comparative Example 1

[0073] The preparation method of dressing SAPU is as follows: directly immerse the polyurethane sponge PU in a sodium alginate solution (viscosity of 80 mPas, 0.01 g / mL) and place it in a shaker at 37°C to react for 2 hours, and then freeze-dry to obtain the dressing SAPU.

[0074] Comparative Example 2

[0075] The preparation method of dressing ZAPU-L is as follows: the polyurethane sponge PU is first immersed in a zinc ion solution (12 mg / mL) and then directly added with a sodium alginate solution (viscosity 80 mPas, 0.01 g / mL), and placed in a shaker at 37°C to react for 2 hours, and then freeze-dried to obtain the dressing ZAPU-L.

[0076] Comparative Example 3

[0077] The difference from Example 1 is that step 2) is to immerse the dressing in a zinc chloride solution (12 mg / mL) for 20 seconds and then immerse it in the prepared sodium alginate solution for 20 seconds; the rest is the same as Example 1, and the surface morphology of the prepared dressing is as follows Fig. 27 As shown, the open-pore structure inside the dressing sponge showed a gelled wrinkled state with unclear layers.

[0078] Comparative Example 4

[0079] The difference from Example 1 is that in step 3), "repeat step B) three times" is changed to "repeat step B) once". The rest is the same as Example 1. The surface morphology of the prepared dressing is as follows: Fig.28 As shown, the morphology and structural integrity of the sponge were not affected and exhibited open cell structure and soft foam characteristics similar to those of the base sponge.

[0080] The antibacterial dressing prepared in Example 1 and the dressing prepared in Comparative Examples 1-2 were subjected to physical and chemical property characterization and biological performance testing, as follows:

[0081] The pore structure changes of the antibacterial dressing ZAPU prepared in Example 1, the dressing ZAPU-L prepared in Comparative Example 2, the dressing SAPU prepared in Comparative Example 1 and the polyurethane sponge PU were observed by scanning electron microscopy to confirm the uniformity of the coating and the integrity of the porous structure. The results are as follows: Figure 6As shown in the figure, it can be seen that the polyurethane sponge PU and the ZAPU prepared in Example 1 both exhibit porous and interconnected structures, and the ZAPU prepared in Example 1 maintains good porous properties after modification, and a gelled wrinkled structure appears on the surface, that is, the sodium alginate-zinc ion gel layer adheres to the sponge surface after freeze-drying to form an uneven interface. Compared with the blended cross-linked ZAPU-L prepared in Comparative Example 2, the pore structure of the ZAPU prepared in Example 1 is more stable and has clear layers. The internal open pore structure of the SAPU prepared in Comparative Example 1 is loose, the layers are unclear, and the sodium alginate is easy to block the sponge diameter after drying.

[0082] The zinc ion release performance of the antibacterial dressing ZAPU prepared in Example 1, the dressing ZAPU-L prepared in Comparative Example 2, the dressing SAPU prepared in Comparative Example 1, and the polyurethane sponge PU were investigated. Specifically, the zinc ions in the sample and the color developer 5-Br-PADAP in the reagent were used as the Elabscience Zinc (Zn) Colorimetric Assay Kit. The zinc ions in the sample and the color developer 5-Br-PADAP in the reagent can form a colored complex, and the color depth is proportional to the zinc ion concentration. Dilute with deionized water, mix the extracts of ZAPU, ZAPU-L, SAPU and PU with reagent 2 (protein precipitant) in a volume ratio of 1:1, centrifuge at 4°C and a centrifugal force of 13780 for 10 minutes, and take the supernatant for testing. Add the color developer, use an enzyme marker (545-575nm) to measure the OD value, and then follow the formula provided in the test kit, (concentration (μmol / L) = (ΔA 560-b )÷a×2 * ×f; where y = 0.01534x-0.00139, R 2 =0.9997; y: OD value of standard well - OD value of blank well (OD value when standard concentration is 0), x: concentration of standard, a: slope of standard curve, b: intercept of standard curve, f: dilution multiple of sample before adding to detection system, 2*: dilution multiple of sample during pretreatment) to calculate the zinc ion concentration. Test results are as follows Figure 7 As shown in the figure, it can be seen that the zinc ion release performance of the antibacterial dressing ZAPU prepared in Example 1 increases with the extension of the immersion time, and the release amount of zinc ions gradually increases, indicating that the antibacterial dressing ZAPU prepared in Example 1 can achieve slow and continuous zinc ion release and enhance the antibacterial effect. Compared with the ZAPU-L dressing prepared in Comparative Example 2, the short-term and multiple modifications of gelation can achieve long-term continuous release of zinc ions. No zinc ions were added to PU and SAPU, and the release amount in each time period was 0.

