Application of N-acetylcysteine modified molybdenum sulfide quantum dot in preparation of medicine for treating acute kidney injury

Abstract

The invention relates to application of N-acetylcysteine modified molybdenum sulfide quantum dots in preparation of a medicine for treating acute kidney injury, and belongs to the technical field of nano medicine. The N-acetylcysteine modified molybdenum sulfide quantum dots used in the invention can realize kidney specific accumulation based on ultra-small particle size and hydrophilicity; active uptake of renal proximal tubule epithelial cells is realized through specific binding of N-acetyl and the anion transporter 1; and accurate positioning of mitochondria is realized by virtue of affinity of mitochondrial membrane protein of N-acetylcysteine. In a pathological microenvironment of acute kidney injury, on one hand, the quantum dot can directly remove mitochondrial active oxygen through valence conversion of the molybdenum element; on the other hand, released N-acetylcysteine provides a glutathione synthesis precursor, degraded molybdenum ions supplement a molybdenum active center of mitochondrial amidoxime reductase, an endogenous anti-oxidation defense system is reconstructed synergistically, damage to renal tubular epithelial cells is relieved, and renal functions are recovered.

Description

Technical Field

[0001] The present invention relates to the field of nanomedicine technology, and particularly relates to the application of N-acetylcysteine modified molybdenum sulfide quantum dots in the preparation of drugs for treating acute kidney injury. Background Art

[0002] Acute Kidney Injury (AKI) is a clinical critical illness characterized by a sharp decline in renal function. The global annual incidence is approximately 13 million cases (85% in developing countries), the incidence rate among inpatients is as high as 21.6%, and the overall mortality rate is 23%. Although supportive therapies such as hemodialysis can temporarily relieve symptoms, they cannot reverse the pathological process of tubular injury. Approximately 30% of AKI patients progress to chronic kidney disease or even end-stage kidney disease due to maladaptive repair, leading to a sharp increase in medical costs and a heavier social burden. This severe situation highlights the urgent need for new drug research and development in the field of AKI treatment.

[0003] Recent studies have revealed that mitochondrial damage in Proximal Tubular Epithelial Cells (PTECs) is the pathological core of AKI. As the core unit of renal reabsorption function, the mitochondrial density of PTECs is 3-5 times higher than that of ordinary cells. This extraordinary metabolic activity becomes a fatal weakness in AKI. Ischemia, nephrotoxic substances, or inflammatory stimuli trigger a sharp increase in the electron leakage rate of the mitochondrial respiratory chain, leading to an outbreak of Reactive Oxygen Species (ROS). Highly reactive ROS causes systemic damage through the following pathways: ① Impaired oxidation of biological macromolecules: ROS preferentially attacks the phospholipids in the inner mitochondrial membrane (resulting in the opening of the membrane permeability transition pore), mtDNA (lacking histone protection), and respiratory chain enzyme complexes, inducing an energy metabolism collapse; ② Activation of the apoptotic cascade: The loss of mitochondrial membrane potential triggers the release of cytochrome c, activating the Caspase-dependent apoptotic pathway; ③ Inflammatory storm: mtDNA leaked from mitochondria activates the type I interferon signal through the cGAS-STING pathway, recruiting neutrophil and macrophage infiltration and exacerbating tissue damage.

[0004] To counteract oxidative damage, the body has evolved two defense systems: ① Enzyme antioxidant system: such as mitochondrial amidoxime reducing component mARC (Molybdenum-containing Amidoxime Reducing Component) containing molybdenum cofactor, which is specifically distributed in kidney mitochondria and maintains genomic stability by catalyzing the reduction reaction of N-hydroxylated toxic substances; ② Molecular antioxidant network: centered around glutathione (GSH), which directly neutralizes ROS and repairs lipid peroxidation damage. However, in AKI, the endogenous defense system undergoes a double collapse ── molybdenum metabolism imbalance (loss of mARC) and GSH depletion, ultimately forming a vicious cycle of "oxidative damage - defense failure".

[0005] Facing this complex mechanism, the limitations of traditional antioxidant strategies are becoming increasingly prominent: this strategy only focuses on the immediate clearance of ROS, but ignores the functional reconstruction of the endogenous antioxidant system. The defects of this "one-legged walking" treatment mode have two dilemmas at the mechanistic level: on the one hand, it is difficult for exogenous antioxidants to achieve high-precision targeting of kidney PTECs mitochondria, resulting in limited ROS neutralization efficiency; on the other hand, the loss of mARC enzyme activity caused by molybdenum element loss and the collapse of the GSH system cannot be reversed, leading to the continuous development of the pathological process of oxidative damage towards chronicity. The breakthrough of this therapeutic dilemma must establish a new intervention paradigm of "external repair and internal consolidation", which not only achieves the precise and efficient clearance of ROS (external repair), but also reconstructs the damaged endogenous defense network (internal consolidation). Summary of the Invention

[0006] The present invention aims to solve the technical problem in the prior art that the treatment of AKI lacks a therapeutic drug that can achieve high-precision targeting of PTECs mitochondria and the coordination of exogenous ROS clearance and endogenous antioxidant system repair, and provides the use of N-acetylcysteine-modified molybdenum sulfide quantum dots in the preparation of drugs for treating acute kidney injury. The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention can achieve kidney-specific accumulation based on their ultra-small particle size and hydrophilicity; the N-acetyl group of N-acetylcysteine binds to anion transporter 1 on the surface of PTECs to drive active cell uptake, and precisely locates to the mitochondrial damage site depending on the high affinity of N-acetylcysteine for mitochondrial outer membrane proteins. In terms of the mechanism of action, this quantum dot directly scavenges mitochondrial ROS through the valence state conversion of surface molybdenum ions, while supplementing molybdenum elements to repair the active center of molybdenum-containing enzyme mARC, and cooperates with the glutathione synthesis precursor provided by N-acetylcysteine to reconstruct the endogenous antioxidant defense network, ultimately achieving multi-dimensional treatment from targeted delivery, oxidative stress blockade to endogenous antioxidant repair, significantly improving renal function and inhibiting the pathological progression of acute kidney injury.

[0007] To solve the above technical problems, the technical solution of the present invention is as follows:

[0008] Use of N-acetylcysteine-modified molybdenum sulfide quantum dots in the preparation of a drug for treating acute kidney injury.

