阅读说明：本技术 有机小分子近红外二区荧光染料及其制备方法和应用 (Organic small-molecule near-infrared two-region fluorescent dye and preparation method and application thereof ) 是由 王其 许兴鹏 蔡杰 刘加伟 夏辉 熊炎威 于 2021-09-22 设计创作，主要内容包括：本发明公开了一种有机小分子近红外二区荧光染料,并公开了该染料及其纳米颗粒水溶液的制备方法和应用。本发明基于吡咯并吡咯二酮单元合成了一种新型有机小分子荧光材料,此设计合成步骤简单,结构特征明显。通过纳米共沉淀方法制得具有良好水溶性、生物相容性及靶向性的纳米颗粒,该纳米颗粒具有优良的近红外二区荧光成像、光声成像、光动力及光热转换性能,可用于近红外二区荧光成像/光声成像指导下的光热/光动力联合治疗试剂的制备,为单一波长激发的NIR-II荧光成像引导的光疗开辟新的领域。(The invention discloses an organic small-molecule near-infrared two-region fluorescent dye, and discloses a preparation method and application of the dye and a nanoparticle aqueous solution thereof. The novel organic micromolecule fluorescent material is synthesized based on the pyrrolopyrroledione unit, the design and synthesis steps are simple, and the structural characteristics are obvious. The nano-particles with good water solubility, biocompatibility and targeting property are prepared by a nano-coprecipitation method, have excellent near-infrared two-region fluorescence imaging, photoacoustic imaging, photodynamic and photothermal conversion performances, can be used for preparing photothermal/photodynamic combined treatment reagents under the guidance of near-infrared two-region fluorescence imaging/photoacoustic imaging, and open up a new field for NIR-II fluorescence imaging guided phototherapy excited by single wavelength.)

1. An organic micromolecule near-infrared two-region fluorescent dye is characterized in that the main component of the dye is a pyrrolopyrrole-dione unit derivative, and the structural formula of the dye is as follows:

2. a preparation method of an organic small molecule near-infrared two-region fluorescent dye is characterized by comprising the following steps:

mixing 4-bromo o-phenylenediamine and 2, 5-bis (2-octyldodecyl) -3, 6-bis (5-boronic acid pinacol ester thienyl) -pyrrolopyrrole dione with a phosphorus catalyst and a palladium catalyst, vacuumizing, introducing nitrogen, then adding a solvent and an alkaline solution, reacting at 85-95 ℃ for 45-50 h, spin-drying the obtained crude product, and purifying the obtained product in a rotary powder manner.

3. The preparation method of the organic small-molecule near-infrared two-region fluorescent dye according to claim 2, wherein the molar ratio of the 4-bromoo-phenylenediamine, the 2, 5-bis (2-octyldodecyl) -3, 6-bis (5-boronic acid pinacol ester thienyl) -pyrrolopyrrole dione, the phosphorus catalyst and the palladium catalyst is (3-5) to 1: (0.1-0.2): (0.2-0.3).

4. The method of claim 2, wherein the phosphorus catalyst is tris (o-methylphenyl) phosphorus and the palladium catalyst is tris (dibenzylideneacetone) dipalladium.

5. The method for preparing the organic small-molecule near-infrared two-region fluorescent dye according to claim 2, wherein the solvent is anhydrous toluene, and the alkaline solution is 1mol/L K₃PO₄And (3) solution.

6. The nano-particle aqueous solution of the organic small-molecule near-infrared two-region fluorescent dye as claimed in claim 1, which is prepared by a nano-coprecipitation method, comprising the following steps:

dissolving the pyrrolopyrrole-dione unit derivative and Pluronic F127 in tetrahydrofuran, adding water, and ultrasonically oscillating for 3-5 min;

removing tetrahydrofuran in the solution, and then filtering by a water phase filter membrane and ultra-filtering by a centrifuge to prepare the nano-particle aqueous solution of the organic micromolecule near-infrared two-zone fluorescent dye.

