PH response type self-supply H2O2 material with antibacterial property and preparation method thereof

Abstract

The invention discloses a pH response type self-supply H2O2 material with antibacterial performance, which comprises a dressing main body, the material is provided with a chitosan shell and internal peroxide, the peroxide is self-decomposed under an acidic condition to release H2O2 with bactericidal activity and substances harmless to a human body, and the dressing main body is provided with Prussian blue. Compared with the prior art, the preparation method has the advantages that 1, decomposition of a chitosan shell under an acidic condition is matched, and H2O2 is released by peroxide under the acidic condition, so that accumulation of a bactericide at an infected part is enhanced, and toxicity to surrounding tissues can be reduced at the same time; the defect that in the prior art, large damage is possibly caused to surrounding healthy tissues is overcome, and bacterial drug resistance cannot be caused; 2, prussian blue has obvious color change and good stability, reliable indication information can be provided in scenes such as analysis experiments, and detection and antibiosis of bacterial infection can be realized at the same time;

Description

Technical Field

[0001] The present invention relates to the technical field, and in particular to a pH-responsive self-supplied H2O2 material with antibacterial properties and a preparation method thereof. Background Art

[0002] When some drugs in the prior art are used for covering treatment of wounds, these drugs generally only play a restorative role, but they are easy to cause bacterial growth and infection around the wound tissue, so some bactericidal drugs are often added to the basic restorative drugs for use in conjunction. However, the direct use of bactericidal drugs will first make the bacteria have a certain drug resistance before the bacteria are produced, and long-term use will easily cause greater damage to the surrounding healthy tissues. At the same time, the drugs in the prior art cannot quickly and intuitively observe the production of bacteria. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a pH-responsive self-supplied H2O2 material with antibacterial properties and a preparation method thereof in view of the deficiencies raised in the above-mentioned background technology.

[0004] In order to solve the above technical problems, the technical solution provided by the present invention is: a pH-responsive self-supplied H2O2 material with antibacterial properties, which includes a dressing body having a chitosan shell and internal peroxide.

[0005] Furthermore, the dressing body contains Prussian blue.

[0006] The specific steps of the preparation method are as follows:

[0007] Step 1: Preparation of peroxide, wherein the peroxide includes ZnO2, CaO2, etc.

[0008] Step 2: Preparation of dressing;

[0009] Step 3: Dressing preparation with Prussian blue.

[0010] Furthermore, the specific content of the dressing preparation in step 2 is as follows: the chitosan powder is fully dissolved with the acetic acid solution of the corresponding peroxide, the dissolved chitosan-ion solution is freeze-dried, the obtained sponge-like acetic acid-chitosan dressing is fully stirred with a 5% sodium hydroxide solution, and then a 30% hydrogen peroxide solution is added to react for 0.5h, and then the alkali solution is poured out, the aqueous solution of the dressing is squeezed out, and the sponge-like dressing is washed with ultrapure water for 4-5 times, the dressing is squeezed out, and placed in a centrifuge tube filled with anhydrous ethanol. The dressing immediately absorbs the ethanol and quickly sinks to the bottom of the centrifuge tube, and is placed in a -20°C refrigerator for cryopreservation to obtain a peroxide-chitosan dressing.

[0011] Furthermore, the peroxide-chitosan dressing prepared in step 2 is placed in a K4[Fe(CN)6] solution, squeezed with tweezers to allow the dressing to absorb the solution, then the dressing is gently clipped out and immersed in a FeCl3 solution for 6 to 7 minutes. The operation is repeated twice to ensure that the dressing is evenly dyed. The sponge-like dressing is washed with ultrapure water for about 2 to 3 times, the dressing is squeezed dry, and placed in a centrifuge tube containing anhydrous ethanol. The dressing immediately absorbs ethanol and quickly sinks to the bottom of the centrifuge tube, and is placed in a -20°C refrigerator for cryopreservation to obtain a Prussian blue-peroxide-chitosan dressing.

[0012] Further, the preparation of Prussian blue-ZnO2-chitosan is as follows: weigh chitosan powder, add zinc acetate solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan-zinc ion mixed solution, after ultrasonic degassing, pre-freeze at -80°C, and after the solution is completely frozen, move it into a vacuum freeze dryer for freeze drying for 8 hours. After completion, the obtained spongy zinc acetate-chitosan dressing is injected into the inner tank of the reactor with 5% sodium hydroxide solution, and the spongy zinc acetate-chitosan dressing and a stirring bar are placed, the inner tank lid is covered, and stirred on a magnetic stirrer. After the stirring is completed, a 30% hydrogen peroxide solution is added, and the alkali solution is poured out after reacting for 0.5 hours, and the alkali solution is squeezed out. The aqueous solution of the dressing is taken out, the sponge-like dressing is washed with ultrapure water for about 4-5 times, the dressing is squeezed dry, and placed in a centrifuge tube filled with about anhydrous ethanol, and stored in a -20°C refrigerator. After squeezing out the ethanol in the dressing with tweezers, the dressing is placed in a K4[Fe(CN)6] solution, and the dressing is squeezed with tweezers to make the dressing absorb the solution. The dressing is then gently clipped out and immersed in a FeCl3 solution for 6-7 minutes. The operation is repeated twice to make the dressing evenly dyed. The sponge-like dressing is washed with ultrapure water for about 2-3 times, the dressing is squeezed dry, and placed in a centrifuge tube filled with anhydrous ethanol. The dressing immediately absorbs the ethanol and quickly sinks to the bottom of the centrifuge tube, and is stored in a -20°C refrigerator to obtain a Prussian blue-ZnO2-chitosan dressing.

