Chiral gold nanorod with core-shell structure, preparation method of chiral gold nanorod and application of chiral gold nanorod in medicine preparation

Abstract

The invention discloses a chiral gold nanorod with a core-shell structure, a preparation method of the chiral gold nanorod and application of the chiral gold nanorod to preparation of drugs, the chiral gold nanorod takes an achiral gold nanorod as a core, takes one or more of 1, 1 '-co-2-naphthylamine, 1, 1'-co-2-naphthol and 2, 2 '-binaphthalene as chiral ligands, and takes one or more of 1, 1'-co-2-naphthylamine, 1, 1 '-co-2-naphthol and 2, 2'-binaphthalene as the core to prepare the chiral gold nanorod with the core-shell structure. And forming chiral micelles with hexadecyl trimethyl ammonium chloride, and inducing secondary growth of gold to synthesize the chiral gold nanorod with a core-shell structure. The chiral gold nanorod is used for preparing a medicine for treating mouse in-situ glioblastoma, and the transfer of glioblastoma cells in the brain can be inhibited by performing tail intravenous injection administration on the chiral gold nanorod, so that diseases are improved.

Description

Technical Field

[0001] This invention relates to the field of biomedical materials technology, specifically to a chiral gold nanorod with a core-shell structure, its preparation method, and its application in drug preparation. Background Technology

[0002] Glioblastoma is the most common and aggressive primary malignant brain tumor in adults. Originating from glial cells in the brain, particularly astrocytes, its malignant characteristics include high cell proliferation, abnormally vigorous angiogenesis, and extremely invasive growth. Tumor cells rapidly spread and infiltrate surrounding brain tissue, blurring the boundaries with normal brain tissue, making complete surgical resection difficult. Furthermore, its high heterogeneity, with significant differences in genetics and 12-24 phenotypes among different tumor cells, makes treatment exceptionally challenging and results in a very high recurrence rate.

[0003] The current standard treatment for glioblastoma is a comprehensive approach based on maximal and safe surgical resection, combined with postoperative radiotherapy and concurrent chemoradiotherapy with temozolomide and adjuvant chemotherapy. The primary goal of surgery is to remove as much tumor tissue as possible while preserving vital neurological function to the greatest extent possible. However, due to the invasive nature of the tumor, complete resection is almost impossible, and postoperative imaging often shows residual tumor cells. Therefore, radiotherapy follows, targeting the tumor bed and surrounding potentially infiltrated areas to kill any remaining cancer cells. The chemotherapy drug temozolomide, because it can cross the blood-brain barrier, can be administered concurrently with radiotherapy for six cycles of adjuvant chemotherapy.

[0004] Despite aggressive multimodal treatment, the prognosis for glioblastoma remains very poor, ranking among the worst-prognostic cancers. The median survival is approximately 15 to 18 months, with only about 5% of patients surviving for more than 5 years.

[0005] Nanomedicine is one of the core applications of nanotechnology in the medical field, offering revolutionary solutions to many bottlenecks in glioblastoma treatment. Current research indicates that glioma development is accompanied by abnormal metabolism of chiral amino acid molecules in vivo; therefore, exploring the regulatory effects of chiral nanomedicines on glioblastoma presents new opportunities for its treatment. The synthesis of chiral gold nanomaterials is complex, and the chiral signals of most chiral gold nanorods are concentrated in the visible light region (400-780 nm), which is not conducive to further therapeutic applications in the near-infrared biological window (700-1700 nm). Furthermore, the electrical charge on the surface of traditional gold makes it somewhat biotoxic, posing significant risks for in vivo application. Summary of the Invention

[0006] The purpose of this invention is to provide a chiral gold nanorod with a core-shell structure, its preparation method, and its application in drug preparation. The chiral gold nanorod with a core-shell structure can be used to prepare a drug for treating glioblastoma in situ in mice.

[0007] In one aspect of the invention, a method for preparing chiral gold nanorods with a core-shell structure is provided. According to an embodiment of the invention, using a non-chiral gold nanorod as the core and at least one of 1,1'-bi-2-naphthylamine, 1,1'-bi-2-naphthol, and 2,2'-bidinaphthalene as a chiral ligand, chiral gold nanorods with a core-shell structure are synthesized by inducing secondary growth of gold through the formation of chiral micelles with hexadecyltrimethylammonium chloride.

