A drug loading and delivery method and a cell carrying method of a core-shell mesoporous micro-nano robot

Abstract

The present application relates to the technical field of targeted cargo delivery, and more particularly to a drug loading and delivery method and a cell carrying method of core-shell mesoporous micro-nanorobot. The drug loading and delivery method is realized based on the drug loading capacity of the mesoporous structure, the magnetism of the iron oxide core and the photothermal effect of the polydopamine shell. The core-shell mesoporous micro-nanorobot can adsorb and load drugs through the capillary force and electrostatic force generated by the mesoporous structure; then the movement of the core-shell mesoporous micro-nanorobot is driven by an external magnetic field; when the core-shell mesoporous micro-nanorobot approaches the target area, the pore structure is irradiated by near-infrared light, the temperature of the pore structure is increased and the thermal vibration is accompanied, the drugs in the mesoporous structure are effectively released to the target area, and the drug delivery effect is achieved. At the same time of drug loading and delivery, the core-shell mesoporous micro-nanorobot has a carrying capacity after clustering under the magnetic field, and carries cells through two methods of eddy current carrying and contact adhesion. The targeted cargo delivery of targeted drugs and cells and other cargos can be realized by the micro-nanorobot.

Description

Technical Field

[0001] This invention relates to the field of targeted cargo delivery technology, and more specifically to a drug loading and delivery method and a cell delivery method using a core-shell mesoporous micro / nano robot. Background Technology

[0002] Precision medicine, as a core research area of ​​21st-century medicine, has become a key development technology at the strategic level for countries worldwide. Targeted cargo delivery is at the heart of precision medicine, delivering not only targeted drugs like doxorubicin but also functional cells used in cell therapy, such as T cells and erythrocytes. With continuous breakthroughs in medical technology bottlenecks, targeted cargo delivery technology will bring new core driving forces to precision medicine, propelling its development. Micro- and nano-robotics are emerging cutting-edge technologies characterized by their small size, good controllability, and high thrust-to-weight ratio. They can convert external physical field energy into mechanical energy for their own motion, offering significant advantages in the biomedical field and providing a new breakthrough for targeted cargo delivery technology. However, current technologies do not yet support targeted cargo delivery using micro- and nano-robotics. This technological gap limits the further development of targeted cargo delivery technology but also presents new challenges and opportunities for researchers. Innovatively applying micro- and nano-robotics to targeted cargo delivery is expected to bring new core driving forces to precision medicine, propelling its leapfrog development. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, this invention provides a core-shell mesoporous micro / nano robot for targeted cargo delivery, and proposes a drug loading and delivery and cell transport method based on the core-shell mesoporous micro / nano robot. Its beneficial effect is that targeted cargo delivery such as targeted drugs and cells can be achieved through micro / nano robots.

[0004] The technical solution adopted by this invention to solve its technical problem is:

[0005] A drug loading and delivery method for a core-shell mesoporous micro / nano robot, the drug loading and delivery method being based on the drug loading capacity of its mesoporous structure, the magnetism of the iron oxide core, and the photothermal effect of the polydopamine shell;

[0006] First, core-shell mesoporous micro-nano robots can adsorb and load drugs through capillary and electrostatic forces generated by their mesoporous structure.

[0007] It is then driven to move by an external magnetic field;

[0008] When approaching the target area, near-infrared light is used for irradiation. Because polydopamine can generate a photothermal effect under near-infrared light irradiation, the temperature of the pore structure increases and is accompanied by thermal vibration, which effectively releases the drug in the mesopores to the target area, thereby achieving the drug delivery effect.

[0009] A cell delivery method using core-shell mesoporous micro / nano robots is disclosed. While delivering drugs, the core-shell mesoporous micro / nano robots, when clustered in a magnetic field, possess carrying capacity and deliver cells through both eddy current carrying and contact adhesion methods.

[0010] The eddy current carrying method is as follows:

[0011] First, the iron oxide magnetic core of the core-shell mesoporous micro-nano robot is paramagnetic and rotates stably under the uniform rotating magnetic field generated by the Helmholtz coil, generating small eddies around it. Under the combined attraction of the eddies and the attraction generated after the magnetic iron oxide core is magnetized, the micro-nano robot forms a cluster. Furthermore, due to the viscosity of the polydopamine surface, the cluster structure is stable.

[0012] Driven by a magnetic field, a cluster of core-shell mesoporous micro-nano robots that roll at high speed generates a rotating vortex. The gravity generated by the vortex attracts and carries the cells. After reaching the target area, the cells are released by adjusting the external magnetic field parameters to reduce the rotation speed.

