Micro-fluidic chip for intracellular substance delivery based on magnetic response membrane

Abstract

The invention provides a micro-fluidic chip based on a magnetic response membrane and used for delivering substances in cells, the micro-fluidic chip comprises a chip main body 10, a first surface of the chip main body 10 is provided with a micro-channel 11 and a cavity 12, the middle part of the micro-channel 11 is communicated with the cavity 12 through a transition area 13, and a necking opening, close to the end of the micro-channel 11, of the transition area 13 is a jet flow nozzle 14; a magnetic material film layer 30; the chip base 20 is provided with a through hole 21; wherein the first surface of the chip main body 10 is bonded with the first surface of the magnetic material film layer 30 to seal the microchannel 11 and the cavity 12, the chip base 20 is bonded with the second surface of the magnetic material film layer 30, and the magnetic material film layer 30 is excited by an external magnetic field to generate vibration, so that a culture medium in the cavity 12 generates synthetic jet at the jet nozzle 14; and the material acts on cells flowing through the micro-channel 11, so that the cells are perforated, and the delivery of the material in the cells is flexibly and efficiently realized.

Description

Technical Field

[0001] The present invention relates to the field of microfluidic biotechnology, and in particular to a microfluidic chip for intracellular substance delivery based on a magnetic-responsive membrane. Background Art

[0002] The delivery of exogenous macromolecules into cells is crucial in basic biology and clinical applications. However, the cell membrane, as a natural biological barrier, strictly prevents the entry of biological macromolecules into cells, resulting in extremely low efficiency of drug or molecule delivery into cells. To overcome this obstacle, various methods for intracellular drug or molecule delivery have emerged in recent years, including carrier-based biological methods and membrane disruption-based physical methods. However, the substances in carrier-based biological methods are restricted by specific cell types, with low delivery efficiency, and can cause adverse immune reactions to cells or even permanent damage.

[0003] With the development of micro-nano technology, there have been more and more studies on intracellular substance delivery based on membrane disruption. This method can bypass endocytosis and create transient pores in the cell membrane through external forces. Before the cell membrane reseals, exogenous molecules rapidly diffuse into the cell interior through the transient pores, completing the delivery of macromolecular substances. Although this method shows advantages in delivery efficiency, problems such as cell clogging of channels and uneven squeezing of cells also limit its development and application space. Currently, the physical methods based on membrane disruption include the microchannel constriction extrusion method and the water perforation method based on cell extrusion. The operation of delivering cells by microchannel constriction extrusion is simple, but its biggest drawback is that it is easy to clog the channels. The water perforation technology based on cell extrusion has advantages such as high throughput, high transfection efficiency, and high cell viability. However, the water perforation technology is currently only limited to suspension cell types, the delivery process is uneven, and most microchannels have problems of cell clogging; moreover, the water perforation technology utilizes the momentum of fluid counterflow, requiring the chip to withstand a large pressure, and the transfection efficiency is greatly affected by the flow rate and Reynolds index, and the internal fluid flow cannot be precisely controlled. Summary of the Invention

[0004] Embodiments of the present invention provide a microfluidic chip for intracellular substance delivery based on a magnetic-responsive membrane to at least solve one of the problems existing in the related art. To achieve this purpose, the present invention is realized through the following technical solutions.

[0005] The present invention provides a microfluidic chip based on a magnetic response film for intracellular material delivery, comprising: a chip body, a microchannel and a cavity are arranged on a first surface of the chip body, a middle part of the microchannel and the cavity are communicated through a transition region, and a constriction at a microchannel end of the transition region is a jet nozzle; a magnetic material film layer; a chip base, the chip base has a through hole for enabling a magnetic core tip of an external alternating current coil to approach the magnetic material film layer; wherein, the first surface of the chip body is bonded to a first surface of the magnetic material film layer to seal the microchannel and the cavity, the chip base is bonded to a second surface of the magnetic material film layer, and the through hole of the chip base corresponds to a position of the cavity of the chip body, and the magnetic material film layer generates vibration under the excitation of an external magnetic field, so that a culture medium in the cavity generates a synthetic jet at the jet nozzle, acts on cells flowing in the microchannel, and uses the momentum of the synthetic jet to open pores of the cells to achieve material delivery.