[0009] In the above technical solution, further preferably, use of the N-acetylcysteine-modified molybdenum sulfide quantum dots in the preparation of a drug for treating acute kidney injury that can achieve the synergism of oxidative stress blockade and endogenous antioxidant repair.

[0010] In the above technical solution, further preferably, the N-acetylcysteine-modified molybdenum sulfide quantum dots have the ability to target PTECs mitochondria.

[0011] In the above technical solution, further preferably, the N-acetylcysteine-modified molybdenum sulfide quantum dots are spherical in shape and have a particle size between 4 and 8 nm.

[0012] In the above technical solution, further preferably, the N-acetylcysteine-modified molybdenum sulfide quantum dots are prepared by a hydrothermal reaction using ammonium molybdate, thiourea, and N-acetylcysteine as raw materials.

[0013] In the above technical solution, still further preferably, the ammonium molybdate and thiourea are precursors, and the N-acetylcysteine is a capping agent.

[0014] In the above technical solution, still further preferably, the mass ratio of ammonium molybdate, N-acetylcysteine, and thiourea is 500 - 800 mg: 200 - 400 mg: 80 - 100 mg.

[0015] In the above technical solution, still further preferably, the temperature of the hydrothermal reaction is 200 - 250 °C, and the duration is 4 - 8 hours.

[0016] The beneficial effects of the present invention are:

[0017] Application of N-acetylcysteine-modified molybdenum sulfide quantum dots provided by the present invention in the preparation of drugs for treating acute kidney injury. The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention can achieve kidney-specific accumulation based on their ultra-small particle size and hydrophilicity; achieve active uptake by renal proximal tubular epithelial cells through the specific binding of N-acetyl groups to anion transporter 1; and achieve precise mitochondrial localization by virtue of the mitochondrial membrane protein affinity of N-acetylcysteine. In the pathological microenvironment of acute kidney injury, on the one hand, the quantum dots can directly scavenge mitochondrial reactive oxygen species through the valence state conversion of molybdenum elements; on the other hand, the released N-acetylcysteine provides a glutathione synthesis precursor, and the degraded molybdenum ions supplement the molybdenum active center of mitochondrial amidoxime reductase, synergistically reconstructing the endogenous antioxidant defense system, thereby reducing the damage of renal tubular epithelial cells and restoring kidney function. More specifically:

[0018] The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention are obtained by a simple and convenient synthesis method, and the raw materials used are inexpensive and easily available, and the synthesis method is simple.

[0019] The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention are prepared by a hydrothermal reaction using ammonium molybdate, thiourea and N-acetylcysteine as raw materials, and are spherical in shape, have good water solubility, have a small size ( Figure 1 ) and carry a strong negative charge ( Figure 2 ).

[0020] The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention have excellent broad-spectrum free radical scavenging activity ( Figure 3 ).

[0021] The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention can release N-acetylcysteine under the stimulation of hydrogen peroxide ( Figure 4 ).

[0022] The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention can be significantly enriched in the kidneys of mice ( Figure 5 ).

[0023] The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention can be effectively taken up by human renal tubular epithelial cells HK-2, and when treated with anion transporter inhibitors or co-incubated with N-acetylcysteine, drug uptake is inhibited ( Figure 6 ).

[0024] The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention can be highly localized in the mitochondria of human renal tubular epithelial cells HK-2 ( Figure 7 ).

[0025] The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention can effectively restore the pathological morphology and renal function of the kidneys of AKI mice( Figure 8 ).

[0026] The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention can significantly reduce the ROS level in the renal tissue of AKI mice and restore the mARC and GSH contents( Figure 9 ).

[0027] The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention can significantly inhibit apoptosis in the renal tissue of AKI mice( Figure 10 ).

[0028] The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention can significantly inhibit inflammatory cell infiltration in the renal tissue of AKI mice( Figure 11 ).

[0029] The N-acetylcysteine-modified molybdenum sulfide quantum dots used in the present invention have good biocompatibility, and single high-dose injection and long-term administration have no effect on the tissue structure and morphology of the heart, liver, spleen, pancreas, and kidneys of normal mice( Figure 12 ). BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0031] Figure 1 It is a characterization diagram of the N-acetylcysteine-modified molybdenum sulfide quantum dots prepared in Example 1. Among them, A is a transmission electron microscope image, and B is a particle size statistical diagram.

[0032] Figure 2 It is a Zeta potential diagram of the N-acetylcysteine-modified molybdenum sulfide quantum dots prepared in Example 1.

[0033] Figure 3 It is a diagram of the in vitro free radical scavenging effect of the N-acetylcysteine-modified molybdenum sulfide quantum dots prepared in Example 1. Among them, A is superoxide anion, B is hydroxyl radical, C is hydrogen peroxide, and D is peroxynitrite anion.

[0034] Figure 4 It is an ultraviolet spectrum diagram of the release of N-acetylcysteine by the N-acetylcysteine-modified molybdenum sulfide quantum dots prepared in Example 1 under hydrogen peroxide stimulation.

[0035] Figure 5 It is a fluorescence image of the main organs of a mouse 9 hours after injection after the N-acetylcysteine-modified molybdenum sulfide quantum dots prepared in Example 1 are fluorescently labeled and injected into the mouse body via the tail vein.

[0036] Figure 6 Fluorescence images of N-acetylcysteine-modified molybdenum sulfide quantum dots prepared in Example 1 after fluorescence labeling and uptake by human renal tubular epithelial cells HK-2.

[0037] Figure 7 Co-localization fluorescence images of N-acetylcysteine-modified molybdenum sulfide quantum dots prepared in Example 1 after fluorescence labeling with different organelles in human renal tubular epithelial cells HK-2.

[0038] Figure 8 Histopathological staining and renal function index graphs of the kidneys of normal mice, control group mice, AKI mice, and mice injected with N-acetylcysteine-modified molybdenum sulfide quantum dots prepared in Example 1.

[0039] Figure 9 Results graphs of ROS fluorescence staining, mARC immunofluorescence staining, and GSH / GSSH levels in the renal tissues of normal mice, control group mice, AKI mice, and mice injected with N-acetylcysteine-modified molybdenum sulfide quantum dots prepared in Example 1.

[0040] Figure 10 TUNEL staining graphs of the renal tissues of normal mice, control group mice, AKI mice, and mice injected with N-acetylcysteine-modified molybdenum sulfide quantum dots prepared in Example 1.

