Preparation method and application of Prussian blue nano material with NIR-II absorption characteristic

Abstract

The invention aims to provide a preparation method and application of a Prussian blue nano-material with NIR-II absorption characteristic, and belongs to the technical field of Prussian blue nano-materials, the method comprises the following steps: enabling melanin (water-soluble) and ferricyanide salt to react in a dilute acid solution, then adding polyvinylpyrrolidone, and carrying out centrifugal drying to form the Prussian blue nano-material. The prepared MPB has an efficient light absorption characteristic in a region of 900-1200 nm, and can be effectively used for NIR-IIPA / PTT.

Description

Technical Field

[0001] The invention belongs to the technical field of Prussian blue nanomaterials, and specifically relates to a preparation method and application of a Prussian blue nanomaterial with NIR-II absorption characteristics. Background Art

[0002] Prussian blue (PB, Fe4[Fe(CN)6]) is an antidote approved by the U.S. Food and Drug Administration (FDA) and is commonly used in the clinical treatment of poisoning by radioactive elements such as thallium. Due to its tunable size and excellent performance, PB plays an important role in the diagnosis and treatment of drug delivery, photothermal therapy, and molecular imaging.

[0003] Photoacoustic imaging (PA) is an emerging non-invasive diagnostic technology that combines the advantages of optical imaging and ultrasound imaging, with excellent sensitivity, high resolution and real-time imaging capabilities. However, in the visible light and first near-infrared window (NIR-Ⅰ, 700-900 nm), its tissue penetration depth and spatial resolution are limited. In contrast, photoacoustic contrast agents in the second near-infrared window (NIR-Ⅱ, 900-1700 nm) have stronger penetration, higher signal-to-noise ratio, and better imaging quality, and can provide more comprehensive and in-depth physiological and pathological information in vivo.

[0004] Although PB has considerable absorbance under near-infrared light (NIR), it is often used as a PA contrast agent and photothermal converter for diagnosis and photothermal therapy (PTT). However, its maximum near-infrared absorption peak is usually located in the range of 690-720 nm, and its absorption characteristics in the NIR-Ⅱ region are weak, and have little to do with changes in its basic physical properties such as size, structure and morphology. At present, there is still a lack of effective preparation methods for the NIR-Ⅱ absorption characteristics of PB. In addition, in the only reports on PB with NIR-Ⅱ absorption characteristics, the preparation methods of these PBs are complicated, and their biocompatibility needs to be improved. Therefore, it is of great significance and challenge to adjust the maximum absorbance of PB in the NIR-Ⅱ region and further enhance its PA and PTT capabilities to meet the needs of accurate and efficient diagnosis and treatment. Summary of the invention

[0005] The purpose of the present invention is to provide a preparation method of a Prussian blue nanomaterial with NIR-Ⅱ absorption characteristics and its application. The method can easily and massively prepare functionalized Prussian blue nanomaterials (MPB). The MPB prepared by the method exhibits superior absorption characteristics in the NIR-Ⅱ region, significantly enhances PA performance and photothermal conversion efficiency, and can be effectively used in NIR-Ⅱ PA / PTT.

[0006] The present invention adopts the following technical solution: A method for preparing a Prussian blue nanomaterial having NIR-Ⅱ absorption characteristics comprises the following steps: S1. Dissolve melanin (water-soluble) and ferrocyanide salt in a dilute acid solution, and disperse them uniformly by ultrasonication to obtain a homogenized solution; S2, the homogenized solution prepared in step S1 is transferred to a beaker, placed in a constant temperature stirrer and stirred at a constant speed of 500-1200 r / min, and then polyvinyl pyrrolidone is added step by step, and stirred at room temperature for 1-4 hours until the solution is transparent to obtain a homogenized mixed solution; S3. Transfer the homogenized mixed solution obtained in S2 to a round-bottom flask, heat it to 60-90°C, react for 8-24 hours, then centrifuge the obtained solution at a speed of 3500-12000 r / min, and finally dry it to obtain the functionalized Prussian blue nanomaterial MPB with NIR-Ⅱ absorption characteristics.