[0083] The water absorption capacity of wound dressings is an important property for evaluating the effectiveness of wound exudate cleaning. An ideal wound dressing should maintain wound moisturization while effectively preventing excessive exudate from accumulating on the wound surface.

[0084] The water absorption of commercially available gauze (Guaze for short), polyurethane sponge PU, dressing SAPU prepared in comparative example 1, and antibacterial dressing ZAPU prepared in example 1 was measured, and the water absorption can be evaluated according to the YY / T0471.1-2004 method. The gauze, PU, ​​SAPU and ZAPU dry samples used for measurement were weighed in triplicate, then immersed in phosphate buffered saline (PBS, pH=7.4), and finally placed in an oven at 37°C for 10 minutes. After standing for 30 seconds, the sample taken out with tweezers was weighed until the droplet formation stopped, and the water absorption capacity of the sponge was calculated according to the formula.

[0085]

[0086] Where: m1-initial mass of sponge, g; M2-mass of sponge after absorbing water, g. Test results are as follows Figure 8 The weight of gauze after absorption is 1.2 times of its dry weight, while the weight of ZAPU prepared in Example 1 after absorption is 15 times of its dry weight, which is significantly higher than that of gauze, and the absorption capacity is not weakened after modification, and is also increased compared with the weight of PU and SAPU after absorption. This shows that ZAPU prepared in Example 1 has a very strong liquid absorption capacity.

[0087] Porosity usually affects the performance of biomaterials, including liquid absorption, water retention and water vapor permeability. The porosity of polyurethane sponge PU, dressing SAPU prepared in Comparative Example 1 and antibacterial dressing ZAPU prepared in Example 1 was measured by liquid volume displacement method, weighing the sample and measuring and calculating its volume (cylindrical, radius r is about 1.1 cm, thickness h is about 0.5 cm), weighing its mass, recording it as W1, and placing it in anhydrous ethanol and soaking it for 5 minutes to fully absorb anhydrous ethanol. Then take the sample out of the anhydrous ethanol, gently absorb and wipe off the excess anhydrous ethanol, and immediately weigh and record the mass W2. The porosity of the sample is calculated using the following formula:

[0088]

[0089] Where W1 and W2 are the initial weight and final weighing weight of the sponge sample, respectively. The porosity was calculated based on three parallel sample tests and expressed as the arithmetic mean and standard deviation (M±SD, n=3). The test results are shown in Fig. 9As shown, the results show that the porosity of ZAPU prepared in Example 1 is 83.14±0.3%, which is higher than 80.96±1.3% of PU and 80.10±0.5% of SAPU prepared in Comparative Example 1, indicating that the short-term multiple modification method increases the interconnectivity of the pores, and the interconnected pores increase the specific surface area of ​​the sponge, allowing the pores to absorb more ethanol, thereby increasing the measured porosity. Combined with scanning electron microscope (SEM) images Figure 6 Analysis shows that the ZAPU prepared in Example 1 exhibits a regular and complete porous structure, which provides the advantage of efficient absorption of exudate for its application in wound dressings.

[0090] An ideal wound dressing should maintain wound moisturization while effectively preventing excessive exudate from accumulating on the wound surface. A certain degree of moisture and gas permeability through the wound dressing is important for preventing excessive dehydration of the wound and accumulation of exudate. Therefore, an appropriate water vapor permeability (WVTR) is also particularly important. The permeability of the antibacterial dressing ZAPU prepared in Example 1, the SAPU dressing prepared in Comparative Example 1, and the PU were measured, and the water vapor permeability (WVTR) of the dressing was measured according to YY / T0471.2-2004. First, a certain amount of pure water was added to the centrifuge tube, and the sponge dressings ZAPU, SAPU and PU prepared in Example 1 were cut into uniform shapes and placed at the mouth of the centrifuge tube, and then the device was placed in a constant temperature box at 37°C. After different time periods, the specific formula for measuring the volume change was as follows:

