Hydrogel microneedle capable of controllably releasing antibacterial agent to diabetic wounds and preparation method of hydrogel microneedle

Abstract

The invention relates to A61M37 / 00, in particular to a hydrogel microneedle capable of controllably releasing an antibacterial agent to a diabetic wound and a preparation method of the hydrogel microneedle. The hydrogel microneedle is prepared from the following components: a composite antibacterial agent, a gel matrix, metal ions and water, the composite antibacterial agent comprises at least one of polysaccharide antibacterial agents, imidazole antibacterial agents, thiazole antibacterial agents, isothiazolone derivative antibacterial agents, quaternary ammonium salt antibacterial agents, quaternary phosphonium salt antibacterial agents, pyridinium salt antibacterial agents, organic tin antibacterial agents, guanidine salt antibacterial agents, phenol antibacterial agents and vanillin antibacterial agents; the gel matrix comprises at least one of hyaluronic acid or a derivative thereof, polyvinyl alcohol or a derivative thereof, polyvinylpyrrolidone or a derivative thereof, gelatin or a derivative thereof, and chitosan or a derivative thereof. The microneedle prepared from the composite antibacterial agent, the gel matrix, metal ions and water has excellent anti-inflammatory, anti-oxidation, mechanical strength and drug sustained-release effects, and can be used for continuously and effectively improving the pathological environment on diabetic wounds.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biomedical materials, A61M37 / 00, and in particular to a hydrogel microneedle for controlled release of an antibacterial agent to a diabetic wound and a preparation method thereof. BACKGROUND

[0002] A chronic wound is a wound that enters a pathologic inflammatory state and does not follow the healing schedule of a healthy wound, stagnates in its development and can remain unresolved indefinitely. A diabetic wound is a type of chronic wound and is a serious complication of diabetes, which often leads to high treatment costs and high amputation rates; many researchers have explored that the main reason for the stagnation of wound healing is unresolved infection, and therefore it is imperative to develop an effective treatment strategy for diabetic wounds.

[0003] Microneedle therapy can deliver drugs to the skin in a painless manner, effectively and long-term improve the physiological environment of the wound, but the existing drug-loaded microneedles have low transdermal permeability and drug loading rate, single function, and poor coverage and treatment effect on wounds.

[0004] Chinese patent CN114159551A discloses a soluble double-layer drug-loaded microneedle patch for chronic wound repair and a preparation method thereof, the patch includes a tip containing a polymer matrix material and a backing layer containing an antibacterial and anti-inflammatory drug, the polymer matrix material is one or a mixture of several of carboxymethyl chitosan, gelatin, collagen, chitosan, carboxymethyl chitosan, and sodium alginate, and the antibacterial and anti-inflammatory drug includes one of tetracycline hydrochloride, ciprofloxacin, dexamethasone, curcumin, cordycepin, and gentamicin, although the patch has good transdermal permeability, the drugs in the microneedle have the risk of drug resistance and adverse reactions in the human body, and the treatment effect of the microneedle still needs to be improved. SUMMARY

[0005] To solve the above technical problems, the present application first provides a hydrogel microneedle for controlled release of an antibacterial agent to a diabetic wound and a preparation method thereof.

[0006] Further, the preparation ingredients of the hydrogel microneedle include a composite antibacterial agent, a gel matrix, metal ions, and water.

[0007] Further, the preparation ingredients of the hydrogel microneedle include 0.1-10wt% of a composite antibacterial agent solution, 0.2-15wt% of a gel matrix solution, and 0.05-10wt% of a metal ion solution.

[0008] Further, the composite antibacterial agent includes at least one of polysaccharide, imidazole, thiazole, isothiazolone derivative, quaternary ammonium salt, quaternary phosphonium salt, pyridine salt, organic tin, and guanidine salt, phenol, and vanillin antibacterial agent, but is not limited thereto.

[0009] Further, the composite antibacterial agent is a polysaccharide antibacterial agent modified by a quaternary ammonium salt antibacterial agent.

[0010] Further, the polysaccharide antibacterial agent comprises at least one of plant polysaccharide, microbial polysaccharide, and animal polysaccharide; preferably, the polysaccharide antibacterial agent is plant polysaccharide.