[0006] Further, the magnetic material film layer is a composite film prepared by mixing carbonyl iron powder and PDMS, wherein the mass ratio of carbonyl iron powder to PDMS is greater than 1.

[0007] Further, the magnetic material film layer is a PDMS micromagnet sandwich film, including a PDMS top layer, a PDMS bottom layer and a permanent magnet micromagnet layer sandwiched between the PDMS top layer and the PDMS bottom layer.

[0008] Further, the magnetic material film layer is a PDMS micromagnet sandwich film, including a PDMS top layer, a PDMS bottom layer and a micromagnet layer prepared by mixing carbonyl iron powder and PDMS sandwiched between the PDMS top layer and the PDMS bottom layer.

[0009] Further, the amplitude of the magnetic material film layer is not less than 5 μm.

[0010] Further, the thickness of the magnetic material film layer is 0.1 - 2 mm.

[0011] Further, the size of the magnetic material film layer is not less than 5×5 mm.

[0012] Further, the diameter of the cavity is not less than 2 mm, the width of the microchannel is not less than 20 μm, and the height of the cavity (12) is greater than the height of the microchannel (11).

[0013] Further, the transition region is in a shape similar to a triangle, a bottom edge of the shape similar to a triangle is connected to the cavity, a top angle of the shape similar to a triangle is connected to the microchannel, and the top angle of the shape similar to a triangle is the jet nozzle.

[0014] Further, the ratio of the base length of the shape of the similar triangle to the opening width of the apex angle is not less than 3:1.

[0015] Further, the chip body further includes a culture medium inlet, a cell inlet, and a cell outlet that penetrate the second surface of the chip body. The culture medium inlet and the transition region are located on opposite sides of the cavity. The cell inlet and the cell outlet are respectively located at both ends of the microchannel, and the directions in which the cell inlet and the cell outlet penetrate the second surface of the chip body are respectively obtuse angles with respect to the extending direction of the microchannel.

[0016] The embodiments of the present invention have the following beneficial effects:

[0017] (1) In the present invention, by integrating the magnetoresponsive film layer into the microfluidic chip, under the excitation of an alternating magnetic field, a synthetic jet with a controllable output frequency is generated, and the synthetic jet acts on the cells flowing unidirectionally in the microchannel of the microfluidic chip, so that the cells are squeezed and deformed, realizing the non-invasive delivery of biological macromolecules.

[0018] (2) The microfluidic chip for intracellular substance delivery based on the magnetoresponsive film provided by the present invention, by the method of using the synthetic jet to act on the cells for substance delivery, on the basis of ensuring high throughput, realizes the control of the jet momentum by adjusting the parameters of the synthetic jet, thereby realizing the precise control of cell membrane perforation. Compared with the water perforation technology, it is more flexible and universal, more efficient, and precisely controllable.

[0019] (3) Since the present invention uses the momentum of the synthetic jet to perforate the cells to achieve the delivery of exogenous substances, it fundamentally avoids the channel blockage problem that cannot be avoided by the water perforation technology, and does not require too high a flow rate, and has a low pressure requirement for the microchannel in the microfluidic chip.

[0020] (4) The microfluidic chip provided by the present invention is simple to prepare and low in cost. Compared with the chip of the water perforation technology, it can be plugged and used immediately, and is not limited to the type of suspended cells. By simply adjusting the parameters of the synthetic jet, the efficient delivery of exogenous substances to different cells can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0022] Figure 1 It is a schematic structural diagram of a microfluidic chip for intracellular substance delivery based on a magnetoresponsive film according to an embodiment of the present invention;

[0023] Figure 2Relationship between the amplitude and vibration frequency of composite films with different CI / PDMS mass ratios according to embodiments of the present invention;

[0024] Figure 3 Relationship between the amplitude and vibration frequency of composite material films with different sizes when the magnetic induction intensity is 100 mT and the mass ratio CI / PDMS = 2 according to embodiments of the present invention;

[0025] Figure 4 Relationship between the amplitude and frequency of the PDMS micromagnet interlayer film when the micromagnetic material is a CI-PDMS composite film with different mass ratios as a micromagnet;

[0026] Figure 5 Change situation of the position of the NdFeB micromagnet interlayer film within 4 s at 100 Hz;

[0027] Figure 6 Experimental schematic diagram of intracellular material delivery using synthetic jets according to embodiments of the present invention.

