A method for regulating β-amyloid protein aggregation based on circularly polarized light and its application

Abstract

This invention discloses a method for regulating β-amyloid protein aggregation based on circularly polarized light and its application. The method includes electrostatically binding an amino-modified upconversion luminescent nanoparticle to a SiO2-coated chiral optically active nanostructure to obtain an upconversion chiral nanomaterial; coating the surface of the upconversion chiral nanomaterial with a biocompatible coating and a brain-targeting ligand, then mixing it with β-amyloid protein, and targeting the region with 5–100 mW / cm² light. 2 Irradiation with an 800–1400 nm laser for 15–30 min excites upconversion chiral nanomaterials to emit circularly polarized light. This circularly polarized light inhibits the aggregation of β-amyloid protein by interfering with the formation of its β-sheet conformation. This invention utilizes circularly polarized light (CPL) to induce changes in key protein site interactions, thereby altering the conformation of protein aggregation. This process is reversible and highly spatially selective. Animal experiments have verified that this method can effectively block Aβ aggregation and improve cognitive function.

Description

Technical Field

[0001] This invention belongs to the field of protein conformation regulation technology, specifically involving a method for regulating β-amyloid protein aggregation based on circularly polarized light and its application. Background Technology

[0002] The aggregation process of β-amyloid (Aβ) fibers typically involves three stages: (1) amyloid precursor protein (APP) is cleaved by β and γ secretases to generate Aβ monomers; (2) Aβ monomers form prepolymers with β-sheet structures through intermolecular interactions; (3) the prepolymers further aggregate into Aβ fibers and are deposited outside nerve cells, inducing neurotoxicity and loss of function.

[0003] Current strategies for regulating Aβ aggregation include: (1) inhibiting Aβ monomer generation through BACE1 or γ-secretase inhibitors; (2) intervening in the Aβ monomer / prepolymer aggregation process or promoting the degradation of existing fibers using small molecules, antibodies, etc.; (3) using neuroprotective agents to block secondary damage caused by Aβ aggregation; and (4) combined strategies such as immune clearance. However, these approaches are difficult to fundamentally prevent the pathological aggregation process of Aβ, and they have low selectivity and drug toxicity. Therefore, there is an urgent need to explore novel intervention methods. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of the invention, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0006] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for regulating β-amyloid protein aggregation based on circularly polarized light.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] By electrostatically bonding SiO2-coated chiral optically active nanostructures with amino-modified upconversion luminescent nanoparticles, upconversion chiral nanomaterials can be obtained.

[0009] After coating the surface of upconversion chiral nanomaterials with a biocompatible coating and brain-targeting ligands, they were mixed with β-amyloid protein and targeted at the region at a concentration of 5–100 mW / cm². 2Irradiation with an 800–1400 nm laser for 15–30 min excites upconversion chiral nanomaterials to emit circularly polarized light. The circularly polarized light inhibits the aggregation of β-amyloid protein by interfering with the formation of the β-sheet conformation.

[0010] As a preferred embodiment of the method for regulating β-amyloid protein aggregation based on circularly polarized light described in this invention, the upconversion luminescent nanoparticles emit ultraviolet or visible light with a wavelength of 280-700 nm when excited by near-infrared light with a wavelength of 800-1100 nm.

[0011] As a preferred embodiment of the method for regulating β-amyloid protein aggregation based on circularly polarized light according to the present invention, wherein the chiral optically active nanostructure modulates the emitted light into either left-handed or right-handed circularly polarized light.

[0012] As a preferred embodiment of the method for regulating β-amyloid protein aggregation based on circularly polarized light according to the present invention, the chiral optically active nanostructure includes one of a plasma nanostructure with chiral signal and an upconversion nanoparticle with chiral signal.

[0013] As a preferred embodiment of the method for regulating β-amyloid protein aggregation based on circularly polarized light according to the present invention, the plasma nanostructure with chiral signal includes one of gold, silver, platinum, palladium, and copper.

[0014] As a preferred embodiment of the method for regulating β-amyloid protein aggregation based on circularly polarized light described in this invention, wherein the upconversion luminescent nanoparticles comprise NaYF4:Yb 3+ / Tm 3+ NaYF4:Yb 3+ / Er 3+ NaYF4:Yb 3+ / Ho 3+ NaGdF4:Yb 3+ / Tm 3+ NaGdF4:Yb 3+ / Er 3+ NaGdF4:Yb 3+ / Ho 3+ 、LiYF4:Yb 3+ / Tm 3+ 、LiYF4:Yb 3+ / Er 3+ 、LiYF4:Yb 3+ / Ho 3+ Y2O3:Yb 3+ / Tm 3+ Y2O3:Yb 3+ / Er 3+ Y2O3:Yb 3+ / Ho 3+ NaLuF4:Yb 3+ / Tm 3+ NaLuF4:Yb 3+ / Er 3+ NaLuF4:Yb 3+ / Ho 3+ .

