A continuous preparation device and method for magnetic lipid micro-nano bubbles

Abstract

The invention discloses a continuous preparation device and method of magnetic lipid micro-nano bubbles. The invention forms a gas-liquid two-phase Taylor flow in a microchannel reactor to quickly obtain saturated droplets, then applies an alternating magnetic field to induce magnetic nanoparticles in the Taylor flow saturated droplets to produce a magnetocaloric effect, and the high-temperature surface of the magnetic nanoparticles produces bubbles and induces phospholipid molecules to self-assemble at the bubble interface, thereby realizing continuous preparation of magnetic lipid micro-nano bubbles, and at the same time, a gas-liquid separation unit and a gas recovery device are arranged at the end of the reactor. The invention adopts a gas-liquid two-phase Taylor flow to enhance the gas-liquid mass transfer efficiency and thus efficiently dissolve the gas, shortening the formation time of the saturated droplets. At the same time, the magnetic lipid micro-nano bubbles prepared by the continuous method have a high yield, a uniform particle size distribution, and the gas can be recycled.

Description

Technical Field

[0001] The invention relates to a device for continuously preparing magnetic lipid micro-nano bubbles and also relates to a method for continuously preparing magnetic lipid micro-nano bubbles. Background Art

[0002] Micro-nano bubbles refer to bubbles with particle diameters ranging from tens of nanometers to ten microns. Micro-nano bubbles have unique physicochemical properties and physiological activities such as small size, large specific surface area, slow bubble rise rate, high gas solubility rate, Matthew effect and long-range hydrophobic force, and are widely used in industrial and biomedical engineering fields.

[0003] Magnetic lipid micro-nanobubbles integrate many advantages of micro-nanobubbles, phospholipids and magnetic nanoparticles. Coating phospholipid materials on the surface of micro-nanobubbles can significantly improve the stability of micro-nanobubbles. At the same time, magnetic lipid micro-nanobubbles have good biocompatibility and low cytotoxicity, which can enable them to obtain magnetically controlled targeted drug delivery, multimodal imaging and magnetic hyperthermia. Patent 202110606441.6 proposes a method for preparing magnetic lipid micro-nanobubbles based on magnetocaloric effect-induced interfacial self-assembly, which realizes the efficient and uniform preparation of magnetic lipid micro-nanobubbles. However, this process is based on an intermittent process and requires the gas to be dissolved in the solution in advance to form saturation. The preparation process is cumbersome and inefficient, and it is easy to cause differences in the properties of magnetic lipid micro-nanobubbles prepared in different batches. These shortcomings limit the large-scale production and application of magnetic lipid micro-nanobubbles. Summary of the invention

[0004] Purpose of the invention: One purpose of the present invention is to provide a device capable of continuously preparing magnetic lipid micro-nano bubbles; another purpose of the present invention is to provide a method capable of continuously preparing magnetic lipid micro-nano bubbles.

[0005] Technical solution: The continuous preparation device of magnetic lipid micro-nano bubbles described in the present invention comprises a microchannel reactor, a gas-liquid separation unit and a gas storage device, wherein the gas-liquid separation unit is located on the discharge port side of the microchannel reactor, and the gas-liquid separation unit is connected to the gas storage device through a connecting pipe; wherein the microchannel reactor comprises a fluid channel, and a liquid inlet pipe and an air inlet pipe are connected to the feed port side of the fluid channel, an ultrasonic device is provided on the outer wall of the fluid channel between the liquid inlet pipe and the air inlet pipe, the liquid inlet pipe and the fluid channel are arranged in a Y shape; the air inlet pipe and the fluid channel are arranged in a T shape; along the material flow direction, at the rear end where the air inlet pipe is arranged, the fluid channel passes through the interval with an alternating magnetic field and then extends into the gas-liquid separation unit.

[0006] Among them, the inner diameter ratio of the liquid inlet pipe to the fluid channel is 0.5-2; the inner diameter ratio of the air inlet pipe to the fluid channel is 0.8-1.5; this range is convenient for the connection between the pipes.

[0007] Wherein, the ultrasonic device is a constant temperature ultrasonic device, and the constant temperature ultrasonic device is fixed on the outer side wall of the channel.

