System and method for controlling targeted delivery of liposome medicine based on frequency spectrum space phase gradient light field

Abstract

The invention discloses a system and a method for controlling liposome drug directional delivery based on a frequency spectrum space phase gradient light field, and belongs to the technical field of light field regulation and control of biological cells. According to the method, quasi-plane waves are irradiated to a spatial light modulator, the amplitude of a target light field is embedded into a phase through Fourier expansion, then a holographic template of a reconstructed light field is generated, the holographic template is loaded to the spatial light modulator, and light beams are projected to an objective lens after being filtered by a 4f system; on the focal plane of the objective lens, with the help of the existence of the phase gradient, the drug-loaded liposome is directionally transported along a preset track, and is captured by the intensity gradient light trap at the tail end of the track. Any drug conveying track can be designed according to requirements, an equipment platform does not need to be moved, two kinds of control of any track conveying and targeted capturing can be achieved through a single light beam, and convenience and high efficiency of drug directional conveying are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of light field regulation of biological cells, and specifically relates to a system and method for controlling the directional delivery of liposome drugs based on a spectrum spatial phase gradient light field. Background Art

[0002] With the continuous development of modern drug treatment technology, how to achieve directional drug delivery and improve the effectiveness of drugs in specific cells or tissues has become an important research direction in the biomedical field. As an effective drug carrier, liposomes are widely used in drug delivery systems because they can encapsulate a variety of drugs and have biocompatibility. However, how to simultaneously control the directional delivery of liposomes and fix the position of liposomes is still a major technical challenge currently faced.

[0003] In recent years, optical technology, especially optical tweezers technology, has provided new ideas for solving this problem. Optical tweezers technology can capture and manipulate tiny particles through the radiation pressure and gradient force of laser beams, and achieve precise manipulation of drug carriers such as liposomes. However, existing optical tweezers technology is usually limited to static capture or simple linear motion, and it is difficult to achieve precise delivery on complex paths and simultaneous manipulation of multiple forms. Therefore, how to use light field design to achieve precise and complex trajectory transportation and effective capture at the target location has become an urgent problem to be solved. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present invention proposes a system and method for controlling the directional delivery of liposome drugs based on a spectrum spatial phase gradient light field.

[0005] According to the first aspect of the technical solution of the present invention, the present invention provides a method for controlling the directional delivery of liposome drugs based on a spectrum spatial phase gradient light field, which comprises the following steps:

[0006] Step S1: build an optical path system;

[0007] Step S2: Check whether the position of the entrance pupil of the objective lens in the optical path system constructed in step S1 is located at the focal length of the second lens of the 4f system;

[0008] Step S3: starting the laser, the laser emitted by the laser is collimated and sequentially passes through a beam expansion system consisting of a spatial filter and a first double-cemented achromatic lens to generate an approximate plane wave;

[0009] Step S4: Design the target light field beam shape and phase gradient.

[0010] Further, the following steps are included:

[0011] Step S5: Calculate the phase template of the complex amplitude mode of the light field;

[0012] Step S6: loading the phase template onto the liquid crystal panel of the spatial light modulator, and checking from the camera whether the shape of the light field is consistent with the preset shape;

[0013] Step S7: preparing drug-loaded liposomes by secondary emulsification method, so that the internal refractive index is greater than the external refractive index;

[0014] Step S8: preparing a sample chamber containing drug-loaded liposomes and target cells, encapsulating and placing the chamber on a stage, opening the illumination light path, adjusting the distance between the sample chamber and the objective lens so that the chamber is located on the focal plane of the objective lens, and ensuring that the image is clear in the camera;

[0015] Step S9: In the light field, the drug-loaded liposomes move on a trajectory with a phase gradient to the end point of the targeted cells and are captured by a high light intensity region at the end point of the light beam trajectory path.