[0015] As a preferred embodiment of the method for regulating β-amyloid protein aggregation based on circularly polarized light described in this invention, the upconversion luminescent nanoparticles further include NaYF4:Yb 3+ / Tm 3+ NaYF4:Yb 3+ / Er 3+ NaYF4:Yb 3+ / Ho 3 + NaGdF4:Yb 3+ / Tm 3+ NaGdF4:Yb 3+ / Er 3+ NaGdF4:Yb 3+ / Ho 3+ 、LiYF4:Yb 3+ / Tm 3+ 、LiYF4:Yb 3+ / Er 3+ 、LiYF4:Yb 3+ / Ho 3+ Y2O3:Yb 3+ / Tm 3+ Y2O3:Yb 3+ / Er 3+ Y2O3:Yb 3+ / Ho 3+ NaLuF4:Yb 3+ / Tm 3+ NaLuF4:Yb 3+ / Er 3+ NaLuF4:Yb 3+ / Ho 3+ One type is the kernel-shell structure.

[0016] As a preferred embodiment of the method for regulating β-amyloid protein aggregation based on circularly polarized light according to the present invention, wherein: the biocompatible coating includes one of polyethylene glycol, polydopamine, and cell membrane camouflage coating; the polyethylene glycol has a content of 2000-20000 Da; the polydopamine has a thickness of 5-50 nm when used as a biocompatible coating; and the cell membrane camouflage coating includes one of erythrocyte membrane and neutrophil membrane.

[0017] As a preferred embodiment of the method for regulating β-amyloid aggregation based on circularly polarized light according to the present invention, the brain-targeting ligand includes one or more of the following: a transferrin receptor TfR antibody, a transferrin receptor TfR antibody fragment, angiopep-2 peptide, an ApoE mimic peptide, and neutrophil membrane; the sequence of the angiopep-2 peptide is TFFYGGSRGKRNNFKTEEY; and the sequence of the ApoE mimic peptide is LRKLRKRLL.

[0018] Another objective of this invention is to overcome the shortcomings of the prior art and provide an application of a method for regulating β-amyloid protein aggregation based on circularly polarized light in the treatment of Alzheimer's disease.

[0019] Beneficial effects of this invention:

[0020] (1) This invention achieves efficient circularly polarized light (CPL) generation through upconversion excitation and chiral nanostructures, improving the precision and safety of light intervention. The upconversion luminescent core can emit ultraviolet or visible light with a wavelength of 280-700nm under near-infrared light excitation with a wavelength of 800-1100nm. The chiral optically active structure is used to modulate the emitted light into left-handed circularly polarized light (L-CPL) or right-handed circularly polarized light (R-CPL). The biocompatible coating and brain-targeting ligand on the surface are used to improve the stability and brain accumulation capacity in vivo. Near-infrared light with a wavelength of 800-1400nm is applied to the target area to excite the nanofunctional material to emit circularly polarized light. The circularly polarized light interferes with the β-sheet conformation of Aβ peptide, ultimately inhibiting its aggregation and reducing neurotoxicity.

[0021] (2) Unlike existing small molecule or antibody pathways, this invention provides a novel, non-drug-based treatment approach for Alzheimer's disease; animal experiments have verified that this method can effectively block Aβ aggregation and improve cognitive function.

[0022] (3) Circularly polarized light (CPL) can be used to induce changes in the interaction of key protein sites, thereby altering the conformation of protein aggregation. This process is reversible and highly spatially selective. By adjusting the chirality (L / D type) and wavelength of circularly polarized light (CPL), it can be adapted to different protein aggregation systems (such as the K18 fragment of Tau protein and the NAC region of α-synuclein). Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is the circular dichroism spectrum of the Aβ secondary structure corresponding to the chiral change of amino acids in this invention.

[0025] Figure 2 This is the circular dichroism spectrum of the Aβ second-order structure after irradiation with circularly polarized light of different wavelengths in this invention.

