Preparation method of multifunctional skin soothing gel dressing

Abstract

The invention discloses a preparation method of a multifunctional skin soothing gel dressing, which comprises the following steps: forming a stable complex from nano-silver and protease by using an ascorbic acid reduction method, preparing a liposome co-loading system by using an ultrasonic-high pressure homogenization combined technology, and simultaneously encapsulating aloe polysaccharide and cucumber extract at an encapsulation rate of gt; the multifunctional skin soothing gel dressing is prepared by the following steps of: firstly, preparing chitosan by using an ionic gel method, preparing chitosan nanoparticles by using an ionic gel method, and finally, mixing at gradient temperature under the protection of nitrogen, so as to obtain the multifunctional skin soothing gel dressing. On the basis of completely retaining the traditional components, synergistically improving the transdermal efficiency, the curative effect durability and the safety through nanoscale structure recombination, so that the skin soothing gel dressing has the advantages that the skin soothing efficiency is greatly improved, and the application prospect is wide. A brand new solution is provided for treatment of chronic skin inflammations such as atopic dermatitis and eczema.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical technology, specifically to a method for preparing a multifunctional skin-soothing gel dressing. Background Technology

[0002] Current treatments for skin inflammation face three major technical bottlenecks: poor drug permeability, short-lived efficacy, and significant side effects. Traditional skin medications, such as corticosteroids, can relieve symptoms in a short time, but long-term use can easily lead to skin atrophy and drug resistance. On the other hand, topical medications containing natural active ingredients, such as aloe vera and allantoin, are difficult to achieve ideal efficacy due to their large molecular weight, poor stability, and low transdermal absorption rate. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing a multifunctional skin-soothing gel dressing. While retaining the traditional formula composition, it reconstructs the transdermal efficiency, efficacy durability, and safety through nanoscale interactions between components, making it suitable for long-term treatment and management of chronic skin inflammations such as atopic dermatitis and eczema.

[0004] To achieve the above objectives, the solution of the present invention is: A method for preparing a multifunctional skin-soothing gel dressing includes the following steps: Step 1: Preparation of silver nanoparticle-protease complex: First, silver nitrate solution and protease were pre-complexed at a mass ratio of 1:1.2 at 3~5℃ for 30 minutes. Ascorbic acid was added dropwise and the reaction was stirred at 23~27℃ for 2 hours. After purification by centrifugation in a 100 kDa ultrafiltration tube, nano-silver-protease complexes with a particle size of 20~50 nm (PDI<0.15) were obtained. Step 2, Preparation of liposomes: Then, DPPC, cholesterol, and active ingredients were dissolved in chloroform at a ratio of DPPC:cholesterol:active ingredient = 7:3:2.5~5. After rotary evaporation to form a film, the film was hydrated with preheated phosphate buffer at pH 6.8, and then subjected to ultrasonication for 5 minutes with a 200W probe and high-pressure homogenization at 800 bar for 3 cycles to obtain liposomes with a particle size of 105~135 nm and an encapsulation efficiency >85%. The active ingredients include aloe polysaccharide and cucumber sterol in a mass ratio of 3:1; Step 3: Preparation of chitosan nanoparticles: Then, chitosan quaternary ammonium salt with a degree of deacetylation of 90% was dissolved in 1% acetic acid solution to obtain chitosan solution. Then, the chitosan solution was crosslinked with 0.1%~0.3% (w / v) sodium tripolyphosphate aqueous solution at a volume ratio of 3:1 under stirring for 20~30 minutes. Allantoin and acidic protease were loaded by physical adsorption at a mass ratio of 1:1. After purification by centrifugation in a 50 kDa ultrafiltration tube, chitosan nanoparticles were obtained, forming a positively charged targeting system. Step 4: Preparation of PLGA microspheres: PLGA was then dissolved in dichloromethane as the oil phase; the manganese oxide-tannic acid complex was dispersed in an aqueous solution containing 1% (w / v) polyvinyl alcohol (PVA) as the aqueous phase; the oil phase and the aqueous phase were mixed at a volume ratio of 1:3, homogenized at high speed to form a primary emulsion, poured into a 0.5% (w / v) PVA aqueous solution, stirred and solidified for 4 h, centrifuged and washed multiple times, and freeze-dried to obtain PLGA microspheres with a particle size of 130~170 nm; Step 5: Prepare the gel dressing: Finally, under nitrogen protection, press 100 wt % of the formula ratio, use 15 wt %~20 wt Dissolve % poloxamer 407 in pure water at 3-5°C for 2 hours, then add 0.002% poloxamer solution sequentially at 14-16°C. wt % ~0.005 wt % nano silver-protease complex, added at 11~13℃ wt %~3 wt % liposomes, add 0.5% at 7~9℃ wt %~2 wt % chitosan nanoparticles, 0.2 wt %~0.4 wt % sodium hyaluronate and 0.005 wt % ~ 0.01 wt % PLGA microspheres, stirred for 20-30 minutes, and sterilized by irradiation to obtain a gel dressing; the amount of pure water used is the balance.

[0005] In step 1, the molar ratio of silver nitrate to ascorbic acid in the silver nitrate solution is 1:1.2, and the stirring speed is 500~800 rpm.

[0006] In step 2, the mass of chloroform used is 10 to 20 times the total mass of DPPC, cholesterol, and active ingredients, the temperature of rotary evaporation is 38 to 42°C, and the vacuum degree of rotary evaporation is -0.09 MPa.

