CN109331182B

CN109331182B - Polydopamine-modified conductive polymer nano material and preparation method and application thereof

Info

Publication number: CN109331182B
Application number: CN201811577916.8A
Authority: CN
Inventors: 鲍碧清; 汪联辉; 童丽
Original assignee: Nanjing University of Posts and Telecommunications
Current assignee: Nanjing University of Posts and Telecommunications
Priority date: 2018-12-24
Filing date: 2018-12-24
Publication date: 2021-05-28
Anticipated expiration: 2038-12-24
Also published as: CN109331182A

Abstract

The invention discloses a poly-dopamine-modified conductive polymer nano material, and a preparation method and application thereof. The material has uniform size, strong near infrared absorption and high-efficiency photo-thermal performance, can quench the fluorescence of the nano particles, enhances the photo-thermal performance and photo-acoustic signals of the nano particles, has good biocompatibility, has rich functional groups on the surface, is convenient for modifying various functional ligands, and has good application potential in the aspect of photo-thermal treatment.

Description

Polydopamine-modified conductive polymer nano material and preparation method and application thereof

Technical Field

The invention belongs to the technical field of organic photoelectric and biological materials. In particular to a preparation method of a polydopamine modified conductive polymer nano material and application thereof in the field of photo-thermal treatment.

Background

The tumor is a fatal disease which seriously threatens human health and is difficult to overcome, and the traditional treatment method of the tumor is mainly surgical therapy, chemotherapy or radiotherapy; these treatments are often accompanied by toxic side effects and poor therapeutic effects. With the continuous development of scientific technology, researchers develop various novel treatment schemes gradually, wherein photothermal therapy is widely concerned by the medical field as a non-invasive and tolerable tumor treatment means, and the method has the action principle that light energy is converted into heat energy, the heat energy concentrated on tumor tissue parts is utilized to enhance the blood circulation of the tumor parts, improve the supply of oxygen and kill the tumor tissues or cancer cells. The photothermal therapy has the advantages of small wound, less side effect, high selectivity and the like, the method becomes a main means for treating tumors in the future, and how to select a proper photothermal material directly determines the action effect of the method.

In recent years, the synthetic application of organic conjugated polymer nanoparticles having strong Near Infrared (NIR) absorption and good biocompatibility has become a research hotspot of scientific researchers in the fields of biosensing, fluorescence imaging, photoacoustic imaging, photothermal therapy and the like. However, most of the existing organic conjugated polymer nanoparticles have the problems of nanoparticle dissociation, poor structural stability and the like, and the surfaces of the nanoparticles do not have functional groups for further bioconjugation, so that the particle surfaces are not easy to functionalize, and the factors limit the further application of the materials in the field of tumor treatment.

Polydopamine is a biopolymer material with unique coating quality and excellent biocompatibility, and has been widely used for forming thin surface adhesives on the surfaces of various materials. If the poly-dopamine is coated on the surface of the organic conjugated polymer nanoparticles, the surface of the poly-dopamine is provided with abundant functional groups, so that the poly-dopamine is convenient to functionalize, and a new idea is developed for further developing the organic conjugated polymer nanoparticles for photothermal therapy.

Disclosure of Invention

Aiming at the problems of poor stability and difficult surface modification of organic conjugated polymer nanoparticles in the prior art, the invention provides a poly-dopamine modified conductive polymer nano material, which can realize easy surface functionalization of conductive polymer nanoparticles and can be used for photo-thermal treatment of tumors to effectively ablate the tumors.

The technical scheme of the invention is as follows: the conductive polymer nano material PSBTBT @ PDA NPs modified by the polydopamine is formed by coating dopamine on the surface of conductive polymer nano particles PSBTBT NPs, and the PSBTBT @ PDA NPs have uniform particle size and the particle size of 68-71 nm.

The preparation method of the polydopamine-modified conductive polymer nano-material mainly comprises the following preparation steps:

1) preparing conductive polymer PSBTBT into nano-particle PSBTBT NPs by a reprecipitation method;

2) adding PSBTBT NPs into a Tris-HCl buffer solution containing dopamine, and shaking for 8-10h at room temperature;

3) and (3) cleaning the product obtained in the step (2) by using ultrapure water, and centrifugally purifying for 3 times to obtain a final product, namely, the poly-dopamine modified conductive polymer nano-particles PSBTBT @ PDA NPs, which are dispersed in the ultrapure water.

Further, the concentration of the PSBTBT NPs solution in the step 2 is 0.08mg/mL, the concentration of dopamine in a Tris-HCl buffer solution is 0.5mg/mL, the concentration of the Tris-HCl buffer solution is 10mM, and the pH value is 8.5.

Further, in the step 3, the centrifugal rotation speed is 12000rpm/min, and the centrifugal time is 15-20 min.

Further, the preparation steps of the PSBTBT NPs are as follows: firstly, preparing tetrahydrofuran solution of PSBTBT; then quickly pumping the tetrahydrofuran solution of PSBTBT into ultrapure water in an ultrasonic state for 8-10 min; and finally removing tetrahydrofuran by using a rotary evaporation method, and filtering by using a 0.22 mu m aqueous phase filter head to obtain PSBTBT NPs.

