Antibacterial polyurethane sponge and preparation method thereof

Abstract

The present invention relates to the technical field of medical dressings, in particular to an antibacterial polyurethane sponge and its preparation method. The antibacterial dressing obtained by adding an antibacterial active ingredient to a molded polyurethane sponge dressing by immersion or spraying has low antibacterial durability. To solve this problem, the present invention pre-disperses an aqueous dispersion of an antibacterial agent in a polyurethane prepolymer and then foams it, which allows the antibacterial agent to be encapsulated in the porous structure of the polyurethane sponge, achieving the effect of sustained release of antibacterial metal ions, and the prepared antibacterial polyurethane sponge has good antibacterial durability.

Description

Antibacterial polyurethane sponge and preparation method thereof Technical Field

[0001] The present invention relates to the technical field of medical dressings, in particular to an antibacterial polyurethane sponge and a preparation method thereof. Background Art

[0002] With the development and improvement of medical technology, more and more functional dressings are being used for wound care. Compared with traditional dressings, various antimicrobial dressings that can prevent or control wound infection are increasingly used in clinical practice, and their effectiveness is widely recognized by medical staff and patients.

[0003] The antibacterial dressings on the market include foam, sponge, hydrogel and other dressings. The antibacterial and antibacterial ingredients in the dressings are natural plant and animal extracts, soluble metal ion solutions, metal complexes, nano-scale metal powder inclusion materials, etc. Among them, foam or sponge dressings are the current research hotspots. For example, Chinese invention patent CN104072798B discloses a method for preparing a nanoparticle-modified sponge dressing with antibacterial function, which uses a sponge as a base material and soaks it in a soluble metal salt solution or / and a nano-metal oxide particle dispersion, and then uses ultrasonic treatment to obtain a sponge dressing with antibacterial properties. For example, Chinese invention patent CN201510995203.3 discloses a foam-based dressing and its preparation method, wherein the foam-based dressing is composed of a base frame made of a sheet-like foam dressing and a gel material filled in the pores of the base frame. The foam-based dressing also contains copper ions, silver ions or nanosilver with antibacterial properties.

[0004] Currently, sponge or foam dressings are mainly added with antibacterial active ingredients by soaking or spraying. This approach has some disadvantages:

[0005] (1) Adding a soluble metal salt solution to the surface of a foam or sponge dressing by soaking or spraying, and then drying it. When the dressing is applied to the wound, the soluble metal salt in the dressing quickly releases metal ions into the wound, making it difficult to control the release rate and concentration of the metal ions. This results in no lasting antibacterial effect and can easily lead to the accumulation of a large amount of metal ions in the wound, resulting in excessively high local ion concentrations and skin discoloration.

[0006] (2) Adding nano-metal oxide antibacterial materials to the dressing surface in the form of gel, coating or microspheres has a good antibacterial effect. However, nano-metal particles have poor adhesion to the dressing surface and can easily enter the human blood and accumulate in human tissues or organs. They are difficult to be metabolized and excreted and can easily produce high toxicity.

[0007] Summary of the Invention

[0008] In view of the problems existing in the prior art, the technical problem to be solved by the present invention is that the antibacterial dressing obtained by adding antibacterial active ingredients to the formed sponge dressing by immersion or spraying has poor antibacterial durability.

[0009] The technical solution adopted by the present invention to solve the technical problem is as follows: the present invention provides an antibacterial polyurethane sponge, comprising a component A and a component B, wherein the mass ratio of the component A to the component B is 1:(0.5-5);

[0010] The component A comprises the following ingredients in parts by weight:

[0011]

[0012] The component B is a polyurethane prepolymer;

[0013] The antibacterial polyurethane sponge is prepared by adding the component A to the component B before polyurethane foaming.

[0014] Specifically, the antibacterial agent is a metal oxide antibacterial agent.

[0015] Specifically, the metal oxide antibacterial agent is one or more of copper oxide, cuprous oxide, zinc oxide, and silver oxide.

[0016] Specifically, the suspending agent is a natural polymer suspending agent or a synthetic polymer suspending agent.

[0017] Specifically, the natural polymer suspending agent is gum arabic, gum tragacanth, apricot gum, peach gum, gum bletilla, agar or deacetated chitin.