[0026] Figure 3 The images show the morphology (A) of the chiral helical gold nanoparticles (LH-GNRs and DH-GNRs) prepared in Example 1 and Comparative Example 1 of this invention, the circular dichroism (CD) of LH-GNRs and DH-GNRs (B), and their corresponding asymmetry factor spectra (C).

[0027] Figure 4 The upconversion luminescent nanoparticles NaGdF4:Yb prepared in Example 1 of this invention 3+ / Er 3+ TEM image of the NaYF4 core-shell structured nanoparticles.

[0028] Figure 5 The NaGdF4:Yb in Embodiment 1 of the present invention 3+ / Er 3+ Fluorescence spectra of @NaYF4 core-shell nanoparticles under laser excitation at 808 nm and 980 nm.

[0029] Figure 6 TEM images (A) and (B) of the SiO2-coated chiral helical gold nanoparticles prepared in Example 1 and Comparative Example 1 of this invention, respectively.

[0030] Figure 7 The fluorescence emission spectra of the upconversion chiral nanomaterials prepared in Example 1 and Comparative Example 1 of this invention under 808 nm laser excitation are shown.

[0031] Figure 8 The images show circular dichroisms of the Aβ1-42 aggregates in Examples 2 and 2-4 of this invention.

[0032] Figure 9 The images show the ThT fluorescence detection spectra of Aβ1-42 aggregates in Examples 2 and 2-4 of this invention.

[0033] Figure 10 These are TEM images of the Aβ1-42 aggregation state in Embodiment 2, Comparative Example 2, and Comparative Examples 4-5 of the present invention.

[0034] Figure 11 These are fluorescence microscopy images of nerve cells in Example 3 and Comparative Examples 6-7 of the present invention.

[0035] Figure 12 This is a trajectory diagram of the mice in each group searching for the hidden escape platform in Example 4 of the present invention.

[0036] Figure 13 The images show the ThT fluorescence of the hippocampus tissue of mice in each group in Example 4 of this invention. Detailed Implementation

[0037] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0038] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0039] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0040] A preliminary study was conducted to investigate the effect of amino acid chiral changes on the secondary structure of Aβ. Since L-type amino acids gradually transform into D-type amino acids in the cerebrospinal fluid of aged individuals, particularly serine (D-Ser) and aspartic acid (D-Asp), the serine (S) and aspartic acid (D) in Aβ1-42DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGL MVGGVVIA were modified to form D-type amino acids, specifically d-Aβ1-42 (all aspartic acid is D-type), s-Aβ1-42 (all serine is D-type), and ds-Aβ1-42 (all aspartic acid and serine are D-type). These were dissolved in 10 mM Tris-HCl buffer (75 μM concentration), incubated at 37°C for 24 h, and the changes in circular dichroism (CD) were measured. The results are as follows: Figure 1 As shown in the figure, the results indicate that Aβ1-42, with all amino acids in the L-form, still exhibits a significant negative CD signal at 200 nm, suggesting it is mainly composed of disordered monomers. In contrast, the D-form d-Aβ1-42, s-Aβ1-42, and ds-Aβ1-42 all show negative signals at 216 nm and a significant positive signal at 200 nm, characteristic of the β-sheet conformation. This suggests that the chirality of the constituent amino acids significantly influences the aggregation mode of Aβ, and that the D-form amino acids may accelerate their aggregation to form fibrous structures.

[0041] A preliminary study was conducted to investigate the effect of circularly polarized light irradiation of different wavelengths on Aβ aggregation. Lasers of different wavelengths (285 nm, 365 nm, 405 nm, 550 nm, 650 nm) in the ultraviolet-visible region were selected. The unpolarized light was converted into circularly polarized light (CPL) by passing it through a linear polarizer and a quarter-wave plate. Left-handed circularly polarized light (L-CPL) and right-handed circularly polarized light (R-CPL) were obtained by adjusting the fast axis of the quarter-wave plate to -45° and +45° with the polarization direction of the linearly polarized light, respectively. The CPLs of different wavelengths were then interacted with Aβ at a concentration of 100 mW / cm². 2 Irradiation was performed for 15 minutes daily for three consecutive days, and changes in the secondary structure of Aβ were detected using circular dichroism spectroscopy. The results showed that all wavelengths of laser irradiation exhibited characteristic spectra corresponding to the β-sheet conformation, i.e., a positive signal at 200 nm and a negative signal around 216 nm. However, after irradiation with 550 nm R-CPL, the corresponding CD signal was significantly weaker than at other wavelengths. Secondary structure conversion calculations indicated that the Aβ aggregates corresponding to R-CPL irradiation mainly consisted of antiparallel β-sheets and disordered monomers, such as... Figure 2 As shown in the figure, this indicates that different wavelengths of CPL irradiation have different effects on Aβ aggregation, while 550nm R-CPL irradiation inhibits Aβ aggregation, while other wavelengths of CPL promote aggregation to some extent.