[0028] Reference numerals:

[0029] 10 - Chip body, 20 - Chip base, 30 - Magnetic material film layer, 11 - Microchannel, 12 - Cavity, 13 - Transition region, 14 - Jet nozzle, 21 - Through hole, 22 - Alternating current coil, 15 - Culture medium inlet, 16 - Cell inlet, 17 - Cell outlet. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will elaborate on each implementation manner of the present invention with reference to the drawings. However, those of ordinary skill in the art can understand that in each implementation manner of the present invention, many technical details are proposed for the convenience of readers to understand the present application. However, even without these technical details and various changes and modifications based on the following implementation manners, the technical solutions claimed in the present application can still be achieved. The division of the following embodiments is for the convenience of description and should not constitute any limitation to the specific implementation manner of the present invention. The various embodiments can be combined and cross-referenced with each other on the premise of no contradiction.

[0031] The present invention provides a microfluidic chip based on a magnetic response membrane for intracellular material delivery. Figure 1 Schematic structural diagram of a microfluidic chip based on a magnetic response membrane for intracellular material delivery according to embodiments of the present invention. As Figure 1As shown in the figure, the microfluidic chip includes: a chip body 10, a chip base 20, and a magnetic material film layer 30 disposed between the chip body 10 and the chip base 20. One surface of the chip body 10 is provided with a microchannel 11 and a cavity 12. The microchannel 11 and the cavity 12 are equivalent to open groove structures. The microchannel 11 and the cavity 12 are connected through a transition region 13. Among them, the constriction at the end of the transition region 13 close to the microchannel 11 is the jet nozzle 14. Figure 1 The part in the right dotted box is an enlarged view of the transition region 13. The chip base 20 has a through hole 21, and the through hole 21 is used to make the magnetic core tip of the external AC coil 22 approach the magnetic material film layer 30.

[0032] In this embodiment, both the chip body 10 and the chip base 20 are PDMS (polydimethylsiloxane)-based chips. Among them, the first surface (lower surface) of the chip body 10 is bonded to the first surface of the magnetic material film layer 30 to enclose the microchannel 11 and the cavity 12 into a closed space. The chip base 20 and the second surface of the magnetic material film layer 30 are bonded. For example, in this embodiment, the bonding is realized by a plasma machine. It should be noted that the through hole 21 of the chip base 20 corresponds to the cavity 12 of the chip base 20 in the vertical direction, so that the magnetic core tip of the external coil exactly corresponds to the cavity position. When a controllable alternating magnetic field is applied, the magnetic material film layer 30 vibrates under the excitation of the external magnetic field, so that the culture medium in the cavity 12 generates a synthetic jet at the jet nozzle 14. The synthetic jet acts on the cells flowing in the microchannel 11, and the momentum of the synthetic jet is used to open holes in the cells to achieve material delivery.

[0033] In this embodiment, the cavity 12 is used to store the culture medium, and it can be circular or approximately circular in shape, with a diameter of not less than 2 mm; the microchannel 11 is an elongated channel, with a width of not less than 20 μm; the height of the cavity 12 can be higher than that of the microchannel 11. For example, the height of the cavity is 80 μm to 140 μm, and the height of the microchannel 11 can be 60 μm to 120 μm. The volume ratio of the cavity 12 to the microchannel 11 is 6.3:1, so that the cavity 12 is equivalent to a liquid storage tank relative to the microchannel 11.