[0013] The contact adhesion method is as follows:

[0014] The core-shell mesoporous micro-nano robot swarm uses surface hydrophilicity and viscosity to adhere to cells, and then carries the cells to move under the drive of a magnetic field. After reaching the target area, the swarm rotates horizontally by adjusting the direction of the external magnetic field to rotate horizontally and release the cells.

[0015] A core-shell mesoporous micro / nano robot for targeted cargo delivery consists of a magnetic core made of iron oxide and a mesoporous shell made of polydopamine, with the polydopamine mesoporous shell disposed on the outside of the magnetic core made of iron oxide.

[0016] A drive control device for a core-shell mesoporous micro / nano robot for targeted cargo delivery, the drive control device comprising a magnetic field generator and an infrared light field generator;

[0017] The magnetic field generating device is a three-dimensional Helmholtz coil. The signal generator produces a sinusoidal electrical signal, which is amplified by a power amplifier and then input into the Helmholtz coil. By changing the phase and amplitude of the electrical signal, the magnetic field strength generated by the three pairs of coils is adjusted and combined to generate a uniform rotating magnetic field in any direction in space. The uniform rotating magnetic field includes a forward rolling rotation mode and a horizontal rotation mode. Driven by the Helmholtz coil, the core-shell mesoporous micro-nano robot rolls and moves in any direction and swarms.

[0018] The infrared light field generating device is an infrared laser generator. The infrared laser generator can emit 808nm near-infrared light at a fixed power to excite core-shell mesoporous micro-nano robots to produce a photothermal effect. The intensity of the emitted infrared light can be adjusted by regulating the power through a controller.

[0019] A fabrication process for a core-shell mesoporous micro / nano robot for targeted cargo delivery includes the preparation of a sol-gel magnetic core and the preparation of a chemically synthesized mesoporous shell.

[0020] In the preparation process of the sol-gel magnetic core, ferric chloride reacts with sodium hydroxide to generate ferric hydroxide colloid. The ferric hydroxide colloid seeds are heated in an environment containing sodium sulfate and transformed into ferric oxide and gradually grow from the initial seed state to a spindle shape, and finally grow into an ellipsoidal ferric oxide magnetic core.

[0021] During the preparation of mesoporous shells through chemical synthesis, dopamine nanoparticles gradually aggregate and grow on the surface of the iron oxide magnetic core due to the hydrophilicity of the surface and the interaction of electrostatic forces.

[0022] Furthermore, due to the influence of the poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer, namely P123, on the degree of dopamine aggregation on the surface of the magnetic core, a polydopamine shell with a mesoporous structure will be generated on the surface of the iron oxide core.

[0023] Ultimately, a core-shell mesoporous micro / nano robot encapsulated in polydopamine was obtained.

[0024] The porosity of the mesoporous shell of the core-shell mesoporous micro / nano robot is adjusted by changing the amount of ammonia and P123 used in the preparation of the chemically synthesized mesoporous shell.

[0025] During the synthesis of polydopamine mesoporous shells, the degree of dopamine aggregation by P123 is affected by the acidity or alkalinity of the environment. The increase in ammonia concentration leads to increased alkalinity in the solution, resulting in a denser mesoporous structure. In addition, as the concentration of P123 in the solution decreases, dopamine will tightly aggregate on the surface of the core and grow to form nanoscale radial mesopores.

[0026] The beneficial effects of the drug loading and delivery method and cell delivery method of the core-shell mesoporous micro / nano robot of the present invention are as follows:

[0027] The prepared polydopamine / iron oxide core-shell mesoporous micro-nano robot can respond to an external magnetic field and convert the magnetic energy of the external magnetic field into the mechanical energy of its own motion to move. By controlling the strength, direction and frequency of the rotating magnetic field of the three-dimensional Helmholtz coil, the motion of the polydopamine / iron oxide core-shell mesoporous micro-nano robot can be precisely controlled.

[0028] The prepared polydopamine / iron oxide core-shell mesoporous micro / nano robots can load drugs through their surface mesoporous structures;

[0029] The porosity of the polydopamine shell of the prepared polydopamine / iron oxide core-shell mesoporous micro / nano robot can be stably adjusted, enriching its drug loading diversity.

[0030] The prepared polydopamine / iron oxide core-shell mesoporous micro / nano robots can release drugs by responding to infrared light through the photothermal effect generated by the surface polydopamine structure;

[0031] The prepared polydopamine / iron oxide core-shell mesoporous micro / nano robots can cluster together in a magnetic field and form stable clusters.