[0011] Further, the polysaccharide antibacterial agent comprises at least one of astragalus polysaccharide, medlar polysaccharide, seaweed polysaccharide, beta-glucan, chitosan, carboxymethyl chitosan, cellulose, polysaccharide, gelidium amansii polysaccharide, moringa oleifera polysaccharide, aloe polysaccharide, dendrobium polysaccharide, and purple sweet potato polysaccharide.

[0012] Further, the polysaccharide antibacterial agent comprises beta-glucan.

[0013] Further, the quaternary ammonium salt antibacterial agent is an organic quaternary ammonium salt, preferably at least one of glycidyl quaternary ammonium salt, glucoside quaternary ammonium salt, fructoside quaternary ammonium salt, glucose fatty acid ester quaternary ammonium salt, glucosamine quaternary ammonium salt, and alkyl dimethyl quaternary ammonium salt.

[0014] Further, the organic quaternary ammonium salt is glycidyl quaternary ammonium salt.

[0015] Further, the preparation method of the composite antibacterial agent is grafting the quaternary ammonium salt antibacterial agent to the structure of the polysaccharide antibacterial agent. The two are used in combination to effectively enhance the broad-spectrum antibacterial, antioxidant, anti-inflammatory, and other effects of the microneedle.

[0016] Further, the mass ratio of the polysaccharide antibacterial agent and the quaternary ammonium salt antibacterial agent is 1:(0.3-1.5), preferably 1:(0.5-1.2), and more preferably 1:(0.7-1.1). The application designs the grafting of the quaternary ammonium salt antibacterial agent on the structure of the polysaccharide antibacterial agent to ensure the activity of the small-molecule quaternary ammonium salt antibacterial agent and prevent the antibacterial components from precipitating out. Compared with the overflow type antibacterial agent formed by directly adding the antibacterial agent to the gel structure, the contact type antibacterial agent prepared in the application has more stable antibacterial performance and a longer effective period in the microneedle. Optimizing the use amount of the two ensures the optimal grafting amount of the quaternary ammonium salt antibacterial agent, which not only makes the antibacterial activity of the microneedle optimal but also ensures that no pathological toxicity is generated.

[0017] In a preferred embodiment, the mass ratio of the polysaccharide antibacterial agent and the quaternary ammonium salt antibacterial agent is 1:(0.9-1.0).

[0018] Further, the preparation method of the composite antibacterial agent is adding 0.01-1wt% of an organic quaternary ammonium salt solution to 0.02-10wt% of a polysaccharide antibacterial agent solution, stirring and reacting at room temperature, and then washing, filtering, and drying the product.

[0019] Preferably, the polysaccharide antibacterial agent solution has a mass concentration of 0.05-2wt%, and the solvent is dimethyl sulfoxide.

[0020] Further, the gel matrix includes, but is not limited to, at least one of hyaluronic acid (HA) or its derivatives, polyvinyl alcohol (PVA) or its derivatives, polyvinylpyrrolidone (PVP) or its derivatives, gelatin (GEL) or its derivatives, chitosan (CS) or its derivatives.

[0021] Preferably, the gel matrix includes chitosan or its derivatives, and more preferably chitosan derivatives.

[0022] Further, the chitosan derivatives are selected from at least one of carboxymethyl chitosan, chitosan hydrochloride, chitosan sulfate.

[0023] Preferably, the chitosan derivative is carboxymethyl chitosan (CMCS). The gel matrix of the present application forms an organic-metal coordination structure with metal ions, and the presence of multiple coordination sites in the structure can form a larger coordination network, which gives the microneedle a basic mechanical structure. Preferably, when carboxymethyl chitosan is used as the gel matrix, it itself exhibits a high degree of mutual crosslinking, which can effectively enhance the mechanical strength of the formed microneedle, directly realizing the targeted treatment effect of the microneedle, and in addition, it and the composite antibacterial agent produce stronger intermolecular interaction, which can also effectively slow down the rapid release of the antibacterial agent.

[0024] Further, the metal ions include, but are not limited to, at least one of silver ions, aluminum ions, calcium ions, potassium ions, zinc ions, and iron ions.

[0025] Preferably, the metal ions include aluminum ions.

[0026] Further, the metal ions are derived from a salt containing metal ions, including but not limited to at least one of its sulfate, carbonate, nitrate, halide, bicarbonate, and organic acid salt.