[0018] Specifically, the synthetic polymer suspending agent is sodium carboxymethyl cellulose, methyl cellulose, carboxypropyl methyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, pyrrolidone, sodium acrylate, acrylate or α-glucan.

[0019] Specifically, the wetting agent is one or more of glycerol, polyethylene glycol-2000, polyethylene glycol-3000, polyethylene glycol-3350, polyethylene glycol 4000, polyethylene glycol 6000, and polyethylene glycol 8000.

[0020] Specifically, the stabilizer is one or more of polysorbate 40, polysorbate 60, polysorbate 65, polysorbate 80, polysorbate 85, Span 20, Span 40, Span 60, Span 65, Span 80, Span 85, poloxamer PE6200, poloxamer PE6400, poloxamer PE6800, poloxamer PE9200, and poloxamer F68.

[0021] Specifically, the water is purified water, water for injection or deionized water.

[0022] Specifically, the viscosity of the polyurethane prepolymer is 6000-21000 mPa·s.

[0023] Specifically, the polyurethane prepolymer is VORANATE TM T-80 or WanCURE TP611.

[0024] On the other hand, the present invention also provides a method for preparing the antibacterial polyurethane sponge as described above, which is prepared according to the following steps:

[0025] (1) Mix the antibacterial agent, suspending agent, wetting agent, stabilizer, and water according to the formula to obtain component A;

[0026] (2) Component A and component B were added simultaneously from different pipes into a high shear mixing device at a mass ratio of 1:(0.5-5), and stirred at 6000 rpm for 1-5 seconds to obtain component C;

[0027] (3) Component C is quickly extruded onto the surface of release paper or into a mold for foaming and maturation, and then dried at 40-60° C. for 20-50 min to obtain an antibacterial polyurethane sponge.

[0028] The beneficial effects of the present invention are:

[0029] (1) The antibacterial polyurethane sponge is prepared by adding component A (aqueous dispersion system of the antibacterial agent) to component B (prepolymer) before polyurethane foaming. That is, the aqueous dispersion system of the antibacterial agent is added to the prepolymer before polyurethane foaming, so that the antibacterial agent is wrapped in the porous structure of the polyurethane sponge, achieving the effect of slowly releasing the antibacterial metal particles, so that the prepared antibacterial polyurethane sponge has good antibacterial durability;

[0030] (2) The present invention adds a certain amount of suspending agent to the aqueous dispersion system of the antibacterial metal oxide (metal oxide antibacterial agent), so that the antibacterial agent can be better dispersed in the polyurethane sponge, which is very beneficial to further improve the antibacterial property of the polyurethane sponge dressing;

[0031] (3) The aqueous dispersion system of the antimicrobial agent of the present invention is easy to clean and can be thoroughly cleaned using common solvents such as water and ethanol without causing contamination to the inner wall of the reactor. Different types of metal oxide antimicrobial agents can be replaced at any time. DETAILED DESCRIPTION

[0032] The present invention will now be further described in detail with reference to the embodiments.

[0033] Example 1

[0034] Component A was obtained by uniformly mixing 0.01 g of copper oxide with a particle size of 130 nm, 0.2 g of gum arabic, 0.2 g of poloxamer PE6800, 0.2 g of PEG-2000, and 65 g of water for injection.

[0035] (2) 100 g of component A and 50 g of WanCURE TP611 were added simultaneously into a high shear mixer from different pipes and stirred at 6000 rpm for 2 seconds to obtain component C;

[0036] (3) Component C was quickly extruded onto the surface of the release paper to form foam, and a gap was formed using a pressing roller. The thickness of the foam was adjusted to 10 mm, and the foam was aged at room temperature for 4 min, and then dried at 40 ° C for 20 min to obtain an antibacterial polyurethane sponge with a foaming density of 150 kg / m 3 , the open cell diameter is 0.01mm.