[0007] Furthermore, the ferrocyanide salt in step S1 includes any one of potassium ferrocyanide, potassium ferrocyanide, sodium ferrocyanide, and sodium ferrocyanide.

[0008] Furthermore, the pH of the dilute acid solution in step S1 is 6-8, including any one of hydrochloric acid, sulfuric acid, acetic acid, and citric acid.

[0009] Further, the mass volume ratio of the melanin (water-soluble), ferrocyanide salt and dilute acid solution in step S1 is (10 mg 200 mg): (10 mg 200 mg): (3 mL-100 mL); The frequency of the ultrasonic dispersion is 25 kHz-80 kHz, and the time of the ultrasonic dispersion is 10-60 min.

[0010] Furthermore, the mass of the polyvinyl pyrrolidone in step S2 is 0.2-0.6 g.

[0011] A functionalized Prussian blue nanomaterial with near-infrared second-zone light absorption properties is applied to NIR-ⅡPA / PTT.

[0012] The beneficial effects of the present invention are as follows: 1. The present invention provides a functionalized Prussian blue nanomaterial (MPB) having near-infrared second-zone light absorption characteristics, which is formed by reacting melanin (water-soluble) and ferrocyanide salt in a dilute acid solution, adding polyvinyl pyrrolidone, and centrifugally drying; the prepared MPB has efficient light absorption characteristics in the 900-1200 nm region and can be effectively used in NIR-Ⅱ PA / PTT.

[0013] 2. The preparation method of the present invention is simple and can be prepared in large quantities.

[0014] 3. The MPB composition of the present invention is simple and safe, and has excellent biocompatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a transmission electron microscope (TEM) image of the MPB synthesized in Example 1 of the present invention.

[0016] Figure 2 This is the XRD spectrum of MPB synthesized in Example 1 of the present invention.

[0017] Figure 3 This is the UV absorption spectrum of MPB synthesized in Example 1 of the present invention.

[0018] Figure 4 This is the oxygen release spectrum of MPB synthesized in Example 1 of the present invention.

[0019] Figure 5 This is the temperature change curve of MPB with different concentrations synthesized in Example 1 of the present invention under laser irradiation over time.

[0020] Figure 6 The photothermal performance spectrum of the MPB synthesized in Example 1 of the present invention under laser irradiation with different laser power densities Figure 7 This is the photothermal cycle spectrum of the MPB synthesized in Example 1 of the present invention.

[0021] Figure 8 This is a photothermal conversion efficiency spectrum calculated according to the photothermal cooling curve of the MPB synthesized in Example 1 of the present invention.

[0022] Fig. 9 These are NIR-Ⅱ 3D PA images of MPB of different concentrations synthesized in Example 1 of the present invention.

[0023] Fig.10 These are NIR-Ⅱ 3DPA images of the lesion site at different times after the MPB synthesized in Example 1 of the present invention was injected into the tail vein. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not 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.

[0025] Example 1 The preparation of functionalized Prussian blue nanomaterials with NIR-Ⅱ absorption comprises the following steps: S1. Dissolve melanin (water-soluble) and potassium ferrocyanide in a dilute acid solution, the mass volume ratio of melanin (water-soluble), potassium ferrocyanide and dilute acid solution is 100 mg: 100 mg: 40 mL, and disperse them uniformly by ultrasonic dispersion at a frequency of 60 KHz and a time of 30 min to obtain a homogenized solution; S2, the homogenized solution obtained in step S1 was transferred to a beaker, and then placed in a constant temperature stirrer for uniform stirring at a speed of 600 r / min, and then polyvinyl pyrrolidone was added step by step, with a mass of 0.4 g, and stirred at high speed for 3 h at room temperature until the solution was transparent to obtain a homogenized mixed solution; S3. The homogenized mixed solution prepared in S2 was transferred to a round-bottom flask, heated to 70 °C, and reacted for 12 h. The obtained solution was then centrifuged at a speed of 8000 r / min. Finally, the functionalized Prussian blue nanomaterial (MPB) with NIR-Ⅱ absorption characteristics was obtained by drying.