[0027] In a preferred embodiment, the preparation components of the hydrogel microneedle include 1-4wt% of the composite antibacterial agent solution, 0.5-5wt% of the gel matrix solution, and 0.1-0.5wt% of the metal ion solution.

[0028] Further, the volume ratio of the composite antibacterial agent solution, the gel matrix solution, and the metal ion solution is 1:(0.3-5):(0.1-3). Generally, the antibacterial performance of the microneedle is improved as the content of the composite antibacterial agent increases, but in the microneedle structure of the present application, the metal ions provide chemical crosslinking, and there are hydrogen bonds and van der Waals forces between the polar groups of the composite antibacterial agent and the gel matrix, that is, physical crosslinking. The chemical crosslinking and the physical crosslinking interact with each other, and the three components jointly give the structure of the gel and the microneedle. Only when the three components are kept within a suitable content range, can the best joint action be played, and the antibacterial effect, the sustained-release performance, and the structural stability of the gel are effectively improved.

[0029] Preferably, the volume ratio of the composite antibacterial agent solution, the gel matrix solution, and the metal ion solution is 1:(0.5-2):(0.3-2). In the present application, all the solutions are prepared with water unless otherwise specified.

[0030] Through the formulation design of the present application, the cumulative release amount of the antibacterial component of the prepared gel microneedle within 4h can be controlled to be less than 55%, preferably less than 45%, and the cumulative release amount of the antibacterial component within 8h can be controlled to be less than 85%, preferably less than 75%.

[0031] Further, the preparation method of the hydrogel microneedle comprises the following steps:

[0032] S1, according to the corresponding volume ratio, the composite antibacterial agent solution, the gel matrix solution, and the metal ion solution are mixed and stirred, and then poured into a mold;

[0033] S2, vacuum treatment is performed at 20-40℃ for 1-30min, and then the mold is placed in a drying oven for drying. After the mold is peeled off, the hydrogel microneedle is obtained.

[0034] Further, the temperature of the vacuum treatment in S2 is 22-28℃, preferably 25℃.

[0035] Further, the drying temperature of the drying oven is 25-60℃, preferably 27-40℃.

[0036] Further, the microneedle array and the microneedle patch constituted by the microneedle can be used for treating diabetic wound repair.

[0037] Advantages

[0038] 1, the microneedle prepared by the composite antibacterial agent, the gel matrix, and the metal ion has high biocompatibility, degradability, antibacterial, anti-inflammatory, antioxidant, and multiple functions of promoting blood vessel proliferation. By optimizing the types and contents of the components, the mechanical strength and the drug sustained-release effect of the microneedle can be effectively improved.

[0039] 2、The composite antibacterial agent of the application is a polysaccharide antibacterial agent modified by a quaternary ammonium salt antibacterial agent, and the composite use can enhance the antibacterial, anti-inflammatory performance, promote cell proliferation and other biological activities of the microneedle. The quaternary ammonium salt antibacterial agent is grafted into the structure of the polysaccharide antibacterial agent, which can effectively improve the antibacterial stability and antibacterial period of the microneedle.

[0040] 3、The microneedle of the application has excellent mechanical stability, and has good wound repair, collagen neogenesis and inflammation inhibition capacity when used for treating diabetic wounds by a microneedle patch. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 : (a) QDex / CS, (b) QDex / CMCS, (c) QDex / CS / Al 3+ , (d) QDex / CMCS / Al 3+ SEM images of the gels;

[0042] Figure 2 : Infrared spectrum of the composite antibacterial agent QDex of Example 1;

[0043] Figure 3 : (a) QDex / CMCS / Al 3+ and (b) QDex / CS / Al 3+ gel real object pictures;

[0044] Figure 4 : (a) QDex / CS, (b) QDex / CMCS, (c) QDex / CS / Al 3+ , (d) QDex / CMCS / Al 3+ Gel rheological behavior of the gels;

[0045] Figure 5 : Optical picture of the hydrogel microneedle of Example 1 (the right picture is a partial enlarged view of the left picture);

[0046] Figure 6 : (a) QDex / CS, (b) QDex / CMCS, (c) QDex / CS / Al 3+ , (d) QDex / CMCS / Al 3+ Gel microneedle force / micromovement diagram of the microneedle corresponding to the gels;

[0047] Figure 7 : Healing diagrams of the mouse diabetic ulcer model wounds after 1 day, 7 days and 14 days of treatment by the microneedles corresponding to the QDex / CS, QDex / CMCS, QDex / CS / Al 3+ , QDex / CMCS / Al 3+ gels. DETAILED DESCRIPTION

[0048] Embodiment

[0049] Embodiment 1

[0050] The embodiment provides a hydrogel microneedle capable of controlled release of an antibacterial agent to a diabetic wound, and ingredients for preparing the hydrogel microneedle include: 2wt% of a composite antibacterial agent solution, 1wt% of a gel matrix solution, and 0.2wt% of a metal ion solution.