[0008] In addition, the method for preparing a chiral gold nanorod with a core-shell structure according to the above embodiments of the present invention may also have the following additional technical features:

[0009] In some embodiments of the present invention, the preparation method of the non-chiral gold nanorods includes the following steps:

[0010] (1) Sodium borohydride solution was injected into a mixed solution of chloroauric acid and hexadecyltrimethylammonium bromide to react and obtain a small gold seed solution;

[0011] (2) Dissolve hexadecyltrimethylammonium bromide and sodium oleate in water, add silver nitrate solution, react at 30°C for 10-30 min, add chloroauric acid aqueous solution, adjust pH value after reacting for a period of time, then inject ascorbic acid solution, and finally add small gold seed solution to obtain non-chiral gold nanorods.

[0012] In some embodiments of the present invention, in step (1), the concentration ratio of chloroauric acid, hexadecyltrimethylammonium bromide, and sodium borohydride is (1-2):(200-500):(150-300); the reaction time is 2-30 min; wherein, chloroauric acid provides the gold source; hexadecyltrimethylammonium bromide acts as a surfactant to stabilize the reaction system; and sodium borohydride acts as a reducing agent to reduce the trivalent gold ions in chloroauric acid to the 0-valent state.

[0013] In step (2), the molar ratio of hexadecyltrimethylammonium bromide, sodium oleate, silver nitrate, ascorbic acid solution, and chloroauric acid aqueous solution is (180-360):(40-60):(10-15):(1-2):(1-2), and the volume of gold seed solution added is 0.1-2 mL / 500 mL of the reaction system; the reaction time is 24-48 h; the pH is adjusted using hydrochloric acid to adjust the pH to 0.8-2. The hexadecyltrimethylammonium bromide and sodium oleate dual surfactants stabilize the reaction system and assist in the anisotropic growth of gold nanorods; silver nitrate can induce the anisotropic growth of gold nanorods; hydrochloric acid can adjust the pH of the reaction system, thereby adjusting the aspect ratio of the gold rods; ascorbic acid is a reducing agent that can reduce the trivalent gold ions in chloroauric acid to the 0-valent state.

[0014] In some embodiments of the present invention, the diameter of the achiral gold nanorod core is 5-25 nm and the length is 60-120 nm; the transverse and longitudinal plasmon resonance absorption characteristic peaks of the achiral gold nanorod core are located at 500-600 nm and 700-1000 nm, respectively.

[0015] In some embodiments of the present invention, the preparation method is as follows: chloroauric acid aqueous solution is added to a mixed solution of chiral ligand (concentration of 2.5 mM) and hexadecyltrimethylammonium chloride (concentration of 100 mM), ultrapure water is added to adjust the solution concentration, then achiral gold nanorods are added, and then ascorbic acid is added to react and synthesize chiral gold nanorods with a core-shell structure.

[0016] In some embodiments of the present invention, the molar ratio of chloroauric acid, chiral ligand, hexadecyltrimethylammonium chloride, and ascorbic acid is (1-2):(1-2):(20-80):(300-330), and the amount of achiral gold nanorods added is 10 μL / 1 mL of reaction volume; the reaction synthesis time is 20-360 min. Chloroauric acid provides the gold source; the chiral ligand induces the helical deposition of gold atoms on the surface of the achiral gold nanorods, thereby generating a chiral signal; hexadecyltrimethylammonium chloride acts as a surfactant to stabilize the reaction system and, together with the chiral ligand, forms chiral micelles that induce the helical deposition of gold atoms on the surface of the achiral gold nanorods; the achiral gold nanorods provide sites for gold atom deposition; and ascorbic acid acts as a reducing agent to reduce the trivalent gold ions in chloroauric acid to 0-valent gold atoms.

[0017] In another aspect of the invention, a method for preparing chiral gold nanorods with a core-shell structure is proposed. Using achiral gold nanorods as the core, chiral micelles are formed at high concentrations by the chiral ligands required by this invention and hexadecyltrimethylammonium chloride, inducing gold atoms to grow in a helical morphology within the achiral gold nanorods. The chiral gold nanorods obtained by this method exhibit extremely strong chiral optical activity (i.e., circular dichroism signal). Compared to previously reported chiral gold nanorod particles, due to their long-range plasmon resonance effect, their chiral optical activity extends to the near-infrared I and near-infrared II regions, which are the biotherapeutic windows. This is beneficial for exploring the interaction between chiral structures and living organisms, and further exploring their effects in disease diagnosis and treatment.

[0018] In addition, the chiral gold nanorods with a core-shell structure according to the above embodiments of the present invention may also have the following additional technical features:

[0019] In some embodiments of the present invention, the chiral gold nanorod core has a diameter of 30-60 nm and a length of 100-200 nm. The absorption characteristic peak of the chiral gold nanorod is located at 550-1000 nm, and the chiral characteristic peak is located at 500-1250 nm.