[0091]

[0092] Where: m0-initial mass of the centrifuge tube containing sponge and water, g;

[0093] m t -The mass of the entire device after time t, g;

[0094] S-the area of ​​the centrifuge tube orifice, mm;

[0095] t-the number of days the whole device is placed in the constant temperature incubator, d; the control group is the blank group, that is, the bottle mouth is not covered with any dressing. Fig.10 The results show that the water vapor permeability (WVTR) of the ZAPU prepared in Example 1 is 2875.4 g·m 2 / day, which was significantly lower than that of the blank group (14708.9 g·m 2 / day), reducing water loss by 80.45%. Compared with PU and SAPU prepared in Comparative Example 1, ZAPU prepared in Example 1 maintains an ideal water vapor permeability, which helps to regulate the moisture of the wound and avoid excessive dehydration.

[0096] In vitro antibacterial performance investigation: The colony counting method was used, and the culture medium with only Staphylococcus aureus and Escherichia coli was used as the control group to evaluate the antibacterial activity of polyurethane sponge PU, dressing SAPU prepared in comparative example 1, and antibacterial dressing ZAPU prepared in example 1 against Escherichia coli and Staphylococcus aureus. PU, SAPU, and ZAPU sponges were cut into a cylinder with a height of 5 mm and a diameter of 20 mm, and sterilized by ultraviolet for 30 minutes. 4 mL of PBS was added to the sterilized sponge for full soaking, and then 200 uL of Staphylococcus aureus and Escherichia coli solutions (10 6 CFU / mL) at 37℃ for 2h. After the incubation is completed, dilute the bacterial solution and take 100uL of the bacterial solution to spread on the agar plate. After incubation at 37℃ for 24h, observe the colonies on the agar plate and take pictures. Fig.11 As shown, the active bactericidal performance of the ZAPU dressing prepared in Example 1 was evaluated by colony counting experiments. Compared with the blank control group, the inhibition rates of PU and SAPU prepared in Comparative Example 1 on Staphylococcus aureus were 8.5% ± 1.0 and 30.2% ± 2.0, respectively, and the inhibition rates on Escherichia coli were 11.25% ± 0.9 and 36.36% ± 1.9, respectively. The antibacterial effect of ZAPU prepared in Example 1 was significantly better than both, and the inhibition rates on Staphylococcus aureus (90.23% ± 0.5) and Escherichia coli (91.23% ± 1.2) showed excellent effects, which was mainly attributed to the inhibitory effect of zinc ions on bacterial biofilms and their metabolic interference.

[0097] In order to test the in vitro bacterial barrier performance of the ZAPU combined hard shell prepared in Example 1, the bacterial barrier effects of the polyurethane sponge PU, the dressing SAPU prepared in Comparative Example 1, and the antibacterial dressing ZAPU combined hard shell prepared in Example 1 (the hard shell is the part of the closed device for nail channel wounds that does not include the dressing) were evaluated. The specific method is: a cylindrical dressing sponge with a height of 10 mm and a diameter of 22 mm was sterilized by ultraviolet for 30 minutes, then embedded in a rubber shell, and sterilized by ultraviolet again. Then, it was placed in an acrylic cylinder with a diameter of 25 mm and a height of 15 mm. A hyaluronic acid air filter membrane (HAFM) with a diameter of 22 mm was placed on a clean transparent plate. It should be noted that HAFM is a porous filter membrane constructed by an ethanol-induced phase separation strategy (a porous filter membrane for efficient capture and instant quantitative detection of air pathogens prepared in Example 1 of Patent 202410540252.7). The bottom of the cylinder was in contact with the filter membrane (but not with the polyurethane sponge). The aerosol bottle (containing Staphylococcus aureus (S. aureus, ATCC29213) and Escherichia coli (E. coli, ATCC8739) bacterial solution, (1×10 4CFU / L, 5mL) nozzle covered the acrylic cylinder, aimed at the above dressing sponge, and sprayed for 30 seconds. After the end, let it stand for 1 minute, take out the HAFM and place it in the LB culture dish for 30 seconds, wait for the membrane to dissolve, then spread the plate. After incubation at 37℃ for 24 hours, observe the colonies on the agar plate and take pictures. Fig.12 As shown. Regarding the passive antibacterial performance of the closed device (PINSHIELD for short), the experimental results show that the closed device has a bacteria blocking rate of up to 99% for Staphylococcus aureus and Escherichia coli, which is significantly better than traditional gauze dressings. The first layer of physical barrier of the closed device effectively prevents the invasion of exogenous bacteria, but due to the short-term test, the antibacterial factors in the functional inner layer have not yet played a bactericidal role, and only a very small number of bacteria pass through the gaps to enter the bottom filter membrane and colonize. However, because the pores of gauze are too large and it is difficult for bacteria to attach, the bacteria blocking effect on Staphylococcus aureus is 20%±0.4, and the bacteria blocking effect on Escherichia coli is only 16.8%±1.6.