[0041] Figure 11 Immunohistochemical staining graphs of neutrophil and macrophage infiltration in the renal tissues of normal mice, control group mice, AKI mice, and mice injected with N-acetylcysteine-modified molybdenum sulfide quantum dots prepared in Example 1.

[0042] Figure 12 Histopathological staining graphs of major organs after intravenous injection of N-acetylcysteine-modified molybdenum sulfide quantum dots prepared in Example 1 at a single high dose and a therapeutic dose for four consecutive weeks (once a week) in normal mice. Detailed implementation manners

[0043] The inventive concept of the present invention is as follows: In order to solve the technical problem in the prior art that there is a lack of therapeutic drugs for AKI treatment that can achieve high-precision targeting of PTECs mitochondria and synergistically scavenge exogenous ROS and repair the endogenous antioxidant system, the present invention provides a molybdenum disulfide quantum dot modified with N-acetylcysteine for the treatment of acute kidney injury. The molybdenum disulfide quantum dot modified with N-acetylcysteine used in the present invention is prepared by a hydrothermal reaction using ammonium molybdate and thiourea as precursors and N-acetylcysteine as a capping agent. Its morphology is spherical, with ultra-small size, negatively charged surface and excellent broad-spectrum free radical scavenging activity. The molybdenum disulfide quantum dot modified with N-acetylcysteine of the present invention can achieve kidney-specific accumulation based on its ultra-small particle size and hydrophilicity; achieve active uptake by renal proximal tubular epithelial cells through the specific binding of N-acetyl group to anion transporter 1; and achieve precise mitochondrial localization by virtue of the mitochondrial membrane protein affinity of N-acetylcysteine. In the pathological microenvironment of acute kidney injury, on the one hand, this quantum dot can directly scavenge mitochondrial reactive oxygen species through the valence state conversion of molybdenum element; on the other hand, the released N-acetylcysteine provides a precursor for glutathione synthesis, and the degraded molybdenum ions supplement the molybdenum active center of mitochondrial amidoxime reductase, synergistically reconstructing the endogenous antioxidant defense system, thereby reducing the damage of renal tubular epithelial cells and restoring kidney function.

[0044] The present invention provides an application of a molybdenum disulfide quantum dot modified with N-acetylcysteine in the preparation of a drug for treating acute kidney injury.

[0045] Furthermore, it is an application of a molybdenum disulfide quantum dot modified with N-acetylcysteine having the ability to target PTECs mitochondria in the preparation of a drug for treating acute kidney injury that can achieve the synergism of oxidative stress block and endogenous antioxidant repair.

[0046] Furthermore, the molybdenum disulfide quantum dot modified with N-acetylcysteine is prepared by a hydrothermal reaction using ammonium molybdate, thiourea and N-acetylcysteine as raw materials. The prepared molybdenum disulfide quantum dot modified with N-acetylcysteine is spherical-like, and the particle size is between 4 - 8 nm. The specific preparation process is as follows:

[0047] Step (1) Synthesis:

[0048] Dissolve ammonium molybdate and N-acetylcysteine in ice ultrapure water, add thiourea to the above precursor solution under ice bath stirring, stir and mix, and then carry out a hydrothermal reaction on the solution at a temperature of 200 - 250 °C for a duration of 4 - 8 hours;

[0049] The mass ratio of ammonium molybdate, N-acetylcysteine and thiourea is 500 - 800 mg: 200 - 400 mg: 80 - 100 mg;

[0050] Step (2) Purification:

[0051] Centrifuge the sample obtained in step (1) at a high speed. The centrifugation conditions are 12,000 rpm for 10 - 15 minutes. Discard the precipitate, take the supernatant, and perform dialysis under anaerobic conditions to remove unreacted impurities. The dialysis duration is 2 - 4 hours, and the ultrapure water is changed every 0.5 hours.

[0052] Step (3) Freeze-drying:

[0053] After dialysis, centrifuge the sample obtained in step (2) at a high speed, discard the precipitate, take the supernatant, freeze it in a -20°C refrigerator, and then transfer it to a vacuum freeze dryer. After freeze-drying, N-acetylcysteine-modified molybdenum sulfide quantum dot powder is obtained.

[0054] The technical solutions of the present invention are clearly and completely described below through examples. However, it should be understood that the following examples do not limit the protection scope of the present invention.

[0055] Example 1

[0056] (1) Synthesis of N-acetylcysteine-modified molybdenum sulfide quantum dots:

[0057] Weigh 650 mg of ammonium molybdate powder, 200 mg of N-acetylcysteine crystals, and 80 mg of thiourea powder. Dissolve ammonium molybdate and N-acetylcysteine in 40 mL of ice-cold ultrapure water. Place a magnetic stir bar in the mixed liquid system, and add the thiourea powder to the above precursor solution under vigorous stirring in an ice bath. Stir and mix until the solid raw drug is dissolved. Transfer the solution to a 100 mL high-pressure reaction kettle and react at 200°C for 4 hours.

[0058] (2) Purification:

[0059] Take the sample obtained in step (1) and centrifuge it at 12,000 rpm for 10 minutes to remove the precipitate. Place the supernatant in a dialysis bag with a molecular weight cut-off of 3.5 KD, and then place the dialysis bag in 2 L of ultrapure water. Perform dialysis under anaerobic conditions at room temperature (the dialysis tank is filled with nitrogen), and change the ultrapure water every 0.5 hours. Dialyze for a total of 2 hours to remove unreacted impurities.

[0060] (3) Freeze-drying:

[0061] After dialysis, transfer the liquid obtained in step (2) to a 50 mL centrifuge tube, centrifuge it at 12,000 rpm for 10 minutes, discard the precipitate and take the supernatant, freeze it in a -20°C refrigerator for 1.5 hours, and then transfer it to a vacuum freeze dryer. After freeze-drying for 72 hours, N-acetylcysteine-modified molybdenum sulfide quantum dot 1 powder (NMDs) is obtained.

[0062] Example 2

[0063] (1) Synthesis of N-acetylcysteine-modified molybdenum sulfide quantum dots:

[0064] Weigh 700 mg of ammonium molybdate powder, 250 mg of N-acetylcysteine crystals and 85 mg of thiourea powder. Dissolve ammonium molybdate and N-acetylcysteine in 40 mL of ice-cold ultrapure water. Place a magnetic stir bar in the mixed liquid system, and under vigorous stirring in an ice bath, add the thiourea powder to the above precursor solution. Stir and mix until the solid raw drug is dissolved. Transfer the solution to a 100 mL high-pressure reaction kettle and react at 200 °C for 4 hours.