[0020] In another aspect of the invention, the application of chiral gold nanorods with a core-shell structure is proposed. According to an embodiment of the invention, the chiral gold nanorods with a core-shell structure are used to prepare a drug for treating glioblastoma in situ in mice.

[0021] Furthermore, the application of chiral gold nanorods with a core-shell structure according to the above embodiments of the present invention may also have the following additional technical features:

[0022] In some embodiments of the present invention, the chiral gold nanorods with the core-shell structure are incubated in a methoxy-mercapto-polyethylene glycol solution (37°C, 300 rpm for 3 hours) to obtain a drug for treating glioblastoma in situ in mice. Surface modification of the chiral gold nanorods with methoxy-polyethylene glycol-mercapto groups can reduce their surface charge, thereby reducing their adsorption in vivo and improving their biocompatibility. Furthermore, because methoxy-polyethylene glycol-mercapto groups have excellent shape-preserving properties, they do not affect the chiral optical activity of the chiral gold nanorods due to their helical morphology.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] (1) This invention uses achiral gold nanorods as the core, and induces gold atoms to grow in a helical morphology within the achiral gold nanorods by forming chiral micelles with chiral ligands and hexadecyltrimethylammonium chloride at high concentrations. Due to the unique long-range plasmon resonance effect of gold nanorods, plasmon resonance signals can be generated in a longer wavelength range. Furthermore, the growth of helical chiral wrinkles on the gold nanorods extends the chiral signal of the chiral gold nanorods to the near-infrared I region of the biotherapy window, which is beneficial for subsequent biological applications.

[0025] (2) In this invention, the surface of chiral gold nanorods is modified by methoxy polyethylene glycol-thiol, which reduces the surface charge of the chiral gold nanorods, thereby reducing the biotoxicity of the chiral gold nanorods and improving their biocompatibility, which is beneficial for the subsequent exploration of their in vivo applications. Attached Figure Description

[0026] Figure 1 This is a transmission electron microscope image of the non-chiral gold nanorods in Example 1 of the present invention;

[0027] Figure 2 This is a molecular structure diagram of the chiral ligand ((R)-(+)-1,1'-bi-2-naphthylamine) in Example 1 of the present invention;

[0028] Figure 3 This is a transmission electron microscope image of the chiral gold nanorods in Example 1 of the present invention;

[0029] Figure 4 This is a scanning electron microscope image of the chiral gold nanorods in Example 1 of the present invention;

[0030] Figure 5 The circular dichroism spectrum and ultraviolet-visible-near-infrared extinction spectrum of the chiral gold nanorods in Example 1 of this invention are shown below.

[0031] Figure 6 This is a graph showing the surface potential changes of chiral gold nanorods before and after treatment with methoxy-mercapto-polyethylene glycol in Application Example 1 of this invention.

[0032] Figure 7 This is a schematic diagram of the process for treating mouse glioblastoma with chiral gold nanorods in Example 1 of the present invention.

[0033] Figure 8 This is an in vivo fluorescence imaging of the glioma model mice used in Example 1 of this invention;

[0034] Figure 9The images shown are representative brain tissue staining images of mice in the experimental group (right image: treated with chiral gold nanorods dispersed in phosphate buffer solution as a therapeutic drug) and the control group (left image: not treated with chiral gold nanorods, but only injected with phosphate buffer solution via the tail vein) after 10 days of treatment with chiral gold nanorods in Example 1 of this invention. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] A method for preparing chiral gold nanorods with a core-shell structure includes the following steps:

[0038] (1) Inject 0.6 mL of freshly prepared 0.01 mol / L sodium borohydride solution into a 10 mL mixed solution of chloroauric acid (0.25 mM) and hexadecyltrimethylammonium bromide (0.1 M), and continue the reaction for 60 min to prepare the small gold seed solution.

[0039] (2) Dissolve 7.0 g of hexadecyltrimethylammonium bromide and 1.234 g of sodium oleate in 250 mL of water, and add 24 mL of 4 mmol / L silver nitrate solution. After the solution becomes colorless, add 3.6 mL of hydrochloric acid to adjust the pH value, and then add 1.25 mL of 0.064 mol / L ascorbic acid solution. Finally, add 0.4 mL of gold seed solution to the growth solution obtained by mixing the above solutions. Continue the reaction for 48 h to obtain chiral gold nanorod seeds.

[0040] like Figure 1 As shown, the non-chiral gold nanorod seeds have uniform size and good dispersibility.

[0041] (3) Add 1 mL of 5 mmol / L chloroauric acid solution to a mixed solution of chiral (R)-(+)-1,1'-bi-2-naphthylamine and hexadecyltrimethylammonium chloride, then add 1 mL of non-chiral gold nanorod seeds, and then add 0.4 mL of 0.8 mol / L ascorbic acid to synthesize chiral gold nanorods with a core-shell structure.