[0007] In step 3, the concentration of the chitosan quaternary ammonium salt is 0.5% (w / v), the volume ratio of the chitosan quaternary ammonium salt to the acetic acid solution is 1:10, the mass ratio of the allantoin to the chitosan solution is 1:5, and the pH of the acidic protease is 5.0.

[0008] In step 3, the stirring speed is 300~500 rpm.

[0009] In step 4, the ratio of lactic acid to glycolic acid in the PLGA is 75:25, the molecular weight of the PLGA is 30 kDa, the manganese oxide-tannic acid complex is prepared by manganese oxide and tannic acid in a mass ratio of 1:1, and the drug loading of the PLGA microspheres on the manganese oxide-tannic acid complex is ≥15%.

[0010] In step 4, the ratio of PLGA to dichloromethane is 1:20 (w / v), and the ratio of manganese oxide-tannic acid complex to 1% PVA aqueous solution is 1:50.

[0011] In step 4, the high-speed homogenization speed is 8000~10000 rpm, the high-speed homogenization time is 2 min, the stirring speed is 500 rpm, the centrifugal washing speed is 8000~10000 rpm, and the centrifugal washing time is 10 min.

[0012] In step 5, the stirring speed is 100~200 rpm.

[0013] Following the above technical solution, the present invention provides a method for preparing a multifunctional skin-soothing gel dressing. Firstly, a core-shell structured nano-silver-protease complex is constructed at the molecular level. Specifically, silver ions are reduced in situ in the hydrophobic domain of the protease molecule (molecular weight 28 kDa) using ascorbic acid reduction. Stable Ag-S and Ag-N coordination bonds are formed through the coordination of thiol (-SH) and amino (-NH2) groups. Each protease molecule can load 15-20 silver clusters with a particle size of 3-5 nm, ultimately forming a particle size distribution of 20-50 nm. A homogeneous complex of nanosilver (PDI < 0.15) with a defined protein coating layer (approximately 2-3 nm thick) was confirmed by cryo-electron microscopy (Cryo-EM). This unique structural design extended the in vitro release half-life of nanosilver from 8 hours in conventional formulations to 36 hours (PBS buffer, 37°C). Furthermore, through protein barrier action, it increased the survival rate of HaCaT cells from 52% to 86% with free nanosilver (CCK-8 assay, 24 h). In vitro release experiments showed that the nanosilver-protease complex achieved a cumulative release rate of 82% within 72 hours (PBS buffer, 37°C), with a release half-life of 36 hours. It also retained the bioactivity of the protease in degrading inflammatory mediators such as interleukin-6 and tumor necrosis factor.

[0014] Secondly, a four-level delivery system was established in the formulation: 1. Cationic liposomes (DPPC:cholesterol=7:3) encapsulating aloe polysaccharides (molecular weight 40~50 kDa) and cucumber sterol; 2. Chitosan quaternary ammonium salt (molecular weight 50 kDa, degree of deacetylation 90%) nanoparticles loaded with allantoin and acidic protease (optimal pH=5.0); 3. PLGA microspheres (lactic acid:glycolic acid=75:25) for sustained release of manganese oxide-tannic acid complex; 4. Temperature-sensitive poloxamer 407 gel matrix. This multi-level structure ensures that each component is released sequentially during transdermal delivery. Franz diffusion cell experiments confirmed that its cumulative penetration amount reached 3.2 times (24 h) of traditional creams (such as hydrocortisone cream). Accelerated testing over 6 months verified that the system exhibited a particle size change of <8%, an active ingredient retention rate of >95%, and clinical data showed that it shortened the time to effectiveness to 2~3 days and reduced the adverse reaction rate to 4.2%, significantly superior to traditional therapies.

[0015] This invention innovatively develops a multifunctional skin-soothing gel dressing based on nano-silver-protease complex technology. By forming a stable complex between nano-silver and protease through electrostatic and hydrophobic interactions, it not only significantly prolongs the action time of nano-silver (in vitro sustained release for over 72 hours), but also utilizes the encapsulation effect of protease molecules to reduce its cytotoxicity by 68%, while retaining the protease's ability to degrade inflammatory mediators (such as interleukin-6 and tumor necrosis factor). Furthermore, this complex, together with other nano-sized components in the formulation (such as liposome-loaded aloe polysaccharides and cucumber extract, and chitosan nanoparticles encapsulating allantoin), constructs a four-dimensional synergistic network of "moisturizing-anti-inflammatory-antibacterial-repair": the amphiphilic structure of liposomes simultaneously delivers hydrophilic / hydrophobic components to enhance transdermal absorption; the positive charge of chitosan nanoparticles targets the inflamed site to increase local concentration; the nano-silver-protease complex and chlorphenesin form a dual mechanism of "immediate sterilization-long-lasting antibacterial"; and the manganese oxide-tannic acid nanocomplex (ORAC≥800 μmol TE / g) synergistically regulates the redox microenvironment with the buffer system, enabling the gel to maintain pH While maintaining a concentration of 5.5 to 6.5, it enhances overall antioxidant capacity by scavenging reactive oxygen species (ROS) and activating the Nrf2 pathway. Ultimately, while fully preserving traditional ingredients, it achieves a synergistic improvement in transdermal efficiency, efficacy durability, and safety through nanoscale structural reorganization, providing a novel solution for the treatment of chronic skin inflammations such as atopic dermatitis and eczema. Attached Figure Description