[0008] The method for continuously preparing magnetic lipid micro-nano bubbles based on the above device is specifically as follows: the magnetic nanoparticle suspension and the phospholipid dispersion are respectively introduced into the microchannel reactor from the two liquid inlets of the air inlet pipe, and when flowing through the channel area with the ultrasonic device, the magnetic nanoparticle suspension and the phospholipid dispersion are fully mixed to form a mixed solution; the gas is transported from the air inlet pipe to the microchannel reactor to form a stable Taylor flow with the mixed solution, and an alternating magnetic field is applied in the Taylor flow stable section, and the magnetic nanoparticles excite the magnetocaloric effect in the alternating magnetic field, and bubbles are generated in the saturated droplets of the Taylor flow, and at the same time, phospholipids are induced to self-assemble at the bubble interface, and the fluid flowing through the alternating magnetic field enters the gas-liquid separation unit at the end of the microchannel reactor to obtain a liquid containing magnetic lipid micro-nano bubbles, and the unreacted gas enters the gas storage device through the connecting pipe. The magnetic lipid micro-nano bubbles are phospholipid-encapsulated bubbles containing iron oxide nanoparticles, which have a core-shell structure, the phospholipid membrane is coated on the micro-nano bubbles, and the magnetic nanoparticles are dispersed in the phospholipid membrane.

[0009] The magnetic nanoparticle suspension is an iron oxide nanoparticle suspension, in which the concentration of the iron oxide nanoparticles is 20 to 30 μg / mL; the surface of the iron oxide nanoparticles is modified by oleic acid, citric acid, chitosan, polyethylene glycol, polyethyleneimine, or polylysine; and the particle size of the iron oxide nanoparticles is 10 to 200 nm.

[0010] The lipid dispersion is an aqueous solution of phospholipids, and the concentration of phospholipids in the aqueous solution is 0.2-0.4 mg / mL.

[0011] Among them, the flow ratio of the magnetic nanoparticle suspension and the phospholipid dispersion entering the microchannel reactor is 0.5-2; this flow ratio can make the two raw material liquids in the two liquid inlet pipes mix more evenly, which is convenient for subsequent mixing; if it is not within this range, that is, when the flow difference between the two liquid raw material channels is too large, the high-flow fluid will flow into the low-flow fluid pipe, resulting in increased asymmetry in this area, disordered velocity flow field distribution, and uneven convergence.

[0012] Wherein, in the microchannel reactor, the gas-liquid phase flow rate ratio is 1-2; a flow rate ratio that is too large or too small is not conducive to the generation of Taylor flow, and a gas-liquid flow rate ratio within the range of 1-2 is conducive to the generation of Taylor flow, and the gas-liquid flow rate ratio also directly affects the bubble length in the Taylor flow, and the bubble length affects the gas-liquid mass transfer rate, thereby affecting the gas saturation time. At this gas-liquid flow rate ratio, the gas saturation time is 1-10 minutes, thereby greatly improving the production efficiency; the Taylor flow reaction residence time in the alternating magnetic field is 3-5 minutes, which can be extended by improving the alternating magnetic field instrument, lengthening the coil (alternating magnetic field source), extending the length of the alternating magnetic field, or setting the microchannel section in the alternating magnetic field into a stacked spiral shape, or controlling the flow rate of the gas-liquid phase to adjust the Taylor flow reaction residence time in the alternating magnetic field, and the length of the residence time will affect the alternating magnetic field on the magnetic lipid bubble magnetic field action time, thereby affecting the self-assembly time of the magnetic heating induced liposome.

[0013] Among them, the oscillation frequency of the alternating magnetic field is 5 to 50 KHz (relative to the static magnetic field, the alternating magnetic field changes periodically, and the oscillation frequency is the number of cycles of the alternating magnetic field changing per second. The oscillation frequency affects the magnetothermal conversion efficiency (SAR value, unit: watt / second) of the magnetic iron oxide nanoparticles. The same mass of iron oxide nanoparticles, the same magnetic field action time, the temperature rise amplitude under the action of magnetic fields of different frequencies is different. The higher the frequency, the greater the temperature rise amplitude), and the power is 50 to 500W.

[0014] Wherein, the temperature of the ultrasonic device is 20-50°C, and the ultrasonic power is 10-100W.