The poly-dopamine modified conductive polymer nano material can be applied to photothermal treatment of tumors.

The invention has the beneficial effects that:

1. the preparation method of the poly-dopamine-modified conductive polymer nano-material disclosed by the invention is simple, mild in condition, cheap and easily available in raw materials, and the prepared product is uniform in size and good in biocompatibility;

2. compared with unmodified conductive polymer nanoparticles, the poly-dopamine-modified conductive polymer nano material disclosed by the invention not only improves biocompatibility, but also has abundant functional groups on the surface, so that various functional ligands can be conveniently modified;

3. the poly-dopamine-modified conductive polymer nano material disclosed by the invention can quench the fluorescence of conductive polymer nano particles and enhance the photo-thermal property and photo-acoustic signals of the conductive polymer nano particles;

4. the poly-dopamine-modified conductive polymer nano material disclosed by the invention can be used for photo-thermal treatment of tumors, effectively ablating the tumors and killing cancerated cells.

Drawings

FIG. 1 is a schematic diagram of the preparation process of PSBTBT @ PDA NPs in example 1 of the present invention;

FIG. 2 is a TEM image of PSBTBT @ PDA NPs in example 1 of the present invention;

FIG. 3 is a graph showing UV absorption and fluorescence emission spectra of PSBTBT NPs and PSBTBT @ PDA NPs in example 2;

FIG. 4 is an infrared spectrum of surface functionalization of PSBTBT @ PDA NPs in example 3 of the present invention;

FIG. 5a is a graph of photo-thermal temperature rise under laser irradiation of PSBTBT NPs and PSBTBT @ PDA NPs in example 4 of the present invention;

FIG. 5b is a photo-acoustic spectrum of PSBTBT NPs and PSBTBT @ PDA NPs under laser irradiation in example 4 of the present invention;

FIG. 6 is a graph showing cytotoxicity test results of PSBTBT NPs and PSBTBT @ PDA NPs in example 5, wherein FIG. 6a is a graph showing the experimental results of an experimental group irradiated with a laser, and FIG. 6b is a graph showing the experimental results of a control group not irradiated with a laser;

FIG. 7 is a graph showing the photothermal temperature curve of a mouse, the tumor volume and the body weight of the mouse, for the photothermal treatment of the tumor using PSBTBT @ PDA NPs according to example 6 of the present invention, wherein FIG. 7a is a graph showing the photothermal temperature curve, FIG. 7b is a graph showing the tumor volume change of the mouse, and FIG. 7c is a graph showing the body weight change.

Detailed Description

The following examples further illustrate the present invention but are not to be construed as limiting the invention. Modifications and substitutions to methods, procedures, or conditions of the invention may be made without departing from the spirit of the invention.

Example 1

Fig. 1 is a preparation route diagram of a poly-dopamine-modified conductive polymer nanomaterial, and the specific preparation method is as follows:

(1) preparation of conductive Polymer (PSBTBT) tetrahydrofuran solution: weighing 1 mg of PSBTBT, adding 12 mL of tetrahydrofuran, and carrying out ultrasonic treatment to completely dissolve the PSBTBT;

(2) under the ultrasonic state, 2 mL of conductive polymer tetrahydrofuran solution is rapidly injected into 10 mL of ultrapure water, and ultrasonic treatment is carried out for 8 min;

(3) removing tetrahydrofuran by rotary evaporation, and filtering with 0.22 μm filter head to obtain conductive polymer nanoparticles (PSBTBT NPs);

(4) adding the conductive polymer nanoparticle solution (0.08 mg/mL) to Tris-HCl buffer (10 mM, pH = 8.5) containing dopamine (0.5 mg/mL), shaking at room temperature for 8 h;

(5) and (3) cleaning the product in the step (4) by using ultrapure water, and centrifugally purifying for 3 times to obtain a final product, namely, poly-dopamine modified conductive polymer nanoparticles (PSBTBT @ PDA NPs), which are dispersed in the ultrapure water.

The prepared PSBTBT @ PDA NPs were observed using a Transmission Electron Microscope (TEM). The aqueous solution of PSBTBT @ PDA NPs was dropped onto a carbon-coated copper mesh and dried at room temperature and observed using a transmission electron microscope, as shown in FIG. 2, and it can be seen from FIG. 2 that the PSBTBT @ PDA NPs were uniform in size and about 70 nm in particle size.

Example 2 uv absorption and fluorescence emission testing of PSBTBT @ PDA NPs:

solutions of PSBTBT NPs and PSBTBT @ PDA NPs (15 μ g/mL) in example 1 were formulated and tested for their absorption and emission spectra, with the results shown in FIG. 3, and the test data indicated that polydopamine was successfully coated and fluorescence of PSBTBT NPs was successfully quenched.