[0032] Polydopamine / iron oxide core-shell mesoporous micro-nano robots can load and transport cells via eddy current-carrying cell transport after forming a cluster. This non-contact transport method allows for rapid loading, flexible movement, and no damage to the cells.

[0033] Polydopamine / iron oxide core-shell mesoporous micro-nano robots can load and transport cells through a contact adhesion cell transport method after forming a cluster. This contact transport method has good loading and transport stability, strong resistance to flow field interference, and can be used for long-distance transport.

[0034] Polydopamine / iron oxide core-shell mesoporous micro-nano robots integrate drug loading and delivery with cell transport capabilities, which can simultaneously meet a variety of application needs, bringing new ideas to the design of carriers for drug delivery and cell manipulation, and have broad application prospects in the biomedical field. Attached Figure Description

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and specific implementation methods.

[0036] Figure 1 A schematic diagram illustrating the fabrication process mechanism of core-shell mesoporous micro / nano robots;

[0037] Figure 2 Flowchart of the fabrication process for core-shell mesoporous micro / nano robots;

[0038] Figure 3 Scanning electron microscope image and energy dispersive spectroscopy (EDS) spectrum of a core-shell mesoporous micro / nano robot;

[0039] Figure 4 Scanning electron microscope image of porosity adjustment for a core-shell mesoporous micro / nano robot;

[0040] Figure 5 Transmission electron microscope image of a core-shell mesoporous micro / nano robot;

[0041] Figure 6Light absorption curves and fluorescence images for drug loading onto core-shell mesoporous micro / nano robots;

[0042] Figure 7 A diagram illustrating the swarming mechanism and experiments of core-shell mesoporous micro / nano robots.

[0043] Figure 8 Schematic diagram of the vortex-carrying cell transport mechanism and experiment of a core-shell mesoporous micro / nanorobot;

[0044] Figure 9 This diagram illustrates the contact and adhesion mechanism of core-shell mesoporous micro / nanorobots for cell transport and provides experimental results. Detailed Implementation

[0045] This invention proposes a polydopamine / iron oxide core-shell mesoporous micro / nanorobot with tunable porosity. Based on the paramagnetism of its iron oxide magnetic core, this core-shell micro / nanorobot can be driven and clustered under a magnetic field. Based on the mesoporous structure of its polydopamine shell, the core-shell micro / nanorobot can serve as a carrier for targeted drugs. Based on the viscosity of its polydopamine shell, the core-shell micro / nanorobot can adhere to cells and act as a carrier for targeted cell delivery. This polydopamine / iron oxide core-shell mesoporous micro / nanorobot, which integrates targeted drug delivery and cell delivery functions, provides a novel approach to carrier design for targeted cargo delivery technology, promotes the deep integration of biomedicine and materials science, and will significantly advance the development of precision medicine technology.

[0046] The fabrication of polydopamine / iron oxide core-shell mesoporous micro / nano robots involves a two-step process, such as... Figure 1 As shown. The specific process for preparing the sol-gel magnetic core is as follows: Sodium hydroxide solution (90 mL, 5 mol / L) is slowly added dropwise to ferric chloride solution (100 mL, 2 mol / L), and stirred for 10 minutes using a mechanical stirrer. Sodium sulfate solution (10 mL, 0.3 mol / L) is added, and stirred for 10 minutes using a mechanical stirrer. The resulting solution is transferred to a glass bottle (250 mL), placed in a muffle furnace, and heated at 100°C for 8 days. The resulting solution is washed with anhydrous ethanol and centrifuged 4 times. The resulting solution is further washed with deionized water and centrifuged 4 times. The resulting solution is placed in a drying oven and dried at 60°C-90°C (preferably 80°C) for 8-16 (preferably 12) hours to obtain the iron oxide core.

[0047] The specific process for preparing the chemically synthesized mesoporous shell is as follows: Iron oxide core (20 mg), dopamine hydrochloride (0.2 g), polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123) (35 mg), and polyoxyethylene-polypropylene oxide (F127) (75 mg) are added to an Erlenmeyer flask. Then, anhydrous ethanol (7.5 ml) and deionized water (7.5 ml) are added. The resulting dispersion is ultrasonically treated for 5-15 minutes. 1,3,5-trimethylammonium chloride is added to the resulting uniform dispersion. Benzene (0.6 ml) was sonicated for 10-20 minutes. The dispersion was then magnetically stirred, and ammonia (0.3 mL, 28%) was added during stirring. The mixture was magnetically stirred at room temperature for 2-4 hours. The resulting solution was washed with anhydrous ethanol and centrifuged four times. It was then further washed with deionized water and centrifuged four times. The resulting solution was placed in a drying oven at 60-90°C (preferably 80°C) for 8-16 hours (preferably 12 hours) to obtain a polydopamine / iron oxide core-shell mesoporous micro / nano robot. Figure 2 As shown. Scanning electron microscope (SEM) image and energy dispersive spectroscopy (EDS) spectrum of polydopamine / iron oxide core-shell mesoporous micro / nano robots, as shown. Figure 3 As shown.