[0051] The composite antibacterial agent solution is prepared by dissolving a composite antibacterial agent in water, the gel matrix solution is prepared by dissolving a gel matrix in water, and the metal ion solution is prepared by dissolving a salt containing metal ions in water.

[0052] The composite antibacterial agent is glycidyltrimethylammonium chloride grafted β-glucan; the mass ratio of β-glucan and glycidyl chloride used in the preparation process is 1:1; the preparation method of the composite antibacterial agent is as follows: 0.08wt% of a β-glucan solution is prepared by using dimethyl sulfoxide, 0.06wt% of a glycidyltrimethylammonium chloride solution is added, stirring is performed at room temperature under N2 protection for 48h; the reaction product is washed twice with isopropyl alcohol, then filtered, and vacuum dried at room temperature for 24h, to obtain the composite antibacterial agent (quaternary ammonium saltified dextran, denoted as: QDex).

[0053] The gel matrix is carboxymethyl chitosan (CMCS).

[0054] The metal ion is aluminum ion (III).

[0055] The preparation method of the hydrogel microneedle includes the following steps:

[0056] S1, the composite antibacterial agent solution, the gel matrix solution and the metal ion solution are mixed and stirred uniformly according to a volume ratio of 1:1:0.5, and the mixed solution is poured into a PDMS mold (1000μm high, 1cm*1cm);

[0057] S2, vacuum treatment is performed at 25°C and-0.08~-0.1MPa for 3min, then the PDMS microneedle array mold is placed in a vacuum drying box at 30°C for drying for 5h, the PDMS microneedle array mold is peeled off, and the QDex / CMCS / Al 3+ Hydrogel microneedle and array thereof.

[0058] Embodiment 2

[0059] The embodiment provides a hydrogel microneedle capable of controlled release of an antibacterial agent to a diabetic wound, and ingredients for preparing the hydrogel microneedle include: 2wt% of a composite antibacterial agent solution, 1wt% of a gel matrix solution, and 0.2wt% of a metal ion solution.

[0060] The composite antibacterial agent solution is prepared by dissolving the composite antibacterial agent in water, the gel matrix solution is prepared by dissolving the gel matrix in water, and the metal ion solution is prepared by dissolving a salt containing metal ions in water.

[0061] The composite antibacterial agent comprises glycidyltrimethylammonium chloride and beta-glucan, and the mass ratio of beta-glucan to glycidyltrimethylammonium chloride is 1:1.1. The preparation method of the composite antibacterial agent comprises the following steps: preparing a 0.1wt% beta-glucan solution by using dimethyl sulfoxide, adding a 0.04wt% glycidyltrimethylammonium chloride solution to the beta-glucan solution, stirring at room temperature under N2 protection for 24 hours, washing the reaction product with isopropyl alcohol twice, filtering, and vacuum drying at room temperature for 36 hours to obtain the composite antibacterial agent (quaternary ammonium saltified dextran, denoted as QDex).

[0062] The gel matrix is carboxymethyl chitosan (CMCS).

[0063] The metal ion is aluminum ion (III).

[0064] The preparation method of the hydrogel microneedle comprises the following steps:

[0065] S1, mixing and stirring the composite antibacterial agent solution, the gel matrix solution and the metal ion solution in a volume ratio of 1:0.5:2, and pouring the mixed solution into a PDMS mold (1000μm high, 1cm*1cm);

[0066] S2, vacuum treatment at 25°C and -0.08~-0.1MPa for 5min, and then drying in a vacuum drying oven at 30°C for 8h to peel off the PDMS microneedle array mold, so as to obtain the hydrogel microneedle and its array.

