Preparation method for CT (computed tomography) contrast media based on second-generation polyamide-amine dendrimer/gold nanoparticles

Abstract

The invention relates to a preparation method for a CT (computed tomography) contrast media based on the second-generation polyamide-amine dendrimer / gold nanoparticles. The preparation method comprises the following steps of: weighing the second-generation polyamide-amine dendrimers with tail ends which are amino groups in aqueous solution, adding chloroauric acid solution in a water-bath condition, and magnetically stirring and reacting for 3 hours; cooling at a room temperature and then performing acetylation treatment; dialyzing the solution after the reaction, performing freeze-drying treatment to obtain a final product; and evaluating the in-vivo and in-vitro CT contrast performances of the product. The product prepared by the preparation method disclosed by the invention is simple and environment-friendly in preparation process, good in stability and cytocompatibility, and capable of showing a good in-vivo CT contrast effect.

Description

technical field

[0001] The invention belongs to the biomedical application field of nanoparticles, in particular to a preparation method of a CT contrast agent based on second-generation polyamide-amine dendrimers / gold nanoparticles. Background technique

[0002] CT (computed tomography) technology has become one of the most widely used molecular imaging methods because of its excellent spatial and density resolution, and is widely used in clinical practice. Although it has a good imaging effect on bone tissue, the application of CT technology to various organs and other soft tissues is quite limited. In the specific use process, the assistance of contrast agent is often required. Most of the contrast agents currently used clinically are iodine-based small molecule contrast agents. This contrast agent has disadvantages such as short circulation time in the body and potential renal toxicity. Therefore, it is necessary to develop new contrast agents. To date, the developme...

Examples

Embodiment 1

[0049] Take HAuCl 4 50mg, dissolved in distilled water, magnetic shock to fully dissolve it evenly, and prepare a solution with a concentration of 30mg / mL. Take the second generation polyamide-amine dendrimers (G2.NH 2 ) 162.97mg, dissolved in 16mL distilled water, and magnetically oscillated to fully dissolve and evenly. The solution was preheated in a 60 °C water bath for 20 min. Take HAuCl 4 Add 2.061mL of the solution into the preheated dendrimer solution. The temperature was maintained at 60° C., and the reaction was stirred by magnetic force for 3.0 h. After the reaction, the resulting solution was dialyzed against distilled water (6 times, 2 L / time). Then freeze-dry to obtain dendrimers / gold nanoparticles before acetylation, and store at -20°C.

[0050] The UV-Vis test results show that the absorption peak in the spectrum is located at 521nm (attached figure 2 ). This indicates that gold nanoparticles were successfully prepared in the system. TEM test results ...

Embodiment 2

[0052] Get the dendrimer / gold nanoparticle solution (G2.NH 2 , 74.48mg), cooled at room temperature for 1h. Add 308.7μL of triethylamine and stir for 0.5h. After that, 174.7 μL of acetic anhydride was added, and the reaction was stirred for 24 h. After the reaction, the reaction mixture was dialyzed with PBS buffer (3 times, 2L / time) and distilled water (3 times, 2L / time), and then freeze-dried to obtain the acetylated dendrimer / gold Nanoparticles, stored at -20°C.

[0053] 1 The results of the H NMR spectrum showed that the peak of acetylmethyl group (1.87ppm) appeared after the acetylation reaction, indicating that the acetylation reaction was successfully carried out (attached figure 1 ). The UV-Vis test results show that the absorption peak in the spectrum is located at 521nm (attached figure 2 ). This indicates that after acetylation, the size of gold nanoparticles does not change significantly. TEM test results show that: the size distribution of the prepared go...

Embodiment 3

[0055] The prepared acetylated dendrimers / gold nanoparticles were taken and prepared as a 0.2 mg / mL aqueous solution. Afterwards, adjust its pH (5.0, 6.0, 7.0, 8.0) with 0.1M hydrochloric acid or sodium hydroxide. After standing at room temperature for 20 minutes, carry out the ultraviolet test.