[0065] (2) The purification and lyophilization steps are the same as those in Example 1, and the obtained product is called N-acetylcysteine-modified molybdenum sulfide quantum dot 2.

[0066] Example 3

[0067] (1) Synthesis of N-acetylcysteine-modified molybdenum sulfide quantum dots:

[0068] Weigh 750 mg of ammonium molybdate powder, 300 mg of N-acetylcysteine crystals and 90 mg of thiourea powder. Dissolve ammonium molybdate and N-acetylcysteine in 40 mL of ice-cold ultrapure water. Place a magnetic stir bar in the mixed liquid system, and under vigorous stirring in an ice bath, add the thiourea powder to the above precursor solution. Stir and mix until the solid raw drug is dissolved. Transfer the solution to a 100 mL high-pressure reaction kettle and react at 220 °C for 4 hours.

[0069] (2) The purification and lyophilization steps are the same as those in Example 1, and the obtained product is called N-acetylcysteine-modified molybdenum sulfide quantum dot 3.

[0070] Example 4

[0071] (1) Synthesis of N-acetylcysteine-modified molybdenum sulfide quantum dots:

[0072] Weigh 800 mg of ammonium molybdate powder, 350 mg of N-acetylcysteine crystals and 95 mg of thiourea powder. Dissolve ammonium molybdate and N-acetylcysteine in 40 mL of ice-cold ultrapure water. Place a magnetic stir bar in the mixed liquid system, and under vigorous stirring in an ice bath, add the thiourea powder to the above precursor solution. Stir and mix until the solid raw drug is dissolved. Transfer the solution to a 100 mL high-pressure reaction kettle and react at 250 °C for 5 hours.

[0073] (2) The purification and lyophilization steps are the same as those in Example 1, and the obtained product is called N-acetylcysteine-modified molybdenum sulfide quantum dot 4.

[0074] Example 5

[0075] (1) Synthesis of N-acetylcysteine-modified molybdenum sulfide quantum dots:

[0076] Weigh 800 mg of ammonium molybdate powder, 400 mg of N-acetylcysteine crystals and 100 mg of thiourea powder. Dissolve ammonium molybdate and N-acetylcysteine in 40 mL of ice-cold ultrapure water. Place a magnetic stir bar into the mixed liquid system, and add the thiourea powder to the above precursor solution under vigorous stirring in an ice bath until the solid raw material drug is dissolved. Transfer the solution to a 100 mL high-pressure reactor and react at 250 °C for 6 hours.

[0077] (2) The purification and lyophilization steps are the same as those in Example 1, and the obtained product is called molybdenum sulfide quantum dots modified with N-acetylcysteine 5.

[0078] Example 6

[0079] (1) The synthesis steps of molybdenum sulfide quantum dots modified with N-acetylcysteine are the same as those in Example 1;

[0080] (2) Purification

[0081] Take the sample obtained in step (1) and remove the precipitate by centrifugation at 12,000 rpm for 10 minutes. Place the supernatant in a dialysis bag with a molecular weight cut-off of 3.5 KD, and then place the dialysis bag in 2 L of ultrapure water. Perform dialysis under anaerobic conditions (the dialysis tank is filled with nitrogen) at room temperature, change the ultrapure water every 0.5 hours, and dialyze for a total of 2.5 hours to remove unreacted impurities.

[0082] (3) The lyophilization step is the same as that in Example 1, and the product obtained after lyophilization is called molybdenum sulfide quantum dots modified with N-acetylcysteine 6.

[0083] Example 7

[0084] (1) The synthesis steps of molybdenum sulfide quantum dots modified with N-acetylcysteine are the same as those in Example 1;

[0085] (2) Purification

[0086] Take the sample obtained in step (1) and remove the precipitate by centrifugation at 12,000 rpm for 10 minutes. Place the supernatant in a dialysis bag with a molecular weight cut-off of 3.5 KD, and then place the dialysis bag in 2 L of ultrapure water. Perform dialysis under anaerobic conditions (the dialysis tank is filled with nitrogen) at room temperature, change the ultrapure water every 0.5 hours, and dialyze for a total of 3 hours to remove unreacted impurities.

[0087] (3) The lyophilization step is the same as that in Example 1, and the product obtained after lyophilization is called molybdenum sulfide quantum dots modified with N-acetylcysteine 7.

[0088] Example 8

[0089] (1) The synthesis steps of molybdenum sulfide quantum dots modified with N-acetylcysteine are the same as those in Example 1;

[0090] (2) Purification

[0091] Take the sample obtained in step (1) and remove the precipitate by centrifugation at 12,000 rpm for 10 minutes. Place the supernatant in a dialysis bag with a molecular weight cut-off of 3.5 KD, and then place the dialysis bag in 2 L of ultrapure water. Dialyze under anaerobic conditions (nitrogen gas is filled in the dialysis tank) at room temperature, changing the ultrapure water every 0.5 hours for a total of 3.5 hours to remove unreacted impurities.

[0092] (3) The freeze-drying step is the same as in Example 1, and the product obtained after freeze-drying is called molybdenum disulfide quantum dots 8 modified with N-acetylcysteine.

[0093] Example 9

[0094] (1) The synthesis steps of molybdenum disulfide quantum dots modified with N-acetylcysteine are the same as in Example 1;

[0095] (2) Purification

[0096] Take the sample obtained in step (1) and remove the precipitate by centrifugation at 12,000 rpm for 10 minutes. Place the supernatant in a dialysis bag with a molecular weight cut-off of 3.5 KD, and then place the dialysis bag in 2 L of ultrapure water. Dialyze under anaerobic conditions (nitrogen gas is filled in the dialysis tank) at room temperature, changing the ultrapure water every 0.5 hours for a total of 4 hours to remove unreacted impurities.

[0097] (3) The freeze-drying step is the same as in Example 1, and molybdenum disulfide quantum dots 9 modified with N-acetylcysteine are obtained after freeze-drying.

[0098] The ammonium molybdate, thiourea, N-acetylcysteine, the temperature and time of the hydrothermal reaction, and the dialysis time in the above examples can also be any values within the aforementioned defined ranges, and no further examples will be given here.