[0067] Example 3

[0068] The embodiment provides a hydrogel microneedle capable of releasing an antibacterial agent to a diabetic wound in a controllable manner, and the preparation components of the hydrogel microneedle comprise: 4wt% of a composite antibacterial agent solution, 0.5wt% of a gel matrix solution and 0.5wt% of a metal ion solution.

[0069] The composite antibacterial agent solution is prepared by dissolving the composite antibacterial agent in water, the gel matrix solution is prepared by dissolving the gel matrix in water, and the metal ion solution is prepared by dissolving a salt containing metal ions in water.

[0070] The composite antibacterial agent comprises glycidyltrimethylammonium chloride and beta-glucan; the mass ratio of beta-glucan and glycidyltrimethylammonium chloride is 1:0.7; the preparation method of the composite antibacterial agent is as follows: a 0.05wt% beta-glucan solution is prepared by using dimethyl sulfoxide, 0.08wt% glycidyltrimethylammonium chloride solution is added thereto, and stirring is carried out at room temperature for 72h under N2 protection; the reaction product is washed with isopropyl alcohol for 3 times, then filtered, and vacuum dried at room temperature for 36h to obtain the composite antibacterial agent (quaternary ammonium saltified dextran, denoted as QDex).

[0071] The gel matrix is carboxymethyl chitosan (CMCS).

[0072] The metal ion is aluminum ion (III).

[0073] The preparation method of the hydrogel microneedle comprises the following steps:

[0074] S1, the composite antibacterial agent solution, the gel matrix solution and the metal ion solution are mixed and stirred uniformly according to a volume ratio of 1:2:0.3, and the mixed solution is poured into a PDMS mold (1000μm high, 1cm*1cm);

[0075] S2, vacuum treatment is carried out at 25℃ and-0.08~-0.1MPa for 5min, then the PDMS microneedle array mold is placed in a vacuum drying box at 30℃ for drying for 5h, and the PDMS microneedle array mold is peeled off to obtain the hydrogel microneedle and the array thereof.

[0076] Example 4

[0077] The volume ratio of the composite antibacterial agent solution, the gel matrix solution and the metal ion solution is 1:4:0.5.

[0078] Example 5

[0079] The volume ratio of the composite antibacterial agent solution, the gel matrix solution and the metal ion solution is 1:0.3:3.

[0080] Example 6

[0081] The volume ratio of the composite antibacterial agent solution, the gel matrix solution and the metal ion solution is 1:0.3:3.

[0082] The composite antibacterial agent solution is prepared by dissolving beta-glucan and glycidyltrimethylammonium chloride in water.

[0083] Example 7

[0084] The embodiment provides a hydrogel microneedle capable of controlled release of an antibacterial agent to a diabetic wound, and preparation ingredients of the hydrogel microneedle include: 2wt% of a composite antibacterial agent solution, 1wt% of a gel matrix solution and 0.2wt% of a metal ion solution.

[0085] The composite antibacterial agent solution is prepared by dissolving a composite antibacterial agent in water, the gel matrix solution is prepared by dissolving a gel matrix in water, and the metal ion solution is prepared by dissolving a salt containing metal ions in water.

[0086] The composite antibacterial agent is glycidyltrimethylammonium chloride grafted β-glucan, a mass ratio of the β-glucan and glycidyl chloride used in the preparation process is 1:1, and a preparation method of the composite antibacterial agent is as follows: 0.08wt% of a β-glucan solution is prepared by using dimethyl sulfoxide, 0.06wt% of a glycidyltrimethylammonium chloride solution is added to the β-glucan solution, stirring is conducted at room temperature under N2 protection for 48 hours, the reaction product is washed twice with isopropyl alcohol, then filtered, and vacuum dried at room temperature for 24 hours, so that the composite antibacterial agent (quaternary ammonium saltized dextran, denoted as QDex) is obtained.

[0087] The gel matrix is chitosan (CS).

[0088] The metal ion is aluminum ion (III).

[0089] The preparation method of the hydrogel microneedle includes the following steps.

[0090] S1, the composite antibacterial agent solution, the gel matrix solution and the metal ion solution are mixed and stirred uniformly according to a volume ratio of 1:1:0.5, and the mixed solution is poured into a PDMS mold (1000 μm high, 1 cm*1 cm);

[0091] S2, vacuum treatment is conducted at 25 DEG C and-0.08 to-0.1 MPa for 3 minutes, then the PDMS microneedle array mold is placed in a vacuum drying box at 30 DEG C for drying for 5 hours, the PDMS microneedle array mold is peeled off, and the QDex / CS / Al 3+ The hydrogel microneedle and the array thereof.

