Photodegradation-driven high polymer nanomotor and preparation method and application thereof

Abstract

The application relates to a light-degradation-driven high-molecular nanomotor and a preparation method, and aims to solve the environmental pollution and biological safety problems caused by the degradation difficulty or long cycle of the nanomotor power assembly. The nanomotor has an asymmetric nanostructure and is assembled by a light-degradation high-molecular assembly and a biocompatible high-molecular effective load in a nanometer scale. The preparation method comprises the following steps: 1. uniformly mixing a light-degradation high-molecule and a biocompatible high-molecule in an organic solvent to prepare a mixture A; 2. mixing the mixture A and water at a high speed to prepare a mixture B; and 3. removing the organic solvent to prepare the nanomotor. Under light, the light-degradation assembly absorbs light energy to degrade and generate bubbles, which push the nanomotor to move in the solution. The start / stop of the nanomotor is controlled by the on / off of the light source, and the fast / slow movement of the nanomotor is controlled by the strong / weak of the light source. The structure of the light-degradation assembly is gradually degraded and finally completely destructed with the reaction, so that the biological safety and environmental pollution problems of the nanomaterial are relieved.

Description

Technical Field

[0001] This invention belongs to the field of nanorobot technology, specifically relating to a photodegradation-driven polymer nanomotor, its preparation method, and its application. Background Technology

[0002] Nanomotors are artificially synthesized nanoscale intelligent devices that convert external energy (light, electricity, magnetism, heat, chemical energy, etc.) into mechanical energy for autonomous movement. They are programmable to perform complex tasks and can also perform directional transport in liquid media. The advantages of nanomotors lie in their active motion characteristics and excellent manipulation, enabling the loading, transport, and release of nanoscale cargo. They have great application potential in fields such as environmental remediation, biosensing, and microsurgery. Nanomotors possess various propulsion and control mechanisms. The most widely studied mechanisms include bubble propulsion, self-diffusion electrophoresis, autoelectrophoresis, interfacial tension, and chemical concentration gradients. Currently, bubble propulsion mainly involves placing a nanoscale metal catalyst within the nanomotor as an energy conversion power component to spontaneously degrade hydrogen peroxide in the solution, generating oxygen bubbles to propel the nanomotor. Light is the most effective energy donor for nanomotors because of its long-distance, penetrating, and on-demand on / off control capabilities. Motion can be remotely controlled. Metal photocatalysts, as energy conversion power components, are typically assembled onto the nanomotor through encapsulation, and the directional propulsion of the nanomotor is manipulated through photocatalytic reactions.

[0003] However, existing metal photocatalyst power components are highly dependent on chemical media, allowing them to operate only in environments with high concentrations of catalytic substrates, and thus are not suitable for a wide range of applications. Secondly, the stable nanostructure and non-degradability of nanoscale metal photocatalysts pose long-term biosafety and environmental pollution risks. To address these issues and achieve safer and more efficient operation of nanomotors, the development and fabrication of widely applicable and rapidly degradable nanomotors is crucial.

[0004] A search revealed no patent publications related to this invention's patent application. Summary of the Invention

[0005] The technical limitation that this invention aims to overcome is that existing photoresponsive bubble-propelled nanomotors can only use non-degradable photoresponsive metal catalysts as power components to catalyze the generation of bubbles in the surrounding chemical medium to provide kinetic energy for the nanomotors. At the same time, the problems that this invention aims to solve also include the biosafety and environmental pollution problems caused by the inability of the energy conversion power components of existing nanomotors to degrade rapidly after completing their work or tasks.

[0006] To address the above problems, this invention provides a photodegradation-driven nanomotor and its preparation method.

[0007] The technical solution adopted by this invention to solve its technical problem is:

[0008] The photodegradation-driven nanomotor is assembled from an organic polymer energy conversion power component with photoresponsive degradation groups and a biocompatible polymer payload. Under illumination, the photoresponsive power component spontaneously undergoes a photodegradation reaction, converting light energy into chemical energy, breaking down the photoresponsive degradation groups, and controllably releasing bubbles in the solution to manipulate the nanomotor's movement. This photodegradation reaction is independent of the solution's composition and properties. As the light exposure process progresses, the organic polymer power component gradually degrades into biocompatible small molecule fragment pairs, thus achieving completely controllable deconstruction of the nanoscale power component.