[0042] In this invention, the surface potential ζ is obtained by testing the zeta-potential module in a nanoparticle size analyzer.

[0043] Example 1

[0044] This embodiment provides a method for preparing upconversion chiral nanomaterials, specifically:

[0045] (1) Preparation of chiral optically active nanostructures:

[0046] In 10 mL of 0.1 M cetyl ammonium bromide (CTAB) solution, 25 mM chloroauric acid (HAuCl4) was added, and 600 μL of 10 mM NaBH4 was added with stirring to reduce HAuCl4 and prepare a gold seed solution.

[0047] 160 μL of gold seed solution was added to a growth solution containing CTAB (10 mL, 0.1 M), hydroquinone HQ (500 μL, 0.1 M), HAuCl4 (200 μL, 25 mM), and silver nitrate AgNO3 (70 μL, 0.1 M), and the solution was allowed to grow at 30 °C for 12 h to obtain gold nanorods.

[0048] Based on gold nanorods, 60 μL of 10 mM L-cysteine ​​(L-Cys) was added as a chiral inducer under the protection of 10 mM CTAB, followed by HAuCl4 (56 μL, 25 mM), AgNO3 (70 μL, 10 mM), and ascorbic acid AA (32 μL, 0.1 M). After static growth at 70 °C for 1 h, chiral helical gold nanoparticles, namely LH-GNRs, were obtained.

[0049] (2) Preparation of upconversion luminescent nanoparticles:

[0050] GdCl3 (0.78 mmol), YbCl3 (0.2 mmol), and ErCl3 (0.02 mmol) were dissolved in 5 mL of deionized water. 0.5 mL of sodium acetate (1 M) was added as a morphology modifier, and 10 mL of an aqueous solution containing NH4F (4 mmol) and sodium citrate (Na3cit) (0.1 M) was rapidly injected. Under N2 protection, the mixture was heated to 90 °C for dehydration and deoxygenation. The temperature was then increased to 200 °C at a rate of 5 °C / min for a hydrothermal reaction for 3 h to prepare NaGdF4:YbCl3. 3+ / Er 3+ The kernel was washed three times with ethanol and then vacuum dried at 60°C.

[0051] The kernel was dispersed in 5 mL of cyclohexane, 0.2 mL of oleylamine (OAm) was added, and 5 mL of ethanol was slowly added dropwise until turbidity was reached. The mixture was centrifuged to obtain oil-soluble particles, which were then dispersed in 10 mL of octadecene ODE. YCl3 (0.5 mmol) was added, and the mixture was injected into NH4F (0.5 mmol) solution at 280 °C at a rate of 0.5 mL / min for 1 h. The mixture was then rapidly cooled to room temperature to obtain NaGdF4:Yb. 3+ / Er 3+ @NaYF4 core-shell structured nanoparticles.

[0052] (3) Preparation of upconversion chiral nanomaterials:

[0053] Take 0.5 nM of LH-GNRs prepared in step (1), disperse it in 0.75 mM CTAB solution, adjust the pH to 11, add 30 μL of 20% TEOS ethanol solution, react for 0.5 h, and then add the same amount of TEOS solution to react. Add the solution three times in total, stir and react for 24 h, wash with 10 mM NH4NO3 to remove the CTAB template agent, and then wash with ethanol and water multiple times to obtain SiO2-coated chiral helical gold nanoparticles, namely LH-GNRs@SiO2;

[0054] The NaGdF4:Yb prepared in step (2) contains 20 mg of the solution. 3+ / Er 3+ A 5 mL solution of NaYF4 core-shell nanoparticles in cyclohexane was mixed with a 5 mL solution of dichloromethane containing 20 mg of nitronium tetrafluoroborate (NOBF4) at room temperature and gently stirred for 10 min to produce a white precipitate. The precipitate was collected by centrifugation and redispersed in 10 mL of dimethylformamide (DMF) to form a clear solution. 0.2 mmol of aminoethylpyridine (AEP) was added, and the mixture was stirred at room temperature for 60 min. Then, 20 mL of acetone was added to precipitate the precipitate. The precipitate was collected by centrifugation and repeatedly washed with DMF and water to remove excess AEP, yielding amino-modified NaGdF4:Yb 3+ / Er 3+ @NaYF4 core-shell structured nanoparticles;

[0055] 100 μL of amino-modified NaGdF4:Yb 3+ / Er 3+ @NaYF4 core-shell structured nanoparticles were added to 10 mL of LH-GNRs@SiO2 solution and allowed to stand for 1 h to allow electrostatic bonding between the two. Centrifugation yielded upconversion chiral nanomaterials, namely LH-GNRs@SiO2@UCNPs.