[0092] Comparative Example 1

[0093] The embodiment provides a hydrogel microneedle capable of controlled release of an antibacterial agent to a diabetic wound, and preparation ingredients of the hydrogel microneedle include: 2wt% of a composite antibacterial agent solution, 1wt% of a gel matrix solution.

[0094] The composite antibacterial agent solution is prepared by dissolving a composite antibacterial agent in water, and the gel matrix solution is prepared by dissolving a gel matrix in water.

[0095] The composite antibacterial agent is the same as that in Embodiment 1.

[0096] The gel matrix is chitosan (CS).

[0097] The preparation method of the hydrogel microneedle comprises the following steps:

[0098] S1, according to the volume ratio of 1:1:0.5, the composite antibacterial agent solution, the gel matrix solution, the water solution is mixed and stirred uniformly, the mixed solution is poured into the PDMS mold (high 1000 μm, 1 cm*1 cm);

[0099] S2, under the condition of 25 DEG C, -0.08~ -0.1 MPa, vacuum treatment for 3 min, then placed in 30 DEG C vacuum drying box and dried for 5 h, then the PDMS microneedle array mold is peeled off, and the QDex / CS material microneedle and its array can be obtained after the mold is peeled off.

[0100] Comparative example 2

[0101] The hydrogel microneedle for controlled release of antibacterial agent to diabetic wound provided in the embodiment comprises: 2wt% of a composite antibacterial agent solution and 1wt% of a gel matrix solution.

[0102] The composite antibacterial agent solution is prepared by dissolving the composite antibacterial agent in water, and the gel matrix solution is prepared by dissolving the gel matrix in water.

[0103] The composite antibacterial agent is the same as that in example 1.

[0104] The gel matrix is carboxymethyl chitosan (CMCS).

[0105] The preparation method of the hydrogel microneedle comprises the following steps:

[0106] S1, according to the volume ratio of 1:1:0.5, the composite antibacterial agent solution, the gel matrix solution, the water solution is mixed and stirred uniformly, the mixed solution is poured into the PDMS mold (high 1000 μm, 1 cm*1 cm);

[0107] S2, under the condition of 25 DEG C, -0.08~ -0.1 MPa, vacuum treatment for 3 min, then placed in 30 DEG C vacuum drying box and dried for 5 h, then the PDMS microneedle array mold is peeled off, and the QDex / CMCS material microneedle and its array can be obtained after the mold is peeled off.

[0108] Performance test method:

[0109] The mixed solution obtained in step S1 of example 1, example 7 and comparative example 1-2 is introduced into the mold respectively, and the gel is formed after standing, and the following gel performance tests 1-4 are carried out.

[0110] 1, scanning electron microscope: by the attachedFigure 1 It can be seen that neither QDex / CS in Comparative Example 1 nor QDex / CMCS in Comparative Example 2 can form a hydrogel and does not have a three-dimensional mesh structure; QDex / CS / Al in Example 7 3+ The three-dimensional mesh structure is not obvious enough, and the crosslinking density is low; while the QDex / CMCS / Al of Example 1 3+ It has a clearly visible three-dimensional mesh structure and a high degree of cross-linking, with relatively dense cross-linking.

[0111] 2. Infrared spectrum: According to the attached... Figure 2 It can be known that 3000-3500cm -1 The increased peak value at 1442 cm⁻¹ indicates enhanced CH stretching vibration, which is due to the four organic groups in the quaternary ammonium salt molecule inducing CH stretching vibration. -1 The characteristic peaks mainly reflect the interaction between quaternary ammonium ions and organic groups, indicating that the chemical grafting method was successfully used to prepare quaternary ammonium salt-treated dextran (QDex).

[0112] 3. Gelability: [The text abruptly ends here, likely due to an incomplete sentence or missing information.] Figure 3 It can be seen that: QDex / CMCS / Al in Example 1 3+ (a) Compared with QDex / CS / Al in Example 7 3+ (b) The gelling properties are good, uniform, and transparent, indicating that quaternized dextran and carboxymethyl chitosan or chitosan can form a gel under certain conditions; since chitosan itself has a pale yellow color, QDex / CS / Al 3+ The gel has a certain color.