[0009] The preparation method adopted by this invention to solve its technical problem is used to prepare any of the above-described photodegradation-driven nanomotors, and includes the following steps:

[0010] 1) Step S1: The photodegradable polymer and the polymer loading are thoroughly mixed in an organic solvent to form mixture A.

[0011] 2) Step S2: Quickly mix the aqueous solution with mixture A to obtain mixture B.

[0012] 3) Step S3: Remove the organic solvent in the solution by heating, rotary evaporation and dialysis, thus forming a stable photodegradation-driven nanomotor.

[0013] The method for preparing photodegradation-driven nanomotors described in this invention can control the morphology, quantity, and distribution of the prepared nanomotors. The preparation process can be carried out manually or automatically. The process is simple, convenient, and fast, and can achieve continuous production.

[0014] Optionally, the organic solvent is characterized in that it includes at least one organic solvent selected from the following solvents that are miscible with water: tetrahydrofuran, acetone, acetonitrile, diethyl ether, methanol, ethanol, isopropanol, dimethylformamide, dimethyl sulfoxide, etc.

[0015] Optionally, the photodegradable group comprises at least one of photoresponsive groups such as azo groups and peroxy groups.

[0016] Optionally, the feature is that the effective polymeric load includes at least one of organic polymers such as polylactic acid, polyurethane, polypeptide, and polymethacrylate.

[0017] This invention describes an operation control method for a photodegradation-driven nanomotor. The motor's start / stop is controlled by turning the light source on / off, and the motor's speed is controlled by adjusting the light source intensity.

[0018] Optionally, the selection of the light source wavelength includes at least one light source wavelength in the range of 250 nm ultraviolet wavelength to 2500 nm infrared wavelength.

[0019] Optionally, the application scenarios of the photodegradation-driven nanomotor of the present invention include at least one of the following scenarios: deionized water, distilled water, aqueous solution containing organic compounds, aqueous solution containing inorganic compounds, aqueous solution containing cells, and aqueous solution containing microorganisms.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The photodegradation-driven nanomotor described in this invention can be assembled and synthesized through a simple, rapid, and automated preparation process. Under light irradiation, the photodegradable polymer components of the nanomotor spontaneously degrade, releasing energy and generating bubbles, effectively providing power to the nanomotor. Its motion behavior is unaffected by the surrounding chemical medium, achieving ultrafast light-driven propulsion. The nanostructure of the energy conversion component can be completely decomposed into small molecule biocompatible fragments, solving the problems of biosafety and environmental pollution associated with engineered nanomaterials. Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating the driving principle of the photodegradation-driven polymer nanomotor of the present invention.

[0023] Figure 2 This is a schematic diagram of the preparation process of the photodegradation-driven polymer nanomotor of the present invention; Detailed Implementation

[0024] The embodiments of the present invention are described in detail below. It should be noted that these embodiments are descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0025] Unless otherwise specified, the methods used in this invention are conventional methods in the art.

[0026] Specific examples of organic polymers with photodegradable groups:

[0027] Polyurethane with uniformly distributed azo groups in the polymer chain was prepared by ternary polycondensation of azodimethylhydroxybutylacrylamide, polycaprolactone diol, and hexamethylene diisocyanate. Under ultraviolet light irradiation, the azo groups underwent photodegradation and broke down, producing nitrogen gas. This reaction followed first-order kinetics, and the polyurethane gradually decomposed into smaller molecular weight fragments through photodegradation.

[0028] Example of a photodegradation-driven polymer nanomotor fabrication process:

[0029] Polyurethane containing azo groups and an equal amount of polyglutamic acid benzyl ester were dissolved in tetrahydrofuran solution and thoroughly mixed to obtain a solution concentration of 1 mg / mL; [The process was repeated here.] Figure 2 The multi-inlet vortex mixer shown rapidly mixes a tetrahydrofuran (solvent) stream and a water stream (antisolvent) containing a polymer mixture (THF / water = 1 / 1, v / v). The tetrahydrofuran / water mixture flows directly into an antisolvent water reservoir (THF / water / water reservoir = 1 / 1 / 1, v / v / v). The THF organic solvent in the solution is removed by heating, rotary evaporation, or dialysis, thus forming a stable photodegradation-driven nanomotor.