[0056] Comparative Example 1

[0057] The difference between this comparative example and Example 1 is that the chiral inducer in step (1) is changed to D-cysteine ​​(D-Cys) to prepare dextrorotatory gold nanoparticles (DH-GNRs). The rest of the preparation process is the same as in Example 1, and the upconversion chiral nanofunctional material DH-GNRs@SiO2@UCNPs of this comparative example is obtained.

[0058] The morphology of the chiral helical gold nanoparticles (LH-GNRs and DH-GNRs) prepared in step (1) of Example 1 and Comparative Example 1 was tested by TEM, and the results are as follows: Figure 3 Figure A shows the helical structure on the material surface. The average length of LH-GNRs is 83.7 nm, and the average cross-sectional diameter is 25.5 nm; the average length of DH-GNRs is 89.5 nm, and the average cross-sectional diameter is 26.1 nm.

[0059] The circular dichroism (CD) spectra of LH-GNRs and DH-GNRs and their corresponding asymmetry factor spectra were tested, and the results are as follows: Figure 3 As shown in B and Figure 3 As shown in Figure C, it can be seen that LH-GNRs and DH-GNRs have obvious CD signals at 540nm and 740nm, indicating that they have circularly polarized light modulation performance near these two wavelengths.

[0060] The upconversion luminescent nanoparticles NaGdF4:Yb prepared in step (2) of Example 1 were tested by TEM. 3+ / Er 3+ The morphology of the @NaYF4 core-shell structured nanoparticles is as follows: Figure 4 As shown in the figure, the particle size of the nanoparticle is 6.5 ± 0.7 nm. Simultaneously, the surface potential ζ of the particle was measured to be -32.8 ± 3.2 mV, which is due to the presence of oleic acid on the particle surface.

[0061] In Test Example 1, NaGdF4:Yb 3+ / Er 3+ Fluorescence spectra of @NaYF4 core-shell structured nanoparticles under 808 nm and 980 nm laser excitation, such as Figure 5 As shown in the figure, the core-shell nanoparticles exhibit significant luminescence at 540 nm and 660 nm when excited at wavelengths of 808 nm and 980 nm, respectively. The fluorescence at 540 nm is significantly stronger than that at 660 nm, exhibiting green fluorescence.

[0062] The morphology of the chiral helical gold nanoparticles (LH-GNRs@SiO2 and DH-GNRs@SiO2) coated with SiO2 in step (3) of Example 1 and Comparative Example 1 was tested by TEM, and the results are as follows: Figure 6As shown in Figure A, the left image represents LH-GNRs@SiO2, and the right image represents DH-GNRs@SiO2. It can be seen that the surface of the chiral helical gold nanoparticles was successfully coated with SiO2.

[0063] The test yielded amino-modified NaGdF4:Yb 3+ / Er 3+ The surface potential of the @NaYF4 core-shell structured nanoparticles changes to 22.5±4.5mV, indicating that the nanoparticles change from being negatively charged to being positively charged, which is beneficial for electrostatic bonding with chiral nanostructures. At the same time, the surface of the nanoparticles changes from oleic acid to water-soluble.

[0064] The morphology of the upconversion chiral nanomaterials (LH-GNRs@SiO2@UCNPs and DH-GNRs@SiO2@UCNPs) prepared in Example 1 and Comparative Example 1 was tested by TEM, and the results are as follows: Figure 6 As shown in Figure B, the upconversion nanoparticles are uniformly modified on the surface of the chiral helical gold nanoparticles GNRs@SiO2 coated with SiO2.

[0065] The fluorescence emission spectra of the upconversion chiral nanomaterials prepared in Example 1 and Comparative Example 1 under 808 nm laser excitation were tested, and the results are as follows: Figure 7 As shown, it can be seen that under 808nm laser irradiation, there is a significant fluorescence signal near 520nm.