[0098] Biocompatibility is the basic premise for the clinical transformation of wound dressings. In order to test the biocompatibility of the antibacterial dressing ZAPU prepared in Example 1, we conducted cytotoxicity test and hemolysis test.

[0099] The cytotoxicity of the dressing was evaluated by CCK-8 method. L929 cells were cultured in DMEM medium containing 10% fetal bovine serum and double antibody. ZAPU prepared in Example 1 was immersed in high-glucose medium DMEM for 24 hours, and the sponge extract was obtained after filtration using a 0.22 μm filter membrane (Sartorius, Germany). Then, the extract was diluted to 0.25, 0.5, 0.75 and 1 mg / mL. The L929 cell concentration was adjusted to 5×10 4 cells / mL, 100μL per well was inoculated in a 96-well plate, and after the cells adhered to the wall, the sponge extract of different concentrations was replaced, and then 100μL of sponge extract was used to replace the culture medium and continued to culture for 24h and 72h. After the corresponding culture time, the original culture medium was aspirated, and 100μL of CCK-8 detection solution (CCK-8: DMEM culture medium = 1:9) was added to each well, incubated at 37℃ for 2h, and the OD value was measured at 450nm using an enzyme marker. The calculation formula of cell proliferation rate is as follows:

[0100]

[0101] OD1 and OD0 represent the absorbance values ​​of the experimental object and the negative control, respectively.

[0102] Test results such as Fig.13 As shown in (a), the results showed that compared with the control group, each concentration group had no effect on cell activity and there was no statistical difference.

[0103] Hemolysis experiment: The polyurethane sponge PU, SAPU and the dressing ZAPU prepared in Example 1 were evaluated for hemolysis using anticoagulated whole blood from New Zealand white rabbits. Red blood cells were obtained by centrifuging whole blood at 1500 rpm for 15 minutes and then washed in PBS until the supernatant was colorless. 1 mL of red blood cells was added to 9 mL of sterile PBS and mixed to prepare a red blood cell suspension. Subsequently, 1 mg of the sample was added to 1 mL of diluted blood as the experimental group and then diluted. The red blood cells were added to deionized water and PBS as the positive control and negative control, respectively. After incubation at 37°C for 1 hour, all groups were centrifuged at 2000 rpm for 5 minutes. The absorbance of the supernatant at 540 nm was measured using a UV-visible spectrophotometer. The hemolysis ratio (HR) of the dressing sponge was calculated according to the following formula (5).

[0104]

[0105] OD S Indicates the absorbance of the dressing, OD (+) Indicates the absorbance of positive samples, OD (-) Indicates the absorbance of negative samples. The hemolysis rate of wound dressings is less than 2%, which is the minimum standard for the clinical application of biomedical materials. Fig.13 (b) As shown. The results showed that the extract of ZAPU prepared in Example 1 released from the dressing had no significant effect on the viability of L929 cells, proving that it has good biocompatibility. In addition, through live and dead cell staining and hemolysis tests, the hemolysis rates of PU and SAPU were 0.21% ± 0.05, 0.61% ± 0.1, respectively, and the hemolysis rate of ZAPU was 1% ± 0.1%, verifying its safety and meeting the clinical standards for medical materials.