[0037] Example 2

[0038] (1) 0.5 g of cuprous oxide (110 nm in particle size), 1.0 g of sodium carboxymethyl cellulose, 0.5 g of polysorbate 60, 1 g of PEG-3000, and 97 g of purified water were mixed to obtain component A;

[0039] (2) 100 g of component A and 100 g of WanCURE TP611 were added simultaneously into a high shear mixer from different pipes and stirred at 6000 rpm for 5 seconds to obtain component C;

[0040] (3) Component C was quickly extruded onto the surface of the release paper to form foam, and the thickness of the foam was adjusted to 10 mm. The foam was aged at room temperature for 5 min and then dried at 50 ° C for 30 min to obtain an antibacterial polyurethane sponge with a foaming density of 130 kg / m 3 , the open cell diameter is 0.03mm.

[0041] Example 3

[0042] (1) 1.0 g of silver oxide with a particle size of 150 nm, 1.0 g of sodium carboxymethyl cellulose, 1.0 g of polysorbate 60, 2.0 g of PEG-3000, and 95.0 g of purified water were mixed to obtain component A;

[0043] (2) Mix 100g of component A with 400g Add them into a high shear mixing device simultaneously from different pipes, stir and mix at 6000 rpm for 5 seconds to obtain component C;

[0044] (3) Component C was quickly extruded into a mold to form a block foam, which was aged at room temperature for 7 minutes and then dried at 40°C for 50 minutes to obtain a block antibacterial polyurethane sponge with a foaming density of 90 kg / m 3 , the diameter of the open cells is 0.05 mm.

[0045] Example 4

[0046] (1) 1.0 g of zinc oxide with a particle size of 160 nm, 1.0 g of tragacanth gum, 0.5 g of polysorbate 20, 3 g of sorbitan oleate (Span 80), and 94.5 g of purified water were mixed to obtain component A;

[0047] (2) Mix 100g of component A with 90g of VORANATE TM T-80 was added to the high shear mixing device from different pipes at the same time, and stirred at 6000 rpm for 5 seconds to obtain component C;

[0048] (3) Component C was quickly extruded into a mold to form a block foam, which was aged at room temperature for 5 minutes and then dried at 60°C for 20 minutes to obtain a block antibacterial polyurethane sponge with a foam density of 140 kg / m 3 , the diameter of the open cells is 0.03 mm.

[0049] Example 5

[0050] (1) 10 g of silver oxide with a particle size of 150 nm, 5 g of agar, 5 g of polysorbate 85, 5 g of PEG-8000, and 85 g of deionized water were mixed to obtain component A;

[0051] (2) Mix 100g of component A with 500g Add them into a high shear mixing device simultaneously from different pipes, stir and mix at 6000 rpm for 5 seconds to obtain component C;

[0052] (3) Component C was quickly extruded into a mold to form a block foam, which was aged at room temperature for 8 minutes and then dried at 40°C for 50 minutes to obtain a block antibacterial polyurethane sponge with a foaming density of 85 kg / m 3 , the open cell diameter is 0.05mm.

[0053] Example 6

[0054] (1) 5 g of cuprous oxide (120 nm in particle size), 3 g of α-glucan, 2 g of polysorbate 40, 2 g of PEG-6000, and 88 g of purified water were mixed to obtain component A;

[0055] (2) 100 g of component A and 200 g of WanCURE TP611 were added simultaneously into a high shear mixer from different pipes and stirred at 6000 rpm for 5 seconds to obtain component C;

[0056] (3) Component C was quickly extruded onto the surface of the release paper to form foam, a gap was formed using a pressing plate, and the thickness of the foam was adjusted to 10 mm. The foam was aged at room temperature for 8 min and then dried at 50 ° C for 30 min to obtain an antibacterial polyurethane sponge with a foaming density of 90 kg / m 3 , the open cell diameter is 0.05mm.

[0057] Comparative Example 1 is the same as Example 3, except that no suspending agent is added in Comparative Example 1.

[0058] Example 7 is the same as Example 3, except that the suspending agent in Example 7 is gum arabic.

[0059] Example 8 is the same as Example 3, except that the suspending agent in Example 8 is tragacanth gum.

[0060] Example 9 is the same as Example 3, except that the suspending agent in Example 9 is agar.

[0061] Example 10 is the same as Example 3, except that the suspending agent in Example 10 is α-glucan.

[0062] Comparative Example 2 is the same as Example 3, except that the surfactant polyoxyethylene polyoxy-propylene copolymer F68 is used in place of tragacanth gum.