[0066] Example 2

[0067] This embodiment provides a method for regulating β-amyloid protein aggregation based on circularly polarized light, specifically as follows:

[0068] After mixing 0.1 nM of the upconversion chiral nanomaterial LH-GNRs@SiO2@UCNPs prepared in Example 1 with 75 μM Aβ1-42, the target region was treated with 100 mW / cm². 2 After irradiation with an 808nm laser for 15 minutes, the upconversion chiral nanomaterials are excited to emit left-handed circularly polarized light.

[0069] Comparative Example 2

[0070] This comparative example provides a method for regulating β-amyloid protein aggregation based on circularly polarized light, specifically:

[0071] The upconversion chiral nanomaterials DH-GNRs@SiO2@UCNPs prepared in Comparative Example 1 (0.1 nM) were mixed with 75 μM Aβ1-42, and the target region was then subjected to a reaction at 100 mW / cm². 2 After irradiation with an 808nm laser for 15 minutes, the upconversion chiral nanomaterials are excited to emit right-handed circularly polarized light.

[0072] Comparative Example 3

[0073] The difference between this comparative example and Example 2 is that no upconversion chiral nanomaterials were added; instead, 75 μM Aβ1-42 was directly laser-treated. All other methods were the same as in Example 2.

[0074] Comparative Example 4

[0075] The 75 μM Aβ1-42 in this comparative example was neither enriched with upconversion chiral nanomaterials nor subjected to laser treatment.

[0076] The aggregation characteristics of Aβ1-42 in Examples 2 and Comparative Examples 2-4 were detected by circular dichroism spectroscopy, and the results are as follows: Figure 8 As shown. According to Figure 8 It can be seen that as the time is extended to 24h, the negative peak at 200nm of the CD spectrum of Aβ1-42 after treatment in Comparative Example 3 disappears, while a new negative peak appears at 210nm, indicating that Aβ1-42 has aggregated. The peaks of Aβ1-42 interacting with LH-GNRs@SiO2@UCNPs and with DH-GNRs@SiO2@UCNPs are all shifted to the right compared to the initial monomer, but the Aβ1-42 after treatment with LH-GNRs@SiO2@UCNPs shifts to the right the least, and the corresponding CD peak is the smallest.

[0077] Furthermore, fluorescence detection was performed on the aggregates formed by Aβ1-42 in Examples 2 and Comparative Examples 2-4 using thioflavin (ThT), and the results are as follows: Figure 9 As shown. According to Figure 9 As can be seen, compared with Aβ monomers, the fluorescence signal of Comparative Example 3 significantly increased after 24 hours of aggregation, indicating the formation of Aβ aggregates. However, the fluorescence signals of Aβ1-42 interacting with LH-GNRs@SiO2@UCNPs and with DH-GNRs@SiO2@UCNPs were weaker than those of Aβ under laser irradiation alone, indicating that chiral upconversion nanostructures combined with laser irradiation can significantly inhibit Aβ aggregation. Among these, the fluorescence of Aβ corresponding to LH-GNRs@SiO2@UCNPs combined with laser irradiation was the weakest, decreasing by 38.3% compared to laser irradiation alone, demonstrating a strong inhibition effect.

[0078] Comparative Example 5

[0079] The difference between this comparative example and Example 2 is that no upconversion chiral nanomaterials were added. 75 μM Aβ1-42 was dispersed in PBS buffer and directly laser-treated. All other methods were the same as in Example 2.

[0080] The aggregation state of Aβ1-42 in Example 2, Comparative Example 2, and Comparative Examples 4-5 was observed using TEM. Figure 10 As shown in the figures, the initial Aβ1-42 (Fig. a) exhibits a dispersed morphology. After being dispersed in PBS buffer and treated with laser for 24 hours (Fig. b), it still aggregates into clumps. However, when Aβ1-42 interacts with LH-GNRs@SiO2@UCNPs under laser for 24 hours (Fig. c), this aggregation is alleviated, resulting in a strip-like distribution. However, after interaction with DH-GNRs@SiO2@UCNPs (Fig. d), the aggregation remains in clumps, seemingly showing a tendency to intensify. This indicates that only LH-GNRs@SiO2@UCNPs combined with an 808nm laser is beneficial for suppressing Aβ aggregation.