[0016] Figure 1 The image shows the skin condition of the patient before medication in Example 1. Figure 2 This is a skin condition image of the patient 16 hours after application of the medication in Example 1; Figure 3 The image shows the skin condition of the patient before medication in Example 2. Figure 4 This is a skin condition image of the patient 24 hours after application of the medication in Example 2; Figure 5 This is a skin condition image of the patient 48 hours after application of the medication in Example 2; Figure 6 The image shows the skin condition of the patient in Example 3 before medication. Figure 7 The image shows the skin condition of the patient 2 hours after applying the medication in Example 3. Figure 8 The image shows the skin condition of the patient 16 hours after application of the medication in Example 3. Detailed Implementation

[0017] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0018] A method for preparing a multifunctional skin-soothing gel dressing includes the following steps: Step 1: Preparation of silver nanoparticle-protease complex: First, 0.1 mol / L silver nitrate solution and 1 mg / mL protease were pre-complexed at a mass ratio of 1:1.2 at 3-5℃ for 30 minutes. Ascorbic acid was added dropwise, and the mixture was stirred at 23-27℃ and 500-800 rpm for 2 hours. After purification by centrifugation using a 100 kDa ultrafiltration tube, nano-silver-protease complexes with a particle size of 20-50 nm (PDI<0.15) were obtained. In step 1, the molar ratio of silver nitrate to ascorbic acid in the silver nitrate solution is 1:1.2; Step 2, Preparation of liposomes: Then, DPPC, cholesterol, and active ingredients were dissolved in chloroform at a ratio of DPPC:cholesterol:active ingredient = 7:3:2.5~5. The mixture was then rotary evaporated at 38~42℃ and a vacuum of -0.09 MPa to form a film. After hydration with phosphate buffer (pH=6.8) preheated to 55℃, the film was subjected to ultrasonication for 5 minutes using a 200W probe and high-pressure homogenization cycling at 800 bar for 3 cycles to obtain liposomes with a particle size of 105~135 nm and an encapsulation efficiency >85%. The active ingredients include aloe polysaccharide and cucumber sterol in a mass ratio of 3:1; The amount of chloroform used is 10 to 20 times the total mass of DPPC, cholesterol, and active ingredients; Step 3: Preparation of chitosan nanoparticles: Then, a 0.5% (w / v) chitosan quaternary ammonium salt with a degree of deacetylation of 90% was dissolved in a 1% acetic acid solution to obtain a chitosan solution. The chitosan solution was then mixed with a 0.1%~0.3% (w / v) sodium tripolyphosphate aqueous solution at a volume ratio of 3:1 and stirred at 300~500 rpm for 20~30 minutes for cross-linking. Allantoin and acidic protease at pH=5 were loaded by physical adsorption at a mass ratio of 1:1 and purified by centrifugation through a 50 kDa ultrafiltration tube to obtain chitosan nanoparticles, forming a positively charged targeting system. The volume ratio of the chitosan quaternary ammonium salt to the acetic acid solution is 1:10, and the mass ratio of the allantoin to the chitosan solution is 1:5. Step 4: Preparation of PLGA microspheres: Then, PLGA with a molecular weight of 30 kDa and a lactic acid:glycolic acid ratio of 75:25 was dissolved in dichloromethane as the oil phase; the manganese oxide-tannic acid complex was dispersed in an aqueous solution containing 1% (w / v) PVA as the aqueous phase; the oil phase and the aqueous phase were mixed at a volume ratio of 1:3 and homogenized at 8000~10000 rpm for 2 min to form a primary emulsion, which was poured into a 0.5% (w / v) PVA aqueous solution and stirred and solidified at 500 rpm for 4 h. The mixture was then centrifuged and washed at 8000~10000 rpm for 10 min, and repeated 3 times. Finally, the mixture was freeze-dried at -50℃ for 48 h to obtain PLGA microspheres with a particle size of 130~170 nm. In step 4, the ratio of PLGA to dichloromethane is 1:20 (w / v), and the ratio of manganese oxide-tannic acid complex to 1% PVA aqueous solution is 1:50. In step 4, the manganese oxide-tannic acid complex is prepared by mixing manganese oxide and tannic acid in a mass ratio of 1:1, and the drug loading (manganese oxide-tannic acid complex) of the PLGA microspheres is ≥15%. Step 5: Prepare the gel dressing: Finally, under nitrogen protection, mix 15g of the following formula in the specified proportions. wt %~20 wt Dissolve % poloxamer 407 in pure water at 3-5°C for 2 hours, then add 0.002% poloxamer solution sequentially at 14-16°C. wt % ~0.005 wt % nano silver-protease complex, added at 11~13℃ wt %~3 wt % liposomes, add 0.5% at 7~9℃ wt %~2 wt % chitosan nanoparticles, 0.2 wt %~0.4 wt % sodium hyaluronate and 0.005 wt % ~ 0.01 wt % PLGA microspheres were stirred at 100~200 rpm for 20~30 minutes and then sterilized by irradiation to obtain a gel dressing.

[0019] Unless otherwise specified, all solutions mentioned above use pure water as the solvent.

[0020] The sources of the raw materials used in this invention are shown in Table 1.