[0013] After adopting the above structure, the present invention has the following advantages: 1. The chitosan shell is decomposed under acidic conditions and peroxide is used to release H2O2 under acidic conditions, thereby enhancing the accumulation of the bactericide at the infection site and reducing the toxicity to the surrounding tissues, thereby overcoming the disadvantage of the prior art that the surrounding healthy tissues may be greatly damaged and will not cause bacterial resistance;

[0014] 2. Prussian blue has obvious color changes and good stability. It can provide reliable indication information in analytical experiments and other scenarios, and can simultaneously detect bacterial infections and achieve antibacterial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1It is a schematic diagram of the anti-Staphylococcus aureus effect of a chitosan dressing of a pH-responsive self-supplying H2O2 material with antibacterial properties and a preparation method thereof of the present invention;

[0016] Figure 2 It is a schematic diagram of the anti-Staphylococcus aureus effect of a Prussian blue-chitosan dressing of a pH-responsive self-supplying H2O2 material with antibacterial properties and a preparation method thereof of the present invention;

[0017] Figure 3 It is a schematic diagram of the anti-Staphylococcus aureus effect of a ZnO-chitosan dressing of a pH-responsive self-supplying H2O2 material with antibacterial properties and a preparation method thereof of the present invention;

[0018] Figure 4 It is a schematic diagram of the anti-Staphylococcus aureus effect of a Prussian blue-ZnO-chitosan dressing of a pH-responsive self-supplied H2O2 material with antibacterial properties and a preparation method thereof of the present invention;

[0019] Figure 5 It is a schematic diagram of the anti-Staphylococcus aureus effect of a ZnO2-chitosan dressing of a pH-responsive self-supplied H2O2 material with antibacterial properties and a preparation method thereof;

[0020] Figure 6 It is a schematic diagram of the anti-Staphylococcus aureus effect of Prussian blue-ZnO2-chitosan of a pH-responsive self-supplying H2O2 material with antibacterial properties and a preparation method thereof of the present invention;

[0021] Figure 7 It is a schematic diagram of the anti-Staphylococcus aureus effect of CaO-chitosan of a pH-responsive self-supplying H2O2 material with antibacterial properties and a preparation method thereof of the present invention;

[0022] Figure 8 It is a schematic diagram of the anti-Staphylococcus aureus effect of Prussian blue-CaO-chitosan of a pH-responsive self-supplying H2O2 material with antibacterial properties and a preparation method thereof of the present invention;

[0023] Fig. 9 It is a schematic diagram of the anti-Staphylococcus aureus effect of CaO2-chitosan of a pH-responsive self-supplied H2O2 material with antibacterial properties and a preparation method thereof of the present invention;

[0024] Fig.10 It is a schematic diagram of the anti-Staphylococcus aureus effect of Prussian blue-CaO2-chitosan of a pH-responsive self-supplying H2O2 material with antibacterial properties and a preparation method thereof of the present invention;

[0025] Fig.11It is a schematic diagram of the inspection effect of a pH-responsive self-supplying H2O2 material with antibacterial properties and a preparation method thereof of the present invention;

[0026] Fig.12 It is a schematic diagram of the absorbance curve of auxiliary materials of a pH-responsive self-supplied H2O2 material with antibacterial properties and a preparation method thereof of the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0028] Combined with Figure 1 A pH-responsive self-supplied H2O2 material with antibacterial properties comprises a dressing body, wherein the material comprises a chitosan shell and internal peroxides. The material comprises a chitosan shell and is relatively stable under neutral conditions, but exhibits acid-responsive dissociation characteristics under a slightly acidic environment of bacterial infection. After the chitosan shell dissociates, peroxides such as CaO2 and ZnO2 are released in situ. CaO2 or ZnO2 will self-decompose under acidic conditions to release bactericidal H2O2 and Ca2+ and Zn2+ that are harmless to the human body. ROS are generated by the decomposition of H2O2 to irreversibly destroy bacterial proteins, DNA, etc., thereby achieving the purpose of antibacterial treatment without generating drug resistance. Under neutral environmental conditions of normal tissues, the chitosan shell of the material will not be destroyed and will not release CaO2 or ZnO2. In addition, the H2O2 generated by CaO2 or ZnO2 will self-decompose to generate harmless H2O and O2, and will not damage normal tissues.

[0029] The specific steps are as follows:

[0030] Step 1: Preparation of peroxide, wherein the peroxide includes ZnO2, CaO2, etc.