[0106] A porcine pin tract infection (PSI) model was established to evaluate the bacterial barrier effect of the closed device and its effect on microorganisms. Adult boars (about 40 kg) with wound healing skin structure similar to that of humans were selected as experimental subjects. Anesthesia was induced with 4% sevoflurane and maintained with 2% sevoflurane and 1% oxygen. The hind limbs were shaved and sterile bone screws were inserted into the tibia using povidone-iodine, 70% ethanol and sterile bone screws. After the bone screws were inserted, Staphylococcus aureus (ATCC 25923) suspension (1×10^8 CFU / mL) was sprayed on the position of the bone screws to simulate contamination. The pigs were randomly assigned to the gauze group and the closed device group (abbreviated as PINSHIELD) and dressed separately. The animals were monitored daily for clinical infection symptoms and dressing changes were performed every three days. Vital signs including body temperature and weight were recorded daily. All animal experiments were approved by the Animal Protection Agency and the Qingdao University Use Committee, protocol number QDU-AEC-2024707. The experimental results, such as Fig.14As shown. In the nail tract infection model, on the 7th day, the nail tract in the gauze group was significantly enlarged, the surrounding skin showed obvious redness and swelling, and was accompanied by yellow purulent secretions, indicating that the infection was serious and may have spread to the deep tissue. This situation indicates that the infection has broken through the skin barrier and there is a risk of developing deep soft tissue infection or osteomyelitis. In contrast, the wound surface of the closed device group was clean, with only mild redness and swelling, and no obvious exudate, showing a significant effect in early infection control. By the 14th day, the infection in the gauze group further worsened, the redness and swelling of the skin around the nail tract intensified, the nail tract opening was significantly enlarged, the marginal tissue was congested and blackened, and the secretions were viscous and purulent in appearance, indicating that the infection spread and may be accompanied by the risk of osteomyelitis, highlighting the limitations of traditional gauze in the prevention and control of nail tract infection. In the closed device group, the wound healing signs were obvious, the redness and swelling almost completely subsided, and there was no abnormal secretion in the surrounding tissue, indicating that the infection was effectively controlled. This healing trend highlights the significant advantages of the closed device in the prevention and control of nail tract infection, showing that it may effectively reduce the occurrence of infectious complications in clinical applications.

[0107] CT imaging of the nail tract and bone structure was performed on the gauze group and the closed device group after 14 days. Specifically, after the bone screws were removed, the surrounding bone and tissue structures were evaluated using a dual-energy 128-slice CT scanner (GE Healthcare, USA) with the following parameters: 200 mA tube current, alternating tube voltage 140 kVp and 80 kVp, slice thickness 5 mm, pixel spacing 0.625 mm, DFOV 20 cm 2 The scans were repeated three times on average. The reconstructed images were analyzed using an aw4.7 workstation (GE) (US Healthcare). The images were stored and retrieved through a PACS system. The focus was on evaluating cortical integrity, density changes, and signs of osteomyelitis or abscess formation. CT images are shown in Figure 2. Fig.15 As shown, imaging and pathological examinations on the 14th day further confirmed the significant differences between the two groups. CT images of the gauze group showed that an inflammatory barrier or pseudomembrane formed in the nail channel after nail removal, accompanied by high-density signals, indicating inflammatory calcification deposition. The appearance of low-density foci outside the nail channel indicated tissue fluid exudation and pus formation, further supporting the diagnosis of osteomyelitis. In addition, the low-density signals in the bone marrow cavity around the nail channel and signs of loose nails indicated that the infection had spread to deep tissues, which may affect the stability and healing process of the bone. Relatively speaking, there were no abnormal signals or signs of inflammation in the bone tissue in the CT images of the closed device group, the nail channel was clean without abnormal density signals, the bone marrow tissue density was uniform, and the bone cortical edge was intact. These imaging results show that the closed device of the present invention effectively inhibits inflammatory response and tissue destruction in the prevention and control of nail channel infection.