[0021] Table 1. Raw Material Names and Sources

[0022] Example 1 A method for preparing a multifunctional skin-soothing gel dressing includes the following steps: Step 1: Preparation of silver nanoparticle-protease complex: First, a 0.1 mol / L silver nitrate solution and a 1 mg / mL protease were pre-complexed at 3℃ for 30 minutes at a mass ratio of 1:1.2. Ascorbic acid was then added dropwise, and the mixture was stirred at 23℃ and 500 rpm for 2 hours. After purification by centrifugation using a 100 kDa ultrafiltration tube, nano-silver-protease complexes with a particle size of 20-50 nm (PDI<0.15) were obtained. The molar ratio of silver nitrate to ascorbic acid in the silver nitrate solution was 1:1.2. Step 2, Preparation of liposomes: Then, DPPC, cholesterol, and active ingredients were dissolved in chloroform at a ratio of DPPC:cholesterol:active ingredient = 7:3:4. The mixture was then rotary evaporated at 38°C and a vacuum of -0.09 MPa to form a film. After hydration with phosphate buffer (pH 6.8) preheated to 55°C, the film was subjected to ultrasonication for 5 minutes using a 200W probe and high-pressure homogenization at 800 bar for 3 cycles to obtain liposomes with a particle size of 105–135 nm and an encapsulation efficiency >85%. The active ingredients include aloe polysaccharides and cucumber sterols in a mass ratio of 3:1; the mass of chloroform is 10 times the total mass of DPPC, cholesterol, and the active ingredients. Step 3: Preparation of chitosan nanoparticles: Then, a 0.5% (w / v) chitosan quaternary ammonium salt with a degree of deacetylation of 90% was dissolved in 10 times its volume of 1% acetic acid solution to obtain a chitosan solution. The chitosan solution was then mixed with a 0.1% (w / v) sodium tripolyphosphate aqueous solution at a volume ratio of 3:1 and stirred at 300 rpm for 20 minutes for cross-linking. Allantoin and acidic protease at pH=5.0 were loaded by physical adsorption at a mass ratio of 1:1 and purified by centrifugation through a 50 kDa ultrafiltration tube to obtain chitosan nanoparticles, forming a positively charged targeting system. The mass ratio of allantoin to chitosan solution is 1:5. Step 4: Preparation of PLGA microspheres: Then, PLGA with a molecular weight of 30 kDa and a lactic acid:glycolic acid ratio of 75:25 was dissolved in dichloromethane as the oil phase, with a PLGA to dichloromethane ratio of 1:20 (w / v). The manganese oxide-tannic acid complex was dispersed in an aqueous solution containing 1% (w / v) PVA as the aqueous phase, with a manganese oxide-tannic acid complex to 1% PVA aqueous solution mass ratio of 1:50. The oil phase and aqueous phase were then mixed at a volume ratio of 1:3 and homogenized at 8000 rpm for 2 min to form a primary emulsion. This emulsion was poured into a 0.5% (w / v) PVA aqueous solution and stirred and solidified at 500 rpm for 4 h. The mixture was then centrifuged and washed at 8000 rpm for 10 min, and this process was repeated 3 times. Finally, the mixture was freeze-dried at -50℃ for 48 h to obtain PLGA microspheres with a particle size of 130~170 nm, wherein the PLGA microspheres had a drug loading of ≥15% for the manganese oxide-tannic acid complex. Step 5: Prepare the gel dressing: Finally, under nitrogen protection, according to the formula ratio in Table 2, poloxamer 407 was dissolved in pure water at 3°C ​​for 2 hours. Then, nano-silver-protease complex was added sequentially at 14°C, liposomes were added at 11°C, chitosan nanoparticles, sodium hyaluronate and PLGA microspheres were added at 7°C. The mixture was stirred at 100 rpm for 20 minutes and then sterilized by irradiation to obtain the gel dressing.

[0023] Example 2 A method for preparing a multifunctional skin-soothing gel dressing includes the following steps: Step 1: Preparation of silver nanoparticle-protease complex: First, 0.1 mol / L silver nitrate solution and 1 mg / mL protease were pre-complexed at 4℃ for 30 minutes at a mass ratio of 1:1.2. Ascorbic acid was then added dropwise, and the mixture was stirred at 25℃ and 600 rpm for 2 hours. After purification by centrifugation using a 100 kDa ultrafiltration tube, nano-silver-protease complexes with a particle size of 20-50 nm (PDI<0.15) were obtained. The molar ratio of silver nitrate to ascorbic acid in the silver nitrate solution was 1:1.2. Step 2, Preparation of liposomes: Then, DPPC, cholesterol, and active ingredients were dissolved in chloroform at a ratio of DPPC:cholesterol:active ingredient = 7:3:4. The mixture was then rotary evaporated at 38°C and a vacuum of -0.09 MPa to form a film. After hydration with phosphate buffer (pH 6.8) preheated to 55°C, the film was subjected to ultrasonication for 5 minutes using a 200W probe and high-pressure homogenization at 800 bar for 3 cycles to obtain liposomes with a particle size of 105–135 nm and an encapsulation efficiency >85%. The active ingredients include aloe polysaccharides and cucumber sterols in a mass ratio of 3:1; the mass of chloroform is 15 times the total mass of DPPC, cholesterol, and the active ingredients. Step 3: Preparation of chitosan nanoparticles: Then, a 0.5% (w / v) chitosan quaternary ammonium salt with a degree of deacetylation of 90% was dissolved in 10 times its volume of 1% acetic acid solution to obtain a chitosan solution. The chitosan solution was then mixed with a 0.2% (w / v) sodium tripolyphosphate aqueous solution at a volume ratio of 3:1 and stirred at 400 rpm for 25 minutes for cross-linking. Allantoin and acidic protease at pH=5.0 were loaded by physical adsorption at a mass ratio of 1:1 and purified by centrifugation through a 50 kDa ultrafiltration tube to obtain chitosan nanoparticles, forming a positively charged targeting system. The mass ratio of allantoin to chitosan solution is 1:5. Step 4: Preparation of PLGA microspheres: Then, PLGA with a molecular weight of 30 kDa and a lactic acid:glycolic acid ratio of 75:25 was dissolved in dichloromethane as the oil phase, with a PLGA to dichloromethane ratio of 1:20 (w / v). The manganese oxide-tannic acid complex was dispersed in an aqueous solution containing 1% (w / v) PVA as the aqueous phase, with a mass ratio of 1:50. The oil and aqueous phases were then mixed at a volume ratio of 1:3 and homogenized at 9000 rpm for 2 min to form a primary emulsion. This emulsion was poured into a 0.5% (w / v) PVA aqueous solution and stirred and solidified at 500 rpm for 4 h. The mixture was then centrifuged and washed at 9000 rpm for 10 min, and this process was repeated three times. Finally, the mixture was freeze-dried at -50℃ for 48 h to obtain PLGA microspheres with a particle size of 130~170 nm, wherein the PLGA microspheres had a drug loading of ≥15% for the manganese oxide-tannic acid complex. Step 5: Prepare the gel dressing: Finally, under nitrogen protection, according to the formula ratio in Table 2, poloxamer 407 was dissolved in pure water at 4°C for 2 hours. Then, nano-silver-protease complex was added sequentially at 15°C, liposomes were added at 12°C, chitosan nanoparticles, sodium hyaluronate and PLGA microspheres were added at 8°C. The mixture was stirred at 150 rpm for 25 minutes and then sterilized by irradiation to obtain the gel dressing.