7. The aqueous nanoparticle solution of a small organic molecule near-infrared two-region fluorescent dye according to claim 6, wherein the maximum light absorption wavelength is 635nm ± 10 nm.

8. The aqueous nanoparticle solution of a small organic molecule near-infrared two-region fluorescent dye according to claim 6, wherein the maximum fluorescence emission wavelength is 1000nm ± 10 nm.

9. Use of the small organic molecule near-infrared two-region fluorescent dye according to claim 1 in near-infrared two-region fluorescence imaging and/or photoacoustic imaging.

10. The use of the small organic molecule near-infrared two-region fluorescent dye of claim 1 in the preparation of a photothermal/photodynamic combination therapeutic agent.

Technical Field

The invention belongs to the technical field of biomedical engineering, and particularly relates to an organic small-molecule near-infrared two-region fluorescent dye and a preparation method and application thereof.

Background

Currently, cancer treatment is primarily surgical removal of tumors, supplemented by radiotherapy, and chemotherapy of severe or invasive tumors. However, since chemotherapy has poor selectivity for target cells, and damages normal tissues and cells while killing cancer cells, photodynamic therapy (PDT) and photothermal therapy (PTT) have been tried as new techniques for treating malignant tumors. Photodynamic therapy is a novel means of treating disease based on the interaction of light/photosensitizer/oxygen. The principle is that the ingested medicine generates photodynamic and enzymatic reaction to generate a plurality of Reactive Oxygen Species (ROS), so that the destruction effect on biological macromolecules such as protein, nucleic acid and the like is generated, cytotoxicity is generated, organelle damage is caused, cells are killed, and target tissues are further destroyed to achieve the treatment purpose. Singlet oxygen-based photodynamic therapy requires an adequate supply of oxygen, which limits this treatment modality to treatment of oxygen-deficient lesions. Photothermal therapy (PTT) is a tumor technology with clinical application prospect developed in recent years, and the process is to utilize photothermal diagnosis and treatment reagents to be selectively enriched in focus parts, then utilize near infrared light with strong tissue penetrating power and low phototoxicity to irradiate the focus parts, and the photothermal treatment reagents absorb light energy and convert the light energy into heat energy to increase the temperature of the tumor parts, so that tumor cells are killed, and the purpose of treating tumors is achieved. Compared with traditional tumor treatment methods, the advantages of PTT include: (1) the laser can be selectively used for irradiating the tumor part, so that the whole body effect is avoided, and the aim of minimally invasive treatment is fulfilled; (2) when the temperature of the tumor area reaches more than 42 ℃, cancer cells die due to the influence of factors such as protein denaturation and the like, and the tumor cells are more sensitive to temperature than normal cells, so that the cancer cells can be selectively killed within a certain temperature range without influencing the normal cells; (3) the invasiveness is small. However, single PTT therapy often results in a heat shock response, and therefore combination therapy of both photothermal and photodynamic techniques is considered a viable strategy. However, most of the reported photo-therapeutic agents are often limited by a number of factors, including poor biocompatibility, low near infrared absorption capacity, and undesirable therapeutic effects. Meanwhile, multiple injections of drugs and light exposure are often required during tumor therapy, which results in many unnecessary side effects and increases toxicity in patients.

With the continuous development of nanotechnology, a great deal of nanomaterials are prepared for photothermal therapy. Among them, gold nanomaterials including gold nanorods, nanocages, nanosheets and composite nanostructures are the most widely used photothermal therapeutic agents at present. However, the inherent biological toxicity and non-degradability of these inorganic nanomaterials limit their practical clinical application to some extent. Organic materials are considered to be more biocompatible than inorganic nanoparticles due to their similar elemental composition as biological tissue, as compared to the biotoxicity of inorganic nanomaterials. Among them, the small molecular NIR-II fluorescent dye is an ideal candidate scheme by virtue of good biocompatibility, excellent optical performance and rapid metabolic capability. In addition, the inherent versatility of small molecule NIR-II organic fluorophores also imparts their PTT and PDT effects. However, most of the existing NIR-II fluorescent dyes have complex structures and are difficult to synthesize.