[0031] Step 2: Preparation of dressing. The specific content of the dressing preparation in step 2 is as follows: fully dissolve chitosan powder and acetic acid solution of corresponding peroxide, freeze-dry the dissolved chitosan-ion solution, and fully stir the obtained sponge-like acetic acid-chitosan dressing with 5% sodium hydroxide solution, then add 30% hydrogen peroxide solution to react for 0.5h, pour out the alkali solution, squeeze out the aqueous solution of the dressing, wash the sponge-like dressing with ultrapure water for 4-5 times, squeeze out the dressing, put it into a centrifuge tube filled with anhydrous ethanol, the dressing immediately absorbs ethanol and quickly sinks to the bottom of the centrifuge tube, and put it in a -20°C refrigerator for cryopreservation to obtain a peroxide-chitosan dressing.

[0032] Step 3: Preparation of dressing with Prussian blue. Place the peroxide-chitosan dressing prepared in step 2 into K4[Fe(CN)6] solution, squeeze with tweezers to make the dressing absorb the solution, then gently clip the dressing out and immerse it in FeCl3 solution for 6-7 minutes. Repeat the operation twice to make the dressing evenly dyed. Wash the sponge dressing with ultrapure water for about 2-3 times, squeeze the dressing dry, and place it in a centrifuge tube filled with anhydrous ethanol. The dressing immediately absorbs ethanol and quickly sinks to the bottom of the centrifuge tube. Place it in a -20°C refrigerator for cryopreservation to obtain Prussian blue-peroxide-chitosan dressing.

[0033] The preparation of Prussian blue-ZnO2-chitosan is as follows: weigh chitosan powder, add zinc acetate solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan-zinc ion mixed solution, and after ultrasonic degassing, pre-freeze at -80°C. After the solution is completely frozen, move it into a vacuum freeze dryer for freeze drying for 8 hours. After completion, inject 5% sodium hydroxide solution into the inner tank of the reactor to obtain the spongy zinc acetate-chitosan dressing, and put the spongy zinc acetate-chitosan dressing and a stirring bar into it. Cover the inner tank lid and stir on a magnetic stirrer. After the stirring is completed, add 30% hydrogen peroxide solution, react for 0.5 hours, pour out the alkali solution, and squeeze out the dressing. The dressing was washed with ultrapure water for about 4-5 times, squeezed dry, placed in a centrifuge tube filled with anhydrous ethanol, and stored in a -20°C refrigerator. The ethanol in the dressing was squeezed out with tweezers, and then placed in a K4[Fe(CN)6] solution. The dressing was squeezed with tweezers to make the dressing absorb the solution. The dressing was gently clipped out and immersed in a FeCl3 solution for 6-7 minutes. The operation was repeated twice to make the dressing evenly dyed. The sponge dressing was washed with ultrapure water for about 2-3 times, squeezed dry, and placed in a centrifuge tube filled with anhydrous ethanol. The dressing immediately absorbed the ethanol and quickly sank to the bottom of the centrifuge tube. It was stored in a -20°C refrigerator to obtain a Prussian blue-ZnO2-chitosan dressing.

[0034] The specific experimental examples are as follows:

[0035] Preparation of comparative materials:

[0036] 1. Specific preparation of chitosan:

[0037] Weigh 0.5g chitosan powder, add 25mL 2% acetic acid solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan solution; after ultrasonic degassing, pour about 400μL of the mixed solution into a 48-well plate and pre-freeze at -80℃; after the solution is completely frozen for a period of time, immediately move it into a vacuum freeze dryer for freeze drying for 8h, and after completion, the obtained sponge-like chitosan dressing will be obtained.

[0038] 2. Specific preparation of Prussian blue-chitosan:

[0039] Weigh 0.5g chitosan powder, add 25mL 2% acetic acid solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan solution; after ultrasonic degassing, pour about 400μL of the mixed solution into a 48-well plate and pre-freeze at -80°C; after the solution is completely frozen for a period of time, immediately move it into a vacuum freeze dryer for freeze drying for 8h, and after completion, a sponge-like chitosan dressing will be obtained. The dressing is placed in a 10mL centrifuge tube containing about 10mL anhydrous ethanol. The dressing immediately absorbs ethanol and quickly sinks to the bottom of the centrifuge tube. Weigh 160mg FeCl3 and 20mL ultrapure water to prepare a FeCl3 solution. Liquid, weigh 120mgK4[Fe(CN)6] and 20mL ultrapure water to prepare K4[Fe(CN)6] solution, squeeze out the ethanol in the dressing with tweezers, put it into the K4[Fe(CN)6] solution, squeeze it with tweezers to make the dressing absorb the solution, then gently clip the dressing out, immerse it in FeCl3 solution for 6-7min, repeat the operation twice to make the dressing evenly dyed, wash the sponge dressing with ultrapure water for about 2-3 times, squeeze the dressing, put it into a 10mL centrifuge tube containing about 10mL anhydrous ethanol, the dressing immediately absorbs ethanol and quickly sinks to the bottom of the centrifuge tube, and put it in a -20℃ refrigerator for cryopreservation to obtain Prussian blue-chitosan dressing.

