阅读说明：本技术 一种用于近红外二区成像的双给体共轭聚合物及应用 (Double-donor conjugated polymer for near-infrared two-zone imaging and application thereof ) 是由 邓卫星 舒琦 刘远立 段炼 徐旭 于 2021-10-08 设计创作，主要内容包括：本发明公开了一种用于近红外二区成像的双给体共轭聚合物。分子结构中含有两种不同结构的电子给体单元,和一种电子受体单元。共轭聚合物的光学性质可根据两种电子给体在分子结构中的比例进行调整。此类双给体共轭聚合物吸收波长均大于1100nm,可利用1064nm光源进行成像和治疗,可以实现近红外二区荧光成像,并能有效抑制肿瘤细胞的生长。(The invention discloses a double-donor conjugated polymer for near-infrared two-zone imaging. The molecular structure contains two electron donor units with different structures and one electron acceptor unit. The optical properties of the conjugated polymer can be adjusted according to the ratio of the two electron donors in the molecular structure. The absorption wavelength of the double-donor conjugated polymer is more than 1100nm, and the double-donor conjugated polymer can be used for imaging and treatment by a 1064nm light source, can realize near-infrared two-region fluorescence imaging, and can effectively inhibit the growth of tumor cells.)

1. A double-donor conjugated polymer for near-infrared two-region imaging is characterized in that the molecular structure of the polymer contains two electron donor units with different structures and an electron acceptor unit.

2. A double-donor conjugated polymer for near-infrared two-zone imaging is characterized in that the absorption wavelength of the conjugated polymer is more than 1100nm, and a 1064nm light source can be used for imaging and treatment.

3. The double-donor conjugated polymer for near-infrared two-zone imaging according to claim 1, wherein the double-donor conjugated polymer has the following structural formula:

4. the dual-donor conjugated polymer for near-infrared two-zone imaging according to claim 1, wherein the electron donors in the dual-donor conjugated polymer are (4, 8-bis (5- (2-butyloctyl) thiophen-2-yl) benzo [1,2-b:4,5-b '] dithiophene-2, 6-diyl) Bistrimethyltin (BDT), and 2, 6-dibromo-4, 4-bis (2-ethylhexyl) -4H-cyclopenta [2,1-b:3, 4-b' ] dithiophene (CPDT) with the following structural formula:

5. the dual-donor conjugated polymer for near-infrared two-zone imaging according to claim 1, wherein the two electron acceptors are 4, 8-bis (5-bromo-4- (2-octyldodecyl) thienyl) -benzo [1, 2-c; the structural formula of 4,5-c' ] bis [1,2,5] thiadiazole (BBT) is as follows:

6. the double-donor conjugated polymer for near-infrared two-zone imaging according to claim 4, wherein the molar ratio of the two electron donors is 1:2, 1:1, 2: 1.

7. The use of the double-donor conjugated polymer for near-infrared two-zone imaging according to any one of claims 1 to 5 as a contrast agent for tumor-targeted near-infrared two-window fluorescence imaging.

8. Use of the double-donor conjugated polymer for near-infrared two-zone imaging according to any one of claims 1-5 as a photothermal therapeutic agent for tumor therapy.

Technical Field

The invention relates to a double-donor conjugated polymer for near-infrared two-zone imaging, belonging to the technical field of biomedical imaging.

Background

With the growing number of cancers today, it is becoming very interesting how to make early prevention and diagnosis of them. Photothermal therapy (PTT) combines optical imaging and laser therapy, and has the characteristics of high imaging sensitivity, low treatment side effects, sufficient efficacy, and the like. Fluorescence imaging (FL) and photothermal therapy (PTT) have now proven to be excellent phototherapy systems in preclinical studies. However, many biological tissues in the visible region (400-700 nm) and near infrared region (700-900 nm, NIR-I) have reduced light transmittance and sensitivity due to absorption and scattering of endogenous substances, and adversely affect fluorescence imaging in the visible wavelength range.

In the near-infrared region two (1000-170 nm, NIR-II), the absorption, scattering and autofluorescence of biological tissues are relatively low, and near-infrared light can reach a large penetration depth in biological tissues and can be used for deep tissue imaging, so that it is a popular research in recent years. The PTT materials based on NIR-II fluorescence imaging reported at present mainly comprise inorganic nanoparticles and organic fluorescent materials. The organic fluorescent materials are divided into organic small molecules and conjugated polymers, and the conjugated polymer-based nanoparticles attract more and more researchers' research interest due to excellent optical characteristics such as excellent photostability, strong photo-thermal properties, good structural plasticity, and excellent biocompatibility. But is limited to emission wavelengths less than 900nm and is not suitable for NIR-II fluorescence imaging. Thus, shifting their emission wavelength to the NIR-II window is a challenging task, but is crucial to expand their application in biomedical imaging.