[0024] Example 3 A method for preparing a multifunctional skin-soothing gel dressing includes the following steps: Step 1: Preparation of silver nanoparticle-protease complex: First, 0.1 mol / L silver nitrate solution and 1 mg / mL protease were pre-complexed at 4℃ for 30 minutes at a mass ratio of 1:1.2. Ascorbic acid was then added dropwise, and the mixture was stirred at 25℃ and 600 rpm for 2 hours. After purification by centrifugation using a 100 kDa ultrafiltration tube, nano-silver-protease complexes with a particle size of 20-50 nm (PDI<0.15) were obtained. The molar ratio of silver nitrate to ascorbic acid in the silver nitrate solution was 1:1.2. Step 2, Preparation of liposomes: DPPC, cholesterol, and active ingredients were then dissolved in chloroform at a ratio of DPPC:cholesterol:active ingredient = 7:3:2.5. The mixture was then rotary evaporated at 40±2℃ and a vacuum of -0.09 MPa to form a film. After hydration with phosphate buffer (pH 6.8) preheated to 55℃, the film was subjected to ultrasonication for 3 minutes using a 200W probe and high-pressure homogenization at 800 bar for 3 cycles to obtain liposomes with a particle size of 105–135 nm and an encapsulation efficiency >85%. The active ingredients include aloe polysaccharides and cucumber sterols in a mass ratio of 3:1; the mass of chloroform is 15 times the total mass of DPPC, cholesterol, and the active ingredients. Step 3: Preparation of chitosan nanoparticles: Then, a 0.5% (w / v) chitosan quaternary ammonium salt with a degree of deacetylation of 90% was dissolved in 10 times its volume of 1% acetic acid solution to obtain a chitosan solution. The chitosan solution was then mixed with a 0.2% (w / v) sodium tripolyphosphate aqueous solution at a volume ratio of 3:1 and stirred at 400 rpm for 25 minutes for cross-linking. Allantoin and acidic protease at pH=5.0 were loaded by physical adsorption at a mass ratio of 1:1 and purified by centrifugation through a 50 kDa ultrafiltration tube to obtain chitosan nanoparticles, forming a positively charged targeting system. The mass ratio of allantoin to chitosan solution is 1:5. Step 4: Preparation of PLGA microspheres: Then, PLGA with a molecular weight of 30 kDa and a lactic acid:glycolic acid ratio of 75:25 was dissolved in dichloromethane as the oil phase, with a PLGA to dichloromethane ratio of 1:20 (w / v). The manganese oxide-tannic acid complex was dispersed in an aqueous solution containing 1% (w / v) PVA as the aqueous phase, with a mass ratio of 1:50. The oil and aqueous phases were then mixed at a volume ratio of 1:3 and homogenized at 9000 rpm for 2 min to form a primary emulsion. This emulsion was poured into a 0.5% (w / v) PVA aqueous solution and stirred and solidified at 500 rpm for 4 h. The mixture was then centrifuged and washed at 9000 rpm for 10 min, and this process was repeated three times. Finally, the mixture was freeze-dried at -50℃ for 48 h to obtain PLGA microspheres with a particle size of 130~170 nm, wherein the PLGA microspheres had a drug loading of ≥15% for the manganese oxide-tannic acid complex. Step 5: Prepare the gel dressing: Finally, under nitrogen protection, according to the formula ratio in Table 2, poloxamer 407 was dissolved in pure water at 4°C for 2 hours. Then, nano-silver-protease complex was added sequentially at 15°C, liposomes were added at 12°C, chitosan nanoparticles, sodium hyaluronate and PLGA microspheres were added at 8°C. The mixture was stirred at 150 rpm for 25 minutes and then sterilized by irradiation to obtain the gel dressing.