[0040] 3. Specific preparation of ZnO-chitosan:

[0041] Weigh 0.5g chitosan powder, add 25mL zinc acetate solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan-zinc ion mixed solution; after ultrasonic degassing, pour about 400μL of the mixed solution into a 48-well plate and pre-freeze at -80℃; after the solution is completely frozen for a period of time, immediately move it into a vacuum freeze dryer for freeze drying for 8h, and after completion, pick out the spongy zinc acetate-chitosan dressing with an ear pick and a needle, and place it in 25mL of a reaction mixture. 12 mL of 5% sodium hydroxide solution was injected into the inner pot of the kettle, and the spongy zinc acetate-chitosan dressing and a stirring bar were placed therein. The inner pot lid was closed and stirred on a magnetic stirrer. After reacting for 0.5 h, the alkali solution was poured out, the aqueous solution of the dressing was squeezed out, the spongy dressing was washed with ultrapure water for about 4-5 times, the dressing was squeezed dry, and placed in a 10 mL centrifuge tube containing about 10 mL of anhydrous ethanol. The dressing immediately absorbed the ethanol and quickly sank to the bottom of the centrifuge tube, and was placed in a -20°C refrigerator for cryopreservation to obtain a ZnO-chitosan dressing.

[0042] 4. Specific preparation of Prussian blue-ZnO-chitosan:

[0043] Weigh 0.5g of chitosan powder, add 25mL of zinc acetate solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan-zinc ion mixed solution; after ultrasonic degassing, pour about 400μL of the mixed solution into a 48-well plate and pre-freeze at -80°C; after the solution is completely frozen for a period of time, immediately move it into a vacuum freeze dryer for freeze drying for 8h, and after completion, pick out the obtained spongy zinc acetate-chitosan dressing with an ear pick and a needle, inject 12mL of 5% sodium hydroxide solution into a 25mL reactor liner, and put in the spongy zinc acetate-chitosan dressing and a stirring bar, cover the liner lid, stir on a magnetic stirrer, and after reacting for 0.5h, pour out the alkali solution, squeeze out the dressing's aqueous solution, wash the spongy dressing with ultrapure water for about 4-5 times, squeeze the dressing dry, and put it into a container containing about 10m The dressing was placed in a 10 mL centrifuge tube containing 1 L of anhydrous ethanol and frozen in a -20°C refrigerator for storage. 160 mg FeCl3 and 20 mL of ultrapure water were weighed to prepare a FeCl3 solution. 120 mg K4[Fe(CN)6] and 20 mL of ultrapure water were weighed to prepare a K4[Fe(CN)6] solution. The ethanol in the dressing was squeezed out with tweezers and then placed in the K4[Fe(CN)6] solution. The dressing was squeezed with tweezers to make the dressing absorb the solution. The dressing was then gently clipped out and immersed in the FeCl3 solution for 6 to 7 minutes. The operation was repeated twice to make the dressing evenly dyed. The sponge dressing was washed with ultrapure water for about 2 to 3 times, the dressing was squeezed dry, and placed in a 10 mL centrifuge tube containing about 10 mL of anhydrous ethanol. The dressing immediately absorbed the ethanol and quickly sank to the bottom of the centrifuge tube. The dressing was placed in a -20°C refrigerator for storage to obtain a Prussian blue-ZnO-chitosan dressing.

[0044] 5. Specific preparation of CaO-chitosan:

[0045] Weigh 0.5g chitosan powder, add 25mL calcium acetate solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan-calcium ion mixed solution; after ultrasonic degassing, pour about 400μL of the mixed solution into a 48-well plate and pre-freeze at -80℃; after the solution is completely frozen for a period of time, immediately move it into a vacuum freeze dryer for freeze drying for 8h. After completion, the spongy calcium acetate-chitosan dressing is picked out with an ear pick and a needle, and placed in 25mL of a reaction 12 mL of 5% sodium hydroxide solution was injected into the inner pot, and a spongy calcium acetate-chitosan dressing and a stirring bar were placed in it. The inner pot lid was closed and stirred on a magnetic stirrer. After reacting for 0.5 h, the alkali solution was poured out, the aqueous solution of the dressing was squeezed out, the spongy dressing was washed with ultrapure water for about 4-5 times, the dressing was squeezed dry, and placed in a 10 mL centrifuge tube containing about 10 mL of anhydrous ethanol. The dressing immediately absorbed the ethanol and quickly sank to the bottom of the centrifuge tube, and was placed in a -20°C refrigerator for cryopreservation to obtain a CaO-chitosan dressing.

[0046] 6. Specific preparation of Prussian blue-CaO-chitosan:

[0047] Weigh 0.5g of chitosan powder, add 25mL of calcium acetate solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan-calcium ion mixed solution; after ultrasonic degassing, pour about 400μL of the mixed solution into a 48-well plate and pre-freeze at -80°C; after the solution is completely frozen for a period of time, immediately move it into a vacuum freeze dryer for freeze drying for 8h, and after completion, pick out the obtained sponge-like calcium acetate-chitosan dressing with an ear pick and a needle, inject 12mL of 5% sodium hydroxide solution into a 25mL reactor liner, and put in the sponge-like calcium acetate-chitosan dressing and a stirring bar, cover the liner lid, stir on a magnetic stirrer, and after reacting for 0.5h, pour out the alkali solution, squeeze out the aqueous solution of the dressing, wash the sponge-like dressing with ultrapure water for about 4-5 times, squeeze the dressing dry, and put it into a container containing about 10m The dressing was placed in a 10 mL centrifuge tube containing 1 L of anhydrous ethanol and frozen in a -20°C refrigerator for storage. 160 mg FeCl3 and 20 mL of ultrapure water were weighed to prepare a FeCl3 solution. 120 mg K4[Fe(CN)6] and 20 mL of ultrapure water were weighed to prepare a K4[Fe(CN)6] solution. The ethanol in the dressing was squeezed out with tweezers and then placed in the K4[Fe(CN)6] solution. The dressing was squeezed with tweezers to make the dressing absorb the solution. The dressing was gently clipped out and immersed in the FeCl3 solution for 6 to 7 minutes. The operation was repeated twice to make the dressing evenly dyed. The sponge dressing was washed with ultrapure water for about 2 to 3 times, the dressing was squeezed dry, and placed in a 10 mL centrifuge tube containing about 10 mL of anhydrous ethanol. The dressing immediately absorbed the ethanol and quickly sank to the bottom of the centrifuge tube. The dressing was placed in a -20°C refrigerator for storage to obtain a Prussian blue-CaO-chitosan dressing.

[0048] Preparation of antimicrobial dressings:

[0049] 1. Specific preparation of ZnO2-chitosan:

[0050] Weigh 0.5 g of chitosan powder, add 25 mL of zinc acetate solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan-zinc ion mixed solution; after ultrasonic degassing, pour about 400 μL of the mixed solution into a 48-well plate and pre-freeze at -80°C; after the solution is completely frozen for a period of time, immediately move it into a vacuum freeze dryer for freeze drying for 8 hours. After completion, pick out the spongy zinc acetate-chitosan dressing with an ear pick and a needle, and inject 1 2mL5% sodium hydroxide solution, and put in the spongy zinc acetate-chitosan dressing and a stirring bar, cover the inner pot lid, stir on a magnetic stirrer, add 3mL30% hydrogen peroxide solution, react for 0.5h, pour out the alkali solution, squeeze out the aqueous solution of the dressing, wash the spongy dressing with ultrapure water for about 4-5 times, squeeze out the dressing, put it in a 10mL centrifuge tube containing about 10mL anhydrous ethanol, the dressing immediately absorbs ethanol and quickly sinks to the bottom of the centrifuge tube, and put it in a -20℃ refrigerator for cryopreservation to obtain ZnO2-chitosan dressing.

[0051] 2. Specific preparation of CaO2-chitosan:

[0052] Weigh 0.5g chitosan powder, add 25mL zinc calcium acetate solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan-calcium ion mixed solution; after ultrasonic degassing, pour about 400μL of the mixed solution into a 48-well plate and pre-freeze at -80°C; after the solution is completely frozen for a period of time, immediately move it into a vacuum freeze dryer for freeze drying for 8h, and after completion, pick out the sponge-like calcium acetate-chitosan dressing with an ear pick and a needle, and inject 12mL of 5% hydroxide into the liner of a 25mL reactor. Sodium solution, and put sponge-like calcium acetate-chitosan dressing and a stirring bar, cover the inner pot lid, stir on a magnetic stirrer, add 3mL30% hydrogen peroxide solution, react for 0.5h, pour out the alkali solution, squeeze out the dressing water solution, wash the sponge-like dressing with ultrapure water for about 4-5 times, squeeze out the dressing, put it in a 10mL centrifuge tube containing about 10mL anhydrous ethanol, the dressing immediately absorbs ethanol and quickly sinks to the bottom of the centrifuge tube, and put it in a -20℃ refrigerator for cryopreservation to obtain CaO2-chitosan dressing. The specific preparation of Prussian blue-CaO2-chitosan is as follows:

[0053] Preparation of dressings with simultaneous observation of bacterial production and antibacterial effect:

[0054] 1. Specific preparation of Prussian blue-ZnO2-chitosan:

[0055] Weigh 0.5g chitosan powder, add 25mL zinc acetate solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan-zinc ion mixed solution; after ultrasonic degassing, pour about 400μL of the mixed solution into a 48-well plate and pre-freeze at -80°C; after the solution is completely frozen for a period of time, immediately move it into a vacuum freeze dryer for freeze drying for 8h, and after completion, pick out the obtained spongy zinc acetate-chitosan dressing with an ear pick and a needle, inject 12mL5% sodium hydroxide solution into the 25mL reactor liner, and put the spongy zinc acetate-chitosan dressing and a stirring bar, cover the liner lid, stir on a magnetic stirrer, add 3mL30% hydrogen peroxide solution, react for 0.5h, pour out the alkali solution, squeeze out the dressing aqueous solution, wash the spongy dressing with ultrapure water for about 4-5 times, squeeze the dressing dry, and put it in a refrigerator. The dressing was put into a 10mL centrifuge tube containing about 10mL of anhydrous ethanol and stored in a -20℃ refrigerator. 160mgFeCl3 and 20mL of ultrapure water were weighed to prepare a FeCl3 solution. 120mgK4[Fe(CN)6] and 20mL of ultrapure water were weighed to prepare a K4[Fe(CN)6] solution. The ethanol in the dressing was squeezed out with tweezers and then put into the K4[Fe(CN)6] solution. The dressing was squeezed with tweezers to make the dressing absorb the solution. The dressing was gently clipped out and immersed in the FeCl3 solution for 6-7min. The operation was repeated twice to make the dressing evenly dyed. The sponge-like dressing was washed with ultrapure water for about 2-3 times, the dressing was squeezed dry, and put into a 10mL centrifuge tube containing about 10mL of anhydrous ethanol. The dressing immediately absorbed the ethanol and quickly sank to the bottom of the centrifuge tube. The dressing was stored in a -20℃ refrigerator to obtain a Prussian blue-ZnO2-chitosan dressing.

