Application of moutan bark derived carbon dots in treatment of acute myelogenous leukemia

Abstract

The invention discloses application of moutan bark derived carbon dots in a medicine for treating acute myelogenous leukemia. The moutan bark derived carbon dots obtained by high-temperature heating through a one-step hydrothermal method can significantly inhibit the cell activity of acute myelogenous leukemia, and show excellent oxidative damage resistance and STAT3 signal channel activation inhibition ability in an in-vivo acute myelogenous leukemia resistance experiment. The moutan bark derived carbon dots can significantly inhibit infiltration of acute myelogenous leukemia cells in the liver, spleen and bone marrow, greatly prolong the lifetime of mice with acute myelogenous leukemia, and have no significant toxicity to the weight, main tissue and blood biochemical indexes of the mice. The invention is expected to provide a new technology and a new preparation for acute myelogenous leukemia.

Description

Technical Field

[0001] This invention belongs to the field of traditional Chinese medicine application technology, specifically relating to the application of peony bark-derived carbon dots in the treatment of acute myeloid leukemia. Background Technology

[0002] Acute myeloid leukemia (AML) is a highly aggressive hematologic malignancy primarily caused by the abnormal clonal proliferation of myeloid progenitor cells. This disease is highly heterogeneous, progresses rapidly, and is usually accompanied by bone marrow failure and suppression of normal hematopoietic cell production, ultimately leading to severe conditions such as anemia, infection, bleeding, and organ infiltration. Although traditional chemotherapy, targeted therapy, and hematopoietic stem cell transplantation are the main treatments for AML, patient prognosis is often unsatisfactory. Existing treatment regimens face numerous challenges, including strong drug tolerance, significant side effects, and high treatment costs, necessitating the search for safe, efficient, and precise innovative treatment methods.

[0003] In AML cells, high levels of oxidative damage increase the probability of DNA damage and gene mutations, inducing drug resistance in leukemia cells and reducing the effectiveness of chemotherapy. Oxidative damage is often accompanied by activation of the STAT3 signaling pathway. STAT3 is a key transcription factor widely involved in cell proliferation, differentiation, survival, and immune regulation. Overactivation of STAT3 induces the expression of downstream genes (such as TNFα and IL-6), inhibits anti-tumor immune responses, and simultaneously enhances the proliferative capacity of AML cells, promoting the malignant progression of leukemia. Oxidative damage and overactivation of the STAT3 signaling pathway are important drivers of AML pathogenesis and progression, interacting to exacerbate disease deterioration. Therefore, inhibiting oxidative damage in AML cells and regulating the abnormal activation of the STAT3 signaling pathway can significantly reduce AML cell viability and slow disease progression, representing a novel anti-AML treatment strategy.

[0004] In recent years, with the rapid development of nanotechnology and biomedicine, novel nanomaterials have shown great potential in cancer treatment. Among them, carbon dots (CDs), as an emerging class of carbon-based nanomaterials, have gradually attracted widespread attention from researchers due to their excellent performance in structural stability, chemical property regulation, and biocompatibility. Carbon dots possess unique fluorescence properties, which can be used for diagnostic imaging, and also have the potential for antioxidant, targeted, and drug carrier applications, providing a multifunctional solution for cancer treatment. However, most current research focuses on the structure-activity relationship and preparation process optimization of carbon dots, while research on their application in AML treatment remains limited.

[0005] Functional carbon dots prepared based on traditional Chinese medicine (TCM) have the advantages of being environmentally friendly and sustainable. Meanwhile, enhancing the therapeutic effects of carbon dots by utilizing the bioactive components of TCM has become a research hotspot. Peony bark, as a traditional Chinese medicine, possesses potential pharmacological activities such as antioxidation, anti-inflammation, and anti-tumor activity. Its main components, such as paeonol and ginkgolic acid, have significant effects in inhibiting cancer cell proliferation. Combining the active components of peony bark with the unique properties of carbon dots to prepare peony bark-derived carbon dots can enhance the anti-AML effect by leveraging the natural pharmacological basis of peony bark and the unique properties of nanomaterials, such as the ability to scavenge reactive oxygen species (ROS), thereby achieving a synergistic effect between the pharmacology of TCM and the characteristics of nanomaterials. Summary of the Invention

[0006] Purpose of the Invention: In the face of problems such as strong drug tolerance, side effects, and high treatment costs in AML, the purpose of this invention is to provide the application of peony bark-derived carbon dots in drugs for the treatment of acute myeloid leukemia. These carbon dots are easy to prepare, can inhibit oxidative damage and the STAT3 signaling pathway in AML, reduce AML cell viability, and have in vivo safety.

[0007] Technical solution: In order to solve the above-mentioned technical problems, the present invention provides the application of peony bark-derived carbon dots in drugs for treating acute myeloid leukemia.

[0008] The peony bark-derived carbon dots are prepared from peony bark, a traditional Chinese medicine, using a one-step hydrothermal method.

[0009] The one-step hydrothermal method specifically includes the following steps:

[0010] (1) Grind the peony bark into a fine powder and dissolve it in ultrapure water to obtain a mixture. The mass-volume ratio of the finely ground peony bark powder to pure water is 1:5 g / mL to 1:50 g / mL.

[0011] (2) Place the mixture in a hydrothermal reactor and react at a temperature of 160~300℃.