[0099] The molybdenum disulfide quantum dots modified with N-acetylcysteine synthesized in Example 1 are characterized in terms of structure, performance, efficacy, and safety below. The molybdenum disulfide quantum dots modified with N-acetylcysteine synthesized in Example 1 in the specification drawings are all denoted by NMDs.

[0100] Example 10

[0101] Taking the molybdenum disulfide quantum dots NMDs modified with N-acetylcysteine synthesized in Example 1 as an example, explore their particle size, surface potential, and antioxidant activity. The specific steps are as follows:

[0102] (1) Transmission electron microscopy characterization: Conduct cryo-electron microscopy characterization for NMDs and take transmission electron microscopy images with a TECNAI G2 high-resolution transmission electron microscope. The results are as Figure 1As shown in A and B, NMDs are spherical in water, with good dispersibility and small size (average particle size 4.65 nm).

[0103] (2) Zeta potential characterization: The surface potential of NMDs was detected using a Zeta potential analyzer. The results are as Figure 2 shown. NMDs are negatively charged, and their surface potential is -34.2 mV.

[0104] (3) Evaluation of free radical scavenging ability:

[0105] The NBT method was used to detect the scavenging ability of NMDs against superoxide anions. Different concentrations of NMDs (128, 256, 512, 1024, 2048 μg / mL), methionine (50 μM), riboflavin (2 μM), NBT (1 mM), PBS (100 mM, pH = 7.4), and deionized water were mixed and added to a cuvette. Then, the cuvette was exposed to ultraviolet light for 5 minutes, and the reaction products were mixed by pipetting. The absorbance of the reaction products was measured at a wavelength of 560 nm.

[0106] The TMB method was used to detect the scavenging ability of NMDs against hydroxyl radicals. Different concentrations of NMDs (1, 2, 4, 8 μg / mL), FeSO4 (5 mM), TMB (5 mM), H2O2 (100 mM), PBS (0.01 M, pH = 7.4), and deionized water were mixed and added to a cuvette. After mixing, the reaction was allowed to proceed in the dark for 25 minutes. The reaction products were mixed by pipetting, and the absorbance of the blue diimine-type product was measured at a wavelength of 652 nm.

[0107] The UV spectroscopy method was used to detect the scavenging ability of NMDs against hydrogen peroxide. NMDs (0.1 mg / mL) and hydrogen peroxide at different concentrations (25, 50, 100, 200, 400 μM) were mixed and added to a cuvette. After mixing, the reaction was allowed to proceed for 12 hours. The reaction products were mixed by pipetting, and the absorbance of the reaction products was measured at a wavelength of 210 nm.

[0108] The UV spectroscopy method was used to detect the scavenging ability of NMDs against peroxynitrite anion (ONOO - ). NMDs (0.1 mg / mL) and different concentrations of ONOO - (12.5, 25, 50, 200 mM) were mixed and added to a cuvette. After mixing, the reaction was allowed to proceed for 12 hours. The reaction products were mixed by pipetting, and the absorbance of the reaction products was measured at a wavelength of 210 nm.

[0109] The results of in vitro antioxidant experiments are as Figure 3 shown. As can be seen from the figure, NMDs can efficiently scavenge various reactive oxygen species, such as superoxide anions (Figure 3 In A), hydroxyl radical ( Figure 3 In B), hydrogen peroxide ( Figure 3 In C) and peroxynitrite anion ( Figure 3 In D).

[0110] Example 11

[0111] Mix NMDs (0.1 mg / mL) and hydrogen peroxide (400 μM), place them in a dialysis bag with a molecular weight cut-off of 3.5 KD, and then place the dialysis bag in 2 L of ultrapure water for dialysis. Take the liquid outside the dialysis bag for ultraviolet spectrum scanning at 0, 5, 10, 15, 20, and 25 minutes after dialysis respectively to detect the release of N-acetylcysteine.

[0112] The results are as Figure 4 shown. As can be seen from the figure, the NMDs prepared by the present invention can achieve hydrogen peroxide-responsive release of N-acetylcysteine and show time dependence.

[0113] Example 12

[0114] Taking the molybdenum sulfide quantum dots NMDs modified with N-acetylcysteine synthesized in Example 1 as an example, explore their distribution in various organs of mice. The specific steps are as follows:

[0115] Synthesize fluorescently labeled nanodrugs (FITC-NMDs): Dissolve 10 mg of NMDs in 8 mL of ultrapure water, add 2 mg of fluorescein isothiocyanate FITC (dissolved in 2 mL of DMSO), and stir the reaction in the dark at room temperature for 8 hours. After the reaction, dialyze the solution for 24 hours to remove unreacted impurities to obtain FITC-NMDs.

[0116] Animal feeding: Kunming mice (male, 5 weeks old, 23 - 25 g) are fed with standard diet and water in a clean environment at 24 ± 2 °C and a 12-hour light / dark cycle for 7 days.

[0117] Animal administration and drug distribution detection: Select 3 Kunming mice. Inject 2 mg / kg of fluorescently labeled nanodrugs (FITC-NMDs) via the tail vein. Euthanize the mice 9 hours after injection and collect the main organs, and take fluorescent images of each organ under a stereomicroscope with fluorescence to analyze the in vivo distribution of NMDs.

[0118] The results are as Figure 5 shown. As can be seen from the figure, the molybdenum sulfide quantum dots NMDs modified with N-acetylcysteine prepared by the present invention can be significantly enriched in the kidney tissue of mice.

[0119] Example 13

[0120] Taking the molybdenum sulfide quantum dots NMDs modified with N-acetylcysteine synthesized in Example 1 as an example, its targeting ability to anion transporter 1 was explored. The specific steps are as follows:

[0121] The steps for synthesizing fluorescently labeled nanodrugs (FITC-NMDs) were the same as those in Example 12.

[0122] Culturing human renal tubular epithelial cells HK-2: Prepare DMEM / F-12 medium containing 10% fetal bovine serum to culture HK-2 cells, and place them in an incubator with 5% CO2 at 37°C. Observe the cell status under a microscope and perform operations such as cell medium replacement, cell passage, and cell cryopreservation in a timely manner.