[0026] Figure 1 This is a TEM image of the MPB synthesized in Example 1. As can be seen from the figure, the synthesized nanomaterial particles are uniform in size, present a square block structure, and have a diameter of about 200 nm.

[0027] Figure 2 This is the XRD pattern of MPB synthesized in Example 1. As can be seen from the figure, the diffraction peaks at 17.4°, 24.6°, 35.2° and 39.4° correspond to the (200), (220), (400) and (420) crystal planes, respectively, indicating that MPB is a PB analogue.

[0028] Figure 3 This is the UV absorption spectrum of MPB synthesized in Example 1. Compared with PB, MPB exhibits obvious NIR-Ⅱ light absorption characteristics in the 900-1200 nm region and can be used for NIR-Ⅱ PA / PTT.

[0029] Figure 4 This is the oxygen release spectrum of MPB synthesized in Example 1. As can be seen from the figure, compared with PB and water, MPB has the strongest oxygen production capacity.

[0030] Figure 5 The temperature variation curves of MPB with different concentrations synthesized in Example 1 under laser irradiation over time are shown in the figure. As can be seen from the figure, MPB with different solubility shows rapid temperature rise under laser irradiation, while the temperature of pure water remains almost unchanged.

[0031] Figure 6The photothermal performance spectrum of MPB synthesized in Example 1 under laser irradiation of different laser power densities is shown in FIG. As can be seen from the figure, MPB exhibits rapid temperature rise when irradiated by lasers at different powers, and the greater the power, the higher the temperature rise rate and amplitude.

[0032] Figure 7 This is the photothermal cycle spectrum of the MPB synthesized in Example 1. As can be seen from the figure, MPB can also ensure good photothermal stability performance in a longer cycle time.

[0033] Figure 8 This is a photothermal conversion efficiency spectrum calculated based on the photothermal cooling curve of the MPB synthesized in Example 1. As can be seen from the figure, MPB has a high photothermal conversion efficiency.

[0034] Fig. 9 The NIR-Ⅱ 3D PA images of MPB with different concentrations synthesized in Example 1. As can be seen from the figure, the photoacoustic signal of MPB is linearly correlated with its concentration, and the intensity of the photoacoustic signal increases with the increase of solubility.

[0035] Fig.10 The NIR-Ⅱ 3D PA images of the lesion site at different times after the MPB synthesized in Example 1 was injected through the tail vein. As can be seen from the figure, the MPB solution was injected into myeloma nude mice through the tail vein, and the PA signal at the lesion tissue was collected. The 3D PA signal showed a time-dependent increase in the lesion site, reaching the highest peak at 8 hours after injection. Compared with before injection, the signal increased several times, showing excellent lesion-specific NIR-Ⅱ 3D PA imaging capabilities. At the same time, in vivo experiments showed that MPB has excellent biosafety.

[0036] Example 2 The preparation of functionalized Prussian blue nanomaterials with NIR-Ⅱ absorption comprises the following steps: S1. Dissolve melanin (water-soluble) and sodium ferrocyanide in a dilute acid solution, the mass volume ratio of melanin (water-soluble), sodium ferrocyanide and dilute acid solution is 100 mg: 100 mg: 40 mL, and disperse them uniformly by ultrasonic dispersion at a frequency of 60 KHz and a time of 30 min to obtain a homogenized solution; S2, the homogenized solution obtained in step S1 was transferred to a beaker, and then placed in a constant temperature stirrer for uniform stirring at a speed of 600 r / min, and then polyvinyl pyrrolidone was added step by step, with a mass of 0.3 g, and stirred at high speed for 4 h at room temperature until the solution was transparent to obtain a homogenized mixed solution; S3. The homogenized mixed solution prepared in S2 was transferred to a round-bottom flask, heated to 75 °C, and reacted for 12 h. The obtained solution was then centrifuged at a speed of 8000 r / min. Finally, the functionalized Prussian blue nanomaterial (MPB) with NIR-Ⅱ absorption characteristics was obtained by drying.