Based on the above, a novel organic small-molecule NIR-II fluorescent dye is needed to be developed, and a new direction is provided for the design and development of high-performance nano diagnosis and treatment reagents for clinical application.

Disclosure of Invention

The invention aims to overcome the defects, provides a novel organic small-molecule near-infrared two-zone (NIR-II) fluorescent dye and a preparation method of a nanoparticle aqueous solution of the dye, and the nanoparticles of the dye have good water solubility, biocompatibility and targeting property, and simultaneously have near-infrared two-zone fluorescent imaging capability and good photo-thermal and photo-dynamic effects.

The invention also aims to provide application of the novel organic small molecule near-infrared two-region (NIR-II) fluorescent dye in near-infrared two-region fluorescence imaging and photoacoustic imaging, and application of the novel organic small molecule near-infrared two-region (NIR-II) fluorescent dye in a reagent for photothermal/photodynamic combined therapy under the guidance of near-infrared two-region fluorescence imaging.

In order to realize the purpose, the invention is realized by the following technical scheme:

an organic micromolecule near-infrared two-region fluorescent dye mainly comprises a pyrrolopyrrole-dione unit derivative, and the structural formula of the dye is as follows:

a preparation method of the organic small molecule near-infrared two-region fluorescent dye comprises the following steps:

mixing 4-bromo o-phenylenediamine and 2, 5-bis (2-octyldodecyl) -3, 6-bis (5-boronic acid pinacol ester thienyl) -pyrrolopyrrole dione with a phosphorus catalyst and a palladium catalyst, vacuumizing, introducing nitrogen, then adding a solvent and an alkaline solution, reacting at 85-95 ℃ for 45-50 h, spin-drying the obtained crude product, and purifying the obtained product in a rotary powder manner.

The synthetic route is as follows:

preferably, in the preparation method, the molar ratio of the 4-bromoo-phenylenediamine to the 2, 5-bis (2-octyldodecyl) -3, 6-bis (5-boronic acid pinacol ester thienyl) -pyrrolopyrrole diketone to the phosphorus catalyst to the palladium catalyst is (3-5): 1: (0.1-0.2): (0.2-0.3).

Preferably, in the above preparation method, the phosphorus catalyst is tris (o-methylphenyl) phosphorus, and the palladium catalyst is tris (dibenzylideneacetone) dipalladium (Pd)₂(Dba)₃)。

Preferably, in the above preparation method, the solvent is anhydrous toluene, and the alkaline solution is 1mol/L of K₃PO₄And (3) solution.

The nanoparticle aqueous solution of the organic small-molecule near-infrared two-region fluorescent dye is prepared by performing nano coprecipitation on the organic small-molecule near-infrared two-region fluorescent dye and amphiphilic molecules, and comprises the following steps of:

dissolving the pyrrolopyrrole-dione unit derivative and Pluronic F127 in tetrahydrofuran, adding water, and ultrasonically oscillating for 3-5 min;

removing tetrahydrofuran in the solution, and then filtering by a water phase filter membrane and ultra-filtering by a centrifuge to prepare the nano-particle aqueous solution of the organic micromolecule near-infrared two-zone fluorescent dye.

The maximum light absorption wavelength of the nano-particle aqueous solution prepared by the method is 635nm +/-10 nm.

The maximum fluorescence emission wavelength of the nanoparticle aqueous solution prepared by the method is 1000nm +/-10 nm.

The application of the organic small molecule near-infrared two-zone fluorescent dye in near-infrared two-zone fluorescence imaging refers to that nanoparticle aqueous solution of the organic small molecule near-infrared two-zone fluorescent dye is used as a near-infrared two-zone fluorescence imaging contrast agent.

The application of the organic small-molecule near-infrared two-region fluorescent dye in photoacoustic imaging refers to that a nanoparticle aqueous solution of the organic small-molecule near-infrared two-region fluorescent dye is used as a photoacoustic imaging contrast agent.