Example 3 infrared spectroscopy testing of surface functionalization of PSBTBT @ PDA NPs:

the PSBTBT @ PDA NPs solution in example 1 is prepared, mixed with different ligands (PEG-SH, cRGD and FA) in Tris-HCl buffer (10 mM, pH 8.5), stirred at room temperature for 12 h, centrifugally purified for three times (12000 rpm/min, 20 min), dispersed with ultrapure water, mixed with potassium bromide and dried, and tabletted to test the infrared spectrum of the product, and the result is shown in FIG. 4, and the test data shows that the surface of PSBTBT @ PDA NPs can successfully modify different ligands, thereby showing the advantage of easy surface functionalization.

Example 4 in vitro photothermal and photoacoustic testing of PSBTBT @ PDA NPs:

solutions of PSBTBT NPs and PSBTBT @ PDA NPs from example 1 (100. mu.g/mL) were prepared and blanked with ultrapure water. Placing the prepared solution in a centrifuge tube, and then using a laser with the wavelength of 635 nm and the power density of 0.5W/cm²Irradiating for 5 min. The results are shown in fig. 5a, and the test data shows that the temperature rise of PSBTBT @ PDA NPs within 5 min is significantly higher than that of the conductive polymer nanoparticles without coated poly-dopamine.

Solutions of PSBTBT NPs and PSBTBT @ PDA NPs from example 1 (100. mu.g/mL) were prepared and photoacoustic spectra were measured by pulsed laser at 680 to 975 nm. As shown in fig. 5b, the test data indicates that the photoacoustic signal of PSBTBT @ PDA NPs is significantly higher than that of the conductive polymeric nanoparticles without coated polydopamine. This example shows that polydopamine enhances the photothermal properties and photoacoustic signal of the nanoparticles.

Example 5 cytotoxicity testing of PSBTBT @ PDA NPs:

solutions of PSBTBT NPs and PSBTBT @ PDA NPs were prepared at 0, 10, 25, 50, 100. mu.g/mL, respectively. Inoculating HeLa cells on a 96-well plate, incubating for 24 h, removing culture solution in the well, adding materials with different concentrations, incubating for 24 h, and using a laser with a wavelength of 635 nm at a power density of 0.5W/cm²The cells were irradiated at intensity for 5 min and incubated for 4 h after addition of MTT reagent. The control group differs from the experimental group in that no laser irradiation was used. It can be seen from fig. 6b that all samples showed little toxicity in the absence of laser irradiation. It can be seen from fig. 6a that PSBTBT @ PDA NPs showed excellent photothermal properties at high concentrations under laser irradiation, killing most of the cells. This example shows that the prepared PSBTBT @ PDA NPs have good biocompatibility, and after illumination, have good killing effect on cancer cells through photothermal effect.

Example 6 photothermal therapy testing of PSBTBT @ PDA NPs:

200 μ L of 175 μ g/mL PSBTBInjecting T @ PDA NPs into mice in tail vein, and after 4 h, using a laser with the wavelength of 635 nm at the power density of 0.8W/cm²Irradiation at intensity for 5 min, as reflected in FIG. 7a, the mouse temperature can be raised to about 65 ℃; tumor volume and mouse body weight were measured every other day, fig. 7b reflects that the tumors of mice injected with PSBTBT @ PDA NPs were completely ablated the next day and no regrowth occurred in the later stages; figure 7c reflects little change in mouse body weight, indicating that the material is nearly non-toxic and is capable of effectively ablating mouse tumors.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. However, the above description is only an example of the present invention, the technical features of the present invention are not limited thereto, and any other embodiments that can be obtained by those skilled in the art without departing from the technical solution of the present invention should be covered by the claims of the present invention.

Claims

1. A preparation method of a conductive polymer nano material modified by polydopamine is characterized in that the nano material PSBTBT @ PDA NPs is formed after dopamine is coated on the surface of conductive polymer nano particles PSBTBT NPs, the particle size of the PSBTBT @ PDA NPs is uniform, the particle size is 68-71nm, and the main preparation steps of the nano material are as follows:

3) washing the product in the step 2 with ultrapure water, and centrifugally purifying for 3 times to obtain a final product PSBTBT @ PDA NPs which is dispersed in the ultrapure water;

the concentration of the PSBTBT NPs solution in the step 2 is 0.08mg/mL, the concentration of dopamine in a Tris-HCl buffer solution is 0.5mg/mL, the concentration of the Tris-HCl buffer solution is 10mM, and the pH value is 8.5;

the photo-thermal performance and photo-acoustic signals of the nano particles coated with the poly-dopamine are enhanced, and the finally prepared nano material has good biocompatibility and no toxicity;

wherein the structural formula of PSBTBT is as follows:

2. the method for preparing the poly-dopamine-modified conductive polymer nanomaterial in claim 1, wherein the centrifugation speed in step 3 is 12000rpm/min, and the centrifugation time is 15-20 min.

3. The method for preparing the polydopamine-modified conductive polymer nanomaterial as claimed in claim 2, wherein the PSBTBT NPs are prepared by the following steps: firstly, preparing tetrahydrofuran solution of PSBTBT; then quickly pumping the tetrahydrofuran solution of PSBTBT into ultrapure water in an ultrasonic state for 8-10 min; and finally removing tetrahydrofuran by using a rotary evaporation method, and filtering by using a 0.22 mu m aqueous phase filter head to obtain PSBTBT NPs.