[0056] 2. Specific preparation of Prussian blue-CaO2-chitosan:

[0057] Weigh 0.5g chitosan powder, add 25mL calcium acetate solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan-calcium ion mixed solution; after ultrasonic degassing, pour about 400μL of the mixed solution into a 48-well plate and pre-freeze at -80°C; after the solution is completely frozen for a period of time, immediately move it into a vacuum freeze dryer for freeze drying for 8h, and after completion, pick out the obtained spongy calcium acetate-chitosan dressing with an ear pick and a needle, inject 12mL5% sodium hydroxide solution into the 25mL reactor liner, and put the spongy calcium acetate-chitosan dressing and a stirring bar, cover the liner lid, stir on a magnetic stirrer, add 3mL30% hydrogen peroxide solution, react for 0.5h, pour out the alkali solution, squeeze out the dressing aqueous solution, wash the spongy dressing with ultrapure water for about 4-5 times, squeeze the dressing dry, and put The dressing was put into a 10mL centrifuge tube containing about 10mL of anhydrous ethanol and stored in a -20℃ refrigerator. 160mgFeCl3 and 20mL of ultrapure water were weighed to prepare FeCl3 solution. 120mgK4[Fe(CN)6] and 20mL of ultrapure water were weighed to prepare K4[Fe(CN)6] solution. The ethanol in the dressing was squeezed out with tweezers and then put into K4[Fe(CN)6] solution. The dressing was squeezed with tweezers to make the dressing absorb the solution. The dressing was gently clipped out and immersed in FeCl3 solution for 6-7min. The operation was repeated twice to make the dressing evenly dyed. The sponge dressing was washed with ultrapure water for about 2-3 times, the dressing was squeezed dry, and put into a 10mL centrifuge tube containing about 10mL of anhydrous ethanol. The dressing immediately absorbed the ethanol and quickly sank to the bottom of the centrifuge tube. The dressing was stored in a -20℃ refrigerator to obtain Prussian blue-CaO2-chitosan dressing.

[0058] like Figure 1 Shown: The anti-Staphylococcus aureus effect of chitosan dressing,

[0059] Protocol: Chitosan dressings were incubated with Staphylococcus aureus for 24 hours, and the turbidity of the culture medium, the color of chitosan, and the number of bacterial colonies after plate coating were observed.

[0060] Analysis of experimental results: Before incubation, the solution was clear and transparent, and the dressing was white. After incubation, the solution was turbid (proving bacterial formation), the dressing was light yellow (failed to indicate bacterial formation), a precipitate was formed, and colonies were produced after plating (further indicating bacterial formation and that the dressing had no antibacterial effect).

[0061] like Figure 2 Shown: Anti-Staphylococcus aureus effect of Prussian blue-chitosan dressing

[0062] Protocol: Prussian blue-chitosan was incubated with Staphylococcus aureus for 24 hours, and the turbidity of the culture medium, the color of chitosan, and the number of bacterial colonies after plate coating were observed.

[0063] Analysis of experimental results: Before incubation, the solution was clear and transparent, and the dressing was blue. After incubation, the solution became turbid (proving bacterial formation), the dressing faded (bacteria were formed, causing the solution pH <7, Prussian blue dissociated and unable to adhere to the dressing), and was light yellow with precipitation formed. Colonies were produced after plating (further proving that the dressing had no antibacterial effect and Prussian blue indicated bacterial formation).

[0064] like Figure 3 Shown: Anti-Staphylococcus aureus effect of ZnO-chitosan dressing

[0065] Protocol: ZnO-chitosan dressings were incubated with Staphylococcus aureus for 24 hours. The turbidity of the culture medium, the color of chitosan, and the number of bacterial colonies after plate coating were observed.

[0066] Analysis of experimental results: Before incubation, the solution was clear and transparent, and the dressing was white. After incubation, the solution was turbid (proving bacterial formation), the dressing was light yellow (failed to indicate bacterial formation), a precipitate was formed, and colonies were produced after plating (further indicating bacterial formation and that the dressing had no antibacterial effect).

[0067] like Figure 4 Shown: Anti-Staphylococcus aureus effect of Prussian blue-ZnO-chitosan dressing

[0068] Protocol: Prussian blue-ZnO-chitosan dressings were incubated with Staphylococcus aureus for 24 hours, and the turbidity of the culture medium, the color of chitosan, and the number of bacterial colonies after plate coating were observed.