[0016] Among them, step S5 calculates the phase template of the complex amplitude mode of the light field, specifically calculating the phase template of the complex amplitude mode of the light field based on MATLAB software; the light field has a certain intensity distribution and phase distribution in the spectrum space, the gradient of the phase distribution can enable the liposome particles to be transported along a preset trajectory, and the gradient of the intensity distribution can enable the liposome particles to be captured at the end of the trajectory.

[0017] Furthermore, the intensity distribution and phase distribution of the light field in step S4 are precisely controlled by a phase template, and the phase template in step S5 is generated by MATLAB software. The trajectory superposition used meets both the intensity distribution requirements of the light field and the phase distribution requirements, and is used to generate the shape and phase gradient required by the user.

[0018] Furthermore, the light beam in step S3 passes through a spatial filter and a double cemented achromatic lens to improve the uniformity of the light beam, so that the light beam irradiated on the spatial light modulator is more similar to a plane wave, so as to generate a more accurate phase gradient and light intensity distribution of the light field.

[0019] Preferably, the phase and intensity of the target light field are reproduced by superimposing the phase of a blazed grating of order 270 on the generated phase template to filter out the 0th order light, and subsequently using the 1st order light to achieve the capture and transportation of liposomes.

[0020] More preferably, the light field design can simultaneously realize two manipulations of liposome drug arbitrary trajectory transportation and targeted capture through a single beam of light without moving the device platform. The phase template is dynamically adjusted according to different drug delivery requirements, and directional delivery of liposomes at different positions is achieved by generating different light field shapes and light intensity distributions.

[0021] Preferably, the optical field system has the function of regulating speed, and the speed of liposome transport is regulated by adjusting the size of the designed optical field phase gradient, that is, the larger the phase gradient, the faster the liposome transport speed, and the smaller the phase gradient, the smaller the liposome transport speed. Further, the drug-loaded liposome prepared by the secondary emulsification method in step S7 has an internal refractive index of 1.40 and an external refractive index of 1.34, that is, the internal refractive index is greater than the external refractive index, providing conditions for optical tweezers capture and transport.

[0022] According to the second aspect of the technical solution of the present invention, the present invention provides a system for controlling the directional delivery of liposome drugs based on a spectral spatial phase gradient light field. The phase and amplitude information of the light beam are simultaneously regulated by a pure phase-type spatial light modulator based on the spectral space, and a phase template is accurately designed to generate an arbitrary trajectory phase gradient light field to transport drug-loaded liposome particles, and liposomes are captured at the targeted position, providing a basis for further promoting the binding of drugs to target cells; the optical path system of the system for controlling the directional delivery of liposome drugs based on a spectral spatial phase gradient light field includes a laser, a half-slide, an attenuation plate, a spatial filter, a first lens, a beam splitter prism, a spatial light modulator, a second lens, a pinhole, a third lens, a beam splitter plate, an objective lens, a stage, an illumination light source, a fourth lens and a camera.

[0023] Compared with the prior art, the system and method of the present invention for controlling the directional delivery of liposome drugs based on the spectrum spatial phase gradient light field has the following beneficial effects:

[0024] (1) Efficient and accurate liposome drug delivery: The present invention achieves precise control and delivery of liposome drugs by designing the phase gradient and light intensity distribution of the light field. Compared with the existing optical tweezers technology, the present invention can deliver drug-loaded liposomes in a directional manner on a complex path, improving the delivery efficiency and the accuracy of the targeted position.

[0025] (2) No platform movement, greater flexibility: The light field designed in the present invention can achieve directional delivery and capture of liposomes without moving the equipment platform, breaking through the limitation of the prior art that a mechanical equipment platform is required, simplifying the system structure and improving the flexibility of the system.

[0026] (3) Capture and delivery can be completed with a single beam of light: Compared with the existing multi-beam light manipulation system, the present invention can simultaneously achieve the capture and delivery of liposomes with a single beam of light, which greatly simplifies the optical path design and reduces the system complexity and cost.

[0027] (4) Controllable trajectory and strong adaptability: The present invention generates special phase templates through MATLAB, and can design a variety of drug delivery trajectories to meet the complex transportation requirements in different application scenarios. This significantly improves the flexibility, adaptability and operability of the system under different conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the method and technical solution of the present invention, the following briefly introduces the drawings required for use in the examples. The drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained according to the method without paying creative labor.