[0015] The present invention realizes continuous preparation of magnetic lipid micro-nano bubbles based on gas-liquid two-phase Taylor flow in a microchannel. By generating gas-liquid two-phase Taylor flow in a microchannel reactor, gas-liquid mass transfer is accelerated, and droplets can efficiently dissolve gas, shortening the gas saturation time. At the same time, by magnetothermal induction in the microchannel reactor to generate bubbles and phospholipid interface self-assembly in saturated droplets, controllable preparation of magnetic lipid micro-nano bubble particle size is achieved.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: the device of the present invention can realize the continuous preparation of magnetic lipid micro-nano bubbles. Compared with the batch preparation of magnetic lipid micro-nano bubbles, the gas-liquid mass transfer efficiency is increased by forming a gas-liquid two-phase Taylor flow, and the dissolution rate of the gas in the droplets is increased, thereby shortening the time required to form saturated droplets, thereby improving the preparation efficiency of magnetic lipid micro-nano bubbles. At the same time, the continuously prepared magnetic lipid micro-nano bubbles have good consistency and uniform particle size distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural principle diagram of the device of the present invention. DETAILED DESCRIPTION

[0018] like Figure 1 As shown, the continuous preparation device of magnetic lipid micro-nano bubbles of the present invention comprises a microchannel reactor 2, a gas-liquid separation unit 4 and a gas storage device 3, wherein the gas-liquid separation unit 4 is located at the discharge port side of the microchannel reactor 2, and the gas-liquid separation unit 4 is connected to the gas storage device 3 through a connecting pipe 9; wherein the microchannel reactor 2 comprises a fluid channel 21, a liquid inlet pipe 22 and an air inlet pipe 23 are connected to the feed port side of the fluid channel 21, an ultrasonic device 7 is provided on the outer wall of the fluid channel 21 between the liquid inlet pipe 22 and the air inlet pipe 23, and the liquid inlet pipe 22 and the fluid channel 21 are arranged in a Y shape (the liquid inlet pipe and the fluid channel are arranged in a Y shape (or the two liquid inlet pipes are arranged in a V shape) to make the two raw material liquids mix evenly. When the flow rates of the two raw material liquids are different, if they are In a T-shaped arrangement, the high-flow solution easily flows into the low-flow solution channel, causing the local flow rate to be turbulent, resulting in uneven mixing of the two solutions at the junction; when in a Y-shaped arrangement, due to the Y-shaped structural guidance, the high-flow liquid is not easy to flow into the low-flow liquid channel); the air inlet pipe 23 and the fluid channel 21 are arranged in a T-shape (the air inlet channel and the fluid channel are arranged in a T-shape to facilitate the formation of a gas-liquid Taylor flow, and the liquid in the fluid channel is easily broken by the gas in the air inlet pipe at the junction, and the formation of a gas segment is a necessary condition for generating a Taylor flow), the liquid inlet pipe 22 has two liquid inlets (1, 8), and the bottom of the air inlet pipe 23 is provided with an air inlet 6; along the material flow direction, at the rear end of the air inlet pipe 23, the fluid channel 21 passes through the interval 5 with an alternating magnetic field and then extends into the gas-liquid separation unit 4. The ultrasonic device 7 is a constant temperature ultrasonic device, which is fixed on the outer wall of the fluid channel 21.

[0019] Example 1: Continuous preparation of magnetic lipid xenon micro-nano bubbles

[0020] Using 20 μg / mL citric acid-modified iron oxide nanoparticle suspension and 400 μg / mL phospholipid aqueous solution as raw materials, a metering pump was used to transport the iron oxide nanoparticle suspension and the phospholipid aqueous solution from two inlets of the microchannel reactor inlet pipeline to the microchannel reactor, and the flow ratio of the two solutions was 1, and the flow rate was 1.5 mL / min.

[0021] The constant temperature ultrasonic device was turned on, the temperature was set to 28°C, the power was set to 30W, the iron oxide nanoparticle suspension and the phospholipid aqueous solution in the microchannel reactor were ultrasonically mixed, and xenon gas was pumped into the microchannel reactor from the air inlet at the lower end of the microchannel reactor. The apparent flow rate ratio of the mixed solution to the xenon gas was 1. After the mixed solution and the xenon gas generated a stable gas-liquid two-phase Taylor flow, the alternating magnetic field was turned on, the alternating magnetic field oscillation frequency was 50KHz, and the power was 500W (the iron oxide nanoparticles generated heat in the magnetic field, which reduced the gas solubility in the saturated droplets, and bubbles were precipitated from the droplets. The phospholipids in the solution were wrapped outside the bubbles). The saturated droplets in the Taylor flow reacted in the alternating magnetic field for 5 minutes and then flowed into the gas-liquid separation unit. The gas-liquid separation unit separated the xenon gas and the solution and collected the prepared magnetic lipid micro-nano bubbles. The separated xenon gas flowed into the gas recovery tank for recycling and reuse. The collected magnetic lipid micro-nano bubbles had an average particle size of 301.5nm, a PDI of 0.268, and a zeta potential of -39.6mV.