Disclosure of Invention

In order to solve the technical problem, the invention provides a double-donor conjugated polymer for near-infrared two-zone imaging. Aims to improve the water solubility, biocompatibility and targeting property of the conjugated polymer-based nano particle, the fluorescence intensity of the near-infrared two regions and the photothermal conversion property, realize the fluorescence imaging of the near-infrared two regions and effectively inhibit the growth of tumor cells.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a double-donor conjugated polymer for near-infrared two-region imaging is characterized in that the molecular structure of the polymer contains two electron donor units with different structures and an electron acceptor unit.

The structural formula of the double-donor conjugated polymer is as follows:

the donors in the double-donor conjugated polymer are (4, 8-bis (5- (2-butyloctyl) thiophen-2-yl) benzo [1,2-b:4,5-b '] dithiophene-2, 6-diyl) Bistrimethyltin (BDT), and 2, 6-dibromo-4, 4-bis (2-ethylhexyl) -4H-cyclopenta [2,1-b:3, 4-b' ] dithiophene (CPDT), and the structural formula is as follows:

the electron acceptor is 4, 8-bis (5-bromo-4- (2-octyldodecyl) thienyl) -benzo [1, 2-c; the structural formula of 4,5-c' ] bis [1,2,5] thiadiazole (BBT) is as follows:

the molar ratio of the two electron donors is 1:2, 1:1 and 2: 1.

The invention also provides application of the double-donor conjugated polymer for near-infrared two-zone imaging in a near-infrared two-zone fluorescence imaging contrast agent.

The invention also provides the application of the double-donor conjugated polymer for near-infrared two-zone imaging as a near-infrared two-zone photothermal treatment agent.

Has the advantages that: the invention discloses a double-donor conjugated polymer for near-infrared two-zone imaging, wherein an amphiphilic triblock polymer F127 is utilized to form a nanoparticle aqueous solution, and the nanoparticle aqueous solution has good water solubility, biocompatibility, targeting property, excellent near-infrared two-zone fluorescence intensity and photothermal conversion property, can realize near-infrared two-zone fluorescence imaging, and can effectively inhibit the growth of tumor cells.

Drawings

FIG. 1 is a transmission electron micrograph of the double donor conjugated polymer nanoparticles obtained in example 1;

FIG. 2 is an ultraviolet spectrum of the nano-particle of the conjugated polymer of the dual donor obtained in example 1;

FIG. 3 is a fluorescence spectrum of the double-donor conjugated polymer nanoparticles obtained in example 1;

FIG. 4 is an ultraviolet spectrum of the nano-particle of the conjugated polymer of the dual donor obtained in example 2;

FIG. 5 is a fluorescence spectrum of the double-donor conjugated polymer nanoparticles obtained in example 2;

FIG. 6 is an ultraviolet spectrum of the nano-particle of the conjugated polymer of the dual donor obtained in example 3;

FIG. 7 is a fluorescence spectrum of the double-donor conjugated polymer nanoparticles obtained in example 3;

FIG. 8 is a mouse blood vessel and tumor imaging of the dual donor conjugated polymer nanoparticles obtained in example 1;

FIG. 9 is a thermal image of tumor mice with the nanoparticles of the conjugated polymer of the dual donor obtained in example 1;

FIG. 10 shows the therapeutic effect of the nanoparticles of the conjugated polymer of the dual donor obtained in example 1 on tumors.

Detailed Description

The present invention will be further described with reference to the following examples. 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 synthetic route of the near-infrared two-region double-donor conjugated polymer is as follows:

example 1:

the synthesis method of the first double-donor conjugated polymer comprises the following steps:

reacting the monomer 4, 8-bis (5-bromo-4- (2-octyldodecyl) thienyl) -benzo [1, 2-c; 4,5-c ' ] bis [1,2,5] thiadiazole (BBT) (32.32mg, 0.03mmol), (4, 8-bis (5- (2-butyloctyl) thiophen-2-yl) benzo [1,2-b:4,5-b ' ] dithiophene-2, 6-diyl) Bistrimethyltin (BDT) (91.51mg, 0.09mmol), 2, 6-dibromo-4, 4-bis (2-ethylhexyl) -4H-cyclopenta [2,1-b:3,4-b ' ] dithiophene (CPDT) (33.64mg, 0.06mmol), tris (o-tolyl) phosphine (1.38mg, 1.5. mu. mol), tris (o-tolyl) phosphine (1.83mg, 6. mu. mol) were added to a Hilbenz tube, anhydrous toluene (3mL) was added under nitrogen atmosphere, and heated and stirred (120 ℃ C., 70min), and after the reaction is stopped and the temperature is reduced to room temperature, precipitating in methanol, collecting the polymer by centrifugation, and obtaining the double-donor conjugated polymer I which is a reddish brown solid after the solvent is completely volatilized at the room temperature.

The preparation method of the double-donor conjugated polymer-nanoparticle aqueous solution comprises the following steps:

weighing 1mg of a sample of the double-donor conjugated polymer, dissolving the sample in 1mL of tetrahydrofuran, quickly adding the solution into 5mL of ultrapure water containing F127(15mg) under the ultrasonic condition, continuing to perform ultrasonic treatment for 3min, standing, and centrifuging the solution by using an ultrafiltration centrifugal tube with the molecular weight cut-off of 30KD to remove part of water after the tetrahydrofuran is volatilized, thereby finally obtaining a 2mg/mL aqueous solution of the double-donor conjugated polymer, namely nanoparticles.

As shown in FIG. 1, by preparing 0.005mg/mL aqueous solution of nanoparticles and testing the transmission electron micrograph, the nanoparticles with particle diameter of 30nm-70nm are all spherical.

As shown in FIG. 2, an aqueous solution of nanoparticles with a concentration of 0.025mg/mL was prepared and its absorption spectrum was tested. The maximum absorption peak of the double-donor conjugated polymer-nanoparticle aqueous solution is 945nm, and the double-donor conjugated polymer-nanoparticle aqueous solution has stronger absorption within the range of 800-1200 nm.

As shown in FIG. 3, an aqueous solution of nanoparticles at a concentration of 0.025mg/mL was prepared and its fluorescence spectrum was measured. The maximum emission peak of the double-donor conjugated polymer-nanoparticle aqueous solution is 1119nm, and the fluorescence emission exists in the range of 100-1400 nm.

As shown in figure 8, 4T1 tumor mice were selected, 200. mu.L of the double-donor conjugated polymer-nanoparticle aqueous solution (2mg/mL) was injected into the tail vein, the fluorescence signal intensity of the blood vessels and tumor sites of the mice were observed by a near-infrared two-zone imager, and it can be seen from the figure that the near-infrared two-zone fluorescence intensity of the tumor sites continuously increased, reached a peak 24h after injection, and then rapidly decreased, and the blood vessels of the body, abdomen and hind limbs were all observed, and the imaging was clear.

As shown in FIG. 9, 4T1 tumor mouse was selected, 200. mu.L of the double-donor conjugated polymer-nanoparticle aqueous solution (2mg/mL) was injected into the tail vein, and after 24h injection, laser (1064nm, 1W/cm) was used²) The continuous irradiation shows that the temperature of the tumor part of the mouse rapidly rises and quickly reaches a platform area at about 62 ℃ to reach the temperature for tumor cell ablation.

As shown in FIG. 10, two groups of six mice each with 4T1 tumor were selected, and 200. mu.L of the double-donor conjugated polymer-nanoparticle aqueous solution (2mg/mL) was injected into the tail vein, and after 24 hours, the mice were respectively irradiated or not irradiated with laser light (1064nm, 1W/cm) for 5min each day²) Irradiation was continued, and after 15 days, the mice were sacrificed and tumors were collected, and it was understood from the figure that the growth of the tumors was completely inhibited.