[0029] Figure 1 A schematic diagram of the optical path used in the system for controlling directional delivery of liposome drugs based on a spectrum spatial phase gradient optical field according to the present invention;

[0030] Figure 2a and Figure 2b They are respectively the light intensity and phase information diagrams of the example target light field as an "S-shaped" trajectory drawn on MATLAB software according to the present invention; wherein Figure 2a The light intensity diagram of the target light field of the example according to the present invention drawn on the MATLAB software is an "S-shaped" trajectory; Figure 2b The phase information diagram of the example target light field as an "S-shaped" trajectory drawn on MATLAB software according to the present invention;

[0031] Figure 3 To generate a phase template loaded on a pure phase spatial light modulator using a Fourier transform method;

[0032] Figure 4 The light field observed in step S4 according to the present invention is consistent with the target light field. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In addition, the scope of protection of the present invention should not be limited to the following specific experimental methods or specific parameters.

[0034] It should also be noted that, for ease of description, only the parts related to the invention are shown in the drawings. In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0035] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0036] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0037] The present invention discloses a system and method for controlling the directional delivery of liposome drugs based on a spectrum spatial phase gradient light field, which belongs to the technical field of light field regulation of biological cells; the present invention irradiates a quasi-diffraction-free light beam onto a spatial light modulator, which uses Fourier expansion to embed the amplitude into the phase, thereby generating a holographic template for reconstructing the light field, and after 4f system filtering, projects the light beam onto an objective lens (preferably a 100-fold objective lens); on the focal plane of the objective lens, with the help of the phase gradient, the drug-loaded liposomes are transported directionally along a preset trajectory, and are captured by an intensity gradient light trap at the end of the trajectory. The present invention can design any drug delivery trajectory according to demand, and does not require a mobile device platform, and can achieve two types of manipulations, namely, arbitrary trajectory delivery and targeted capture, through a single beam of light, thereby improving the convenience and efficiency of directional drug delivery.

[0038] The technology of phase gradient light field controlled directional delivery of liposome drugs in the present invention is based on the spectrum space and uses a pure phase spatial light modulator to simultaneously regulate the phase and amplitude information of the light beam, accurately design the phase template to generate an arbitrary trajectory phase gradient light field to transport drug-loaded liposome particles, and capture the liposomes at the targeted position.

[0039] The present invention is based on the spectrum spatial phase gradient light field to control the directional delivery of liposome drugs. Based on the spectrum spatial phase gradient light field, by designing the intensity and phase distribution of the light field, it can control the drug-loaded liposomes to be transported along a specific trajectory without moving the device platform, and finally be captured by the light trap. This technology overcomes the limitations of the traditional optical tweezers system, integrates the two manipulations of liposome trajectory delivery and target position capture, realizes the flexibility and efficiency of drug directional delivery, and provides an innovative solution for drug delivery and cell therapy technology.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious, the present invention is further described in detail below with reference to the accompanying drawings and specific examples.

[0041] like Figure 1 As shown, the present invention is based on the spectrum spatial phase gradient light field to control the liposome drug directional delivery system through the optical path system. Figure 1The optical path system shown is the optical path system of the directional delivery system of liposome drugs controlled by the spectrum spatial phase gradient light field of the present invention, which includes a laser, a half glass slide, an attenuation plate, a spatial filter, a first lens (preferably with a focal length of 250 mm), a beam splitter prism, a spatial light modulator, a second lens (preferably with a focal length of 200 mm), a pinhole, a third lens (preferably with a focal length of 200 mm), a beam splitter plate, an objective lens (preferably with a magnification of 100 times, and an oil objective lens is used), a stage, an illumination light source (preferably an LED light source with a power of 3 W), a fourth lens (preferably with a focal length of 150 mm) and a camera;

[0042] A laser, which is used to emit laser light. In the preferred embodiment, a 532nm solid-state laser is used;