[0108] MRI was performed on the soft tissue and medullary cavity of the gauze group and the closed device group after 14 days to measure the signal intensity using t2 weighting. Specifically: MRI scans were performed on a 3.0T MRI system (GE MR750, USA) using a multi-channel animal coil. The imaging sequence included t1 weighting (T1WI), t2 weighting (T2WI) and MENSA (multiple echoes acquired without subtraction) to enhance the detection of inflammatory areas. The parameters are as follows: TR = 3000ms, TE = 67.3ms, FOV = 1cm×1cm, slice thickness = 4mm, slice spacing = 4.5mm, matrix size = 96×128, SAR = 0.875, average = 2. The total imaging time for each sample was approximately 7 minutes and 50 seconds. The images were processed and stored in the PACS system for subsequent analysis, such as Fig.16 As shown in the figure. The MRI scans of the gauze group showed high signal intensity at the nail track site, indicating soft tissue infection extending from the bone marrow cavity, accompanied by patchy high signal areas, suggesting residual infection. Inflammatory pseudomembranes and low signal areas suggest the presence of gas gangrene. In contrast, the nail track site treated by the PINSHIELD group showed no abnormalities on CT or MRI, with clean nail tracks, uniform bone marrow density, and intact cortical bone.

[0109] The above evaluation of the bacterial barrier effect of the closed device and its impact on microorganisms was used to establish a porcine nail tract infection (PSI) model to investigate systemic inflammatory markers in the gauze group and the closed device group, including the white blood cell and neutrophil counts and cytokine (IL-6 and IL-1β) levels on the 7th day. Before dressing change / euthanasia, whole blood samples (10 mL) were collected using a disposable syringe for blood index evaluation. The samples were transported to the laboratory within 2 hours at 4°C using an Icebox for hematological analysis. The results are as follows Fig.17 As shown in the data, blood tests for systemic inflammatory indicators showed that on the 7th day, the white blood cell count, neutrophil count, and inflammatory factors (IL-6 and IL-1β) in the gauze group were significantly higher than those in the closed device group, indicating that the gauze group had an obvious systemic inflammatory response.

[0110] The gauze and the sealed device of the present invention were subjected to histological analysis using HE (hematoxylin-eosin staining) staining to evaluate inflammatory cell infiltration and tissue necrosis, including semi-quantitative analysis of bar graphs (scale bar = 1000 μm). The tissue specimens around the bone nail bundle were fixed with a tissue fixative (Servicebio, G1101-15ML) for 24 hours and dehydrated with a tissue processor (histore). Embedded in paraffin, sectioned (4 μm), and stained. Follow the standard protocol. Stain with hematoxylin and eosin, then dehydrated and coated with neutral balsam. The slides were examined using a Nikon ECLIPSE CI microscope (Nikon, Japan) with high-resolution imaging, and the results are shown in the figure. Fig.18HE staining showed that the tissue around the nail channel in the gauze group had a significant acute inflammatory reaction, manifested as a large number of inflammatory cell infiltration, fibrosis and partial tissue necrosis. In contrast, only a small number of inflammatory cells were observed in the closed device group by HE staining, indicating that the infection control was relatively ideal.

[0111] Immunohistochemical staining of IL-1β was used to evaluate the inflammatory response of the nail tract in the gauze group and the closed device group of the present invention. IL-1β is an important cytokine that plays an important role in immune and inflammatory processes. The accompanying semi-quantitative data are presented in bar graphs (scale bar = 1000 μm). To detect IL-1β, the tissue sections were dewaxed, rehydrated, and the antigen was extracted in citric acid buffer (pH = 6.0). After cutting off the endogenous peroxidase, the sections were blocked with serum and then incubated with the primary antibody IL-1β (Abmart, PK56359M, 1:100) at 4°C overnight. Then incubate with the secondary antibody (Bioss, bs-0295G-HRP, 1:200). DAB staining (Beyotime Biotechnology, P0203) was then performed. After counterstaining with hematoxylin, the sections were dehydrated and mounted and observed under a Nikon ECLIPSE CI microscope (Nikon, Japan), as shown Fig.19 As shown. The results of IL-1β IHC staining showed that the expression of IL-1β in the tissue around the nail channel in the gauze group was significantly upregulated, especially in the area of ​​active inflammation, where the number of IL-1β positive cells increased significantly, reflecting a strong immune response. In the PINSHIELD group, the expression level of IL-1β was lower and the inflammatory response was significantly reduced, indicating that the PINSHIELD group material effectively controlled the infection by reducing the expression of inflammatory factors.