[0123] Verification of the folate receptor targeting of NMDs: (1) Seeding cells on the plate: Digest HK-2 cells in the logarithmic growth phase with trypsin, centrifuge, resuspend them in DMEM F12 medium containing 10% fetal bovine serum to prepare a cell suspension. Add an appropriate amount of the cell suspension to a 6-well plate so that the cell density in each well is about 50%. Place the seeded cell plate in an incubator with 5% CO2 at 37°C and culture for 12 hours. (2) Adding drugs: After 12 hours, discard the old medium and divide it into the following three groups: the FITC-NMDs + probenecid pretreatment group, the FITC-NMDs + N-acetylcysteine co-incubation group, and the FITC-NMDs + PBS group. Pretreatment means pre-adding DMEM F12 medium (containing 10% fetal bovine serum) with 40 μg / mL probenecid to the wells before adding NMDs, and placing them in an incubator with 5% CO2 at 37°C for 30 minutes. Then discard the old medium and add DMEM F12 medium (containing 10% fetal bovine serum) with 40 μg / mL FITC-NMDs. Place the cell plate after adding drugs in an incubator with 5% CO2 at 37°C and culture for 2 hours. (3) Fluorescence observation: After the treatment time is over, discard the old medium, add 200 μL of HBSS to each well and wash 3 times, then place the cell plate under a fluorescence microscope for observation and photography.

[0124] The results are as Figure 6 shown. As can be seen from the figure, after the fluorescently labeled nanodrug (FITC-NMDs) is administered, it can be effectively taken up by HK-2 cells, and the HK-2 cells show bright green fluorescence. However, in the case of probenecid pretreatment or N-acetylcysteine co-incubation, the fluorescence intensity in HK-2 cells is significantly reduced after the administration of FITC-NMDs, indicating the active targeting of NMDs to anion transporter 1.

[0125] Example 14

[0126] Taking the molybdenum sulfide quantum dots NMDs modified with N-acetylcysteine synthesized in Example 1 as an example, the organelle distribution of NMDs in human renal tubular epithelial cells HK-2 was explored. The specific steps are as follows:

[0127] The steps for synthesizing fluorescently labeled nanodrugs (FITC-NMDs) were the same as those in Example 12.

[0128] The steps for culturing human renal tubular epithelial cells HK-2 were the same as those in Example 12.

[0129] Organelle distribution experiment of NMDs: (1) Seeding cells: HK-2 cells in the logarithmic growth phase were digested with trypsin, centrifuged, resuspended in DMEM F12 medium containing 10% fetal bovine serum to prepare a cell suspension. An appropriate amount of the cell suspension was added to a 24-well plate so that the cell density in each well was about 50%. The seeded cell plate was placed in an incubator at 5% CO2 and 37 °C for 12 h. (2) Adding drugs: After 12 h, the old medium was discarded, and DMEM F12 medium (containing 10% fetal bovine serum) containing 40 μg / mL FITC-NMDs was added. The cell plate after adding drugs was placed in an incubator at 5% CO2 and 37 °C for 2 h. After the incubation time ended, the old medium was discarded, and each well was washed 3 times with 200 μL of HBSS and then stained with ER-tracker (endoplasmic reticulum marker), Mito-tracker (mitochondria marker), Golgi-tracker (Golgi apparatus marker), Lyso-tracker (lysosome marker), and Hoechst 33342 (nucleus marker) according to the instructions. (3) Fluorescence observation: After fluorescence staining was completed, the old medium was discarded, and each well was washed 3 times with 200 μL of HBSS. Then the cell plate was placed under a fluorescence microscope for observation and photography, and the co-localization value of the nanodrug with each organelle was calculated using GraphPad Prism9.

[0130] The results are as Figure 7 shown. As can be seen from the figure, FITC-NMDs showed significant targeting specificity to mitochondria in HK-2 cells, and the Pearson correlation coefficient was 0.9138.

[0131] Example 15

[0132] Taking the molybdenum sulfide quantum dots NMDs modified with N-acetylcysteine synthesized in Example 1 as an example, the protective effects on the pathological morphology and renal function of the kidney tissues of AKI mice were explored. The specific steps are as follows:

[0133] Animal feeding and establishment of AKI model: Kunming mice (male, 5 weeks old, 23 - 25 g) were fed with standard diet and water for 7 days in a clean environment at 24 ± 2 °C with a 12-hour light / dark cycle. The method for establishing the AKI mouse model was as follows: After 15 hours of water deprivation, an equal volume of 50% glycerol (8 mL / kg) was intramuscularly injected into the bilateral hindlimbs of the mice, while the normal control group of mice was intramuscularly injected with normal saline under the same conditions.

[0134] Animal grouping, drug administration, and renal function detection: Kunming mice were randomly divided into the following three groups: normal mice + PBS group, AKI mice + PBS group, and AKI mice + 2 mg / kg NMDs group, with 6 mice in each group. Two hours after the establishment of the AKI model, NMDs or an equal volume of 1×PBS was injected into the tail vein of the AKI mice, and an equal volume of 1×PBS was injected into the tail vein of the normal mice. Twenty-four hours after the model was established, the mice in each group were euthanized, and the blood of the mice was collected. The supernatant was obtained by centrifuging at 3000 g for 15 minutes, and the renal function of the mice was evaluated using creatinine (CRE) and blood urea nitrogen (BUN) detection kits. The kidneys of the mice were collected and fixed in 4% paraformaldehyde solution for more than 24 hours. Subsequently, they were immersed in paraffin for embedding, sectioned, and then stained with H&E to evaluate the pathological changes of the mouse renal tissue.

[0135] Paraffin embedding and sectioning of renal tissue: The fixed renal tissue was placed in an embedding cassette and rinsed with running water to remove the fixative remaining in the tissue. The embedding cassette was immersed in gradient ethanol for dehydration, and then immersed in xylene to dissolve the tissue with the embedding medium for infiltration. The clarified tissue block was placed in the melted paraffin, put into a wax melting box and incubated overnight. The wax-impregnated tissue material was placed in the center of a metal embedding frame filled with wax liquid. After dropping wax, it was transferred to ice. After the surface of the wax liquid solidified, the pre-embedded tissue was clamped with forceps, the tissue direction was adjusted, and it was inserted into the wax liquid. The lidless embedding cassette was placed flat on the surface of the mold, covered, wax liquid was dropped to cover the mold, gently pressed, and placed in the solidification area until the wax block was completely solidified. It was cooled at 0 °C for about 30 minutes. The embedded wax block was fixed on a microtome and cut into 4-μm thick slices. The cut slices were placed in heated water to flatten them, then pasted onto glass slides and dried in an incubator at 65 °C to obtain renal tissue sections.