[0022] Example 2: Preparation of magnetic lipid nitrogen micro-nano bubbles

[0023] Using 20 μg / mL citric acid-modified iron oxide nanoparticle suspension and 400 μg / mL phospholipid aqueous solution as raw materials, a metering pump was used to transport the iron oxide nanoparticle suspension and the phospholipid aqueous solution from two inlets of the microchannel reactor inlet pipeline to the microchannel reactor, and the flow ratio of the two solutions was 1, and the flow rate was 1.5 mL / min.

[0024] The constant temperature ultrasonic device was turned on, the temperature was set to 28°C, the power was set to 30W, the iron oxide nanoparticle suspension and the phospholipid aqueous solution in the microchannel reactor were ultrasonically mixed, nitrogen was pumped into the microchannel reactor from the air inlet at the lower end of the microchannel reactor, the apparent flow rate ratio of the mixed solution to the xenon gas was 1, and after the mixed solution and the xenon gas generated a stable gas-liquid two-phase Taylor flow, the alternating magnetic field was turned on, the oscillation frequency of the alternating magnetic field was 50KHz, and the power was 500W. The saturated droplets in the Taylor flow reacted in the alternating magnetic field for 5 minutes and then flowed into the gas-liquid separation unit. The gas-liquid separation unit separated the nitrogen and the solution and collected the prepared magnetic lipid micro-nano bubbles. The separated nitrogen flowed into the gas recovery tank for recycling and reuse. The collected magnetic lipid micro-nano bubbles had an average particle size of 299.6nm, a PDI of 0.239, and a zeta potential of -40.3mV.

[0025] Example 3: Preparation of magnetic lipid sulfur hexafluoride micro-nanobubbles

[0026] Using 20 μg / mL citric acid-modified iron oxide nanoparticle suspension and 400 μg / mL phospholipid aqueous solution as raw materials, a metering pump was used to transport the iron oxide nanoparticle suspension and the phospholipid aqueous solution from two inlets of the microchannel reactor inlet pipeline to the microchannel reactor, and the flow ratio of the two solutions was 1, and the flow rate was 1.5 mL / min.

[0027] The constant temperature ultrasonic device was turned on, the temperature was set to 28°C, the power was set to 30W, the iron oxide nanoparticle suspension and the phospholipid aqueous solution in the microchannel reactor were ultrasonically mixed, sulfur hexafluoride was pumped into the microchannel reactor from the air inlet at the lower end of the microchannel reactor, the apparent flow rate ratio of the mixed solution to the xenon gas was 1, and after the mixed solution and the xenon gas generated a stable gas-liquid two-phase Taylor flow, the alternating magnetic field was turned on, the alternating magnetic field oscillation frequency was 50KHz, the power was 500W, the saturated droplets in the Taylor flow reacted in the alternating magnetic field for 5 minutes and then flowed into the gas-liquid separation unit, the gas-liquid separation unit separated the sulfur hexafluoride and the solution and collected the prepared magnetic lipid micro-nano bubbles, and the separated sulfur hexafluoride flowed into the gas recovery tank for recycling and reuse. The collected magnetic lipid micro-nano bubbles had an average particle size of 287.5nm, a PDI of 0.215, and a zeta potential of -43.7mV.

[0028] Comparative Example 1: Continuous preparation of magnetic lipid xenon micro-nano bubbles

[0029] Using 20 μg / mL citric acid-modified iron oxide nanoparticle suspension and 400 μg / mL phospholipid aqueous solution as raw materials, a metering pump was used to transport the iron oxide nanoparticle suspension and the phospholipid aqueous solution from two inlets of the microchannel reactor inlet pipeline to the microchannel reactor, and the flow ratio of the two solutions was 1, and the flow rate was 1.5 mL / min.