[0042] like Figure 3-4 As shown, the surface of chiral gold nanorods with a core-shell structure exhibits distinct chiral wrinkles. Figure 5As shown, chiral gold nanorods with a core-shell structure exhibit strong chiral optical activity in the visible-near-infrared spectral range.

[0043] Example 2

[0044] A method for preparing chiral gold nanorods with a core-shell structure includes the following steps:

[0045] (1) Inject 0.6 mL of freshly prepared 0.01 mol / L sodium borohydride solution into a 10 mL mixed solution of chloroauric acid (0.25 mM) and hexadecyltrimethylammonium bromide (0.1 M), and continue the reaction for 60 min to prepare the small gold seed solution.

[0046] (2) Dissolve 7.0 g of hexadecyltrimethylammonium bromide and 1.234 g of sodium oleate in 250 mL of water, and add 24 mL of 4 mmol / L silver nitrate solution. After the solution becomes colorless, add 3.6 mL of hydrochloric acid to adjust the pH value, and then add 1.25 mL of 0.064 mol / L ascorbic acid solution. Finally, add 0.4 mL of gold seed solution to the growth solution obtained by mixing the above solutions. Continue the reaction for 48 h to obtain chiral gold nanorod seeds.

[0047] like Figure 1 As shown, the non-chiral gold nanorod seeds have uniform size and good dispersibility.

[0048] (3) Add 1 mL of 5 mmol / L chloroauric acid solution to a mixed solution of chiral (S)-(-)-1,1'-bi-2-naphthylamine and hexadecyltrimethylammonium chloride, then add 1 mL of non-chiral gold nanorod seeds, and then add 0.4 mL of 0.8 mol / L ascorbic acid to synthesize chiral gold nanorods with a core-shell structure.

[0049] Example 3

[0050] A method for preparing chiral gold nanorods with a core-shell structure includes the following steps:

[0051] (1) Inject 0.6 mL of freshly prepared 0.01 mol / L sodium borohydride solution into a 10 mL mixed solution of chloroauric acid (0.25 mM) and hexadecyltrimethylammonium bromide (0.1 M), and continue the reaction for 60 min to prepare the small gold seed solution.

[0052] (2) Dissolve 7.0 g of hexadecyltrimethylammonium bromide and 1.234 g of sodium oleate in 250 mL of water, and add 24 mL of 4 mmol / L silver nitrate solution. After the solution becomes colorless, add 3.6 mL of hydrochloric acid to adjust the pH value, and then add 1.25 mL of 0.064 mol / L ascorbic acid solution. Finally, add 0.4 mL of gold seed solution to the growth solution obtained by mixing the above solutions. Continue the reaction for 48 h to obtain chiral gold nanorod seeds.

[0053] like Figure 1 As shown, the non-chiral gold nanorod seeds have uniform size and good dispersibility.

[0054] (3) Add 1 mL of 5 mmol / L chloroauric acid solution to a mixed solution of (R)-(+)-1,1'-bi-2-naphthol and hexadecyltrimethylammonium chloride, then add 1 mL of non-chiral gold nanorod seeds, and then add 0.4 mL of 0.8 mol / L ascorbic acid to synthesize chiral gold nanorods with a core-shell structure.

[0055] Application Example 1

[0056] A method for preparing chiral gold nanorod drugs includes the following steps:

[0057] The 1 ml of chiral gold nanorods with a core-shell structure prepared in Example 1 was centrifuged, the supernatant was removed, and the nanorods were redispersed in a 20 mmol / L methoxy polyethylene glycol-thiol solution for biocompatibility treatment. The nanorods were shaken at 300 rpm for 3 hours at 37°C to obtain the chiral gold nanorod drug.

[0058] The surface potential changes of chiral gold nanorods before and after treatment with methoxy polyethylene glycol-thiol solution (obtained using a Malvern Zetasizer Nano ZS90 instrument). Figure 6 As shown, the surface potential decreased significantly after treatment, indicating that the biotoxicity of the chiral gold nanorod drug was significantly reduced after polyethylene glycol treatment, demonstrating good biocompatibility, which is beneficial for subsequent in vivo treatment.