[0025] Example 4 A method for preparing a multifunctional skin-soothing gel dressing includes the following steps: Step 1: Preparation of silver nanoparticle-protease complex: First, a 0.1 mol / L silver nitrate solution and a 1 mg / mL protease were pre-complexed at a mass ratio of 1:1.2 at 5 °C for 30 minutes. Ascorbic acid was then added dropwise, and the mixture was stirred at 27 °C and 800 rpm for 2 hours. The mixture was then purified by centrifugation using a 100 kDa ultrafiltration tube to obtain a silver nanoparticle-protease complex with a particle size of 20–50 nm (PDI < 0.15). The molar ratio of silver nitrate to ascorbic acid in the silver nitrate solution was 1:1.2. Step 2, Preparation of liposomes: DPPC, cholesterol, and active ingredients were then dissolved in chloroform at a ratio of DPPC:cholesterol:active ingredient = 7:3:2.5. The mixture was then rotary evaporated at 42°C and a vacuum of -0.09 MPa to form a film. After hydration with phosphate buffer (pH 6.8) preheated to 55°C, the film was subjected to ultrasonication for 5 minutes using a 200W probe and high-pressure homogenization at 800 bar for 3 cycles to obtain liposomes with a particle size of 105–135 nm and an encapsulation efficiency >85%. The active ingredients include aloe polysaccharides and cucumber sterols in a mass ratio of 3:1; the mass of chloroform is 20 times the total mass of DPPC, cholesterol, and the active ingredients. Step 3: Preparation of chitosan nanoparticles: Then, a 0.5% (w / v) chitosan quaternary ammonium salt with a degree of deacetylation of 90% was dissolved in 10 times its volume of 1% acetic acid solution to obtain a chitosan solution. The chitosan solution was then mixed with a 0.3% (w / v) sodium tripolyphosphate aqueous solution at a volume ratio of 3:1 and stirred at 500 rpm for 30 minutes for cross-linking. Allantoin and acidic protease at pH=5.0 were loaded by physical adsorption at a mass ratio of 1:1 and purified by centrifugation through a 50 kDa ultrafiltration tube to obtain chitosan nanoparticles, forming a positively charged targeting system. The mass ratio of allantoin to chitosan solution is 1:5. Step 4: Preparation of PLGA microspheres: Then, PLGA with a molecular weight of 30 kDa and a lactic acid:glycolic acid ratio of 75:25 was dissolved in dichloromethane as the oil phase, with a PLGA to dichloromethane ratio of 1:20 (w / v). The manganese oxide-tannic acid complex was dispersed in an aqueous solution containing 1% (w / v) PVA as the aqueous phase, with a mass ratio of 1:50 between the manganese oxide-tannic acid complex and the 1% (w / v) PVA aqueous solution. The oil and aqueous phases were mixed at a volume ratio of 1:3 and homogenized at 10,000 rpm for 2 min to form a primary emulsion. This emulsion was then poured into a 0.5% (w / v) PVA aqueous solution and stirred and solidified at 500 rpm for 4 h. The mixture was then centrifuged and washed at 10,000 rpm for 10 min, and this process was repeated three times. Finally, the mixture was freeze-dried at -50℃ for 48 h to obtain PLGA microspheres with a particle size of 130~170 nm, wherein the PLGA microspheres had a drug loading of ≥15% for the manganese oxide-tannic acid complex. Step 5: Prepare the gel dressing: Finally, under nitrogen protection, according to the formula ratio in Table 2, poloxamer 407 was dissolved in pure water at 5°C for 2 hours. Then, nano-silver-protease complex was added sequentially at 16°C, liposomes were added at 13°C, chitosan nanoparticles, sodium hyaluronate and PLGA microspheres were added at 9°C, and the mixture was stirred at 200 rpm for 30 minutes. After irradiation sterilization, the gel dressing was obtained.

[0026] Table 2 shows the content of components in each embodiment.

[0027] This multifunctional skin-soothing gel dressing has established the following quality control standards: 1. Physical properties: Particle size distribution: D90 < 200 nm (PDI < 0.2) Viscosity: 10000-15000 cP (25℃); 2. Chemical indicators: Silver content: 0.9~1.1 μg / g (ICP-MS) Active ingredient content: batch variation <5% (HPLC); 3. Biological performance: Bacterial endotoxin: <0.5 EU / ml Antibacterial efficacy: MIC ≤ 1.25 μg / mL against Staphylococcus aureus.

[0028] The characteristics and usage of the gel dressings in each embodiment are described below: Example 1 (Specific type for atopic dermatitis) Target patients: Moderate to severe atopic dermatitis with impaired skin barrier Clinical trials have shown that it significantly shortens the time to relieve itching, improves symptoms of skin erythema and desquamation, and reduces the levels of inflammation-related biomarkers.

[0029] Innovative design: The use of acidic protease-modified silver nanocomplexes enhances the Th2-type inflammatory-targeting liposome co-delivery system and improves the transdermal efficiency of aloe polysaccharides.

[0030] Safety: The adverse reaction rate is low, mainly consisting of transient and mild irritation.

[0031] Example 2 (Chronic Eczema Type) Target patients: those with chronic eczema accompanied by recurrent infections and dry skin. Clinically validated: Significantly improves skin barrier function, reduces the frequency of eczema recurrence, and inhibits the colonization of pathogenic microorganisms.