[0030] The constant temperature ultrasonic device was turned on, the temperature was set to 28°C, the power was set to 30W, the iron oxide nanoparticle suspension and the phospholipid aqueous solution in the microchannel reactor were ultrasonically mixed, and xenon gas was pumped into the microchannel reactor from the air inlet at the lower end of the microchannel reactor. The apparent flow rate ratio of the mixed solution to the xenon gas was 1. After the mixed solution and the xenon gas generated a stable gas-liquid two-phase Taylor flow, the alternating magnetic field was turned on, the alternating magnetic field oscillation frequency was 50KHz, and the power was 500W (the iron oxide nanoparticles generated heat in the magnetic field, which reduced the gas solubility in the saturated droplets, and bubbles were precipitated from the droplets. The phospholipids in the solution were wrapped outside the bubbles). The saturated droplets in the Taylor flow reacted in the alternating magnetic field for 2 minutes and then flowed into the gas-liquid separation unit. The gas-liquid separation unit separated the xenon gas and the solution and collected the prepared magnetic lipid micro-nano bubbles. The separated xenon gas flowed into the gas recovery tank for recycling and reuse. The collected magnetic lipid micro-nano bubbles had an average particle size of 216.9nm, a PDI of 0.893, and a zeta potential of -29.3mV. Too short a residence time in the alternating magnetic field will result in too short a magnetothermal time, the gas in the saturated liquid cannot be better precipitated, and the phospholipids cannot be well induced to self-assemble on the bubble surface, resulting in uneven bubble size and poor stability.

[0031] Comparative Example 2: Continuous preparation of magnetic lipid xenon micro-nano bubbles

[0032] Using 20 μg / mL citric acid-modified iron oxide nanoparticle suspension and 400 μg / mL phospholipid aqueous solution as raw materials, a metering pump was used to transport the iron oxide nanoparticle suspension and the phospholipid aqueous solution from two inlets of the microchannel reactor inlet pipeline to the microchannel reactor, and the flow ratio of the two solutions was 1, and the flow rate was 1.5 mL / min.

[0033] The constant temperature ultrasonic device was turned on, the temperature was set to 28°C, the power was set to 30W, the iron oxide nanoparticle suspension and the phospholipid aqueous solution in the microchannel reactor were ultrasonically mixed, and xenon gas was pumped into the microchannel reactor from the air inlet at the lower end of the microchannel reactor. The apparent flow rate ratio of the mixed solution to the xenon gas was 0.6. After the mixed solution and the xenon gas generated a stable gas-liquid two-phase Taylor flow, the alternating magnetic field was turned on, the alternating magnetic field oscillation frequency was 50KHz, and the power was 500W (the iron oxide nanoparticles generated heat in the magnetic field, which reduced the gas solubility in the saturated droplets, and bubbles were precipitated from the droplets. The phospholipids in the solution were wrapped outside the bubbles). The saturated droplets in the Taylor flow reacted in the alternating magnetic field for 5 minutes and then flowed into the gas-liquid separation unit. The gas-liquid separation unit separated the xenon gas and the solution and collected the prepared magnetic lipid micro-nano bubbles. The separated xenon gas flowed into the gas recovery tank for recycling and reuse. The collected magnetic lipid micro-nano bubbles had an average particle size of 224.5nm, a PDI of 0.987, and a zeta potential of -31.6mV. When the gas flow rate is relatively high, a stable Taylor flow cannot be formed, thereby reducing the gas-liquid mass transfer efficiency and causing the gas phase content in the liquid to be relatively small. At this time, the gas precipitation efficiency under magnetic thermal conditions is low, and the resulting magnetic lipid micro-nano bubbles are small and unstable.

[0034] The present invention forms a gas-liquid two-phase Taylor flow in a microchannel reactor to quickly obtain saturated droplets, then applies an alternating magnetic field to induce magnetic nanoparticles in the Taylor flow saturated droplets to produce a magnetocaloric effect, the high-temperature surface of the magnetic nanoparticles produces bubbles and induces phospholipid molecules to self-assemble at the bubble interface, thereby realizing continuous preparation of magnetic lipid micro-nano bubbles, and simultaneously arranging a gas-liquid separation unit and a gas recovery device at the end of the reactor. The present invention adopts a gas-liquid two-phase Taylor flow to enhance the gas-liquid mass transfer efficiency and thus efficiently dissolve the gas, shortening the formation time of the saturated droplets, and at the same time, the magnetic lipid micro-nano bubbles prepared by the continuous method have a high yield, a uniform particle size distribution, and the gas can be recycled.