[0056] The prepared acetylated dendrimers / gold nanoparticles were taken and prepared as a 0.2 mg / mL aqueous solution. After that, it was placed under different temperature conditions (4, room temperature 20, 37, 50°C). After half an hour of stabilization, a UV test was performed.

[0057] There is no obvious shift and change in the UV spectrum of the product under different pH (5-8) and temperature (4-50°C) conditions, indicating that it has good stability (attached image 3 ).

technical field

[0001] The invention belongs to the biomedical application field of nanoparticles, in particular to a preparation method of a CT contrast agent based on second-generation polyamide-amine dendrimers / gold nanoparticles. Background technique

[0002] CT (computed tomography) technology has become one of the most widely used molecular imaging methods because of its excellent spatial and density resolution, and is widely used in clinical practice. Although it has a good imaging effect on bone tissue, the application of CT technology to various organs and other soft tissues is quite limited. In the specific use process, the assistance of contrast agent is often required. Most of the contrast agents currently used clinically are iodine-based small molecule contrast agents. This contrast agent has disadvantages such as short circulation time in the body and potential renal toxicity. Therefore, it is necessary to develop new contrast agents. To date, the developme...

Examples

Embodiment 1

[0049] Take HAuCl 4 50mg, dissolved in distilled water, magnetic shock to fully dissolve it evenly, and prepare a solution with a concentration of 30mg / mL. Take the second generation polyamide-amine dendrimers (G2.NH 2 ) 162.97mg, dissolved in 16mL distilled water, and magnetically oscillated to fully dissolve and evenly. The solution was preheated in a 60 °C water bath for 20 min. Take HAuCl 4 Add 2.061mL of the solution into the preheated dendrimer solution. The temperature was maintained at 60° C., and the reaction was stirred by magnetic force for 3.0 h. After the reaction, the resulting solution was dialyzed against distilled water (6 times, 2 L / time). Then freeze-dry to obtain dendrimers / gold nanoparticles before acetylation, and store at -20°C.

[0050] The UV-Vis test results show that the absorption peak in the spectrum is located at 521nm (attached figure 2 ). This indicates that gold nanoparticles were successfully prepared in the system. TEM test results ...

Embodiment 2

[0052] Get the dendrimer / gold nanoparticle solution (G2.NH 2 , 74.48mg), cooled at room temperature for 1h. Add 308.7μL of triethylamine and stir for 0.5h. After that, 174.7 μL of acetic anhydride was added, and the reaction was stirred for 24 h. After the reaction, the reaction mixture was dialyzed with PBS buffer (3 times, 2L / time) and distilled water (3 times, 2L / time), and then freeze-dried to obtain the acetylated dendrimer / gold Nanoparticles, stored at -20°C.

[0053] 1 The results of the H NMR spectrum showed that the peak of acetylmethyl group (1.87ppm) appeared after the acetylation reaction, indicating that the acetylation reaction was successfully carried out (attached figure 1 ). The UV-Vis test results show that the absorption peak in the spectrum is located at 521nm (attached figure 2 ). This indicates that after acetylation, the size of gold nanoparticles does not change significantly. TEM test results show that: the size distribution of the prepared go...

Embodiment 3

[0055] The prepared acetylated dendrimers / gold nanoparticles were taken and prepared as a 0.2 mg / mL aqueous solution. Afterwards, adjust its pH (5.0, 6.0, 7.0, 8.0) with 0.1M hydrochloric acid or sodium hydroxide. After standing at room temperature for 20 minutes, carry out the ultraviolet test.

[0056] The prepared acetylated dendrimers / gold nanoparticles were taken and prepared as a 0.2 mg / mL aqueous solution. After that, it was placed under different temperature conditions (4, room temperature 20, 37, 50°C). After half an hour of stabilization, a UV test was performed.

[0057] There is no obvious shift and change in the UV spectrum of the product under different pH (5-8) and temperature (4-50°C) conditions, indicating that it has good stability (attached image 3 ).

Images