[0063] Comparative Example 3 is the same as Example 3, except that no suspending agent is added in Comparative Example 3, the stabilizer is the silicone surfactant L64, and the wetting agent is the surfactant polyoxypropylene polyoxyethylene copolymer F127.

[0064] Comparative Example 4

[0065] Different from Example 3, Comparative Example 4 adopts a method of first preparing a dry polyurethane sponge and then adding an aqueous dispersion system of an antibacterial agent, specifically:

[0066] 1. Sprinkle 1.0g of sodium carboxymethyl cellulose into 98.0g of purified water and soak it. After it is completely dissolved, add 1.0g of silver oxide with a particle size of 150nm and mix evenly to form a suspension.

[0067] 2. Preparation of polyurethane sponge:

[0068] (1) 2.0 g of PEG-3000, 1.0 g of polysorbate 60, and 95.0 g of purified water were mixed to obtain component A-1;

[0069] (2) Mix 98g of A-1 component with 400g Add them into a high shear mixer simultaneously from different pipes, stir and mix at 6000 rpm for 5 seconds to obtain component C-1;

[0070] (3) Component C-1 was quickly extruded into a mold to form a block foam, which was aged at room temperature for 7 minutes and then dried at 40°C for 50 minutes to obtain a block antibacterial polyurethane sponge with a foaming density of 90 kg / m 3 , the diameter of the open cells is 0.05 mm.

[0071] 3. The suspension obtained in step (1) is sprayed onto the polyurethane sponge obtained in step (2) at a uniform speed, and the antibacterial polyurethane sponge is obtained after drying.

[0072] Comparative Example 5

[0073] The difference from Example 3 is that the proportion of sodium carboxymethyl cellulose added in Comparative Example 5 is less than 0.2 g, specifically:

[0074] (1) 1.0 g of silver oxide with a particle size of 150 nm, 0.1 g of sodium carboxymethyl cellulose, 1.0 g of polysorbate 60, 2.0 g of PEG-3000, and 95.9 g of purified water were mixed to obtain 100 g of component A;

[0075] (2) Mix 100g of component A and 400g of component B. Add them into a high shear mixing device simultaneously from different pipes, stir and mix at 6000 rpm for 5 seconds to obtain component C;

[0076] (3) Component C was quickly extruded into a mold to form a block foam, which was aged at room temperature for 7 minutes and then dried at 40°C for 50 minutes to obtain a block antibacterial polyurethane sponge with a foaming density of 90 kg / m 3 , the diameter of the open cells is 0.05 mm.

[0077] Antibacterial test:

[0078] The antibacterial properties of the antibacterial polyurethane sponges obtained in Examples 1-6 and Comparative Examples 1-9 were tested. The specific test results are shown in Table 1:

[0079] The antibacterial rate test standard is tested in accordance with the American AATCC 100-2019 evaluation method for antibacterial textiles.

[0080] Table 1. Antibacterial test results of various embodiments and comparative examples

[0081]

[0082] Determination of metal ion content:

[0083] The samples were first digested and acid-hydrolyzed, and then measured according to the method of GB / T23942-2009 "General Rules for Inductively Coupled Plasma Atomic Emission Spectrometry of Chemical Reagents". The test data are shown in Table 2:

[0084] Table 2. Determination of metal ion release concentrations in various embodiments and comparative examples

[0085]

[0086] From the above results, it can be seen that the antibacterial polyurethane sponge provided by the present invention has good antibacterial effect and long-lasting antibacterial effect; and the antibacterial polyurethane sponge in each embodiment can stably and evenly release metal ions, thereby being able to control and slowly release the metal ions, avoiding a large amount of metal ions being quickly released into the wound, resulting in excessive local ion concentration.

