A kaolin calcium peroxide composite material with antibacterial and hemostatic functions and a preparation method thereof
By loading calcium ions onto the surface of kaolin and introducing hydrogen peroxide to form a kaolin-calcium peroxide composite material, the problem of poor hemostasis and antibacterial effects of existing hemostatic materials in high-infection-risk environments is solved, achieving rapid hemostasis and long-lasting antibacterial effects, and is suitable for a variety of medical carriers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA UNIV OF GEOSCIENCES (WUHAN)
- Filing Date
- 2026-03-05
- Publication Date
- 2026-06-09
AI Technical Summary
Existing hemostatic materials are difficult to achieve rapid hemostasis and effective antibacterial action in high-risk infection environments. Furthermore, the poor stability of peroxide-based antibacterial components leads to an increased risk of secondary infection. Compound systems also suffer from uneven distribution of active components and insufficient batch-to-batch consistency.
Calcium ions are loaded onto the surface of kaolin using a room-temperature precipitation method. By introducing hydrogen peroxide, a kaolin-calcium peroxide composite material is formed, constructing a stable heterogeneous structure with uniform loading in the nanodomain. Combining the coagulation-promoting effect of kaolin and the antibacterial properties of calcium peroxide, the preparation process is simple and easy for large-scale production.
This invention achieves long-term stability and antibacterial effect of kaolin-calcium peroxide composite material, improves hemostatic and antibacterial properties, and is suitable for rapid hemostasis and antibacterial action on open wounds and wounds with high infection risk, reducing the risk of infection. It is also suitable for use in various medical carriers.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of hemostatic materials technology, and in particular to a kaolin-calcium peroxide composite material with both antibacterial and hemostatic functions and its preparation method. Background Technology
[0002] Hemostatic materials are widely used in trauma emergency care, intraoperative hemostasis, and battlefield wound treatment. Current hemostatic technologies mainly include two categories: inorganic mineral hemostatic materials and composite dressings. Mineral hemostatic materials, such as kaolin and zeolite, typically achieve rapid hemostasis by promoting local blood concentration and coagulation cascade reactions through their surface properties and water absorption and concentration effects. Their preparation methods often involve sieving mineral powders, surface modification, or compounding them with substrates such as gauze and sponges before application to the wound. On the other hand, to inhibit bacterial growth in wounds and reduce the risk of infection, existing antibacterial materials often incorporate silver ions, quaternary ammonium salts, antibiotics, or peroxide components. Peroxides such as calcium peroxide release hydrogen peroxide and related active components upon contact with water or wound exudate, thus exerting antibacterial effects. They are often used in antibacterial dressings in powder, granular, or compounded forms with polymer carriers. Based on the clinical need for integrated hemostasis and antibacterial properties, there are also technologies that mix or load hemostatic materials with antibacterial components to prepare composite hemostatic and antibacterial dressings through impregnation, spraying, coating, lamination and other methods.
[0003] However, the aforementioned existing technologies still have some prominent problems: First, mineral hemostatic materials mainly focus on promoting coagulation and absorbing water for hemostasis, with limited intrinsic antibacterial ability. In contaminated wounds or high-risk infection environments, it is difficult to achieve both rapid hemostasis and effective antibacterial activity simultaneously, which can easily lead to an increased risk of secondary infection. Second, the stability of peroxide-based antibacterial components such as calcium peroxide is greatly affected by environmental moisture, resulting in problems such as premature decomposition during storage or use, rapid decay of effective components, and uneven action. Furthermore, when used directly, local concentration fluctuations are likely to occur, making it difficult to balance antibacterial efficacy and biosafety. Third, existing hemostatic and antibacterial compound systems often employ simple physical mixing or multi-step loading, which can easily lead to uneven distribution of active components and insufficient batch consistency. Moreover, some processes are complex, costly, or difficult to scale up, making it difficult to meet the needs of large-scale production and product application.