[0034] In this embodiment, as Figure 1 shown, the transition region 13 can be in a shape similar to a triangle. The base of the shape similar to a triangle is connected to the cavity 12, the apex of the shape similar to a triangle is connected to the microchannel 11, and the apex of the shape similar to a triangle is the jet nozzle 14. The jet nozzle 14 and the microchannel 11 are in a perpendicular position relationship on the same horizontal plane, and the ratio of the length of the base of the shape similar to a triangle to the opening width of the apex is not less than 3:1. The purpose of such a design is to give the jet a buffer transition region, prevent the instantaneous pressure from being too large, and prevent the jet nozzle size from being too small, which will cause too much attenuation of the jet velocity and reduce the energy loss.

[0035] In this embodiment, as Figure 1 shown, the chip body 10 further includes a culture medium inlet 15, a cell inlet 16, and a cell outlet 17 that penetrate the second surface (upper surface) of the chip body 10. The culture medium inlet 15 and the transition region 13 are located on opposite sides of the cavity 12. The cell inlet 16 and the cell outlet 17 are respectively located at both ends of the microchannel 11, and the directions in which the cell inlet 16 and the cell outlet 17 penetrate the upper surface of the chip body 10 are respectively obtuse angles with respect to the extending direction of the microchannel 11, that is, the through holes of the cell inlet 16 and the cell outlet 17 are drilled obliquely downward. This is to prevent cells from passing through a bent channel less than 90° when the chip is used to introduce and discharge cells, which may cause the cells to agglomerate at the bend and block the channel.

[0036] In this embodiment, the thickness of the magnetic material film layer 30 is 100 μm, and the size of the magnetic material film layer 30 is 15 mm × 15 mm. In an alternative embodiment, the magnetic material film layer 30 is a composite film prepared by mixing carbonyl iron powder (CI) and PDMS, and the mass ratio of carbonyl iron powder to PDMS is greater than 1. The specific preparation method is as follows:

[0037] Step 1: Modulate the composite material. First, prepare the PDMS prepolymer, and then add carbonyl iron powder to the liquid PDMS prepolymer according to different mass ratios of CI:PDMS of 1, 2, 3, and 4. Pour the mixture into a mortar and grind it until it is uniform. Finally, place the mixture in a vacuum drying oven and degas it at room temperature for 30 minutes to remove the bubbles in the mixture so that the surface of the film formed in the next step is uniform and smooth.

[0038] Step 2: Spin-coat and cure to form a film. Take a PMMA (polymethyl methacrylate) plate and perform spin-coating on a spin coater. The adhesion between PMMA and the CI-PDMS mixture is poor, and it is easy to detach the mixture from the plate after the film is formed. If materials such as glass plates are selected, surface silanization treatment is required. Drop the carbonyl iron powder and PDMS mixture after degassing at room temperature onto the center of the PMMA plate, with about 2 g of the liquid mixture on each PMMA plate. Place the PMMA plate carrying the mixture in a spin coater, set the initial spin speed to 500 rpm, the acceleration to 200 rpm / s, and the time to 10 s; the target spin speed is 1000 - 3000 rpm, the acceleration is 500 rpm / s, and the time is 30 s. The purpose of the initial lower spin speed is to flatten the liquid mixture on the plate, and then adjust the height or thickness of the spun film and make its surface uniform and smooth through the target spin speed. Finally, place the spin-coated mixture and the PMMA plate together in an oven and heat at 80 °C for 3 h to cure.

[0039] Next, the vibration performance of the CI-PDMS composite film was further tested. To achieve the excitation of synthetic jets in the microfluidic chip, requirements were imposed on the vibration ability of the actuator, i.e., the magnetic film. The amplitude of the magnetic film needed to be no less than 5 μm. An alternating magnetic field was generated by applying a sinusoidal alternating current to both ends of the coil. In this embodiment, an AC coil with a pure iron core having a tip at the center was used. The coil was 3 cm high and had an inner diameter of 8 mm. During the vibration test, the tip of the iron core was aligned with the center of the circular CI-PDMS composite film through the through hole 21 of the chip base 20, and the displacement change of the film was measured using a laser coaxial displacement meter at the other end.