[0048] Scanning electron microscope (SEM) and transmission electron microscope (TEM) images of the porosity adjustment of polydopamine / iron oxide core-shell mesoporous micro / nano robots, as shown below. Figure 4 , Figure 5 As shown. The amounts of ammonia added from left to right are 0.2ml, 0.35ml, and 0.5ml, respectively.

[0049] The drug loading and delivery experimental procedure was as follows: First, polydopamine / iron oxide core-shell mesoporous micro / nano robots were dispersed in phosphate buffer. Then, a 1 mg / ml doxorubicin phosphate buffer solution was added and mixed at a 1:1 volume ratio. The mixture was then placed in the dark for 48 hours with stirring. Subsequently, the drug-loaded polydopamine mesoporous micro / nano robots were washed with phosphate buffer, centrifuged three times, and then dispersed again in phosphate buffer. The light absorption data of the polydopamine / iron oxide core-shell mesoporous micro / nano robots before and after drug loading are shown in the figure below. Figure 6 As shown in (a), the drug-loaded polydopamine / iron oxide core-shell mesoporous micro / nanorobot was dispersed in phosphate buffer and then placed in a Helmholtz coil. The Helmholtz coil was set to a forward rolling rotation mode with magnetic field parameters of 10 mT and 15 Hz. The polydopamine / iron oxide core-shell mesoporous micro / nanorobot rotated in response to changes in the external magnetic field. After reaching the target area, the 808 nm near-infrared light field parameters were adjusted to 6 W / cm², and the light field was turned on for irradiation. Fluorescence was then observed. The fluorescence image of the polydopamine / iron oxide core-shell mesoporous micro / nanorobot is shown below. Figure 6 As shown in (b).

[0050] The experimental procedure for the clustering process was as follows: The Helmholtz coil was selected in a forward rolling rotation mode with magnetic field parameters of 10 mT and 15 Hz. The polydopamine / iron oxide core-shell mesoporous micro / nano robots could respond to changes in the external magnetic field and perform stable rotational motion under these parameters. During the rotation, the robots clustered together, resulting in a cluster of polydopamine / iron oxide core-shell mesoporous micro / nano robots. Figure 7 As shown.

[0051] The eddy current-carrying cell transport experiment procedure is as follows: Red blood cells are centrifuged and dispersed in phosphate buffer to prepare a dispersion, which is then added to a culture dish and placed inside a Helmholtz coil. Next, polydopamine / iron oxide core-shell mesoporous microrobots dispersed in phosphate buffer are added to the phosphate buffer containing the red blood cells. The Helmholtz coil is in a forward rolling rotation mode with magnetic field parameters of 10 mT and 15 Hz. A cluster of microrobots is formed through swarming, driving the cluster to move. Upon approaching the target red blood cells, the Helmholtz coil maintains the forward rolling rotation mode, adjusting the magnetic field parameters to 10 mT and 35 Hz, using eddy currents to transport the cells. Once at the designated area, the magnetic field parameters are adjusted to 10 mT and 15 Hz, releasing the cells. Figure 8 As shown.

[0052] The contact adhesion cell transport experiment procedure is as follows: Red blood cells are centrifuged and dispersed in phosphate buffer to prepare a dispersion. This dispersion is added to a culture dish and placed inside a Helmholtz coil. Then, polydopamine / iron oxide core-shell mesoporous microrobots dispersed in phosphate buffer are added to the phosphate buffer containing red blood cells. The Helmholtz coil is in forward rolling rotation mode with magnetic field parameters of 10 mT and 15 Hz. A cluster of microrobots is generated through aggregation. The microrobots are driven to move and lock onto the target red blood cells. The microrobots then approach the cells, allowing the polydopamine mesoporous microrobots to contact and adhere to the red blood cells. After adhesion is observed, the Helmholtz coil maintains the forward rolling rotation mode with magnetic field parameters of 10 mT and 15 Hz for cell transport. Once the cells reach the designated area, the Helmholtz coil switches to horizontal rotation mode with magnetic field parameters of 10 mT and 25 Hz. The microrobots then rotate horizontally to release the cells, ending the experiment. Figure 9 As shown.