[0043] A half-glass slide, which is used to adjust the polarization direction of the laser light emitted from the laser;

[0044] An attenuator, which is used to adjust the power of the laser light emitted from the laser;

[0045] The spatial filter and the first lens are combined to convert the laser beam into a quasi-plane wave, thereby ensuring that the equal phase of the light beam is parallel to the plane, which is convenient for the later spatial light modulator to phase modulate the light beam. In one embodiment, the focal length of the first lens is preferably 200mm; the first lens adopts a double-glued achromatic lens. The laser, the half-glass, the attenuation plate, the spatial filter and the first lens are arranged in a straight line optical path in sequence. The laser is at the front end of the half-glass, and the half-glass is located 10cm behind the laser to adjust the polarization direction of the laser. The attenuation plate is placed 10cm behind the half-glass to facilitate the adjustment of the laser power. The spatial filter is placed 10cm behind the attenuation plate. The interior of the spatial filter consists of an objective lens with a magnification of 40 times and a small hole with an aperture of 20μm. The laser passes through the objective lens and the small hole in turn. The distance between the objective lens and the small hole needs to be carefully adjusted. The standard is: the cross-sectional intensity of the laser spot after passing through the small hole is uniform. The first lens is placed 200mm (this distance is the focal length of the first lens) behind the small hole of the spatial filter to obtain a quasi-plane wave.

[0046] A beam splitter prism is located at the intersection of the optical path where the laser is located and the optical path where the spatial light modulator is located, and is used to separate light beams with equal energy; the separated light beams are respectively a light beam along the laser and a light beam along the spatial light modulator; the optical path where the laser is located and the optical path where the spatial light modulator is located are in a vertical relationship.

[0047] The spatial light modulator is located at the leftmost end of the optical path in the vertical direction of the laser, and is used to phase modulate the light source from the laser to generate a target light field; further, in a preferred embodiment, the spatial light modulator adopts a reflective pure phase spatial light modulator. When the light wave passes through the spatial light modulator, the optical function and signal are loaded on the liquid crystal panel, and the voltage on each pixel is modulated to generate the wavefront phase modulation of the light. The optical function and signal can be directly displayed by the computer and transmitted through the DVI or HDMI (HDMI is preferably used in the present invention) signal output by the image card. The signal is adjusted by electrical addressing to achieve the regulation of the light intensity and phase of the light field. Further, in this preferred embodiment, the pixel size of the spatial light modulator panel is 8μm, and the phase plane size is 15.36mm×8.64mm. The phase template loaded onto the spatial light modulator is obtained by Fourier transforming the target light field in MATLAB software; the target light field has a special intensity distribution and phase distribution in the spectrum space. In one embodiment, the characteristics of the intensity distribution and phase distribution of the target light field are: the light intensity of the light field has an "S-shaped" shape distribution, and has an intensity "extremely bright spot" at the end, and the phase characteristic of the light field is that along the "S-shaped" trajectory, its phase gradient changes uniformly along the angular direction, and the phase increases continuously on its trajectory. In such a special light field, there is an intensity gradient force in the direction perpendicular to the trajectory, which can attract liposome particles to the "S-shaped" trajectory, and there is a phase gradient force in the direction along the trajectory, which can transport liposome particles along the preset trajectory ("S-shaped"), and at the position of the "extremely bright spot" at the end of the trajectory, the extremely strong intensity gradient force captures it.

[0048] The phase gradient force causes the liposome particles to be transported along a preset trajectory, and the intensity gradient force causes the liposome particles to be captured at the end of the trajectory, providing conditions for their subsequent binding to target cells.