[0040] The variation of the amplitude of the composite films with different CI / PDMS mass ratios with the vibration frequency is as Figure 2 shown. It can be observed that the amplitude of the film decreases rapidly with the increase of the vibration frequency. When the frequency reaches above 60 Hz, the amplitudes of the films with different ratios all decrease to no more than 5 μm. At lower frequencies, the film with a higher CI / PDMS mass ratio has a larger amplitude. As the vibration frequency increases, the film with a CI / PDMS mass ratio of 2 has a better vibration effect. On this basis, the vibration effects of composite material films with different sizes at a magnetic induction intensity of 100 mT and a CI / PDMS mass ratio of 2 were also tested, as Figure 3 shown (the letter D represents the film diameter). It can be obtained that within the range of D ≤ 5 mm, the larger the film diameter, the larger the vibration amplitude at the same frequency. As the frequency continuously increases to above 60 Hz, the amplitudes of CI-PDMS composite films with various diameters all decay to less than 6 μm.

[0041] In order to obtain a magnetic response film that can respond quickly to the magnetic field, has a larger vibration amplitude, and better vibration stability, the present invention further proposes a magnetic material film layer 30 in which a magnetic material is embedded in a double-layer PDMS film. The magnetic material drives the surrounding PDMS film with a lower elastic modulus to have a larger vibration amplitude due to its response to the magnetic field. In a preferred embodiment, a CI-PDMS composite film with a diameter of about 500 μm and a thickness of 2 mm and a neodymium iron boron permanent magnet with a thickness of 1 mm and a diameter of 2 mm were respectively selected as the micro-magnons in the PDMS interlayer. The preparation process is as follows:

[0042] Step 1: Prepare the bottom layer film. The PDMS prepolymer solution and the curing agent were added in a ratio of 15:1 in sequence, and the two were stirred evenly and fully mixed, and then degassed in a vacuum drying oven at room temperature. The degassed PDMS was poured on the PMMA plate and the two were put into a spin coater to prepare the bottom layer film. After the spin coating of the bottom layer PDMS film was completed, it was placed in an oven and heated continuously at 80 °C for 30 min. After heating, it was taken out of the oven. At this time, the bottom layer PDMS film was in a semi-cured state. The composite film or micro-magnon was taken and placed on the bottom layer film and gently pressed to embed its bottom surface into the bottom layer PDMS film.

[0043] Step 2: Prepare the top layer film. Pour the PDMS solution over the micro-magnets again so that the micro-magnets are completely wrapped by the PDMS solution, and gently place the PMMA plate into the spin coater. After the spin coating of the top layer PDMS film is completed, place the whole in an oven and continuously heat it at 80 °C for 1.5 h to cure the whole. After the heating is completed, a magnetic film with the micro-magnets sandwiched between two PDMS thin films can be obtained.

[0044] Step 3: Take the film and fix it. Use a scalpel to cut out a square film with a size not less than 5×5 mm centered on the micro-magnets, keep this part of the film and separate the rest from the PMMA plate. This step is to be able to smoothly take out and fix the PDMS micro-magnet sandwich film. Finally, treat the film and the PDMS base with a hole with a diameter of 5 mm together in a plasma etching machine for 2 min. After taking it out, align the center of the hole in the base with the micro-magnets, quickly bond them together and place them in an oven at 80 °C and continuously heat for 8 h to ensure permanent bonding. After the heating is completed, peel the whole from the PMMA plate to complete the preparation of the micro-magnet sandwich film. The PDMS base is obtained by casting from a mold with a column with a diameter of 5 mm and a height of 3 mm made by 3D printing. When casting, the PDMS prepolymer solution and the curing agent are in a ratio of 7:1. After degassing, it is cured by heating at 70 °C for 2 h and then cut to obtain the base. Compared with the punched glass slide, the film bonded and peeled off by the PDMS base has a flatter appearance, stronger bonding, and there are no problems such as easy cracking around the holes.

[0045] Next, further test the vibration performance of the PDMS micro-magnet sandwich film.

