Preparation method of amino-functionalized magnetic microspheres

Abstract

The application discloses a preparation method of amino-modified magnetic microspheres, which comprises the following steps: modifying the surface of magnetic nanoparticles to obtain magnetic microspheres with double bonds on the surface; performing a polymerization reaction on the surface of the magnetic microspheres to form core-shell magnetic beads with a surface polymer; and performing an amino-modification treatment on the core-shell magnetic beads to form amino-modified magnetic microspheres. The magnetic microspheres have strong magnetism, uniform particle size distribution, regular morphology, and small batch difference, and the sensitivity of magnetic bead extraction is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of medical testing technology, specifically to a method for preparing aminated magnetic microspheres. Background Technology

[0002] Currently, in the biomedical field, magnetic nanospheres, as a novel high-analytical functional material, are widely used in drug loading, targeted therapy, nuclear magnetic resonance contrast agents, immobilized enzymes, separation and purification of biomolecules, and in vitro diagnostics. Magnetic microspheres are composed of superparamagnetic inorganic magnetic materials and organic polymers, with particle sizes ranging from hundreds of nanometers to several micrometers. They combine the superparamagnetism of magnetic nanomaterials with the functional properties of polymers and biomolecules. They can respond rapidly under an applied magnetic field. Furthermore, through copolymerization, surface modification, and other chemical reactions, the surface of the polymer microspheres can be endowed with various functional groups, enabling coupling with antibodies, antigens, or other biomolecules to achieve specific functions such as biological recognition, molecular capture, and release. To meet increasingly diverse needs, magnetic polymer microspheres must possess characteristics such as good biocompatibility, high saturation magnetization, a well-defined spherical homogeneous structure, dispersion stability, low non-specific adsorption, and abundant surface functional groups.

[0003] However, most microspheres on the current market still have various problems, such as complex preparation methods, poor magnetic bead performance, and large batch-to-batch differences. In addition, they have disadvantages such as wide particle size distribution, weak magnetism, easy magnetic leakage, poor specificity, and low degree of functionalization. Summary of the Invention

[0004] In view of the problems existing in the prior art, the purpose of this invention is to provide a method for preparing aminated magnetic microspheres, so as to solve the problems of complex surface modification and poor stability of magnetic beads in the prior art.

[0005] To solve the above problems, the present invention adopts the following solution:

[0006] A method for preparing aminated magnetic microspheres includes the following steps:

[0007] Magnetic nanoparticles were modified to obtain magnetic microspheres with surface-modified double bonds;

[0008] The surface of magnetic microspheres is subjected to a polymerization reaction to form core-shell magnetic beads with surface polymers;

[0009] The core-shell magnetic beads were subjected to amination treatment to form amination magnetic microspheres.

[0010] Furthermore, the surface of the magnetic nanoparticles is modified to obtain magnetic microspheres with surface-modified double bonds, including the following steps:

[0011] Magnetic nanoparticles were dispersed in a mixed solution of ethanol and water, and electrolytes, ammonia and silane coupling agent were added. The mixture was reacted at 20-60℃ for 1-24 h to obtain magnetic microspheres with surface-modified double bonds.

[0012] Furthermore, the ratio of ethanol to water is 0.1-1:1; in the mixed solution, the concentration of electrolyte is 0.01-5 wt%, the concentration of ammonia is 0.05-10 wt%, and the concentration of silane coupling agent is 0.05-5 wt%.

[0013] Furthermore, the electrolyte is selected from one or more combinations of potassium chloride, sodium chloride, sodium sulfate, and sodium bicarbonate; the silane coupling agent is selected from one or more combinations of vinyltriethoxysilane, vinyltrimethoxysilane, and methacryloxypropyltrimethoxysilane.

[0014] Furthermore, a polymerization reaction is carried out on the surface of the magnetic microspheres to form core-shell magnetic beads with surface polymers, including the following steps:

[0015] Magnetic microspheres with surface-modified double bonds were dispersed in organic solvent A, and functional monomers, crosslinking agents and initiators were added. The mixture was reacted at 60-80℃ for 4-24 hours to form core-shell magnetic beads with surface polymers.

[0016] Furthermore, the organic solvent A is selected from one or more combinations of acetonitrile, ethanol, methanol, and diethylene glycol dimethyl ether; the functional monomer is selected from one or more of glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether; the crosslinking agent is selected from one or more of divinylbenzene, ethylene glycol dimethacrylate, and N,N'-methylenebisacrylamide; and the initiator is selected from one or more of ammonium persulfate, cumene hydroperoxide, tert-butyl peroxide, and azobisisobutyronitrile.