[0087] The antibacterial polyurethane sponge provided in Comparative Example 1 did not add a suspending agent during the preparation process. Compared with Example 3, the antibacterial persistence deteriorated, and the metal ion release concentration decreased within the same period of time, resulting in poor antibacterial effect. The antibacterial polyurethane sponges provided in Examples 7 to 10, in which the suspending agents were changed to gum arabic, gum tragacanth, agar, and α-glucan, respectively, still had strong antibacterial properties, and the antibacterial rate of 168h was close to that of Example 3, which belongs to the scope of the present invention. The solution provided in Comparative Example 2 used a surfactant, polyoxyethylene polyoxy-propylene copolymer F68, to replace gum tragacanth. Although the antibacterial polyurethane sponge formed had stable metal release, the added polyoxyethylene polyoxy-propylene copolymer F68 had no suspending effect, resulting in a decrease in the antibacterial rate and the metal ion release concentration, affecting the antibacterial effect and antibacterial persistence. The solution provided in Comparative Example 3 is that no suspending agent is added, its stabilizer is a silicone surfactant L64, and the wetting agent is a surfactant polyoxypropylene polyoxyethylene copolymer F127. Its antibacterial effect and the release concentration of metal ions are both reduced compared with Example 3; the solution provided in Comparative Example 4 is to first prepare a polyurethane sponge and then add an aqueous dispersion system containing antibacterial metal ions. It shows a rapid release of metal ions, the release rate fluctuates too much, and the metal ion release is not persistent, affecting its antibacterial rate and persistence. Compared with Example 3, both the persistence and the antibacterial rate are significantly reduced; the solution provided in Comparative Example 5 is that the amount of the added suspending agent sodium carboxymethyl cellulose is less than the range of 0.2-5 parts. Compared with Example 3, although the release of metal ions is stable, the antibacterial rate after 168h is significantly reduced.

[0088] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. An antibacterial polyurethane sponge, characterized in that, it comprises component A and component B, and the mass ratio of component A to component B is 1:(0.5 - 5); Component A, by weight parts, comprises the following components: Component B is a polyurethane prepolymer; The antibacterial polyurethane sponge is prepared by adding component A to component B before polyurethane foaming.

2. The antibacterial polyurethane sponge according to claim 1, characterized in that, the antibacterial agent is a metal oxide antibacterial agent.

3. The antibacterial polyurethane sponge according to claim 2, characterized in that, the metal oxide antibacterial agent is one or more of copper oxide, cuprous oxide, zinc oxide, silver oxide.

4. The antibacterial polyurethane sponge according to claim 1, characterized in that, the suspending agent is a natural polymer suspending agent or a synthetic polymer suspending agent.

5. The antibacterial polyurethane sponge according to claim 4, characterized in that, the natural polymer suspending agent is gum arabic, tragacanth gum, apricot gum, peach gum, bletilla striata gum, agar or deacetylated chitin; the synthetic polymer suspending agent is sodium carboxymethyl cellulose, methyl cellulose, carboxymethylpropyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, povidone, sodium acrylate, acrylate or α-dextran.

6. The antibacterial polyurethane sponge according to claim 1, characterized in that, the wetting agent is one or more of polyethylene glycol - 2000, polyethylene glycol - 3000, polyethylene glycol - 3350, polyethylene glycol 4000, polyethylene glycol 6000, polyethylene glycol 8000.

7. The antibacterial polyurethane sponge according to claim 1, characterized in that, the stabilizer is one or more of polysorbate 40, polysorbate 60, polysorbate 65, polysorbate 80, polysorbate 85, poloxamer PE6200, poloxamer PE6400, poloxamer PE6800, poloxamer PE9200, poloxamer F68.

8. The antibacterial polyurethane sponge according to claim 1, characterized in that, the viscosity of the polyurethane prepolymer is 6000 - 21000 mPa·s.

9. The antibacterial polyurethane sponge according to claim 8, characterized in that, The polyurethane prepolymer is FP504, VORANATE TM T-80 or WanCURE TP611.

10. A preparation method of the antibacterial polyurethane sponge according to any one of claims 1 - 9, characterized in that, it is prepared according to the following steps: (1) According to the formula amount, mix the antibacterial agent, the suspending agent, the wetting agent, the stabilizer and water evenly to obtain component A; (2) Add component A and component B from different pipelines to a high - shear mixing device according to the mass ratio of 1:(0.5 - 5), stir and mix at a speed of 6000 rpm for 1 - 5 s to obtain component C; (3) Extrude component C quickly onto the surface of release paper, the surface of release film or into a mold for foaming and curing, and then dry at 40 - 60 °C for 20 - 50 min to obtain the antibacterial polyurethane sponge.