The application of the organic small-molecule near-infrared two-region fluorescent dye in preparing a photo-thermal/photodynamic combined treatment reagent refers to that the nanoparticle aqueous solution of the novel organic small-molecule near-infrared two-region fluorescent dye is used for preparing a tumor targeted photo-thermal/photodynamic combined treatment reagent.

Compared with the prior art, the invention has the beneficial effects that:

the novel organic micromolecule NIR-II fluorescent material is synthesized based on the pyrrolopyrroledione unit, the design and synthesis steps are simple, and the structural characteristics are obvious.

The organic small-molecule NIR-II dye is prepared into nanoparticles with good water solubility, biocompatibility and targeting property by a simple nano coprecipitation method, the nanoparticles have excellent near-infrared two-region fluorescence imaging capability, photoacoustic imaging capability, photodynamic and photothermal conversion performance, and can be used for preparing photothermal/photodynamic combined treatment reagents under the guidance of near-infrared two-region fluorescence imaging/photoacoustic imaging.

The organic small-molecule NIR-II dye can be used for imaging and phototherapy, shows good inhibition rate on tumor cells, opens up a new field for NIR-II fluorescence imaging guided phototherapy excited by single wavelength, provides a new strategy, and realizes effective treatment of tumors.

Drawings

FIG. 1 is a UV spectrum of an aqueous nanoparticle solution of a small organic molecular NIR-II fluorescent dye prepared in example.

FIG. 2 is a fluorescence spectrum of an aqueous nanoparticle solution of the small organic molecule NIR-II fluorescent dye prepared in example.

Fig. 3 is a DLS diagram of nanoparticles of organic small molecule NIR-II fluorescent dyes prepared in the examples.

FIG. 4 is a near infrared two-zone fluorescence imaging diagram of the nanoparticle aqueous solution of the organic small molecule NIR-II fluorescent dye prepared by the example.

FIG. 5 is a photo-acoustic image of nanoparticle aqueous solution of organic small molecule NIR-II fluorescent dye prepared in example.

FIG. 6 is a photo-thermal change diagram of nanoparticle aqueous solutions of different concentrations of organic small molecule NIR-II fluorescent dyes under the same power illumination.

FIG. 7 is a graph of photothermal changes of the same concentration of an aqueous nanoparticle solution of a small organic molecule NIR-II fluorescent dye under different power illumination.

FIG. 8 shows a nanoparticle aqueous solution of organic small molecule NIR-II fluorescent dye with a certain concentration at 1W/m²Graph of DPBF 414nm UV absorption intensity as a function of time under light.

Detailed Description

The present invention will be described in more detail below with reference to the accompanying drawings and specific experimental methods. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

The reagents used in the practice of the present invention are commercially available, and the instruments used are:

near-infrared two-window fluorescence imager: NIRvana 640-Princeton Instrument

Infrared thermal imager: TESTO869

A laser: MDL-IH-808-1.5W-PSU-II-LED

1. An organic micromolecule near-infrared two-region fluorescent dye mainly comprises a pyrrolopyrrole-dione unit derivative, and the structural formula of the dye is as follows:

the synthetic route of the organic small molecule near infrared two-region (NIR-II) fluorescent dye is as follows:

the preparation method comprises the following specific steps:

85mg of 4-bromoo-phenylenediamine and 100mg of 2, 5-bis (2-octyldodecyl) -3, 6-bis (5-boronic acid pinacol ester thienyl) -pyrrolopyrroledione (molar ratio 5: 1), 20mg of tris (o-methylphenyl) phosphorus, 10mg of tris (dibenzylideneacetone) dipalladium (Pd) were weighed out₂(Dba)₃) (molar ratio 1:3) into a two-neck flaskIn the middle, vacuum pumping and nitrogen gas introduction are carried out. Followed by addition of 30mL of anhydrous toluene, 2mL of K₃PO₄The solution (1mol/L) was reacted in an oil bath at 90 ℃ for 48 hours, and the obtained crude product was spin-dried and purified by column chromatography to obtain the objective product (about 110mg, yield 59.5%).