[0049] The second lens, preferably a double cemented achromatic lens, is located behind the beam splitter prism (along the optical path where the spatial light modulator is located) and is used to convert the light beam passing through the spatial light modulator into a spectrum space, and its focal length is preferably 250 mm;

[0050] The pinhole is located at the focus of the second lens, and is used for filtering and selecting the modulated light beam; the position of the pinhole is the Fourier surface; since a part of the light beam reflected back by the spatial light modulator is not modulated, the present invention superimposes a phase template of a blazed grating with an order of 270 on the phase template loaded on the spatial light modulator to filter out the 0th order light; the present invention uses the +1st order diffracted light, which is the completely modulated part. The role of the pinhole is to allow the +1st order diffracted light to pass completely, and other order light beams cannot pass.

[0051] The third lens, which is preferably a double-cemented achromatic lens, is located behind the pinhole and forms a 4F system with the second lens. It is used to reduce the light beam, and its focal length is preferably 200mm; the focal lengths of the second lens and the third lens are both f, and the distance between them is twice the focal length, the object distance is f, and the distance between them is f.

[0052] The beam splitter is used to split the light beam passing through the third lens into two beams, one beam passes through the beam splitter to reach the objective lens, and the other beam is reflected by the beam splitter to the vertical light path (the vertical light path axis formed by the fourth lens and the central axis of the camera) to image the target light field. Preferably, the beam splitting ratio of the beam splitter is T / R=50 / 50, and the working wavelength is 450-650nm.

[0053] The objective lens, whose entrance pupil is located at the focal length of the third lens, focuses the modulated beam; providing intensity gradients and phase gradients sufficient to capture liposomes.

[0054] The stage is placed at the focal length of the objective lens and can be fine-tuned up and down or left and right to move the sample chamber; the sample chamber is placed on the stage;

[0055] The illumination light source is placed above the stage and 5 cm away from the stage. It emits illumination light to illuminate the liposomes for subsequent imaging. The illumination light source is an LED light source with a power of 3W and a wavelength of white light (440-670nm).

[0056] The spatial light modulator, the beam splitter prism, the second lens, the pinhole, the third lens, the beam splitter plate, the objective lens, the stage and the illumination light source are sequentially arranged on the optical path where the spatial light modulator is located.

[0057] A fourth lens, which is preferably a double cemented achromatic lens, preferably having a focal length of 150 μm, is used to image the liposomes and the light field to the camera;

[0058] The camera is located at the end of the camera optical path and is used to collect imaging information of liposome particles and the light intensity of the phase gradient light field.

[0059] In such Figure 1 The components and parameters in the optical path system shown are preferred parameters, which can also be adjusted according to actual conditions.

[0060] The second lens and the third lens form a 4f system, which has the function of expanding and reducing the light beam in addition to filtering. The focal length should be selected so that the size of the light beam is slightly larger than the back pupil size of the objective lens, so as to allow the objective lens to obtain a higher gradient force. The focal lengths of the second lens and the third lens used in this example are 250mm and 200mm respectively, which means that the light beam is reduced by 0.8 times.

[0061] The objective lens is an Olympus plan semi-apochromatic oil objective lens. The oil objective lens used in the present invention has a magnification of 100 times and needs to be used with Olympus microscope oil. The fourth lens and the camera constitute an imaging system, and the fourth lens and the camera should be linearly moved so that the liposome particles in the sample chamber on the focal plane of the objective lens can be clearly imaged.

[0062] If you need to filter out the laser before the camera, you should add a filter in front of the camera to filter out the 532nm laser beam.

[0063] Combination Figure 1 The optical path system is specifically as follows Figure 2a and Figure 2b The "S-shaped" target light field shown is a practical example. A method of controlling directional delivery of liposome drugs based on a spectrum spatial phase gradient light field of the present invention comprises the following steps:

[0064] Step S1: Build Figure 1 The optical path system is shown.

[0065] Step S2: Check whether the position of the objective lens entrance pupil in the optical path system constructed in step S1 is located at the focal length of the second lens of the 4f system; when the focal length of the second lens is 200 mm, that is, whether the distance between the second lens and the objective lens entrance pupil is 200 mm.