[0046] Figure 4 The relationship between the vibration amplitude and frequency of the PDMS micro-magnet sandwich film when the micro-magnet material is a CI-PDMS composite film with different mass ratios as the micro-magnet. During the test, the magnetic induction intensity is kept at 100 mT. As shown in the figure, the larger the CI / PDMS mass ratio of the composite material, the better the vibration response of the PDMS micro-magnet sandwich film and the larger the amplitude. The amplitude of this sandwich film can reach more than 100 μm within a frequency of 10 Hz, but as the vibration frequency increases, its amplitude drops rapidly. When the vibration frequency reaches 20 Hz, the amplitude of the film is only 5 μm.

[0047] Figure 5 The change of the position of the neodymium iron boron micro-magnet sandwich film at 100 Hz within 4 s. As Figure 5As shown, in the case of a magnetic induction intensity of 100 mT, it can be seen that its displacement amplitude, maximum offset, etc. all show good stability. The test results of the PDMS micromagnetic sandwich film with neodymium iron boron as the magnetic material show that the micromagnetic sandwich film with a diameter of 5 mm can stably output an amplitude of 10 μm at a vibration frequency of 100 Hz in 100 mT, and the experimental test shows that the micromagnetic sandwich film can be reused multiple times, and the response amplitude stability is maintained well for each continuous vibration of more than 30 min.

[0048] The method for realizing intracellular molecular delivery by using the microfluidic chip based on the magnetic response film according to the embodiment of the present invention is as follows.

[0049] Slowly inject the culture medium into the chip through the culture medium inlet 15 at a rate of at most 1 μL / min until the cavity 12 and the microchannel 11 are filled with the culture medium, and then use a steel clip to clamp the silicone tube connected to the culture medium inlet 15 to block the culture medium inlet 15.

[0050] Prepare the cell culture medium containing fluorescent molecules. Take 1 mL of the experimental cell suspension, add culture medium to dilute the cell suspension according to the experimental needs, and then use a pipette to add dextran to the cell suspension in a certain proportion and resuspend it. Aspirate the cell suspension containing dextran into a syringe, connect a silicone tube and a small steel tube to the syringe needle and introduce it into the cell inlet 16, and then fix the syringe in the injection pump. Similarly, the syringe controlled by the extraction pump is connected to the cell outlet 17 through a silicone tube and a small steel tube in sequence and fixed.

[0051] Excite the synthetic jet and introduce it into the cells. Connect the syringe to the inlet and outlet of the PDMS microfluidic chip through a small steel tube, and open the injection and extraction pumps to allow the cells to flow through the microchannel 11. At the same time, turn on the signal generator to apply an alternating voltage across the coil, so that the magnetic material film layer 30 (micromagnetic sandwich film) starts to vibrate, thereby generating a synthetic jet at the jet nozzle 14 in the chip and acting on the cells flowing through the microchannel 11. Then turn on the peristaltic pump to cool the coil by water, and connect the inlet and outlet of the peristaltic pump to the ice water tank. In addition, this study adopts a control experiment. After the control group cells flow into the chip microchannel, no voltage is applied across the coil, that is, no vibration is applied to the micromagnetic sandwich film, and no synthetic jet effect will be generated in the microfluidic chip. Other operations and time are the same as those of the experimental group. Figure 6Schematic diagram of an experiment for intracellular substance delivery using synthetic jets according to an embodiment of the present invention. It can be seen that a synthetic jet is applied to cells flowing unidirectionally in the microchannels of a microfluidic chip, so that the cells are squeezed and deformed under the momentum of the synthetic jet, realizing the non-invasive delivery of biological macromolecules. And due to the application of an alternating magnetic field, within one alternating cycle, the direction of the synthetic jet changes between a forward direction (from the jet nozzle 14 towards the microchannel 11) and a reverse direction (from the microchannel 11 towards the jet nozzle 14), so that the cells are alternately stretched laterally and longitudinally, which is more conducive to realizing squeezing and deformation.