[0017] Furthermore, the core-shell magnetic beads are subjected to amination treatment to form amination-treated magnetic microspheres, including the following steps:

[0018] Core-shell magnetic beads are dispersed in an aqueous solution, and a certain amount of ethylenediamine is added. The mixture is reacted at 70-90℃ for 4-24 hours to form aminated magnetic microspheres.

[0019] Furthermore, in the aqueous solution, the concentration of core-shell magnetic beads is 0.01-10 wt%, and the concentration of ethylenediamine is 10-80 wt%.

[0020] Furthermore, the preparation method of the magnetic nanoparticles is as follows:

[0021] Ferrous salts and sodium acetate were dissolved in ethylene glycol solvent, and an alkaline compound was added to adjust the pH of the pre-reactant. The mixture was stirred for 0.5-5 hours and then reacted at 180-220°C for 6-48 hours to obtain magnetic nanoparticles.

[0022] Furthermore, in the ethylene glycol solvent, the concentration of ferric salt is 0.01-10 wt%, the concentration of sodium acetate is 0.05-15 wt%, and the concentration of alkaline compound is 0.05-10 wt%.

[0023] Furthermore, the trivalent ferric salt is selected from one or more combinations of anhydrous ferric chloride, ferric chloride hexahydrate, ferric sulfate, and ferric nitrate; the alkaline compound is selected from one or more combinations of sodium hydroxide, sodium carbonate, sodium citrate, and sodium bicarbonate.

[0024] The present invention adopts the above technical solution and has the following advantages:

[0025] (1) The magnetic nanoparticles prepared by this invention have high saturation magnetic strength, strong magnetism, uniform particle size distribution, more regular morphology, and a uniform spherical structure.

[0026] (2) In the preparation of silicon-based magnetic microspheres, the present invention introduces an electrolyte, which can affect the adsorption and deposition of silane coupling agent on the surface of nanoparticles, adjust the uniformity and thickness of the silicon layer on the surface of the magnetic fluid, and prepare silicon-based magnetic beads with uniform surface and controllable thickness.

[0027] (3) The present invention carries out the polymerization reaction in an organic solvent, which improves the utilization rate of monomers. The polymer is evenly distributed on the surface of the magnetic beads, forming a complete core-shell structure, which helps to avoid the exposure of the internal magnetic core and ensures the long-term stability of the polymer magnetic microspheres. In addition, the magnetic polymer microspheres are further modified by surface amylation, and the surface groups of the magnetic microspheres have high activity and good modifiability, which is conducive to further expanding their application range. Attached Figure Description

[0028] Figure 1 This is a SEM image of the silicon-based magnetic microspheres in Example 1 of the present invention;

[0029] Figure 2 This is a SEM image of the aminated polymer magnetic microspheres in Example 3 of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0031] Example 1

[0032] (1) Weigh 1g of ferric chloride hexahydrate, 5g of sodium acetate, 2.5g of sodium hydroxide and 2.5g of sodium citrate and dissolve them in 800mL of ethylene glycol solvent. Stir ultrasonically for 0.5h, transfer to 1000mL of polytetrafluoroethylene liner, place in an environment of 180℃ for 6h, cool to room temperature and take out, and obtain magnetic nanoparticles by magnetic separation and washing.

[0033] (2) 1g of magnetic nanoparticles were uniformly dispersed in 100ml of alcohol-water mixed solution (ethanol:water = 1 / 10), 0.1g of sodium chloride electrolyte was added, followed by 0.5ml of ammonia and 0.5ml of vinyltriethoxysilane. The mixture was reacted at 20℃ for 1h. Magnetic microspheres with surface-modified double bonds were obtained by magnetic separation and washing.

[0034] (3) The magnetic beads modified with double bonds were dispersed in 100 ml of acetonitrile, and 0.5 ml of glycidyl acrylate, 0.05 ml of divinylbenzene and 0.01 g of azobisisobutyronitrile were added. The mixture was reacted at 60 °C for 4 h. After magnetic separation and washing, the core-shell magnetic beads modified with the surface polymer were obtained.

[0035] (4) Magnetic polymer microspheres were dispersed in 270 ml of aqueous solution, 30 ml of ethylenediamine was added, and the mixture was reacted at 70 °C for 4 h. The resulting product was obtained by magnetic separation and washing, and then amino-modified magnetic polymer microspheres were obtained.

[0036] Example 2

[0037] (1) Weigh 30g of anhydrous ferric chloride, 60g of sodium acetate, 5g of sodium bicarbonate and 15g of sodium citrate and dissolve them in 800mL of ethylene glycol solvent. Stir ultrasonically for 2h, transfer to 1000mL of polytetrafluoroethylene liner, place in an environment of 200℃ for 15h, cool to room temperature and take out, and obtain magnetic nanoparticles by magnetic separation and washing.