[0037] Example 3 The preparation of functionalized Prussian blue nanomaterials with NIR-Ⅱ absorption comprises the following steps: S1. Dissolve melanin (water-soluble) and potassium ferrocyanide in a dilute acid solution, the mass volume ratio of melanin (water-soluble), potassium ferrocyanide and dilute acid solution is 100 mg: 100 mg: 40 mL, and disperse them uniformly by ultrasonic dispersion at a frequency of 70 KHz and a time of 30 min to obtain a homogenized solution; S2, the homogenized solution obtained in step S1 was transferred to a beaker, and then placed in a thermostatic stirrer for uniform stirring at a speed of 600 r / min, and then polyvinyl pyrrolidone was added step by step, with a mass of 0.3 g, and stirred at high speed for 3 h at room temperature until the solution was transparent to obtain a homogenized mixed solution; S3. The homogenized mixed solution prepared in S2 was transferred to a round-bottom flask, heated to 70 °C, and reacted for 12 h. The obtained solution was then centrifuged at a speed of 8000 r / min. Finally, the functionalized Prussian blue nanomaterial (MPB) with NIR-Ⅱ absorption characteristics was obtained by drying.

[0038] Example 4 The preparation of functionalized Prussian blue nanomaterials with NIR-Ⅱ absorption comprises the following steps: S1. Dissolve melanin (water-soluble) and potassium ferrocyanide in a dilute acid solution, the mass volume ratio of melanin (water-soluble), potassium ferrocyanide and dilute acid solution is 100 mg: 100 mg: 40 mL, and disperse them uniformly by ultrasonic dispersion at a frequency of 60 KHz for 30 min to obtain a homogenized solution; S2, the homogenized solution obtained in step S1 was transferred to a beaker, and then placed in a thermostatic stirrer for uniform stirring at a speed of 600 r / min, and then polyvinyl pyrrolidone was added step by step, with a mass of 0.3 g, and stirred at high speed for 3 h at room temperature until the solution was transparent to obtain a homogenized mixed solution; S3. The homogenized mixed solution prepared in S2 was transferred to a round-bottom flask, heated to 70 °C, and reacted for 12 h. The obtained solution was then centrifuged at a speed of 8000 r / min. Finally, the functionalized Prussian blue nanomaterial (MPB) with NIR-Ⅱ absorption characteristics was obtained by drying.

[0039] Example 5 The preparation of functionalized Prussian blue nanomaterials with NIR-Ⅱ absorption comprises the following steps: S1. Dissolve melanin (water-soluble) and sodium ferrocyanide in a dilute acid solution, the mass volume ratio of melanin (water-soluble), sodium ferrocyanide and dilute acid solution is 100 mg: 100 mg: 40 mL, and disperse them uniformly by ultrasonic dispersion at a frequency of 60 KHz for 30 min to obtain a homogenized solution; S2, the homogenized solution obtained in step S1 was transferred to a beaker, and then placed in a thermostatic stirrer for uniform stirring at a speed of 600 r / min, and then polyvinyl pyrrolidone was added step by step, with a mass of 0.3 g, and stirred at high speed for 3 h at room temperature until the solution was transparent to obtain a homogenized mixed solution; S3. The homogenized mixed solution prepared in S2 was transferred to a round-bottom flask, heated to 70 °C, and reacted for 14 h. The obtained solution was then centrifuged at a speed of 8000 r / min. Finally, the functionalized Prussian blue nanomaterial (MPB) with NIR-Ⅱ absorption characteristics was obtained by drying.

[0040] Example 6 The preparation of functionalized Prussian blue nanomaterials with NIR-Ⅱ absorption comprises the following steps: S1. Dissolve melanin (water-soluble) and potassium ferrocyanide in a dilute acid solution, the mass volume ratio of melanin (water-soluble), potassium ferrocyanide and dilute acid solution is 100 mg: 100 mg: 40 mL, and disperse them uniformly by ultrasonic dispersion at a frequency of 60 KHz and a time of 30 min to obtain a homogenized solution; S2, the homogenized solution obtained in step S1 was transferred to a beaker, and then placed in a thermostatic stirrer for uniform stirring at a speed of 600 r / min, and then polyvinyl pyrrolidone was added step by step, with a mass of 0.3 g, and stirred at high speed for 3 h at room temperature until the solution was transparent to obtain a homogenized mixed solution; S3. The homogenized mixed solution prepared in S2 was transferred to a round-bottom flask, heated to 70 °C, and reacted for 16 h. The obtained solution was then centrifuged at a speed of 8000 r / min. Finally, the functionalized Prussian blue nanomaterial (MPB) with NIR-Ⅱ absorption characteristics was obtained by drying.