[0136] H&E staining: The steps of paraffin embedding and sectioning of each organ tissue were the same as those in Example 11. Subsequently, the tissue sections were immersed in xylene twice for dewaxing, 5 minutes each time, and then immersed in absolute ethanol twice, 5 minutes each time. Subsequently, they were immersed in gradient ethanol (90%, 80%, 70%) once each, 3 minutes each time. The sections were gently rinsed with PBS and the excess liquid around the samples was carefully blotted dry with filter paper. After dewaxing the sections, hematoxylin staining solution was dropped onto the tissue to ensure complete coverage of the tissue, and stained for 10 - 15 minutes. Rinse with running water to wash away the excess staining solution. Differentiate with 1% hydrochloric acid alcohol solution, and return to blue in water for 2 minutes. Eosin staining solution was dropped onto the tissue and stained for about 10 seconds. After eosin staining, immediately immerse in absolute ethanol for dehydration twice (2 minutes each time). Immerse in xylene twice (2 minutes each time), air dry naturally in the fume hood for 10 - 30 minutes, and seal the sections with neutral resin.

[0137] The results were as Figure 8 shown. As can be seen from the figure, NMDs can effectively restore the renal tissue pathological morphology and renal function of AKI mice.

[0138] Example 16

[0139] Taking the N-acetylcysteine-modified molybdenum sulfide quantum dots NMDs synthesized in Example 1 as an example, the effects on the ROS, mARC and GSH levels in the renal tissue of AKI mice were explored. The specific steps were as follows:

[0140] The steps of animal feeding and establishment of AKI model were the same as those in Example 15.

[0141] The steps of animal grouping and administration were the same as those in Example 15.

[0142] The steps of paraffin embedding and sectioning of renal tissue were the same as those in Example 15.

[0143] ROS staining of renal tissue: The renal tissue sections were immersed in xylene twice for dewaxing, 5 minutes each time, and then immersed in absolute ethanol twice, 5 minutes each time. Subsequently, they were immersed in gradient ethanol (90%, 80%, 70%) once each, 3 minutes each time. The sections were gently rinsed with PBS and the excess liquid around the samples was carefully blotted dry with filter paper. Subsequently, the working solution of DHE fluorescent probe was dropped to cover the tissue area, incubated at 37°C in the dark for 30 minutes, thoroughly rinsed with HBSS buffer to remove the unbound probe, and after sealing with an anti-fluorescence quenching mounting medium, the red fluorescence images of the renal tubular area were observed and collected under a fluorescence microscope, and the fluorescence intensity was quantified by image analysis software.

[0144] Immunofluorescence staining of mARC in renal tissue: The renal tissue sections were immersed in xylene twice for dewaxing, 5 minutes each time, and then immersed in absolute ethanol twice, 5 minutes each time. Subsequently, they were immersed in gradient ethanol (90%, 80%, 70%) once each, 3 minutes each time. The sections were gently rinsed with PBS and the excess liquid around the samples was carefully blotted with filter paper. The dewaxed sections were immersed in 1×Tris-EDTA repair solution and incubated in a water bath at 95°C for 15 minutes and then cooled naturally. They were washed 3 times with PBST (3 minutes each time). The non-specific binding sites were blocked with 5% bovine serum albumin for 1 hour and then washed 3 times with PBST (3 minutes each time). The working solution of the anti-mARC primary antibody was added and incubated overnight at 4°C. After washing with PBST, the fluorescent secondary antibody was added and incubated in the dark for 1 hour. The nuclei were stained with DAPI for 5 minutes. After mounting, the samples were observed under a fluorescence microscope.

[0145] Detection of GSH level in renal tissue: Fresh renal tissue samples were taken, added with lysis buffer and homogenized on ice bath. After centrifugation, the supernatant was taken and the GSH level was detected using a commercial kit.

[0146] The results are as Figure 9 shown. As can be seen from the figure, NMDs can effectively reduce the ROS level in the renal tissue of AKI mice and restore the contents of mARC and GSH, showing a synergistic effect of "clearing externally and strengthening internally".

[0147] Example 17

[0148] Taking the N-acetylcysteine-modified molybdenum sulfide quantum dots NMDs synthesized in Example 1 as an example, the inhibition of cell apoptosis in AKI mice was explored. The specific steps are as follows:

[0149] The steps of animal feeding and establishment of AKI model were the same as those in Example 15.

[0150] The steps of animal grouping and drug administration were the same as those in Example 15.

[0151] The steps of paraffin embedding and sectioning of renal tissue were the same as those in Example 15.

[0152] Detection of apoptosis index by TUNEL staining: The renal tissue sections were immersed in xylene twice for dewaxing, 5 minutes each time, and then immersed in absolute ethanol twice, 5 minutes each time. Subsequently, they were immersed in gradient ethanol (90%, 80%, 70%) once each, 3 minutes each time. The sections were gently rinsed with PBS and the excess liquid around the samples was carefully blotted with filter paper. Prepare Proteinase K working solution, TdT incubation buffer, Equilibration Buffer, 0.1% TritonX-100 and 5% bovine serum albumin according to the instructions. Add an appropriate amount of Proteinase K working solution to the samples and incubate at room temperature for 20 minutes; rinse the samples with PBST 2-3 times, 5 minutes each time; add 60 μL of Equilibration Buffer to each sample and incubate at room temperature for 20 minutes; remove most of the 1X Equilibration Buffer, add 50 μL of TdT incubation buffer to the samples, and incubate in the dark in a humid box at room temperature for 60 minutes; remove the incubation solution and wash with PBS (5 minutes); wash 3 times with PBS containing 0.1% TritonX-100 and 5% bovine serum albumin, 5 minutes each time; add an anti-fluorescence quencher containing DAPI to the samples and then mount the coverslips, observe and take pictures under a fluorescence microscope, and scan the fluorescence intensity with Image J.

[0153] The results are as Figure 10 shown. As can be seen from the figure, NMDs can effectively inhibit the apoptosis of renal tissue in AKI mice.