[0038] (2) 5g of magnetic nanoparticles were uniformly dispersed in 100ml of alcohol-water mixed solution (ethanol:water = 3 / 7), 1g of potassium chloride was added, followed by 5ml of ammonia and 2.5ml of methacryloyloxypropyltrimethoxysilane. The mixture was reacted at 40℃ for 8h. Magnetic microspheres with surface-modified double bonds were obtained by magnetic separation and washing.

[0039] (3) The magnetic beads modified with double bonds were dispersed in 100 ml of diethylene glycol dimethyl ether, and 4 ml of a mixture of glycidyl acrylate and glycidyl methacrylate, 0.2 ml of divinylbenzene and 0.1 g of ammonium persulfate were added. The mixture was reacted at 70 °C for 10 h. After magnetic separation and washing, the core-shell magnetic beads with surface polymer modification were obtained.

[0040] (4) Magnetic polymer microspheres were dispersed in 100 ml of aqueous solution, and 100 ml of ethylenediamine was added. The mixture was reacted at 80 °C for 12 h. The resulting product was obtained by magnetic separation and washing, and then amino-modified magnetic polymer microspheres were obtained.

[0041] Example 3

[0042] (1) Weigh 80g of ferric sulfate, 120g of sodium acetate and 80g of sodium carbonate and dissolve them in 800mL of ethylene glycol solvent. Stir ultrasonically for 5h, transfer to 1000mL of polytetrafluoroethylene liner, and react at 220℃ for 48h. After cooling to room temperature, take it out and obtain magnetic nanoparticles by magnetic separation and washing.

[0043] (2) 10g of magnetic nanoparticles were uniformly dispersed in 100ml of alcohol-water mixed solution (ethanol:water = 1 / 1), 5g of sodium bicarbonate was added, followed by 10ml of ammonia and 5ml of methacryloyloxypropyltrimethoxysilane. The mixture was reacted at 60℃ for 24h. Magnetic microspheres with surface-modified double bonds were obtained by magnetic separation and washing.

[0044] (3) The modified magnetic beads with double bonds were dispersed in 100 ml of ethanol, and 10 ml of allyl glycidyl ether, 1 g of N,N'-methylenebisacrylamide and 1 g of cumene hydrogen peroxide were added. The mixture was reacted at 80 °C for 24 h. After magnetic separation and washing, the core-shell magnetic beads with surface polymer modification were obtained.

[0045] (4) The magnetic polymer microspheres were dispersed in 20 ml of aqueous solution, and 80 ml of ethylenediamine was added. The mixture was reacted at 90 °C for 24 h. The resulting product was obtained by magnetic separation and washing, and then amino-modified magnetic polymer microspheres were obtained.

[0046] Example 4

[0047] (1) Weigh 60g of ferric nitrate, 80g of sodium acetate and 30g of sodium citrate and dissolve them in 800mL of ethylene glycol solvent. Stir ultrasonically for 3h, transfer to 1000mL of polytetrafluoroethylene liner, and react at 210℃ for 25h. After cooling to room temperature, take it out and obtain magnetic nanoparticles by magnetic separation and washing.

[0048] (2) 6g of magnetic nanoparticles were uniformly dispersed in 120ml of alcohol-water mixed solution (ethanol / water = 1 / 4), 2g of sodium chloride was added, followed by 7.5ml of ammonia and 1.5ml of vinyltrimethoxysilane. The mixture was reacted at 25℃ for 6h. Magnetic microspheres with surface-modified double bonds were obtained by magnetic separation and washing.

[0049] (3) The modified magnetic beads with double bonds were dispersed in 120 ml of methanol, and 7 ml of a mixture of glycidyl acrylate and glycidyl methacrylate, 0.6 ml of ethylene glycol dimethacrylate and 0.5 ml of tert-butyl peroxide were added. The mixture was reacted at 75 °C for 18 h. After magnetic separation and washing, the core-shell magnetic beads with surface polymer modification were obtained.

[0050] (4) Magnetic polymer microspheres were dispersed in 50 ml of aqueous solution, 100 ml of ethylenediamine was added, and the mixture was reacted at 85 °C for 16 h. The resulting product was obtained by magnetic separation and washing, and then amino-modified magnetic polymer microspheres were obtained.

[0051] like Figure 1 As shown, the silicon-based magnetic microspheres prepared by adding an electrolyte according to this invention have uniform particle size, regular morphology, and small batch variation. Furthermore, this invention facilitates the deposition and adsorption of silica nanoparticles on the surface, resulting in a uniform and dense silicon layer with good modifiability. Figure 2 As shown, the surface morphology of the aminated polymer magnetic microspheres prepared by this invention is regular, and the polymer is evenly distributed on the surface of the magnetic beads, forming a complete core-shell structure, which helps to avoid the exposure of the internal magnetic core and ensures the long-term stability of the polymer magnetic microspheres.