[0112] Representative images of bacterial colonies on agar plates of samples collected from the gauze group and the closed device group at the 7th and 14th days of the porcine nail tract infection (PSI) model were used to evaluate the bacterial barrier effect of the closed device and its effect on microorganisms. The CFU quantification of the microbial load of the nail tract wound was investigated, and the bacterial growth between PINSHIELD and gauze on the 7th and 14th days was compared. Specifically, the tissue sample was minced and resuspended with 2 mL of PBS, the mass volume ratio of the tissue sample and PBS was 1:10, mixed evenly and spread on a solid agar plate. Incubate at 37°C for 12-16 hours, and the bacterial load was determined, specifically: the truncated pins were fixed in electron microscopy fixative (Sevier, G1102) and rinsed with phosphate buffer (PB, pH 7.4). After fixation with osmium acid, the dried samples were coated with gold in a critical point dryer (K850, Quorum) for 240 seconds using an ion sputtering device (MC1000, Hitachi) at an accelerating voltage of 15.00 kV. The formation of biofilms was observed using a scanning electron microscope (JSM-6390LV, Nihon Electronics, Japan). Fig. 20 As shown. On the 7th and 14th days, analysis of samples collected from the tissues surrounding the nail channel showed that the bacterial load in the gauze group was significantly higher than that in the PINSHIELD group. The CFU count results showed that the number of bacteria in the gauze group increased significantly, while the bacterial load in the PINSHIELD group remained at a low level, showing a relatively stable antibacterial effect. By the 14th day, the infection in the gauze group was further aggravated, indicating that the infection continued to worsen, while the bacterial load in the PINSHIELD group was relatively stable throughout the observation period, effectively inhibiting the progression of the infection.

[0113] The PINSHIELD group and the gauze group were compared, and the bacterial barrier effect of the closed device and its effect on microorganisms were analyzed based on 16S rRNA sequencing to establish the taxonomic composition of the microbiome of the nail tract wound at the 14th day in the porcine nail tract infection (PSI) model, such as Fig.21As shown. 16S rRNA sequencing and other microbial level tests were determined by Qingdao Boshang Biotechnology Co., Ltd. Microbial analysis used CTAB method to extract DNA and library construction, specifically: DNA was extracted from the tissue around the nail channel using CTAB lysis buffer and lysozyme. After centrifugation, the supernatant was mixed with phenol chloroform isopropanol, followed by chloroform-isoamyl alcohol treatment and isopropanol precipitation. DNA was washed, air-dried and dissolved in ddH2O, and RNase A was added for RNA digestion. PCR amplification was performed using the 16S rRNA V4 region to assess bacterial diversity. The library was constructed using the NEBNext Ultra II FSDNA PCR-free Library Prep Kit (New England Biolabs) and sequenced on the NovaSeq 6000 platform. Raw reads were assembled and aligned using FLASH (Version 1.2.11) (Magoc et al., 2011) for data quality control and denoising to generate tags. Low-quality reads were filtered using fastp software (Version 0.23.1) (Bokulich et al., 2012) and denoised using the DADA2 plugin in QIIME2 (Version 2022) to obtain high-quality amplicon sequence variants (ASVs). Bacterial taxonomic annotation and phylogenetic tree construction The Silva138.1 database was used for species annotation in QIIME2, and phylogenetic relationships were determined by sequence alignment.

[0114] Fig. 22 The pie chart shows the microbial composition of the gauze group at the genus level, highlighting the significant proportion of pathogenic genera. Fig.23 The pie chart shows the microbial composition of the PINSHIELD group at the genus level, showing an increase in beneficial genera and a decrease in pathogenic bacteria. Figure 21-23 As shown in the figure, it can be seen that PINSHIELD not only reduces the pathogenic bacterial load, but also enhances the diversity of beneficial microbiota. In particular, pathogenic genera such as Staphylococcus and Clostridium are less abundant in the PINSHIELD group, while health-related genera such as Actinomyces and Porphyromonas are significantly enriched ( Figure 22-23 ). These results highlight the potential of the PINSHIELD group to re-establish microbial community balance and promote a healthier wound environment.