[0032] Innovative Design: PLGA Microspheres (0.01 wt %): Achieves sustained release of allantoin and cucumber extract over 72 hours.

[0033] Example 3 (Allergy Recovery Type) Target patients: Patients with skin erythema, papules, itching and barrier damage caused by acute allergies (such as contact dermatitis, urticaria).

[0034] Clinical trials have shown that this treatment rapidly relieves allergy symptoms: erythema area is reduced by 90% and itching disappears 4 hours after application; it also repairs the skin barrier and inhibits excessive immune responses. Innovative Design: Nano-Silver-Protein Complex (0.002) wt%) By precisely controlling the release rate of silver ions (0.05 μg / cm / day), it targets and kills colonizing bacteria (such as Staphylococcus aureus, with a sterilization rate of >99.9%), while using proteases to degrade interleukin-4 and histamine (with an activity retention of ≥90%), thus inhibiting mast cell degranulation. Barrier repair synergistic network: Sodium hyaluronate (0.4%) wt %) Low molecular weight (5 kDa) penetrates deep into the epidermis and forms a three-dimensional moisturizing network with chitosan nanoparticles through hydrogen bonds (in vitro water retention rate ≥90%), synergistically repairing tight junction protein ZO-1 (expression level +2-fold). Long-lasting immune modulation: PLGA microspheres (0.005) wt %): Slow-release allantoin, continuously inhibiting TSLP (thymic stromal lymphopoietin) release, regulating Th1 / Th2 balance; DPPC / cholesterol liposomes (2.0%) wt %): Co-loaded with aloe polysaccharides and cucumber sterols, it enhances epidermal lipid synthesis (ceramide content +40%) and resists allergen penetration.

[0035] Example 4 (Mild version for sensitive skin) Target patients: Patients with sensitive skin, rosacea, or allergic dermatitis Clinically proven: Significantly reduces skin redness and burning sensation, improves skin tolerance, and maintains skin microecological balance.

[0036] Safety Design: Minimal dose of nano-silver combined with natural soothing ingredients, no traditional preservatives added.

[0037] Applicable scenarios: routine care and combined treatment during the acute phase.

[0038] Application Example 1 Description of the condition: The patient is a 9-year-old female diagnosed with atopic dermatitis, with a disease course of 3 years.

[0039] Main symptoms: Extensive erythema and desquamation of the skin on both upper limbs and neck, accompanied by intense itching, with local epidermal lesions and Staphylococcus aureus colonization (bacterial load 10). 6 CFU / cm 2 ), impaired skin barrier function.

[0040] Dosage regimen: Using an intermittent administration regimen, after cleaning the affected area, the gel dressing prepared in Example 1 was applied evenly every 4 hours (q4h) for 16 hours, for a total of 4 administrations. The recovery process was as follows. Figures 1-2 As shown.

[0041] Recovery process ( Figures 1-2 ): Before medication ( Figure 1 : The area of ​​skin erythema accounts for 80%, and obvious scales and scratches are visible on the surface; 16 hours after medication ( Figure 2 The erythema area decreased to 30%, the itching sensation was reduced, and the basic integrity of the epidermis was restored.

[0042] Application Example 2 Description of the condition: The patient is a 45-year-old female with a 5-year history of chronic eczema, accompanied by recurrent bacterial infections and dry, itchy, and burning skin. The skin lesions present with hyperkeratosis, fissures, and exudation. Previous conventional hormone therapy has been ineffective and mild skin atrophy has occurred.

[0043] Dosage regimen: Using an intermittent dosing regimen, the gel dressing prepared in Example 2 was applied to the affected area, with multiple doses administered at 4-hour intervals (q4h). After completing the dosing regimen for 24 hours and 48 hours, the recovery process was as follows. Figures 3-5 As shown.

[0044] Recovery process ( Figures 3-5 ): Before medication ( Figure 3 ): Thickened keratinization of the neck skin, multiple red and swollen areas with slight exudation and burning sensation; 24 hours after medication ( Figure 4 Exudation stopped, and the area of ​​erythema decreased by 50%. 48 hours after medication ( Figure 5 ): The eczema area has basically healed (healing rate 95%).

[0045] After administration, the dryness, itching, and burning sensation of the skin disappeared. Follow-up was conducted every 2 days for 28 days. There were no discomforts or eczema recurrences. It can be used for long-term maintenance treatment.

[0046] Application Example 3 Description of the condition: The patient is a 57-year-old female who presented with an acute allergic reaction on her neck due to contact irritation (from an unknown insect). Symptoms included extensive erythema, dense papules, intense itching (VAS score 9.0), local skin swelling (increased thickness by 1.5 mm), burning sensation, and minor epidermal lesions.

[0047] Dosage regimen: After cleaning the affected area, apply the gel dressing prepared in Example 4 evenly every 2 hours (q4h) for 16 hours (a total of 8 administrations).

[0048] Recovery process ( Figures 6-8 ): Before medication ( Figure 6Diffuse erythema on the neck skin, densely distributed papules, slight epidermal exudation, and swelling area accounting for 70% of the total area; Two hours after medication ( Figure 7 The erythema area decreased by 50%, the pruritus score dropped to 5.2 (VAS), and the burning sensation was significantly reduced. 16 hours after medication ( Figure 8 ): Erythema has basically subsided (area percentage <10%), papules have flattened, and swelling has been completely relieved.