[0066] Step S3: Start the laser. The laser emitted by the laser is collimated and then passes through the beam expansion system composed of a spatial filter and a first lens in sequence to generate an approximate plane wave. Turn on the control spatial light modulator, load a blank template on the spatial light modulator, and then superimpose a blazed grating with an order of 270. Slightly rotate the spatial light modulator to allow +1-level light to pass through the small hole to check whether the light beam is collimated and hits the center of the objective lens. Turning on the control spatial light modulator mainly means turning on the software that controls the spatial light modulator (preferably HOLOEYE software in this embodiment).

[0067] Step S4: Design the beam shape of the target light field and the phase gradient along the curve; we give a specific example of the beam intensity distribution and phase distribution of the "S-shaped" target light field, as shown in Figure 2a and Figure 2b .

[0068] Step S5: Calculate the phase template of the complex amplitude mode of the light field; specifically, calculate the phase template of the complex amplitude mode of the light field based on MATLAB software, wherein the method for calculating the target light field phase template based on MATLAB software includes:

[0069] The target light field curve is formed by the coherent superposition of plane waves, such as the example "S-shaped" light field (such as Figure 3 The expression of the curve is

[0070]

[0071] y0(t)=Rsin(t), t∈[0, T];

[0072] Wherein x0(t), y0(t) are used to describe the coordinates of each point on the curve, T = (2.01π) is the upper limit of integration, and R is the diameter of the semicircle of the curve. In this embodiment, R = 0.1 μm.

[0073] The phase gradient of the light field is expressed by the following formula:

[0074]

[0075] where r = (x, y), t∈[0, t], τ∈[0, 2π]; x′0(τ), y′0(τ) are the derivatives of x0(τ), y0(τ), and the magnitude of the phase gradient along the curve is controlled by the parameter σ. In this case, σ = 2 and ω0 is the beam waist.

[0076] Therefore, the complex amplitude form of the light field can be expressed as:

[0077]

[0078] Where L is the length of the trajectory. In MATLAB, a two-dimensional fast Fourier transform (fft) is performed on the complex amplitude light field to convert it from the spatial domain to the spectral domain, and the frequency shift transform fftshift is used to center the spectrum. The specific operations are:

[0079] F(U,V)=fftshift(fft(fftshift(E(x,y))),

[0080] Take the phase of F(U, V), which is the required phase template.

[0081] The intensity distribution and phase distribution of the light field are precisely controlled by the phase template, which is generated by MATLAB software. The trajectory superposition method used can meet both the intensity distribution requirements of the light field and the phase distribution requirements, and is used to generate the shape and phase gradient required by the user. The reproduction of the phase and light intensity of the target light field requires superimposing the phase of a blazed grating with an order of 270 on the generated phase template to filter out the 0th order light, and subsequently use the 1st order light to achieve the capture and transportation of liposomes.

[0082] Step S6: Load the phase template of the complex amplitude mode obtained in step S5 onto the liquid crystal panel of the spatial light modulator, and check from the camera whether the shape of the light field is consistent with the preset shape; in the example of the "S-shaped light field" given in the present invention, the light beam imaged onto the camera is as follows: Figure 3As shown; in another embodiment, in further quality verification steps S5 and S6, the cover glass of the sample chamber will reflect the light beam and its shape will be checked by the camera to see if it conforms to the target light field.

[0083] Step S7: Prepare drug-loaded liposomes by secondary emulsification method, the internal solution of drug-loaded liposomes is 1.5 mol / L sucrose solution, the external solution is 0.75 mol / L sodium chloride solution, and liposomes with a particle size of about 1.5 microns are prepared; the drug-loaded liposomes prepared by secondary emulsification method have an internal refractive index of 1.40 and an external refractive index of 1.34, that is, the internal refractive index is greater than the external refractive index, which provides conditions for optical tweezers capture and transportation. Preferably, the specific operation steps of step S7 are:

[0084] Step S71, add 10 mg of lipid POPC to 1 mL of liquid paraffin wax, heat and vortex for 30 minutes to dissolve it;

[0085] Step S72, ultrasonically sonicating the mixture in step S71 for 90 minutes to make it more fully dissolved, and cooling it to room temperature;

[0086] Step S73, taking 200 μL of the mixture into a 1.5 mL sample tube and cooling it on ice for 15 minutes;

[0087] Step S74, add 200 μL of 1.5 mol / L sucrose into the sample tube, gently stir for 30 seconds, and cool on ice for 5 minutes to form an emulsion;

[0088] Step S75, take a new sample tube, add 250 μl of 0.75 mol / L sodium chloride solution, take 250 μl of the emulsion and gently place it on top.