Example 2:

the synthesis method of the double-donor conjugated polymer II comprises the following steps:

reacting the monomer 4, 8-bis (5-bromo-4- (2-octyldodecyl) thienyl) -benzo [1, 2-c; 4,5-c ' ] bis [1,2,5] thiadiazole (BBT) (32.32mg, 0.03mmol), (4, 8-bis (5- (2-butyloctyl) thiophen-2-yl) benzo [1,2-b:4,5-b ' ] dithiophene-2, 6-diyl) Bistrimethyltin (BDT) (61.01mg, 0.06mmol), 2, 6-dibromo-4, 4-bis (2-ethylhexyl) -4H-cyclopenta [2,1-b:3,4-b ' ] dithiophene (CPDT) (16.82mg, 0.03mmol), tris (1.38mg, 1.5. mu. mol) benzylideneacetone dipalladium, tris (o-tolyl) phosphine (1.83mg, 6. mu. mol) were added to a Hilbert tube, anhydrous toluene (3mL) was added under nitrogen atmosphere, heated and stirred (120 ℃, 70min), and after the reaction is stopped and the temperature is reduced to room temperature, precipitating in methanol, collecting the polymer by centrifugation, and obtaining the double-donor conjugated polymer II which is a reddish brown solid after the solvent is completely volatilized at the room temperature.

The preparation method of the double-donor conjugated polymer double-nanoparticle aqueous solution comprises the following steps:

weighing 1mg of a second sample of the double-donor conjugated polymer, dissolving the second sample in 1mL of tetrahydrofuran, then quickly adding the solution into 5mL of ultrapure water containing F127(15mg) under the ultrasonic condition, continuing to perform ultrasonic treatment for 3min, and then standing until the tetrahydrofuran is volatilized to obtain a second nanoparticle aqueous solution of the double-donor conjugated polymer.

As shown in FIG. 4, an aqueous solution of nanoparticles at a concentration of 0.025mg/mL was prepared and its absorption spectrum was measured. The maximum absorption peak of the double-donor conjugated polymer double-nanoparticle aqueous solution is 959nm, and the double-donor conjugated polymer double-nanoparticle aqueous solution has stronger absorption in the range of 800-1200 nm.

As shown in FIG. 5, an aqueous solution of nanoparticles at a concentration of 0.025mg/mL was prepared and its fluorescence spectrum was measured. The maximum emission peak of the double-donor conjugated polymer double-nanoparticle aqueous solution is 1110nm, and fluorescence emission is realized in the range of 100-1400 nm.

Example 3:

the synthesis method of the double-donor conjugated polymer III is as follows:

reacting the monomer 4, 8-bis (5-bromo-4- (2-octyldodecyl) thienyl) -benzo [1, 2-c; 4,5-c ' ] bis [1,2,5] thiadiazole (BBT) (64.64mg, 0.06mmol), (4, 8-bis (5- (2-butyloctyl) thiophen-2-yl) benzo [1,2-b:4,5-b ' ] dithiophene-2, 6-diyl) Bistrimethyltin (BDT) (91.51mg, 0.09mmol), 2, 6-dibromo-4, 4-bis (2-ethylhexyl) -4H-cyclopenta [2,1-b:3,4-b ' ] dithiophene (CPDT) (16.82mg, 0.03mmol), tris (1.38mg, 1.5. mu. mol) benzylideneacetone dipalladium (1.83mg, 6. mu. mol), tris (o-tolyl) phosphine (1.83mg, 6. mu. mol) were added to a Hilbenzyl tube, anhydrous toluene (3mL) was added under nitrogen atmosphere, heated and stirred (120 ℃ C., 70min), and after the reaction is stopped and the temperature is reduced to room temperature, precipitating in methanol, collecting the polymer by centrifugation, and obtaining the double-donor conjugated polymer III which is a reddish brown solid after the solvent is completely volatilized at the room temperature.

The preparation method of the double-donor conjugated polymer three-nanoparticle aqueous solution comprises the following steps:

weighing 1mg of three samples of the double-donor conjugated polymer, dissolving the three samples in 1mL of tetrahydrofuran, then quickly adding the solution into 5mL of ultrapure water containing F127(15mg) under the ultrasonic condition, continuing to perform ultrasonic treatment for 3min, and then standing until the tetrahydrofuran is volatilized to obtain the aqueous solution of the three nano-particles of the double-donor conjugated polymer.

As shown in FIG. 6, an aqueous solution of nanoparticles at a concentration of 0.025mg/mL was prepared and its absorption spectrum was measured. The maximum absorption peak of the double-donor conjugated polymer three-nanoparticle aqueous solution is 961nm, and the double-donor conjugated polymer three-nanoparticle aqueous solution has stronger absorption within the range of 800-1200 nm.

As shown in FIG. 7, an aqueous solution of nanoparticles at a concentration of 0.025mg/mL was prepared and its fluorescence spectrum was measured. The maximum emission peak of the double-donor conjugated polymer three-nanoparticle aqueous solution is 1110nm, and fluorescence emission is realized in the range of 100-1400 nm.

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.