[0115] Alpha diversity analysis was performed on the above PINSHIELD group and gauze group, such as Fig.24As shown, Alpha diversity analysis showed that the diversity of the PINSHIELD group was significantly higher than that of the gauze group, indicating that it had a more stable microbial composition. Fig.25 Simper analysis highlighted changes in the relative abundance of pathogenic bacteria and anti-infection genera. The PINSHIELD group significantly reduced the abundance of Staphylococcus aureus, while enriching genera with anti-infection capabilities, such as Porphyromonas and Bacteroides. Fig.26 T-test analysis showed that the abundance of repair-related genera (such as Desulfovibrio) in wounds treated with PINSHIELD group increased significantly, which helped maintain microbial stability, further confirming the role of PINSHIELD group in increasing the abundance of repair-related genera, such as Desulfovibrio, further strengthening its role in pathogen control and microbial balance. Taken together, these results suggest that PINSHIELD group can promote the establishment of an anti-infection microenvironment by reshaping the wound microbiome.

[0116] Using 16S rRNA sequencing technology, we demonstrated that the PINSHIELD group regulates the microbial community by reducing pathogenic bacteria (such as Staphylococcus) and increasing probiotics (such as Actinomycetes). This remodeling of the microbial community supports the hypothesis that enhancing microbial diversity can provide a protective barrier against infection, thereby promoting more efficient wound recovery and reducing complications such as osteomyelitis and delayed healing. The PINSHIELD group can effectively reduce local inflammation, reduce bacterial load, and reduce the abundance of Staphylococcus aureus, while increasing the diversity and richness of health-related flora.

Claims

1. A closed device for nail tract wounds, characterized in that: The invention comprises two groups of shells (1) which are symmetrically arranged, the tails of the two groups of shells (1) are hinged via a rotating shaft (2), a torsion spring (12) is arranged between the tails of the two groups of shells (1), a sealing member (3) is arranged on the inner side of the head of the two groups of shells (1), the two groups of sealing members (3) cooperate with each other, the inner sides of the tops of the two groups of sealing members (3) are provided with semicircular holes (4) which cooperate with each other, the outer sides of the bottoms of the two groups of sealing members (3) are provided with skirts (6), and the interiors of the two groups of sealing members (3) are provided with active and passive synergistic antibacterial dressings.

2. A closed device for nail tract wounds, characterized in that: The inner side surface of the head of the shell (1) is in a "C" shape; a plug plate (7) is provided on the inner side surface of the head of the shell (1), and a slot (8) matching with the plug plate (7) is provided on the sealing member (3).

3. A closed device for nail tract wounds, characterized in that: The skirt (6) is arranged to be inclined downward.

4. A closed device for nail tract wounds, characterized in that: A patch (9) is horizontally arranged on the inner side of the bottom of the sealing member (3).

5. A closed device for nail tract wounds, characterized in that: A groove (10) is provided on the inner side wall of the sealing member (3); and handles (11) are rotatably provided at the tails of the two sets of shells (1).

6. A method for preparing a dressing filled with a closed device for nail tract wounds according to any one of claims 1 to 5, characterized in that: The antibacterial dressing was prepared by alternately immersing a polyurethane sponge matrix in a zinc ion solution and a sodium alginate solution for multiple crosslinking and then freeze-drying.

7. The method for preparing a dressing filled with a closed device for nail tract wounds according to claim 6, characterized in that: The following steps are involved: 1) Immerse the polyurethane sponge in the sodium alginate solution, let it stand, and squeeze out the residual sodium alginate on the surface of the sponge; 2) After being immersed in a zinc chloride solution and allowed to stand, it is immersed in a prepared sodium alginate solution and allowed to stand again; 3) Repeat step 2), finally put into zinc chloride solution and place in a shaker for reaction, and freeze-dry to obtain an antibacterial dressing.

8. The method for preparing a dressing filled with a closed device for nail tract wounds according to claim 7, characterized in that: The standing time in step 1) is 2-5 minutes.

9. The method for preparing a dressing filled with a closed device for nail tract wounds according to claim 7, characterized in that: In step 2), the time for a single immersion in the zinc chloride solution is 10-20 seconds, the time for a single immersion in the sodium alginate solution is 10-20 seconds, and the number of repetitions in step 3) is 3-6 times.

10. The method for preparing a dressing filled with a closed device for nail tract wounds according to claim 7, characterized in that: The concentration of sodium alginate is 0.01-0.02 g / mL, the concentration of zinc ions is 8-20 mg / mL, the shaking reaction temperature in step 3) is 37° C., and the reaction time is 2-6 h.

Images