Claims

1. A method for preparing core-shell mesoporous micro-nanorobots for targeted cargo delivery, characterized by: The preparation of the sol-gel magnetic core and the chemical synthesis of the mesoporous shell; The preparation of the polydopamine / iron oxide core-shell type mesoporous micro-nano robot includes two steps, and the specific process of the preparation of the sol-gel magnetic core is as follows: 90 mL of 5 mol / L sodium hydroxide solution is slowly added into 100 mL of 2 mol / L iron chloride solution, stirred for 10 minutes by using a mechanical stirrer, 10 mL of 0.3 mol / L sodium sulfate solution is added, stirred for 10 minutes by using a mechanical stirrer, the obtained solution is transferred into a 250 mL glass bottle, heated in a muffle furnace at 100 DEG C for 8 days, the obtained solution is washed and centrifuged 4 times with anhydrous ethanol, the obtained solution is further washed and centrifuged 4 times with deionized water, and the obtained solution is dried in a drying oven at 60-90 DEG C for 8-16 hours to obtain an iron oxide core; The specific process of the chemical synthesis of the mesoporous shell is as follows: 20 mg of the iron oxide core, 0.2 g of dopamine hydrochloride, 35 mg of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, and 75 mg of polyoxyethylene polyoxypropylene are added into a conical flask, then 7.5 ml of anhydrous ethanol and 7.5 ml of deionized water are added, the obtained dispersion is ultrasonically treated for 5-15 minutes, 0.6 ml of mesitylene is added into the obtained uniformly dispersed solution, ultrasonically treated for 10-20 minutes, the dispersion is subjected to magnetic stirring, 0.3 mL of 28% ammonia water is added during the stirring process, and the solution is subjected to magnetic stirring at room temperature for 2-4 hours, the obtained solution is washed and centrifuged 4 times with anhydrous ethanol, the obtained solution is further washed and centrifuged 4 times with deionized water, and the obtained solution is dried in a drying oven at 60-90 DEG C for 8-16 hours to obtain a polydopamine / iron oxide core-shell type mesoporous micro-nano robot.

2. The method of claim 1, wherein the method further comprises: providing a mesoporous silica shell on the surface of the magnetic core. In the preparation of the sol-gel magnetic core, iron chloride reacts with sodium hydroxide to generate iron hydroxide colloid, the iron hydroxide colloid seed is converted into iron oxide and gradually grows in the environment containing sodium sulfate under heating, and gradually grows from the initial seed state into a spindle type and finally into an ellipsoidal iron oxide magnetic core; In the preparation of the chemical synthesis of the mesoporous shell, dopamine nanoparticle seeds gradually aggregate and grow on the surface of the iron oxide magnetic core in an alkaline environment due to the hydrophilicity of the surface of the iron oxide magnetic core and the electrostatic force interaction; In addition, the polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, i.e., P123, affects the aggregation degree of dopamine on the surface of the magnetic core, and a polydopamine shell with a mesoporous structure is generated on the surface of the iron oxide core; Finally, a polydopamine-coated core-shell type mesoporous micro-nano robot is obtained.

3. The method of claim 2, wherein the method further comprises: providing a mesoporous silica shell on the surface of the magnetic core. The porosity of the mesoporous shell of the core-shell mesoporous micro-nano robot is adjusted by changing the amount of ammonia water and P123 in the preparation of the chemical synthesis of the mesoporous shell.

4. The method of claim 3, wherein the method further comprises the step of: 4-1) adding a targeting agent to the shell of the core-shell mesoporous micro-nanorobot. In the synthesis process of the polydopamine mesoporous shell, the aggregation degree of P123 to dopamine is affected by the acidity and alkalinity in the environment, and the increase of the ammonia concentration leads to the increase of the alkalinity in the solution, which leads to the densification of the mesoporous structure; in addition, with the decrease of the P123 concentration in the solution, dopamine will be closely aggregated and grown on the surface of the core to form a nanoscale radial mesoporous structure.

5. The core-shell mesoporous micro-nanorobot for targeted cargo delivery of any one of claims 1-4, wherein: The core-shell mesoporous micro-nano robot is composed of a magnetic core composed of iron oxide and a mesoporous shell composed of polydopamine, and the mesoporous shell composed of polydopamine is arranged outside the magnetic core composed of iron oxide.

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