[0113] 4. Gel Rheological Behavior: Test Method: Rheological testing method; Instrument: Advanced rotational rheometer; Test Mode: Oscillation time mode; Parameter Settings: Time 100s, Shear strain γ = 1%, Test temperature: 25℃. Place the sample on the test plate (P20), set the parameters, and start the test. The gel sample should be a cylindrical sample with a diameter of Ф = 1cm and a height of 1cm. When testing non-gel samples, spread them evenly on the test plate, with a spreading volume of 3-5mL.

[0114] According to the appendix Figure 4 It can be seen that, under certain strain conditions, the properties of both QDex / CS in Comparative Example 1 and QDex / CMCS in Comparative Example 2 change with time, indicating that their properties are not stable enough and they do not possess gel properties; while the QDex / CS / Al in Example 7... 3+ Compared with QDex / CMCS / Al in Example 1 3+ The properties remained essentially unchanged, and G' was always greater than G. Meanwhile, QDex / CMCS / Al 3+ G' is greater than QDex / CS / Al3+ G' indicates QDex / CMCS / Al 3+ The properties of the gel are more stable.

[0115] 5. Microneedle morphology: (See attached image) Figure 5 As shown in the figure, the hydrogel microneedles prepared by the technical solution of this application have good microneedle morphology.

[0116] 6. Microneedle Mechanical Properties: Three microneedles were taken from each of the microneedle arrays in Examples 1, 7, and Comparative Examples 1-2 for microneedle mechanical property testing. The results were obtained according to the attached... Figure 6 The results show that QDex / CS in Comparative Example 1, QDex / CMCS in Comparative Example 2, and QDex / CS / Al in Example 7 are superior. 3+ And QDex / CMCS / Al of Example 1 3+ The microneedles prepared from the materials can withstand maximum forces of 0.33 N, 0.43 N, 0.55 N, and 0.75 N, respectively, and exhibit a certain degree of repeatability and fatigue resistance. Among them, QDex / CMCS / Al... 3+ The microneedles exhibited the greatest force, indicating a high degree of cross-linking and a dense three-dimensional network within them. This enhanced the stress resistance of the microneedles, resulting in the successful fabrication of hydrogel microneedles with excellent mechanical properties, which can effectively improve the transdermal performance of the microneedles. The mechanical property test results of other embodiments are shown in Table 1.

[0117] 7. Microneedle drug sustained-release performance: The samples prepared in each example and comparative example were placed on a transdermal apparatus, and the solution in the transdermal diffusion cell was aspirated at certain intervals. The absorbance was measured with a UV spectrophotometer to determine the content of quaternary ammonium salts.

[0118] 8. Animal experiments on microneedle healing: Blank microneedles, QDex / CS microneedles (Comparative Example 1), QDex / CMCS microneedles (Comparative Example 2), and QDex / CS / Al microneedles (Example 7) were used. 3+ Microneedles, QDex / CMCS / Al from Example 1 3+ Microneedles were applied to the wound surface of a mouse model of diabetic ulcers, and the wound healing process was observed and recorded for 14 consecutive days. (According to the attached...) Figure 7 It can be seen that using QDex / CMCS / Al in Example 1 3+ The mice in the microneedle group showed the best wound healing effect, indicating that hydrogel microneedles can significantly promote wound healing.

[0119] Performance test results:

[0120] The mechanical properties and drug sustained-release performance test results of the microneedles in the examples and comparative examples are shown in Table 1.

[0121] Table 1

[0122]

[0123] Summary: According to Table 1, the microneedles prepared by the technical solutions of embodiments 1-3 of the application have excellent mechanical strength and drug release effect.

[0124] It can be seen from Comparative Example 1 and Examples 4-5 that the change of the amount ratio of the gel matrix and metal ions will affect the strength and sustained release effect of the microneedles, because the change of the ratio cannot obtain a three-dimensional cross-linked network with relatively optimal structural density, thereby resulting in the decrease of the strength of the microneedles and the relatively fast release speed of the loaded drug in the microneedles and the poor sustained release effect.