[0069] Analysis of experimental results: Before incubation, the solution was clear and transparent, and the dressing was blue. After incubation, the solution became turbid (proving bacterial formation), the dressing faded (bacteria were formed, causing the solution pH <7, Prussian blue dissociated and unable to adhere to the dressing), and was light yellow with precipitation formed. Colonies were produced after plating (further proving that the dressing had no antibacterial effect and Prussian blue indicated bacterial formation).

[0070] like Figure 5 Shown: Anti-Staphylococcus aureus effect of ZnO2-chitosan dressing

[0071] Protocol: ZnO2-chitosan dressings were incubated with Staphylococcus aureus for 24 hours. The turbidity of the culture medium, the color of chitosan, and the number of bacterial colonies after plate coating were observed.

[0072] Analysis of experimental results: Before incubation, the solution was clear and transparent, and the dressing was white. After incubation, the solution was clear (proving aseptic production), the dressing was light yellow (failed to indicate bacterial production), no precipitate was generated, and no colonies were produced after plating (further proving aseptic production and the dressing had antibacterial effect).

[0073] like Figure 6 Shown: Anti-Staphylococcus aureus effect of Prussian blue-ZnO2-chitosan

[0074] Scheme: Prussian blue-ZnO2-chitosan was incubated with Staphylococcus aureus for 24 hours, and the turbidity of the culture medium, the color of Prussian blue-ZnO2-chitosan, and the number of bacterial colonies after plate coating were observed.

[0075] Analysis of experimental results: Before incubation, the solution was clear and transparent, and the dressing was blue. After incubation, the solution was clear and transparent (proving aseptic production), the dressing did not fade (indicating aseptic production), no precipitate was generated, and no colonies were produced after plating (further proving aseptic production and the dressing has antibacterial effect).

[0076] like Figure 7 Shown: Anti-Staphylococcus aureus effect of CaO-chitosan

[0077] Protocol: CaO-chitosan was incubated with Staphylococcus aureus for 24 hours. The turbidity of the culture medium, the color of CaO-chitosan, and the number of bacterial colonies after plate coating were observed.

[0078] Analysis of experimental results: Before incubation, the solution was clear and transparent, and the dressing was white. After incubation, the solution became turbid (proving bacterial formation), the dressing faded (bacterial formation caused the solution pH to be <7, Prussian blue dissociated and could not adhere to the dressing), and it became light yellow (failed to indicate bacterial formation). Precipitation was generated, and colonies were produced after plating (further indicating bacterial formation and that the dressing had no antibacterial effect).

[0079] like Figure 8 Shown: Anti-Staphylococcus aureus effect of Prussian blue-CaO-chitosan

[0080] Scheme: Prussian blue-CaO-chitosan was incubated with Staphylococcus aureus for 24 hours. The turbidity of the culture medium, the color of Prussian blue-CaO-chitosan, and the number of bacterial colonies after plate coating were observed.

[0081] Analysis of experimental results: Before incubation, the solution was clear and transparent, and the dressing was blue. After incubation, the solution became turbid (proving bacterial formation), the dressing faded (bacterial formation caused the solution pH to be <7, Prussian blue dissociated and could not adhere to the dressing), and it became light yellow (failed to indicate bacterial formation). Precipitation was generated, and colonies were produced after plating (further indicating bacterial formation and that the dressing had no antibacterial effect).

[0082] like Fig. 9 Shown: Anti-Staphylococcus aureus effect of CaO2-chitosan

[0083] Protocol: CaO2-chitosan was incubated with Staphylococcus aureus for 24 hours, and the turbidity of the culture medium, the color of CaO2-chitosan, and the number of bacterial colonies after plate coating were observed.

[0084] Analysis of experimental results: Before incubation, the solution was clear and transparent, and the dressing was white. After incubation, the solution was clear and transparent (proving aseptic production), and the dressing was white (failed to indicate aseptic production). No colonies were produced after plating (further indicating aseptic production and the dressing had an antibacterial effect).

[0085] like Fig.10 Shown: Anti-Staphylococcus aureus effect of Prussian blue-CaO2-chitosan

[0086] Protocol: Prussian blue-CaO2-chitosan was incubated with Staphylococcus aureus for 24 hours. The turbidity of the culture medium, the color of Prussian blue-CaO2-chitosan, and the number of bacterial colonies after plate coating were observed.

[0087] Analysis of experimental results: Before incubation, the solution was clear and transparent, and the dressing was blue. After incubation, the solution was clear and transparent (proving aseptic production), the dressing did not fade (indicating aseptic production), no precipitate was generated, and no colonies were produced after plating (further proving aseptic production and the dressing has antibacterial effect).