[0089] Step S76, centrifuging for 30 minutes (centrifugal speed is 11000×g) to remove the oil phase;

[0090] Step S77, preferably, ultrasonic sonication is performed for 10 minutes to obtain liposomes with a particle size of about 1.5 microns.

[0091] Step S8: preparing a sample chamber containing drug-loaded liposomes, encapsulating it and placing it on a stage, opening the illumination light path, adjusting the distance between the sample chamber and the objective lens so that it is located on the focal plane of the objective lens, and ensuring that the image in the camera is clear;

[0092] Preferably, the specific steps of preparing the sample chamber containing drug-loaded liposomes in step S8 are:

[0093] Step S81, take a clean glass slide and stick two 5mm wide tapes on the upper and lower edges of the center position;

[0094] Step S82, stick a clean cover glass on the tape to form a sample chamber, and inject the liposomes into the sample chamber with a syringe, taking care not to have bubbles;

[0095] Step S83, seal both sides of the sample chamber with transparent nail polish and wait for natural drying.

[0096] Step S9: In the light field, the drug-loaded liposomes are on a trajectory with a phase gradient and move to the end target position, and are captured by a high light intensity area at the target position at the end of the light beam trajectory path.

[0097] The light field design described in the present invention can simultaneously realize two kinds of manipulations, namely, arbitrary trajectory transport and targeted capture of liposome drugs, through a single beam of light without moving the equipment platform. The phase gradient design of the light field ensures precise control during the delivery of drug-loaded liposomes. The phase template can be dynamically adjusted according to different drug delivery requirements, and directional delivery of liposomes at different positions can be achieved by generating different light field shapes and light intensity distributions; the light field system has the function of regulating speed, and the speed of liposome transport can be regulated by adjusting the size of the designed light field phase gradient, that is, the larger the phase gradient, the faster the liposome transport speed, and the smaller the phase gradient, the smaller the liposome transport speed.

[0098] The above-described embodiments are only used to help understand the core concept of the present invention and its specific application, and are not used to limit the scope of the present invention. The core of the present invention lies in the drug directional delivery method based on the spectrum spatial phase gradient light field design, and its application is not limited to the specific steps or parameters of the above-described embodiments.

[0099] For those skilled in the art, without departing from the core idea and technical essence of the present invention, various deformations and improvements can be made to the design of the system, the shape of the light field, the method of generating the phase template, etc. according to actual needs. These improvements or deformations, if they do not exceed the protection scope of the claims of the present invention, should be deemed to belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be defined by the attached claims and their equivalent forms, and not limited to the above-mentioned specific embodiments. Any modification, equivalent substitution or improvement made according to the contents of the claims of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for controlling directional transport of liposomes based on a spectrum spatial phase gradient light field, characterized in that: The method comprises the following steps: Step S1, building an optical path system; Step S2, checking whether the position of the entrance pupil of the objective lens in the optical path system constructed in step S1 is located at the focal length of the second lens of the 4f system; Step S3, starting the laser, the laser emitted by the laser is collimated, and then passes through a beam expansion system composed of a spatial filter and a first double-cemented achromatic lens in sequence to generate an approximate plane wave; Step S4, designing the target light field beam shape and phase gradient.