[0125] It can be seen from Comparative Example 1 and Example 6 that the antibacterial agent is directly mixed and added, which is rapidly released in the microneedles in a short time, and the antibacterial effect also decreases after a period of use; it is illustrated that the design of the graft structure of the composite antibacterial agent in the application can not only effectively improve the antibacterial effect, but also realize the stability of the antibacterial molecules and the increase of the antibacterial period.

[0126] It can be seen from Comparative Example 1 (QDex / CMCS / Al 3+ ), Example 7 (QDex / CS / Al 3+ ), Comparative Example 1 (QDex / CS) and Comparative Example 2 (QDex / CMCS) that the release rate of the antibacterial agent of the hydrogel microneedle of Example 1 is the slowest, the burst release in a short time can be avoided, the long-acting sustained release of the drug is realized, and thus the hydrogel microneedle can exert the persistent antibacterial effect. The release rate of Example 7 is faster than that of Example 1, and the release amount between 8-12h is only 12%, which is not conducive to the treatment effect in this period of time. The release amount of Comparative Examples 1-2 from 0-8h is basically close to the peak value, which is not conducive to the continuous exertion of the drug effect.

Claims

1. A hydrogel microneedle for controlled release of an antimicrobial agent to a diabetic wound, characterized in that, The preparation components of the hydrogel microneedle include: a composite antibacterial agent, a gel matrix, metal ions, and water; the composite antibacterial agent includes at least one of polysaccharide, imidazole, thiazole, isothiazolone derivative, quaternary ammonium salt, quaternary phosphonium salt, pyridine salt, organic tin, guanidine salt, phenol, and vanillin antibacterial agent; The gel matrix includes at least one of hyaluronic acid or its derivative, polyvinyl alcohol or its derivative, polyvinylpyrrolidone or its derivative, gelatin or its derivative, and chitosan or its derivative.

2. The hydrogel microneedle of claim 1, wherein, The preparation components of the hydrogel microneedle include: 0.1-10wt% of a composite antibacterial agent solution, 0.2-15wt% of a gel matrix solution, and 0.05-10wt% of a metal ion solution.

3. The hydrogel microneedle of claim 1, wherein, The composite antibacterial agent is a quaternary ammonium salt antibacterial agent modified polysaccharide antibacterial agent, and the polysaccharide antibacterial agent includes at least one of plant polysaccharide, microbial polysaccharide, and animal polysaccharide.

4. The hydrogel microneedle of claim 3, wherein, The polysaccharide antibacterial agent includes at least one of astragalus polysaccharide, lycium barbarum polysaccharide, algal polysaccharide, beta-glucan, chitosan, carboxymethyl chitosan, cellulose, polysaccharide, gelidium amansii polysaccharide, moringa polysaccharide, aloe polysaccharide, dendrobium polysaccharide, and purple sweet potato polysaccharide; preferably, the polysaccharide antibacterial agent includes beta-glucan.

5. The hydrogel microneedle of claim 3, wherein, The preparation method of the composite antibacterial agent is: grafting a quaternary ammonium salt antibacterial agent to the structure of a polysaccharide antibacterial agent.

6. The hydrogel microneedle of claim 5, wherein, The mass ratio of the polysaccharide antibacterial agent to the quaternary ammonium salt antibacterial agent is 1:(0.3-1.5).

7. The hydrogel microneedle of claim 5, wherein, The mass ratio of the polysaccharide antibacterial agent to the quaternary ammonium salt antibacterial agent is 1:(0.5-1.2), and more preferably 1:(0.7-1.1).

8. The hydrogel microneedle of claim 2, wherein, The volume ratio of the composite antibacterial agent solution, the gel matrix solution, and the metal ion solution is 1:(0.3-5):(0.1-3), and preferably 1:(0.5-2):(0.3-2).

9. The hydrogel microneedle of any one of claims 1-8, wherein, The preparation components of the hydrogel microneedle include: 1-4wt% of a composite antibacterial agent solution, 0.5-5wt% of a gel matrix solution, and 0.1-0.5wt% of a metal ion solution.

10. A method of preparing the hydrogel microneedle according to any one of claims 1-9, characterized in that, The method includes the following steps: S1, mixing and stirring the composite antibacterial agent solution, the gel matrix solution, and the metal ion solution according to the corresponding volume ratio, and pouring into a mold; S2, vacuum treatment at 20-40℃ for 1-30min, and then drying in a drying box, and the hydrogel microneedle is obtained after stripping the mold.

Images