[0004] Therefore, there is an urgent need for a hemostatic and antibacterial integrated composite material that is simple to process, safe and stable, and easy to prepare on a large scale, so as to achieve controllable and long-lasting antibacterial effect while ensuring rapid hemostasis, and improve storage stability and batch repeatability. Summary of the Invention
[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a simple, safe, stable, and easily mass-producible kaolin-calcium peroxide composite material with both antibacterial and hemostatic functions, and its preparation method. This solution achieves long-term stability of the kaolin composite hemostatic material and prepares a kaolin-based multifunctional material with good hemostatic and antibacterial properties.
[0006] The first objective of this invention is to provide a method for preparing a kaolin-calcium peroxide composite material with both antibacterial and hemostatic functions, comprising the following steps: adding kaolin, ammonia, polyethylene glycol, and hydrogen peroxide sequentially to a calcium chloride aqueous solution by stirring; after the reaction is completed, centrifuging, washing, and drying to obtain the kaolin-calcium peroxide composite material.
[0007] Furthermore, the mass ratio of calcium chloride to kaolin is 6:0.5-15.
[0008] Furthermore, the molar ratio of ammonia to calcium ions in the ammonia solution is greater than 6.
[0009] Furthermore, the polyethylene glycol specifically refers to polyethylene glycol 200.
[0010] Furthermore, the concentration of the calcium chloride aqueous solution is 0.8-1.5 g / ml.
[0011] Furthermore, the volume ratio of polyethylene glycol to calcium chloride aqueous solution is 18-22:6.
[0012] Furthermore, the molar ratio of hydrogen peroxide to calcium ions is greater than 5.
[0013] Furthermore, the drying temperature is 50-80℃.
[0014] The first objective of this invention is to provide a kaolin-calcium peroxide composite material with both antibacterial and hemostatic functions prepared by the above-described preparation method.
[0015] This invention employs a room-temperature precipitation method to prepare a kaolin-calcium peroxide composite material with integrated hemostatic and antibacterial functions. First, calcium ions are enriched on the surface or edge sites of kaolin. Then, hydrogen peroxide is introduced under alkaline conditions to promote the nucleation and growth of calcium peroxide at the interface, forming a composite rather than physically mixed kaolin-calcium peroxide composite material. In the kaolin-calcium peroxide composite material, CaO2 is uniformly loaded onto kaolin in the form of nanodomains. Through Si-O-Ca bridging and interface-induced strain, a stable heterogeneous structure of "uniform loading-lattice micro-shrinkage-local amorphous" is constructed. The purity, phase interface are clear, and the surface negative potential is enhanced, laying the structural and interface foundation for subsequent electronic structure regulation, oxygen release / antibacterial and hemostatic performance improvement.
[0016] This invention utilizes the large specific surface area, good adsorption properties, and biocompatibility of kaolin to uniformly distribute nano-calcium peroxide on the surface of kaolin, achieving a good antibacterial effect. Furthermore, the activating coagulation factor properties of kaolin itself and the calcium ion precipitation of calcium peroxide synergistically improve the hemostatic performance of the kaolin-calcium peroxide composite material.
[0017] The composite material prepared by this invention has improved hemostatic performance and enhanced applicability. Kaolin itself has a procoagulant effect (promoting coagulation cascade and platelet-related processes). After composite preparation, the material can form a local microenvironment conducive to coagulation on the wound surface, resulting in faster formation of clots and a more stable hemostatic covering layer. It is suitable for rapid initial hemostasis in open wounds, bleeding wounds, and other scenarios.
[0018] The composite material prepared by this invention has reliable antibacterial properties and can reduce the risk of infection. In the environment of wound exudate, the composite material can gradually release active components, creating local conditions unfavorable to bacterial survival, thereby inhibiting common pathogens and reducing early bacterial load and the risk of secondary infection in wounds. It is especially suitable for contaminated wounds or wounds with a high risk of infection.
[0019] The ammonia water used in this invention is used to provide alkalinity and enhance adsorption; PEG200 is used to improve dispersion, inhibit violent reactions and agglomeration, and improve batch consistency.
[0020] The raw materials used in this invention are readily available and have good biocompatibility. At the same time, the preparation process is relatively simple, highly operable, and easy to produce on a large scale.