[0030] Examples of photoresponse control methods for polymer nanomotors:

[0031] On / off control: Under ultraviolet light, the azo groups absorb light energy, undergo a degradation reaction, and generate bubbles, thereby propelling the motor. Under no light, the azo groups remain stable and do not generate bubbles, thus stopping the motor's active driving motion. Therefore, the movement and stopping of the nanomotor can be controlled by controlling the on / off state of the light source.

[0032] Speed ​​control: The movement speed of the nanomotor in the solution can be controlled by adjusting the light intensity. The ultraviolet light intensity can be adjusted from 0-500 mW / cm². 2 The photodegradation rate of azo groups increases with increasing light intensity, as does the bubble generation rate, thereby driving nanomotors in solution to move at a faster speed, ranging from 1 to 200 μm / s.

[0033] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A photodegradation-driven nanomotor, characterized in that, It is composed of a photodegradable polymer material and a polymer load, and has an asymmetric structure. The photodegradable polymer is a polyurethane with a uniformly distributed azo groups in the polymer chain, obtained by a ternary polycondensation reaction of azodimethylhydroxybutylacrylamide, polycaprolactone diol and hexamethylene diisocyanate. The polymer load is polybenzyl glutamate. The diameter of the nanomotor is 10-1000 nm. Under light irradiation, the photodegradable polymer absorbs light energy, degrades and generates bubbles, thereby driving the nanomotor to move. The photodegradable chemical group in the structure of the photodegradable polymer is an azo group.

2. The method for preparing a photodegradation-driven nanomotor according to claim 1, characterized in that, Includes the following steps: 1) A mixture A is prepared by thoroughly mixing a polymer with photodegradable properties and a polymer loading in an organic solvent. The organic solvent is one or more of tetrahydrofuran, acetone, acetonitrile, diethyl ether, methanol, ethanol, dimethylformamide, or dimethyl sulfoxide. 2) The aqueous solution is rapidly mixed with mixture A to obtain mixture B. The mixing technology adopts nanoprecipitation technology to achieve continuous production. Optionally, a surfactant is added to the aqueous solution, wherein the surfactant is polyethylene glycol or poloxamer. 3) Organic solvents in the solution are removed by heating, rotary evaporation and dialysis, thus forming a stable photodegradation-driven nanomotor.

3. A method for controlling the performance of a photodegradation-driven nanomotor prepared according to any one of claims 1 or the preparation method according to claim 2, characterized in that, Including the following: 1) On / off control: Under light, the photodegradable chemical groups in the polymer structure with photodegradable properties absorb light energy and undergo photodegradation reaction to convert light energy into chemical energy and generate bubbles, thereby propelling the nanomotor. Under no light, the photodegradable chemical groups remain stable and do not generate bubbles, so the nanomotor does not exhibit obvious active propulsion. Therefore, the movement and stopping of the nanomotor can be controlled by controlling the on and off of the light source. 2) Speed ​​control: The photodegradable chemical groups in the polymer structure with photodegradability will accelerate or slow down the photodegradation reaction as the light intensity increases or decreases. The bubble generation rate triggered by the photodegradation reaction will also accelerate or slow down accordingly, thereby realizing the regulation of the movement speed of the nanomotor in the solution. The speed of the photodegradation-driven nanomotor is 1-1000 micrometers / second.

4. An application of a photodegradation-driven nanomotor according to any one of claims 1 or a photodegradation-driven nanomotor prepared by the preparation method according to claim 2, characterized in that, Application scenarios include one or more of the following: deionized water, distilled water, aqueous solutions containing organic compounds, aqueous solutions containing inorganic compounds, aqueous solutions containing cells, or aqueous solutions containing microorganisms.

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