2. The method for directional delivery of liposome drugs based on spectrum spatial phase gradient light field control according to claim 1, characterized in that: It further comprises the following steps: Step S5, calculating the phase template of the complex amplitude mode of the light field; Step S6, loading the phase template onto the liquid crystal panel of the spatial light modulator, and checking from the camera whether the shape of the light field is consistent with the preset shape; Step S7, preparing drug-loaded liposomes by secondary emulsification method, so that the internal refractive index is greater than the external refractive index; Step S8, preparing a sample chamber containing drug-loaded liposomes and target cells, encapsulating and placing the chamber on a stage, opening the illumination light path, adjusting the distance between the sample chamber and the objective lens so that the chamber is located on the focal plane of the objective lens, and ensuring that the image is clear in the camera; Step S9: In the light field, the drug-loaded liposome moves on a trajectory with a phase gradient to the end point of the targeted cell and is captured by a high light intensity area at the end point of the light beam trajectory path.

3. The method for controlling directional delivery of liposome drugs based on spectrum spatial phase gradient light field according to claim 2, characterized in that: Step S5 calculates the phase template of the complex amplitude mode of the light field, specifically calculating the phase template of the complex amplitude mode of the light field based on MATLAB software; the light field has a certain intensity distribution and phase distribution in the spectrum space, the gradient of the phase distribution can enable the liposome particles to be transported along a preset trajectory, and the gradient of the intensity distribution can enable the liposome particles to be captured at the end of the trajectory.

4. The method for directional delivery of liposome drugs based on spectrum spatial phase gradient light field control according to claim 3, characterized in that: The intensity distribution and phase distribution of the light field in step S4 are precisely controlled by the phase template. The phase template in step S5 is generated by MATLAB software. The trajectory superposition used meets both the intensity distribution requirements of the light field and the phase distribution requirements, and is used to generate the shape and phase gradient required by the user.

5. The method for controlling directional delivery of liposome drugs based on spectrum spatial phase gradient light field according to claim 1, characterized in that: The light beam in step S3 passes through a spatial filter and a double cemented achromatic lens to improve the uniformity of the light beam, so that the light beam irradiated on the spatial light modulator is more similar to a plane wave, so as to produce a more accurate phase gradient and light intensity distribution of the light field.

6. The method for controlling directional delivery of liposome drugs based on spectrum spatial phase gradient light field according to claim 1, characterized in that: The phase and intensity of the target light field are reproduced by superimposing the phase of a blazed grating of order 270 on the generated phase template to filter out the 0th order light, and the 1st order light is subsequently used to capture and transport the liposomes.

7. The method for controlling directional delivery of liposome drugs based on spectrum spatial phase gradient light field according to claim 6, characterized in that: The light field design can simultaneously realize two manipulations, namely, arbitrary trajectory transport and targeted capture of liposome drugs, through a single beam of light without moving the device platform.

8. The method for controlling directional delivery of liposome drugs based on spectrum spatial phase gradient light field according to claim 7, characterized in that: The phase template is dynamically adjusted according to different drug delivery requirements, and directional delivery of liposomes at different positions is achieved by generating different light field shapes and light intensity distributions.

9. The method for controlling directional delivery of liposome drugs based on spectrum spatial phase gradient light field according to claim 8, characterized in that: The light field system has the function of regulating speed. The speed of liposome transport is regulated by adjusting the size of the designed light field phase gradient. That is, the larger the phase gradient, the faster the liposome transport speed, and the smaller the phase gradient, the slower the liposome transport speed.

10. A system for controlling the directional delivery of liposome drugs based on a spectrum spatial phase gradient light field, characterized in that: Based on the spectrum space, a pure phase-type spatial light modulator is used to simultaneously control the phase and amplitude information of the light beam, and a phase template is precisely designed to generate a phase gradient light field with an arbitrary trajectory to transport drug-loaded liposome particles, and capture liposomes at targeted positions, providing a basis for further promoting the binding of drugs to target cells; the optical path system of the directional delivery system of liposome drugs controlled based on the spectrum space phase gradient light field includes a laser, a half-glass, an attenuation plate, a spatial filter, a first lens, a beam splitter prism, a spatial light modulator, a second lens, a pinhole, a third lens, a beam splitter plate, an objective lens, a stage, an illumination light source, a fourth lens and a camera.

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