[0021] The kaolin-calcium peroxide composite material prepared by this invention, which has both antibacterial and hemostatic functions, can be further loaded, coated, or filled into common medical carriers (such as gauze, hemostatic sponges, patches, gels, spray coatings, etc.) to achieve usability and processability in different scenarios.
[0022] The preparation process of this invention is relatively simple, highly operable, with controllable quality, acceptable cost, and easy for large-scale production. The process route is based on stirring reaction and centrifugal washing, and the parameters are easy to standardize; the raw materials are readily available and low in cost, and it meets the quality consistency requirements of enterprise scale-up production and regulatory registration, thus possessing industrial application value. Attached Figure Description
[0023] Figure 1 Scanning electron microscope images of CaO2 prepared in Comparative Example 2 and K-CaO2 prepared in Example 1; Figure 2 HRTEM image of K-CaO2 prepared in Example 1; Figure 3 HRTEM image of CaO2 prepared in Comparative Example 2; Figure 4 X-ray diffraction patterns of K, CaO2, and K-CaO2; Figure 5 The antibacterial properties of K, CaO2, and K-CaO2; Figure 6 To assess the antibacterial properties of 3K-CaO2 prepared in Comparative Example 3; Figure 7 The BCI values are for K, CaO2, and K-CaO2. Detailed Implementation
[0024] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments.
[0025] The kaolin ore sample used was provided by Jiangxi Chongyi County Huaming Kaolin Co., Ltd. The kaolin was first ground and crushed, and then sieved through a 200-mesh standard sieve. The kaolin obtained was named K.
[0026] Example 1: A kaolin-calcium peroxide composite material with both antibacterial and hemostatic properties is produced by the following steps: Add 6 g of anhydrous calcium chloride and 60 ml of deionized water to a beaker, stir to dissolve, then add 6 g of kaolin K, stir evenly, then add 30 mL of ammonia water (15 mol / L), stir for 10 min, then add 200 mL of polyethylene glycol 200 (PEG200), stir at 600 rpm for 10 min, then quickly add 30 mL of 30% hydrogen peroxide, and continue stirring for 6 h. After the reaction is complete, centrifuge at 10000 rpm, wash three times with anhydrous ethanol, and dry in a forced-air drying oven. Grind into powder to obtain the precursor powder, named K-CaO2.
[0027] Example 2: This method increases the amount of kaolin added. In a beaker, 6 g of anhydrous calcium chloride and 60 ml of deionized water are added and stirred until dissolved. Then, 12 g of kaolin is added and stirred evenly. Next, 30 mL of ammonia water (15 mol / L) is added and stirred for 10 min. Then, 200 mL of polyethylene glycol 200 (PEG200) is added and stirred at 600 rpm for 10 min. Finally, 30 mL of 30% hydrogen peroxide is quickly added, and stirring continues for 6 h. After the reaction is complete, the mixture is centrifuged at 10,000 rpm, washed three times with anhydrous ethanol, and dried in a forced-air drying oven. The resulting powder, named 2K-CaO2, is ground into a powder.
[0028] Example 3 This method reduces the amount of kaolin added. In a beaker, 6 g of anhydrous calcium chloride and 60 ml of deionized water are added and stirred until dissolved. Then, 0.6 g of kaolin is added and stirred until homogeneous. Next, 30 mL of ammonia (15 mol / L) is added and stirred for 10 min. Then, 200 mL of polyethylene glycol 200 (PEG200) is added and stirred at 600 rpm for 10 min. Finally, 30 mL of 30% hydrogen peroxide is quickly added, and stirring continues for 6 h. After the reaction is complete, the mixture is centrifuged at 10,000 rpm, washed three times with anhydrous ethanol, and dried in a forced-air drying oven. The resulting powder, named K-10CaO2, is ground into a powder.
[0029] Comparative Example 1 Kaolin obtained by sieving through a 200-mesh standard sieve is named K.