[0041] Example 7 The preparation of functionalized Prussian blue nanomaterials with NIR-Ⅱ absorption comprises the following steps: S1. Dissolve melanin (water-soluble) and sodium ferrocyanide in a dilute acid solution, the mass volume ratio of melanin (water-soluble), sodium ferrocyanide and dilute acid solution is 100 mg: 100 mg: 40 mL, and disperse them uniformly by ultrasonic dispersion at a frequency of 70 KHz and a time of 40 min to obtain a homogenized solution; S2, the homogenized solution obtained in step S1 was transferred to a beaker, and then placed in a constant temperature stirrer for uniform stirring at a speed of 800 r / min, and then polyvinyl pyrrolidone was added step by step, with a mass of 0.3 g, and stirred at high speed for 3 h at room temperature until the solution was transparent to obtain a homogenized mixed solution; S3. The homogenized mixed solution prepared in S2 was transferred to a round-bottom flask, heated to 70 °C, reacted for 10 h, and then the obtained solution was centrifuged at a speed of 8000 r / min. Finally, the functionalized Prussian blue nanomaterial (MPB) with NIR-Ⅱ absorption characteristics was obtained by drying.

Claims

1. A method for preparing a Prussian blue nanomaterial having NIR-Ⅱ absorption characteristics, characterized in that: The steps include: S1. Dissolve melanin (water-soluble) and ferrocyanide salt in a dilute acid solution, and disperse them uniformly by ultrasonication to obtain a homogenized solution; S2, the homogenized solution prepared in step S1 is transferred to a beaker, placed in a constant temperature stirrer and stirred at a constant speed of 500-1200 r / min, and then polyvinyl pyrrolidone is added step by step, and stirred at room temperature for 1-4 hours until the solution is transparent to obtain a homogenized mixed solution; S3. Transfer the homogenized mixed solution obtained in S2 to a round-bottom flask, heat it to 60-90°C, react for 8-24 hours, then centrifuge the obtained solution at a speed of 3500-12000 r / min, and finally dry it to obtain the functionalized Prussian blue nanomaterial MPB with NIR-Ⅱ absorption characteristics.

2. The method for preparing a Prussian blue nanomaterial having NIR-Ⅱ absorption characteristics according to claim 1, characterized in that: The ferrocyanide salt in step S1 includes any one of potassium ferrocyanide, potassium ferrocyanide, sodium ferrocyanide, and sodium ferrocyanide.

3. The method for preparing a Prussian blue nanomaterial having NIR-Ⅱ absorption characteristics according to claim 1, characterized in that: The pH of the dilute acid solution in step S1 is 6-8, including any one of hydrochloric acid, sulfuric acid, acetic acid, and citric acid.

4. The method for preparing a Prussian blue nanomaterial having NIR-Ⅱ absorption characteristics according to claim 1, characterized in that: The mass volume ratio of melanin (water-soluble), ferrocyanide salt and dilute acid solution in step S1 is (10 mg 200 mg): (10 mg 200 mg): (3 mL-100 mL); The frequency of the ultrasonic dispersion is 25 kHz-80 kHz, and the time of the ultrasonic dispersion is 10-60 min.

5. The method for preparing a Prussian blue nanomaterial having NIR-Ⅱ absorption characteristics according to claim 1, characterized in that: The mass of the polyvinyl pyrrolidone in step S2 is 0.2-0.6 g.

6. A functionalized Prussian blue nanomaterial having near-infrared second-zone light absorption characteristics prepared by the method described in claim 1 and applied to NIR-ⅡPA / PTT.

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