[0154] Example 18

[0155] Taking the molybdenum sulfide quantum dots NMDs modified with N-acetylcysteine synthesized in Example 1 as an example, explore its inhibitory effect on inflammatory cell infiltration in AKI mice. The specific steps are as follows:

[0156] The steps of animal feeding and establishment of AKI model are the same as those in Example 15.

[0157] The steps of animal grouping and administration are the same as those in Example 15.

[0158] Immunohistochemical staining of inflammatory cell infiltration: The renal tissue sections were immersed in xylene twice for dewaxing, 5 minutes each time, and then immersed in absolute ethanol twice, 5 minutes each time. Subsequently, they were immersed in gradient ethanol (90%, 80%, 70%) once each, 3 minutes each time. The sections were gently rinsed with PBS and the excess liquid around the samples was carefully blotted with filter paper. The dewaxed sections were immersed in 1×Tris-EDTA repair solution and incubated in a water bath at 95°C for 15 minutes and then cooled naturally. They were washed with PBST 3 times (3 minutes each time). Then, an appropriate amount of endogenous peroxidase blocker was added dropwise to the tissue samples on the sections (completely covering the tissue), and they were incubated in a wet box at 37°C for 20 minutes and washed with PBST 3 times (3 minutes each time). Subsequently, the tissue sections were placed in a wet box, and an appropriate amount of 5% bovine serum albumin was added dropwise to the samples and blocked at 37°C for 1 hour and washed with PBST 3 times (3 minutes each time). An appropriate amount of primary antibody working solution of neutrophil marker Ly-6G or macrophage marker F4 / 80 was added dropwise to the samples, and they were incubated in a wet box at 4°C overnight. After incubation, they were rewarmed for 30 minutes and washed with PBST 3 times (2 minutes each time). An appropriate amount of reaction enhancer was added dropwise to the samples and incubated at 37°C for 20 minutes and washed with PBST 3 times (2 minutes each time). An appropriate amount of enzyme-labeled goat anti-mouse / rabbit IgG polymer was added dropwise to the samples and incubated at 37°C for 30 minutes and washed with PBST 3 times (2 minutes each time). An appropriate amount of DAB chromogenic solution (A solution: B solution = 1:20) was added dropwise to the samples and incubated at room temperature for 5 - 8 minutes. Observation was carried out under the microscope until brownish-yellow positivity appeared, and the tissue sections were immersed in tap water to terminate the reaction. An appropriate amount of hematoxylin was added dropwise to the samples for counterstaining for 10 seconds, carefully rinsed for 2 minutes, and differentiated in 1% hydrochloric acid ethanol for 1 second. The tissue sections were dehydrated by immersing them successively in the following liquids: 75% ethanol (6 minutes), 95% ethanol (6 minutes), absolute ethanol (6 minutes). Finally, a small amount of neutral resin was added dropwise to the sample tissue, a clean coverslip was covered, and gently pressed to allow the neutral resin to spread, and photographs were taken under the microscope.

[0159] The results are as Figure 11 shown. As can be seen from the figure, NMDs can significantly reduce the inflammatory cell infiltration in the renal tissue of AKI mice.

[0160] Example 19

[0161] Taking the molybdenum sulfide quantum dots NMDs modified with N-acetylcysteine synthesized in Example 1 as an example, its short-term and long-term safety in vivo was explored. The specific steps are as follows:

[0162] The animal feeding steps were the same as those in Example 15.

[0163] Short-term safety: Animal grouping and administration: Normal Kunming mice were randomly divided into two groups: the S-PBS group and the S-NMDs group, with 6 mice in each group. 100 μL of 1×PBS was injected into the tail vein of the S-PBS group, and 100 μL of the NMDs solution (10 mg / kg) was injected into the tail vein of the S-NMDs group. The mice were euthanized 24 h after injection, and the main organs (heart, liver, spleen, lung, and kidney) were collected for H&E staining.

[0164] Long-term safety: Animal grouping and administration: Normal Kunming mice were randomly divided into two groups, the L-PBS group and the L-NMDs group, with 6 mice in each group. 100 μL of 1×PBS was injected into the tail vein of the L-PBS group, and 100 μL of the NMDs solution (2 mg / kg) was injected into the tail vein of the L-NMDs group. The injection was performed once a week for four weeks. After 28 days, the main organs (heart, liver, spleen, lung, and kidney) of the mice were collected for H&E staining.

[0165] The steps of H&E staining were the same as those in Example 15.

[0166] The results are as Figure 12 shown. As can be seen from the figure, after a single high-dose injection of NMDs (10 mg / kg) or long-term injection of NMDs (treatment dose 2 mg / kg, once a week for four weeks) in normal mice, there was no obvious damage to the main organs of the mice, namely the heart, liver, spleen, pancreas, and kidney, indicating good biosafety.

[0167] In the experimental methods of the above Examples 10-19, the experimental reagents not clearly given, such as working solutions, fixing solutions, primary antibodies, secondary antibodies, etc., are all commonly used reagents in the art.

[0168] Obviously, the above examples are only for clear illustration and not for limitation of the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. Application of N-acetylcysteine-modified molybdenum disulfide quantum dots in the preparation of drugs for treating acute kidney injury.

2. The application according to claim 1, characterized in that Application of the N-acetylcysteine-modified molybdenum disulfide quantum dots in the preparation of drugs for treating acute kidney injury that can achieve the synergy of oxidative stress blockade and endogenous antioxidant repair.

3. The application according to claim 1, characterized in that The N-acetylcysteine-modified molybdenum disulfide quantum dots have the ability of mitochondrial targeting to PTECs.

4. The application according to any one of claims 1 to 3, characterized in that The N-acetylcysteine-modified molybdenum disulfide quantum dots are spherical in shape and have a particle size between 4 and 8 nm.

5. The application according to claim 4, wherein The N-acetylcysteine-modified molybdenum disulfide quantum dots are prepared by hydrothermal reaction using ammonium molybdate, thiourea and N-acetylcysteine as raw materials.

6. The application according to claim 5, wherein The ammonium molybdate and thiourea are used as precursors, and the N-acetylcysteine is used as a capping agent.

7. The application according to claim 5, wherein The mass ratio of ammonium molybdate, N-acetylcysteine and thiourea is 500-800 mg: 200-400 mg: 80-100 mg.

8. The application according to claim 5, characterized in that, The temperature of the hydrothermal reaction is 200-250 °C, and the duration is 4-8 hours.

Images