[0030] Comparative Example 2 This method did not add kaolin. In a beaker, 6 g of anhydrous calcium chloride and 60 ml of deionized water were added and stirred until dissolved. Then, 30 mL of ammonia (15 mol / L) was added and stirred for 10 min. Next, 200 mL of polyethylene glycol 200 (PEG200) was added and stirred at 600 rpm for 10 min. Then, 30 mL of 30% hydrogen peroxide was quickly added, and stirring continued for 6 h. After the reaction was complete, the mixture was centrifuged at 10,000 rpm, washed three times with anhydrous ethanol, and dried in a forced-air drying oven. The resulting powder was ground into a precursor powder and named CaO2.
[0031] Comparative Example 3 This method increases the amount of kaolin added. In a beaker, 6 g of anhydrous calcium chloride and 60 ml of deionized water are added and stirred until dissolved. Then, 18 g of kaolin is added and stirred evenly. Next, 30 mL of ammonia (15 mol / L) is added and stirred for 10 min. Then, 200 mL of polyethylene glycol 200 (PEG200) is added and stirred at 600 rpm for 10 min. Finally, 30 mL of 30% hydrogen peroxide is quickly added, and stirring continues for 6 h. After the reaction is complete, the mixture is centrifuged at 10,000 rpm, washed three times with anhydrous ethanol, and dried in a forced-air drying oven. The resulting powder, named 3K-CaO2, is ground into a powder.
[0032] Morphological and structural characterization analysis: Pure CaO2 is densely aggregated into granular particles, but after the introduction of kaolin, CaO2 nanoparticles are uniformly anchored on the surface of the lamellae and in the interlayer structure, significantly improving particle dispersibility and interfacial stability. Figure 1 ).
[0033] HRTEM images of K-CaO2 show clear lattice striations within the kaolin-loaded CaO2 grains. Figure 2 The interplanar spacings of the (110) and (002) crystal planes were measured to be d = 0.239 nm and d = 0.278 nm, respectively, which are slightly smaller than those of the pure CaO2 sample (d = 0.241 nm and d = 0.284 nm). Figure 3 This indicates that the introduction of kaolin induced lattice compression and strain effects. This lattice contraction is attributed to Ca. 2+ During nucleation and growth, CaO2 undergoes coordination and electrostatic interactions with hydroxyl groups and oxygen bridges on the kaolin surface, resulting in restricted growth of CaO2 at the heterogeneous interface and micro-distortion of the unit cell. Furthermore, amorphous regions are visible in the central areas of some CaO2 grains, indicating that strong interfacial constraints and localized strain lead to localized disorder in the crystal structure. This structural feature may increase oxygen vacancies and defect density, thereby promoting the generation of reactive oxygen species and surface reactivity.
[0034] X-ray diffraction (XRD) showed diffraction peaks consistent with CaO2 (JCPDS 03-0865) at 2θ≈30.1°, 35.6°, 47.3°, and 53.1°, with symmetrical peak shapes and high signal-to-noise ratio. Figure 4 No CaO (32–37°) or CaCO3 (29.4°) signals were observed. The slight positive shift in peak position is consistent with the d-spacing contraction of HRTEM, indicating that the interface constraint induces the average compressive strain. In summary, CaO2 in K-CaO2 is uniformly loaded onto kaolinite in the form of nanodomains. Through Si-O-Ca bridging and interface-induced strain, a stable heterostructure of "uniform loading-lattice micro-contraction-local amorphous" is constructed. The purity, phase interface are clear, and the surface negative potential is enhanced, laying the structural and interface foundation for subsequent electronic structure regulation, oxygen release / antibacterial and hemostatic performance improvement.
[0035] Antibacterial performance analysis: Preparation of LB (Luria-Bertani) medium: Accurately weigh 20 mg of LB broth powder, add 1000 mL of distilled water, heat in an autoclave to dissolve, and cool to obtain a liquid culture medium for bacteria.