2. The preparation method of the nanoparticle aqueous solution of the organic micromolecule near-infrared two-zone fluorescent dye comprises the following steps:

1mg of organic small-molecule NIR-II dye and 20mg of Pluronic F127 are weighed out and dissolved in 1mL of Tetrahydrofuran (THF), the solution is placed in a cell crushing instrument, 5mL of water is rapidly added, and the solution is rapidly shaken for 3min in an ultrasonic environment. Blowing nitrogen to remove THF in the solution, then filtering by using a water-phase filter membrane to obtain water solution nano particles, and finally performing ultrafiltration by using a centrifugal machine to obtain a quantitative nano particle water solution. The ultraviolet absorption spectrum and the fluorescence spectrum of the nanoparticle are shown in fig. 1 and fig. 2, respectively, and the particle size of the nanoparticle is shown in fig. 3.

3. Nanoparticle aqueous solution of organic small-molecule NIR-II fluorescent dye for near-infrared two-zone fluorescence imaging

1ml of the nanoparticle aqueous solution with the concentration of 0.1mg/ml is prepared, the nanoparticle aqueous solution is placed in a small centrifugal tube, and is excited by laser with the wavelength of 808nm under a near-infrared two-zone fluorescence imager to obtain near-infrared two-zone fluorescence imaging, as shown in fig. 4, the result shows that the nanoparticle has excellent infrared two-zone fluorescence imaging capability.

4. Nanoparticle aqueous solution of organic small molecule NIR-II fluorescent dye for photoacoustic imaging

A nanoparticle aqueous solution with a concentration of 1mg/mL is prepared, and is dissolved in a 200 μ L cuvette, and an imaging test is performed on the cuvette by using a photoacoustic imager, and the result is shown in FIG. 5.

5. Nanoparticle aqueous solution photothermal/photodynamic test of organic small molecule NIR-II fluorescent dye

(1) And (3) nano-particle photo-thermal testing:

the photo-thermal performance of the nanoparticle aqueous solution under different solution concentrations and different optical power densities is studied.

Preparing nanoparticles with concentration gradients of 20 μ g/ml, 40 μ g/ml, 60 μ g/ml, 80 μ g/ml and 100 μ g/ml respectivelyThe particle size in the aqueous solution was measured using a laser (660nm, 1W/cm)²) And (3) recording the trend of the solution temperature along with the change of time by an infrared camera, and as shown in fig. 6, under the irradiation of the same laser power, the temperature of the nanoparticle aqueous solution is continuously increased along with the increase of the concentration.

Then, the respective power densities were 0.25W/cm²、0.5W/cm²、0.75W/cm²And 1W/cm²The nanoparticle solution having the same concentration was irradiated with the laser light (660nm) and the temperature change curve of the solution with time was examined, as shown in fig. 7, indicating that the increase in the temperature of the nanoparticle solution was more significant as the laser power density was increased.

(2) Testing the photodynamic performance:

adding the nano-particle aqueous solution into a cuvette, then dropwise adding the DPBF ethanol solution, and respectively using the optical power density of 0.25W/cm²、0.5W/cm²And 1W/m²Is irradiated intermittently with laser light (730nm) for 20s each time, and the change of the ultraviolet absorption peak of DPBF at 414nm is recorded, 1W/m in FIG. 8²And the change trend of the ultraviolet absorption peak at 414nm of the DPBF characteristic peak under illumination with time. The absorption peak of DPBF at 414nm is obviously reduced with the continuous irradiation of laser, thereby reflecting the generation of singlet oxygen in the irradiation process. In addition, the larger the optical power density is, the larger the reduction amplitude of the absorption peak of DPBF at 414nm is, indicating that the nano-particle has better photodynamic performance.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and technical principles of the described embodiments, and such modifications and variations should also be considered as within the scope of the present invention.