[0081] Example 3

[0082] This embodiment investigates the effects of upconversion chiral nanomaterials combined with laser treatment on cytotoxicity. SH-SY5Y nerve cells are used to study how Aβ aggregates induce changes in intracellular reactive oxygen species (ROS) levels, thereby triggering cytotoxicity. Specifically:

[0083] SH-SY5Y neurons in the logarithmic growth phase were injected with 5 × 10⁻⁶ cells. 5 Cells were seeded in 6-well plates. Aβ aggregates that had been simultaneously treated with upconversion chiral nanomaterials LH-GNRs@SiO2@UCNPs and an 808nm laser were added to cell culture medium at a concentration of 5μM and incubated at 37℃ and 5% CO2 for 24h.

[0084] Comparative Example 6

[0085] The difference between this comparative example and Example 3 is that the Aβ aggregates, which have been treated with the upconversion chiral nanomaterials DH-GNRs@SiO2@UCNPs and an 808nm laser, were added to the cell culture medium at a concentration of 5μM and co-cultured at 37°C and 5% CO2 for 24 hours.

[0086] Comparative Example 7

[0087] The difference between this comparative example and Example 3 is that the Aβ aggregates dispersed in PBS that have only been treated with an 808nm laser were added to the cell culture medium at a concentration of 5μM and incubated at 37°C and 5% CO2 for 24 hours.

[0088] The intracellular ROS levels in nerve cells of Example 3 and Comparative Examples 6-7 were detected by DFC staining, and the results are as follows: Figure 11As shown, the left side is a fluorescence microscopy image of Aβ aggregates in PBS buffer (Comparative Example 7), the middle side is a fluorescence microscopy image of Aβ aggregates treated with LH-GNRs@SiO2@UCNPs (Example 3), and the right side is a fluorescence microscopy image of Aβ aggregates treated with DH-GNRs@SiO2@UCNPs (Comparative Example 6).

[0089] from Figure 11 The results showed that in the presence of Aβ aggregates, cells in PBS exhibited strong DCF fluorescence, indicating increased ROS in nerve cells. Adding LH-GNRs@SiO2@UCNPs and irradiating with an 808nm laser significantly reduced ROS levels, effectively mitigating the neurotoxicity caused by Aβ aggregates. However, adding LH-GNRs@SiO2@UCNPs actually increased ROS levels.

[0090] Example 4

[0091] This embodiment is used to verify the effects of upconversion chiral nanomaterials combined with laser treatment on animal behavior, specifically:

[0092] Six-month-old Alzheimer's disease (AD) model mice were selected and injected via tail vein every other day for four consecutive weeks with LH-GNRs@SiO2@UCNPs prepared in Example 1, DH-GNRs@SiO2@UCNPs prepared in Comparative Example 1 (4 mg / kg), and the same volume of PBS buffer. The mice were also irradiated with 808 nm laser from the posterior brain region. Meanwhile, wild-type normal mice were used as controls, and the spatial cognition and memory abilities of the mice were evaluated by water maze test.

[0093] After 5 days of escape training, the escape latency in all groups showed a progressively decreasing trend. Compared to wild-type mice, Alzheimer's disease (AD) model mice exhibited a significant deficiency, demonstrating longer escape times. When AD mice were treated with LH-GNRs@SiO2@UCNPs, their escape times were significantly shorter than those of untreated AD mice, but longer than those of wild-type mice. In contrast, when AD mice were treated with DH-GNRs@SiO2@UCNPs, their escape times were close to those of untreated AD mice.

[0094] Furthermore, the trajectories of mice searching for hidden escape platforms showed that wild-type mice had the shortest paths, while AD model mice had significantly longer paths. After treatment with LH-GNRs@SiO2@UCNPs, the paths of AD model mice were significantly shortened, while after treatment with DH-GNRs@SiO2@UCNPs, the paths of AD model mice were similar to those of untreated mice. Figure 12As shown, it can be seen that only LH-GNRs@SiO2@UCNPs and 808nm laser treatment can effectively improve the cognitive ability of AD mice.

[0095] After euthanasia, hippocampal tissue was extracted from each group of mice for ThT staining. The results showed that, compared to wild-type mice, the brain tissue of AD model mice exhibited significant ThT fluorescence. This fluorescence was significantly attenuated after treatment with LH-GNRs@SiO2@UCNPs, while no significant change in ThT fluorescence was observed after treatment with DH-GNRs@SiO2@UCNPs. Figure 13 As shown in the figure, this result clearly demonstrates that LH-GNRs@SiO2@UCNPs can weaken the aggregation of Aβ fibers in the brain tissue of AD mice.