Claims

1. A device for continuously preparing magnetic lipid micro-nano bubbles, Features: The invention comprises a microchannel reactor (2), a gas-liquid separation unit (4) and a gas storage device (3), wherein the gas-liquid separation unit (4) is located on the discharge port side of the microchannel reactor (2), and the gas-liquid separation unit (4) is connected to the gas storage device (3) via a connecting pipe (9); wherein the microchannel reactor (2) comprises a fluid channel (21), and the feed port side of the fluid channel (21) is connected to a liquid inlet pipe (22) and an air inlet pipe (23); an ultrasonic device (7) is provided on the outer wall of the fluid channel (21) between the liquid inlet pipe (22) and the air inlet pipe (23); the liquid inlet pipe (22) and the fluid channel (21) are arranged in a Y shape; the air inlet pipe (23) and the fluid channel (21) are arranged in a T shape; and along the material flow direction, at the rear end where the air inlet pipe (23) is arranged, the fluid channel (21) passes through a section (5) with an alternating magnetic field and then extends into the gas-liquid separation unit (4).

2. The continuous preparation device of magnetic lipid micro-nano bubbles according to claim 1, Features: The inner diameter ratio of the liquid inlet pipe (22) to the fluid channel (21) is 0.5-2; the inner diameter ratio of the air inlet pipe (23) to the fluid channel (21) is 0.8-1.

5.

3. The continuous preparation device of magnetic lipid micro-nano bubbles according to claim 1, Features: The ultrasonic device (7) is a constant temperature ultrasonic device, and the constant temperature ultrasonic device is fixed on the outer wall of the channel.

4. A method for continuously preparing magnetic lipid micro-nano bubbles based on the device according to claim 1, It is characterized in that Specifically, a magnetic nanoparticle suspension and a phospholipid dispersion are respectively introduced into a microchannel reactor (2) from two liquid inlets of a liquid inlet pipe (22); when flowing through a channel region with an ultrasonic device (7), the magnetic nanoparticle suspension and the phospholipid dispersion are fully mixed to form a mixed solution; a gas is transported from an air inlet pipe (23) into the microchannel reactor (2) to form a stable Taylor flow with the mixed solution; an alternating magnetic field is applied in the Taylor flow stable section; the magnetic nanoparticles excite a magnetothermal effect in the alternating magnetic field, bubbles are generated in the saturated droplets of the Taylor flow, and phospholipids are induced to self-assemble at the bubble interface; the fluid flowing through the alternating magnetic field enters a gas-liquid separation unit (4) at the end of the microchannel reactor (2) to obtain a liquid containing magnetic lipid micro-nano bubbles; and the unreacted gas enters a gas storage device (3) through a connecting pipe (9).

5. The method for continuously preparing magnetic lipid micro-nano bubbles according to claim 4, Features: The magnetic nanoparticle suspension is an iron oxide nanoparticle suspension, and the concentration of the iron oxide nanoparticles in the suspension is 20-30 μg / mL.

6. The method for continuously preparing magnetic lipid micro-nano bubbles according to claim 4, Features: The phospholipid dispersion is an aqueous solution of phospholipids, and the concentration of the phospholipids in the aqueous solution is 0.2-0.4 mg / mL.

7. The method for continuously preparing magnetic lipid micro-nano bubbles according to claim 4, Features: The magnetic nanoparticle suspension and the phospholipid dispersion flow rate ratio is 0.5-2 when entering the microchannel reactor (2).

8. The method for continuously preparing magnetic lipid micro-nano bubbles according to claim 4, Features: In the microchannel reactor (2), the gas-liquid phase flow rate ratio is 1-2, and the Taylor flow reaction residence time in the alternating magnetic field is 3-5 minutes.

9. The method for continuously preparing magnetic lipid micro-nano bubbles according to claim 4, Features: The alternating magnetic field has an oscillation frequency of 5-50KHz and a power of 50-500W.

10. The method for continuously preparing magnetic lipid micro-nano bubbles according to claim 4, Features: The temperature of the ultrasonic device (7) is 20-50°C, and the ultrasonic power is 10-100W.

Images