[0052] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A microfluidic chip based on a magnetic response film for intracellular substance delivery, characterized in that, Comprising: A chip body (10), on the first surface of the chip body (10), there are provided a microchannel (11) and a cavity (12), the middle part of the microchannel (11) and the cavity (12) are communicated through a transition region (13), and the constriction of the transition region (13) near the microchannel (11) end is a jet nozzle (14); A magnetic material film layer (30); A chip base (20), the chip base (20) has a through hole (21), and the through hole (21) is used to make the magnetic core tip of an external alternating current coil (22) approach the magnetic material film layer (30); Wherein, the first surface of the chip body (10) is bonded to the first surface of the magnetic material film layer (30) to enclose the microchannel (11) and the cavity (12), the chip base (20) is bonded to the second surface of the magnetic material film layer (30), and the through hole (21) of the chip base (20) corresponds to the position of the cavity (12) of the chip body (10). The magnetic material film layer (30) generates vibration under the excitation of an external magnetic field, so that the culture medium in the cavity (12) generates a synthetic jet at the jet nozzle (14), acts on the cells flowing in the microchannel (11), and uses the momentum of the synthetic jet to open holes in the cells to achieve material delivery.

2. The microfluidic chip for intracellular substance delivery based on a magnetic response film according to claim 1, wherein The magnetic material film layer (30) is a composite film prepared by mixing carbonyl iron powder and PDMS, wherein the mass ratio of carbonyl iron powder to PDMS is greater than 1.

3. The microfluidic chip for intracellular substance delivery based on a magnetic response film according to claim 1, characterized in that, The magnetic material film layer (30) is a PDMS micro-magnet sandwich film, including a PDMS top layer, a PDMS bottom layer, and a permanent magnet micro-magnet layer sandwiched between the PDMS top layer and the PDMS bottom layer.

4. The microfluidic chip for intracellular substance delivery based on a magnetic response film according to claim 1, characterized in that The magnetic material film layer (30) is a PDMS micro-magnet sandwich film, including a PDMS top layer, a PDMS bottom layer, and a micro-magnet layer prepared by mixing carbonyl iron powder and PDMS sandwiched between the PDMS top layer and the PDMS bottom layer.

5. The microfluidic chip for intracellular substance delivery based on a magnetic response film according to claim 1, wherein The amplitude of the magnetic material film layer (30) is not less than 5 μm.

6. The microfluidic chip for intracellular substance delivery based on a magnetic response film according to claim 1, wherein The thickness of the magnetic material film layer (30) is 0.1 - 2 mm, and the size of the magnetic material film layer (30) is not less than 5 mm × 5 mm.

7. The microfluidic chip for intracellular substance delivery based on a magnetic response film according to claim 1, wherein The diameter of the cavity (12) is not less than 2 mm, the width of the microchannel (11) is not less than 20 μm, and the height of the cavity (12) is greater than the height of the microchannel (11).

8. The microfluidic chip for intracellular substance delivery based on a magnetic response film according to claim 1, wherein The transition region (13) is in a shape similar to a triangle, the bottom edge of the shape similar to a triangle is connected to the cavity (12), the top angle of the shape similar to a triangle is connected to the microchannel (11), and the top angle of the shape similar to a triangle is the jet nozzle (14).

9. The microfluidic chip for intracellular substance delivery based on a magnetic response film according to claim 8, characterized in that, The ratio of the length of the bottom edge of the shape similar to a triangle to the opening width of the top angle is not less than 3:

1.

10. The microfluidic chip for intracellular substance delivery based on a magnetic response film according to claim 1, wherein The chip body (10) further includes a culture medium inlet (15), a cell inlet (16), and a cell outlet (17) that penetrate through the second surface of the chip body (10). The culture medium inlet (15) and the transition region (13) are located on opposite sides of the cavity (12). The cell inlet (16) and the cell outlet (17) are respectively located at two ends of the microchannel (11), and the directions in which the cell inlet (16) and the cell outlet (17) penetrate through the second surface of the chip body (10) are respectively obtuse angles with respect to the direction in which the microchannel (11) extends.

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