[0096] In summary, this invention provides a method for regulating β-amyloid protein aggregation based on circularly polarized light. It achieves efficient CPL generation through upconversion excitation and chiral nanostructures, improving the precision and safety of optical intervention. Specifically, the upconversion luminescent core emits ultraviolet or visible light with wavelengths of 280–700 nm under near-infrared light excitation at wavelengths of 800–1100 nm. The chiral optically active structure modulates the emitted light into left-handed circularly polarized light (L-CPL) or right-handed circularly polarized light (R-CPL). A biocompatible coating and brain-targeting ligand on the surface enhance in vivo stability and brain accumulation capacity. Applying near-infrared light irradiation at wavelengths of 800–1400 nm to the target region excites the nanomaterials to emit circularly polarized light. This circularly polarized light interferes with the β-sheet conformation formation of the Aβ polypeptide, ultimately inhibiting its aggregation and reducing neurotoxicity.

[0097] Unlike existing small molecule or antibody-based approaches, this invention provides a novel, non-drug-based treatment for Alzheimer's disease; animal experiments have verified that this method can effectively block Aβ aggregation and improve cognitive function.

[0098] Circularly polarized light (CPL) can induce changes in the interactions of key protein sites, thereby altering the conformation of protein aggregation. This process is reversible and highly spatially selective. By adjusting the chirality (L / D type) and wavelength of circularly polarized light (CPL), it can be adapted to different protein aggregation systems (such as the K18 fragment of Tau protein and the NAC region of α-synuclein).

[0099] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for regulating β-amyloid protein aggregation based on circularly polarized light, characterized in that: include, By electrostatically binding SiO2-coated left-handed chiral optically active gold nanostructures with amino-modified upconversion luminescent nanoparticles, a left-handed upconversion chiral nanomaterial can be obtained. After coating the surface of a left-handed upconversion chiral nanomaterial with a biocompatible coating and a brain-targeting ligand, it was mixed with β-amyloid protein at a concentration of 5–100 mW / cm². 2 Irradiation with an 800-1100 nm laser for 15-30 min excites the left-handed upconversion chiral nanomaterial to emit 500-600 nm left-handed circularly polarized light. The left-handed circularly polarized light inhibits the aggregation of β-amyloid protein by interfering with the formation of the β-sheet conformation of β-amyloid protein.

2. The method for regulating β-amyloid protein aggregation based on circularly polarized light as described in claim 1, characterized in that: The chiral optically active gold nanostructure exhibits circular dichroism absorption signals in the wavelength range of 500-600 nm, thereby modulating light in this wavelength range into left-handed circularly polarized light.

3. The method for regulating β-amyloid protein aggregation based on circularly polarized light as described in claim 1, characterized in that: The chiral optically active gold nanostructures include plasma nanostructures with chiral signals.

4. The method for regulating β-amyloid protein aggregation based on circularly polarized light as described in claim 1, characterized in that: The upconversion luminescent nanoparticles include NaYF4:Yb 3+ / Er 3+ NaYF4:Yb 3+ / Ho 3+ NaGdF4:Yb 3+ / Er 3+ NaGdF4:Yb 3+ / Ho 3+ 、LiYF4:Yb 3+ / Er 3+ 、LiYF4:Yb 3+ / Ho 3+ Y2O3:Yb 3+ / Er 3+ Y2O3:Yb 3+ / Ho 3+ NaLuF4:Yb 3+ / Er 3+ NaLuF4:Yb 3+ / Ho 3+ One of them.

5. The method for regulating β-amyloid protein aggregation based on circularly polarized light as described in claim 1, characterized in that: The biocompatible coating includes one of polyethylene glycol, polydopamine, and cell membrane camouflage coating; the molecular weight of the polyethylene glycol is 2000~20000 Da; the thickness of the polydopamine as a biocompatible coating is 5~50 nm; the cell membrane camouflage coating includes one of erythrocyte membrane and neutrophil membrane.

6. The method for regulating β-amyloid protein aggregation based on circularly polarized light as described in claim 1, characterized in that: The brain-targeting ligand includes one or more of the following: transferrin receptor TfR antibody, transferrin receptor TfR antibody fragment, Angiopep-2 peptide, ApoE mimic peptide, and neutrophil membrane; the sequence of the Angiopep-2 peptide is TFFYGGSRGKRNNFKTEEY; and the sequence of the ApoE mimic peptide is LRKLRKRLL.

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