[0059] Orthotopic glioma modeling was established by implanting glioblastoma cells (GL261-Luc-GFP cells) into the brains of mice using stereotactic localization technology. Figure 8 In vivo fluorescence imaging of mice used to create an orthotopic glioblastoma model. (Example:) Figure 7As shown, 0.5 mL of the chiral gold nanorod drug synthesized in Example 2 (redispersed in standard concentration PBS phosphate buffer solution after centrifugation) was injected via the tail vein 14 days after modeling. Mice were euthanized 26 days after modeling, and relevant tissues were extracted and embedded for subsequent analysis. A control group was set up, which received a 1 mol / L standard phosphate buffer solution only via the tail vein.

[0060] Mouse brain tissue was extracted, embedded, and sectioned. Hematoxylin-eosin staining was used for staining analysis. Tumor cells showed deeper staining due to their enlarged nuclei and increased nucleocytoplasmic ratio. Figure 9 The images show the staining results of brain tissue sections from mice treated with chiral gold nanorods (left) and mice treated with chiral gold nanorods (right). The results show that the metastasis of glioblastoma in the brain tissue of mice treated with chiral gold nanorods was greatly reduced, indicating that the prepared chiral gold nanorods have a significant therapeutic effect in inhibiting the metastasis of glioblastoma in situ in mice.

[0061] In conclusion, tail vein injection of chiral gold nanorods can reduce the metastasis of glioblastoma in situ in the brain of mice, thus achieving a therapeutic effect.

[0062] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the present invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A method for preparing chiral gold nanorods with core-shell structure, characterized in that: The preparation method of the non-chiral gold nanorod comprises the following steps:

2. The method for preparing a chiral gold nanorod with a core-shell structure according to claim 1, characterized in that, (1) injecting sodium borohydride solution into the mixed solution of chloroauric acid and cetyltrimethylammonium bromide to obtain small gold seed solution; (2) dissolving cetyltrimethylammonium bromide and sodium oleate in water, adding silver nitrate solution, and then adding aqueous chloroauric acid solution after 10-30 min, adjusting pH value after a period of reaction, then injecting ascorbic acid solution, and finally adding small gold seed solution to continuously react to obtain non-chiral gold nanorod.

3. The preparation method of the chiral gold nanorod with core-shell structure according to claim 2, characterized in that: In step (1), the concentration ratio of chloroauric acid, cetyltrimethylammonium bromide and sodium borohydride is (1-2):(200-500):(150-300); and the reaction time is 2-30 min. In step (2), the molar ratio of cetyltrimethylammonium bromide, sodium oleate, silver nitrate, ascorbic acid solution and aqueous chloroauric acid solution is (180-360):(40-60):(10-15):(1-2):(1-2), the volume of the small gold seed solution added is 0.1-2 mL / 500 mL reaction system; the reaction time is 24-48 h; and the pH value is adjusted to 0.8-2 using hydrochloric acid. The diameter of the non-chiral gold nanorod core is 5-25 nm, and the length is 60-120 nm; and the transverse and longitudinal plasmon resonance absorption characteristic peaks of the non-chiral gold nanorod core are located at 500-600 nm and 700-1000 nm, respectively.

4. The method for preparing a chiral gold nanorod with a core-shell structure according to claim 1, characterized in that: The preparation method is as follows: adding aqueous chloroauric acid solution into the mixed solution of chiral ligand and cetyltrimethylammonium chloride, adding ultrapure water to adjust the concentration of the solution, then adding non-chiral gold nanorod, and then adding ascorbic acid to react and synthesize chiral gold nanorod with core-shell structure.

5. The method for preparing a chiral gold nanorod with a core-shell structure according to claim 1, characterized in that, The molar ratio of chloroauric acid, chiral ligand, cetyltrimethylammonium chloride and ascorbic acid is (1-2):(1-2):(20-80):(300-330), and the amount of non-chiral gold nanorod added is 10 μL / 1 mL reaction volume; and the reaction synthesis time is 20-360 min.

6. The method for preparing a chiral gold nanorod with a core-shell structure according to claim 5, characterized in that:

7. The chiral gold nanorod with core-shell structure prepared by the preparation method of any one of claims 1-6. The diameter of the chiral gold nanorod core is 30-60 nm, and the length is 100-200 nm; and the absorption characteristic peak of the chiral gold nanorod is located at 550-1000 nm, and the chiral characteristic peak is located at 500-1250 nm.

8. The chiral gold nanorod with core-shell structure according to claim 7, characterized in that: The chiral gold nanorod with core-shell structure is used for preparing a drug for treating mouse orthotopic glioblastoma.

9. Use of chiral gold nanorods with core-shell structure according to claim 7, characterized in that: ​ 10. Use of chiral gold nanorods with core-shell structure according to claim 9, characterized in that: The chiral gold nanorod with core-shell structure is incubated in methoxy-mercapto polyethylene glycol solution to obtain a drug for treating mouse in-situ glioblastoma.

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