[0052] The magnetic nanoparticles prepared by this invention exhibit high magnetic content, strong magnetism, fast magnetic response speed, and short magnetic time, significantly reducing the waiting time for magnetic beads and improving their working efficiency. The magnetic microspheres prepared by this invention feature a simple process flow, avoiding human error during operation and ensuring stable production. Furthermore, the magnetic microspheres obtained by this invention have regular morphology, uniform particle size, and narrow particle size distribution, reducing batch variation and ensuring performance stability. The magnetic beads prepared by this invention have a regular spherical structure, allowing for better surface functionalization modification. Various functional groups can be uniformly modified on the surface of the magnetic microspheres, ensuring the uniformity and density of surface groups, resulting in better binding efficiency and specific adsorption, improving the stability and lifespan of the magnetic beads during use. The magnetic microspheres prepared by this invention can be better modified for surface functionalization, uniformly modified with multiple functional groups, have a wide range of applications, are easy to operate, and can meet current diversified needs.

[0053] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing aminated magnetic microspheres, characterized in that, Includes the following steps: Magnetic nanoparticles were modified to obtain magnetic microspheres with surface-modified double bonds; The surface of magnetic microspheres is subjected to a polymerization reaction to form core-shell magnetic beads with surface polymers; The core-shell magnetic beads were subjected to amination treatment to form amination magnetic microspheres.

2. The method for preparing aminated magnetic microspheres according to claim 1, characterized in that, Modifying the surface of magnetic nanoparticles to obtain magnetic microspheres with surface-modified double bonds includes the following steps: Magnetic nanoparticles were dispersed in a mixed solution of ethanol and water, and electrolytes, ammonia and silane coupling agent were added. The mixture was reacted at 20-60℃ for 1-24 h to obtain magnetic microspheres with surface-modified double bonds.

3. The method for preparing aminated magnetic microspheres according to claim 2, characterized in that, The ratio of ethanol to water is 0.1-1:1; in the mixed solution, the concentration of electrolyte is 0.01-5 wt%, the concentration of ammonia is 0.05-10 wt%, and the concentration of silane coupling agent is 0.05-5 wt%.

4. The method for preparing aminated magnetic microspheres according to claim 2, characterized in that, The electrolyte is selected from one or more combinations of potassium chloride, sodium chloride, sodium sulfate, and sodium bicarbonate; the silane coupling agent is selected from one or more combinations of vinyltriethoxysilane, vinyltrimethoxysilane, and methacryloxypropyltrimethoxysilane.

5. The method for preparing aminated magnetic microspheres according to claim 1, characterized in that, The process of polymerizing the surface of magnetic microspheres to form core-shell magnetic beads with surface polymers includes the following steps: Magnetic microspheres with surface-modified double bonds were dispersed in organic solvent A, and functional monomers, crosslinking agents and initiators were added. The mixture was reacted at 60-80℃ for 4-24 hours to form core-shell magnetic beads with surface polymers.

6. The method for preparing aminated magnetic microspheres according to claim 5, characterized in that, The organic solvent A is selected from one or more combinations of acetonitrile, ethanol, methanol, and diethylene glycol dimethyl ether; the functional monomer is selected from one or more of glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether; the crosslinking agent is selected from one or more of divinylbenzene, ethylene glycol dimethacrylate, and N,N'-methylenebisacrylamide; and the initiator is selected from one or more of ammonium persulfate, cumene hydroperoxide, tert-butyl peroxide, and azobisisobutyronitrile.

7. The method for preparing aminated magnetic microspheres according to claim 1, characterized in that, The process of amylating core-shell magnetic beads to form amylated magnetic microspheres includes the following steps: Core-shell magnetic beads are dispersed in an aqueous solution, and a certain amount of ethylenediamine is added. The mixture is reacted at 70-90℃ for 4-24 hours to form aminated magnetic microspheres.

8. The method for preparing aminated magnetic microspheres according to claim 7, characterized in that, In the aqueous solution, the concentration of core-shell magnetic beads is 0.01-10 wt%, and the concentration of ethylenediamine is 10-80 wt%.

9. The method for preparing aminated magnetic microspheres according to claim 1, characterized in that, The magnetic nanoparticles are prepared as follows: Ferrous salts and sodium acetate were dissolved in ethylene glycol solvent, and an alkaline compound was added to adjust the pH of the pre-reactant. The mixture was stirred for 0.5-5 hours and then reacted at 180-220°C for 6-48 hours to obtain magnetic nanoparticles.

10. The method for preparing aminated magnetic microspheres according to claim 9, characterized in that, In the ethylene glycol solvent, the concentration of ferric salt is 0.01-10 wt%, the concentration of sodium acetate is 0.05-15 wt%, and the concentration of alkaline compound is 0.05-10 wt%.

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