[0036] Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) were used as Gram-negative and Gram-positive bacteria models, respectively. The antibacterial properties of the samples were evaluated using the plate count method. 10 μL of bacterial cryopreservation solution was added to 10 mL of liquid culture medium, sealed with a bacterial breathable membrane, and incubated at 37 °C and 180 rpm for 12 h in a constant temperature shaker. 500 μL of the bacteria incubated for 12 h was then diluted to a final concentration of 10. 5~6CFU / mL. A certain amount of sample powder was weighed and dispersed into 10 mL of liquid culture medium. 500 μL of diluted bacterial solution was added, and the mixture was sealed with a bacterial breathable membrane and incubated in a constant temperature shaker at 37 ℃ and 180 rpm for 4 h. The bacterial solution was then diluted 10... 4 The samples were coated and incubated upside down in a 37 ℃ constant temperature incubator for 12 h, followed by imaging and recording using a gel imaging system. The experimental samples were kaolin K, CaO2, and K-CaO2, and the experimental bacterial strains were Escherichia coli and Staphylococcus aureus.
[0037] The experimental results of the plate coating method are as follows: Figure 5 and Figure 6 As shown, the original kaolin has poor antibacterial effect. After being loaded with CaO2, the composite material has excellent antibacterial properties. However, as the amount of kaolin added increases to 18g, the antibacterial properties of the composite material disappear.
[0038] Hemostatic properties: In this experiment, each well of a 48-well plate was filled with 10 mg of hemostatic powder (K, CaO2, and K-CaO2) and 200 μL of heavily calcified anticoagulated rabbit blood (comprising 200 μL of anticoagulated rabbit blood and 10 μL of 0.2 mol / L CaCl2). The tubes were rapidly incubated in a preheated constant-temperature bath at 37°C for 4 minutes. After incubation, samples were removed at 1, 1.5, 2, 2.5, 3, 3.5, 4, and 4.5 minutes. To prevent coagulation and dissolve coagulated blood cells, 2.0 mL of deionized water was added to each tube. Subsequently, 1 mL of the supernatant was transferred to a new centrifuge tube and centrifuged at 2000 rpm for one minute. The supernatant was then collected, and the absorbance at 545 nm was measured.
[0039] The blood coagulation index (BCI) was calculated using a formula, and a BCI close to 0 was considered the point at which clotting was complete, with the time point at which hemostasis was achieved. Kaolin can accelerate hemostasis by activating the intrinsic coagulation pathway. We hypothesize that kaolin can also impart excellent hemostatic properties to K-CaO2 in composite materials. Blood coagulation index (BCI) assessment revealed that the K-CaO2 group had the lowest BCI value, indicating that it had the fastest in vitro coagulation rate. Figure 7 ).
[0040] For any points not covered above, existing technologies shall apply.
[0041] Although specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the direction of the invention or exceeding the scope defined by the appended claims. Those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a kaolin-calcium peroxide composite material with both antibacterial and hemostatic functions, characterized in that, The process includes the following steps: Kaolin, ammonia, polyethylene glycol, and hydrogen peroxide are added sequentially to a calcium chloride aqueous solution by stirring. After the reaction is complete, the mixture is centrifuged, washed, and dried to obtain the kaolin-calcium peroxide composite material.
2. The preparation method according to claim 1, characterized in that, The mass ratio of calcium chloride to kaolin is 6:0.5-15.
3. The preparation method according to claim 1, characterized in that, The molar ratio of ammonia to calcium ions in ammonia water is greater than 6.
4. The preparation method according to claim 1, characterized in that, Specifically, polyethylene glycol is polyethylene glycol 200.
5. The preparation method according to claim 1, characterized in that, The concentration of calcium chloride aqueous solution is 0.8-1.5 g / ml.
6. The preparation method according to claim 5, characterized in that, The volume ratio of polyethylene glycol to calcium chloride aqueous solution is 18-22:
6.
7. The preparation method according to claim 1, characterized in that, The molar ratio of hydrogen peroxide to calcium ions is greater than 5.
8. The preparation method according to claim 1, characterized in that, The drying temperature is 50-80℃.
9. A kaolin-calcium peroxide composite material with both antibacterial and hemostatic functions, prepared by the preparation method according to any one of claims 1-8.