[0088] During the experiment, CaO2 was used to test the expected results:

[0089] CaO2 can be used to self-decompose to produce H2O2, and purple-red MnO4- can be reduced to colorless Mn2+ under acidic conditions. That is, through the reduction and fading reaction of potassium permanganate, the presence of peroxide groups in the synthesized CaO2 can be verified, such as Figure 11-12As shown in the figure, after adding CaO2 to the acidic potassium permanganate solution, the color of the solution fades from purple to colorless. It is speculated that this is because CaO2 quickly decomposes under acidic conditions to produce H2O2, and H2O2 reduces purple MnO4- to colorless Mn2+ under acidic conditions, which is consistent with the expected result. The corresponding UV-visible absorption spectrum test data shows that after adding CaO2, the characteristic absorption peak of potassium permanganate at 525nm disappears, that is, potassium permanganate is reduced. The formula is as follows:

[0090] 5H2O2+2MnO4-+6H+→2Mn2++5O2↑+8H2O

[0091] The present invention and its implementation methods are described above, and such description is not restrictive, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by it, and does not deviate from the purpose of the invention, and does not creatively design a structure and implementation method similar to the technical solution, they should all fall within the protection scope of the present invention.

Claims

1. A pH-responsive self-supplied H2O2 material with antibacterial properties, characterized in that: It includes a dressing body, which has a chitosan shell and internal peroxide. It is relatively stable under neutral conditions, but exhibits acid-responsive dissociation characteristics under a slightly acidic environment of bacterial infection. The peroxide will self-decompose under acidic conditions to release bactericidal H2O2 and substances harmless to the human body.

2. A pH-responsive self-supplied H2O2 material with antibacterial properties, characterized in that: The dressing body is provided with Prussian blue.

3. A method for preparing a pH-responsive self-supplied H2O2 material with antibacterial properties according to claims 1-2, characterized in that: The specific steps are as follows: Step 1: Preparation of peroxide, wherein the peroxide includes ZnO2, CaO2, etc.; Step 2: Preparation of dressing; Step 3: Dressing preparation with Prussian blue.

4. The method for preparing a pH-responsive self-supplied H2O2 material with antibacterial properties according to claim 3, characterized in that: The specific content of the dressing preparation in step 2 is as follows: chitosan powder and an acetic acid solution of a corresponding peroxide are fully dissolved, the dissolved chitosan-ion solution is freeze-dried, the obtained sponge-like acetic acid-chitosan dressing is fully stirred with a 5% sodium hydroxide solution, and then a 30% hydrogen peroxide solution is added to react for 0.5h, the alkali solution is poured out, the aqueous solution of the dressing is squeezed out, the sponge-like dressing is washed with ultrapure water for 4-5 times, the dressing is squeezed dry, and placed in a centrifuge tube filled with anhydrous ethanol. The dressing immediately absorbs the ethanol and quickly sinks to the bottom of the centrifuge tube, and is placed in a -20°C refrigerator for cryopreservation to obtain a peroxide-chitosan dressing.

5. The method for preparing a pH-responsive self-supplied H2O2 material with antibacterial properties according to claim 4, characterized in that: Place the peroxide-chitosan dressing prepared in step 2 into the K4[Fe(CN)6] solution, squeeze it with tweezers to make the dressing absorb the solution, then gently clip the dressing out, immerse it in the FeCl3 solution for 6-7 minutes, repeat the operation twice to make the dressing evenly dyed, wash the sponge dressing with ultrapure water for about 2-3 times, squeeze the dressing, and place it in a centrifuge tube filled with anhydrous ethanol. The dressing immediately absorbs the ethanol and quickly sinks to the bottom of the centrifuge tube, and is placed in a -20°C refrigerator for cryopreservation to obtain a Prussian blue-peroxide-chitosan dressing.

6. The method for preparing a pH-responsive self-supplied H2O2 material with antibacterial properties according to claim 5, characterized in that: The preparation of Prussian blue-ZnO2-chitosan is as follows: weigh chitosan powder, add zinc acetate solution and a stirring bar, stir on a heat-collecting constant temperature heating magnetic stirrer until completely dissolved to obtain a chitosan-zinc ion mixed solution, and after ultrasonic degassing, pre-freeze at -80°C. After the solution is completely frozen, move it into a vacuum freeze dryer for freeze drying for 8 hours. After completion, inject 5% sodium hydroxide solution into the inner tank of the reactor to obtain the spongy zinc acetate-chitosan dressing, and put the spongy zinc acetate-chitosan dressing and a stirring bar into it. Cover the inner tank lid and stir on a magnetic stirrer. After the stirring is completed, add 30% hydrogen peroxide solution, react for 0.5 hours, pour out the alkali solution, and squeeze out the dressing. The dressing was washed with ultrapure water for about 4-5 times, squeezed dry, placed in a centrifuge tube filled with anhydrous ethanol, and stored in a -20°C refrigerator. The ethanol in the dressing was squeezed out with tweezers, and then placed in a K4[Fe(CN)6] solution. The dressing was squeezed with tweezers to make the dressing absorb the solution. The dressing was gently clipped out and immersed in a FeCl3 solution for 6-7 minutes. The operation was repeated twice to make the dressing evenly dyed. The sponge dressing was washed with ultrapure water for about 2-3 times, squeezed dry, and placed in a centrifuge tube filled with anhydrous ethanol. The dressing immediately absorbed the ethanol and quickly sank to the bottom of the centrifuge tube. It was stored in a -20°C refrigerator to obtain a Prussian blue-ZnO2-chitosan dressing.

Images