[0049] The above embodiments and figures are not intended to limit the product form and style of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A method for preparing a multifunctional skin-soothing gel dressing, characterized in that: Includes the following steps: Step 1: Preparation of silver nanoparticle-protease complex: First, silver nitrate solution and protease were pre-complexed at a mass ratio of 1:1.2 at 3~5℃ for 30 minutes. Ascorbic acid was added dropwise and the reaction was stirred at 23~27℃ for 2 hours. After purification by centrifugation in a 100 kDa ultrafiltration tube, nano-silver-protease complexes with a particle size of 20~50 nm (PDI<0.15) were obtained. Step 2, Preparation of liposomes: Then, DPPC, cholesterol, and active ingredients were dissolved in chloroform at a ratio of DPPC:cholesterol:active ingredient = 7:3:2.5~5. After rotary evaporation to form a film, the film was hydrated with phosphate buffer at pH 6.8, and then subjected to ultrasonication for 5 minutes with a 200W probe and high-pressure homogenization at 800 bar for 3 cycles to obtain liposomes with a particle size of 105~135 nm and an encapsulation efficiency >85%. The active ingredients include aloe polysaccharide and cucumber sterol in a mass ratio of 3:1; Step 3: Preparation of chitosan nanoparticles: Then, chitosan quaternary ammonium salt with a degree of deacetylation of 90% was dissolved in 1% acetic acid solution to obtain chitosan solution. Then, the chitosan solution was crosslinked with 0.1%~0.3% (w / v) sodium tripolyphosphate aqueous solution at a volume ratio of 3:1 under stirring for 20~30 minutes. Allantoin and acidic protease were loaded by physical adsorption at a mass ratio of 1:

1. After purification by centrifugation in a 50 kDa ultrafiltration tube, chitosan nanoparticles were obtained, forming a positively charged targeting system. Step 4: Preparation of PLGA microspheres: PLGA was then dissolved in dichloromethane as the oil phase; the manganese oxide-tannic acid complex was dispersed in an aqueous solution containing 1% (w / v) PVA as the aqueous phase; the oil phase and aqueous phase were mixed at a volume ratio of 1:3, homogenized at high speed to form a primary emulsion, poured into a 0.5% (w / v) PVA aqueous solution, stirred and solidified for 4 h, centrifuged and washed multiple times, and freeze-dried to obtain PLGA microspheres with a particle size of 130~170 nm; Step 5: Prepare the gel dressing: Finally, under nitrogen protection, press 100 wt % of the formula ratio, use 15 wt %~20 wt Dissolve % poloxamer 407 in pure water at 3-5°C for 2 hours, then add 0.002% poloxamer solution sequentially at 14-16°C. wt % ~0.005 wt % nano silver-protease complex, added at 11~13℃ wt %~3 wt % liposomes, add 0.5% at 7~9℃ wt %~2 wt % chitosan nanoparticles, 0.2 wt %~0.4 wt % sodium hyaluronate and 0.005 wt % ~ 0.01 wt % PLGA microspheres, stirred for 20-30 minutes, and sterilized by irradiation to obtain a gel dressing; the amount of pure water used is the balance.

2. The method for preparing a multifunctional skin-soothing gel dressing according to claim 1, characterized in that: In step 1, the molar ratio of silver nitrate to ascorbic acid in the silver nitrate solution is 1:1.2, and the stirring speed is 500~800 rpm.

3. The method for preparing a multifunctional skin-soothing gel dressing according to claim 1, characterized in that: In step 2, the mass of chloroform used is 10 to 20 times the total mass of DPPC, cholesterol, and active ingredients, the temperature of rotary evaporation is 38 to 42°C, and the vacuum degree of rotary evaporation is -0.09 MPa.

4. The method for preparing a multifunctional skin-soothing gel dressing according to claim 1, characterized in that: In step 3, the concentration of the chitosan quaternary ammonium salt is 0.5% (w / v), the volume ratio of the chitosan quaternary ammonium salt to the acetic acid solution is 1:10, the mass ratio of the allantoin to the chitosan solution is 1:5, and the pH of the acidic protease is 5.

0.

5. The method for preparing a multifunctional skin-soothing gel dressing according to claim 1, characterized in that: In step 3, the stirring speed is 300~500 rpm.

6. The method for preparing a multifunctional skin-soothing gel dressing according to claim 1, characterized in that: In step 4, the ratio of lactic acid to glycolic acid in the PLGA is 75:25, the molecular weight of the PLGA is 30 kDa, the manganese oxide-tannic acid complex is prepared by manganese oxide and tannic acid in a mass ratio of 1:1, and the drug loading of the PLGA microspheres on the manganese oxide-tannic acid complex is ≥15%.

7. The method for preparing a multifunctional skin-soothing gel dressing according to claim 1, characterized in that: In step 4, the ratio of PLGA to dichloromethane is 1:20 (w / v), and the ratio of manganese oxide-tannic acid complex to 1% PVA aqueous solution is 1:

50.

8. The method for preparing a multifunctional skin-soothing gel dressing according to claim 1, characterized in that: In step 4, the high-speed homogenization speed is 8000~10000 rpm, the high-speed homogenization time is 2 min, the stirring speed is 500 rpm, the centrifugal washing speed is 8000~10000 rpm, and the centrifugal washing time is 10 min.

9. The method for preparing a multifunctional skin-soothing gel dressing according to claim 1, characterized in that: In step 5, the stirring speed is 100~200 rpm.

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