[0012] (3) After cooling, further processing by filtration, vacuum filtration, dialysis and vacuum freeze drying yields the most peony bark-derived carbon dots.

[0013] Preferably, the mass-to-volume ratio of finely ground peony bark powder to pure water is 1:10 g / mL, the reaction temperature is 180℃, and the reaction time is 6h.

[0014] The average particle size of the peony bark-derived carbon dots is 4.8 ± 0.5 nm. They exhibit a maximum fluorescence excitation at 360 nm and a maximum fluorescence emission at 450 nm, with a quantum yield (QY) of 8.5 ± 0.6%.

[0015] The concentration of the peony bark-derived carbon dot solution is 1~100 µg / mL.

[0016] Preferably, the concentration of the peony bark-derived carbon dot solution is 50 µg / mL.

[0017] The dosage form of the drug includes liquid preparations, tablets, capsules, or dry suspensions.

[0018] The drug can inhibit the activity of acute myeloid leukemia cells but does not affect normal cells.

[0019] The drug can reduce oxidative damage in acute myeloid leukemia (AML) cells and inhibit the activation of the STAT3 signaling pathway. Furthermore, the drug exhibits excellent in vivo anti-AML oxidative damage capabilities.

[0020] The drug can significantly inhibit the infiltration of acute myeloid leukemia cells in the liver, spleen and bone marrow, and greatly prolong the survival of mice with acute myeloid leukemia.

[0021] The peony bark-derived carbon dots showed no significant toxicity to mouse body weight, major tissues, and blood biochemical indicators.

[0022] The dosage of the peony bark-derived carbon dots is 1~100 mg / kg.

[0023] Preferably, the in vivo dosage of the peony bark-derived carbon dots is 25 mg / kg.

[0024] The in vivo administration methods of the peony bark-derived carbon dots include, but are not limited to, intravenous injection.

[0025] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0026] (1) The present invention adopts a one-step hydrothermal method, using natural Chinese herbal medicine peony bark as raw material. The preparation process is simple, economical, efficient and environmentally friendly, suitable for large-scale production, and helps to significantly reduce the cost of AML treatment.

[0027] (2) The peony bark-derived carbon dots prepared in this invention block the proliferation and invasion of AML cells from the root by simultaneously inhibiting oxidative damage and activation of the STAT3 signaling pathway in AML cells. The dual mechanism of action significantly prolongs the survival time of AML model mice and significantly improves the therapeutic effect, showing good potential for clinical translation.

[0028] (3) The present invention demonstrates through experiments that the carbon dots derived from peony bark have no obvious toxicity to normal tissues and cells, and that there are no significant changes in the weight and blood biochemical indicators of mice. Compared with traditional chemotherapy drugs, it reduces the side effects of treatment and shows excellent in vivo safety.

[0029] (4) The peony bark-derived carbon dots prepared in this invention can effectively inhibit the infiltration of AML cells in the liver, spleen and bone marrow, delay the systemic spread of AML disease and reduce damage to the patient's normal physiological functions.

[0030] In summary, the peony bark-derived carbon dots of the present invention have significant advantages in the treatment of acute myeloid leukemia (AML), providing a safe, efficient, and low-cost novel treatment strategy for AML patients. This solves the problems of strong drug resistance, significant side effects, and high treatment costs in existing technologies, and has broad application prospects. Attached Figure Description

[0031] Figure 1 Figure 1 shows the synthesis and characterization results of peony bark-derived carbon dots; where a is a schematic diagram of the synthesis process of peony bark-derived carbon dots (MCDs); b is a transmission electron microscope (TEM) image of MCDs, with the inset showing the size distribution of MCDs; c is the UV-Vis absorption spectrum, excitation spectrum, and emission spectrum of MCDs, with the inset showing images of MCDs solution under UV light (i) and sunlight (ii); d is a quantum yield (QY) analysis diagram of MCDs.

[0032] Figure 2 The following figures illustrate the therapeutic effects of MCDs on AML mice: a) Schematic diagram of animal experiments (n = 10); b) H&E staining of major organ sections; c) Liver and spleen weights; d) Wright-Giemsa staining of nucleated cells in bone marrow, with black circles indicating infiltrating leukemia cells; e) DCFH staining image of nucleated cells in bone marrow; f) Quantitative data of DCFH staining images obtained using ImageJ software; g) Malondialdehyde (MDA) levels in each group; h) Quantitative results of STAT3 and p-STAT3 expression; i) Serum levels of pro-inflammatory cytokines TNF-α and IL-6.

[0033] Figure 3 The following figures illustrate the therapeutic effects of MCDs on AML mice: a) Immunohistochemical (IHC) staining images of STAT3 and p-STAT3 in nucleated cells of bone marrow; b) Survival curves for each group (n = 10); c) Routine blood data of mice; d) Serum indicators of liver and kidney function in mice.

[0034] Figure 4 The following figures illustrate the therapeutic effects of MCDs on AML mice: a) Schematic diagram of animal experiments (n = 10); b) Changes in body weight; c) Hemolysis rate at different concentrations of MCDs; d) Blood circulation curve of MCDs; e) Biodistribution of MCDs in major organs; f) H&E staining of sections from major organs; g) Routine blood data of mice; h) Serum indicators of liver and kidney function in mice. Detailed Implementation

[0035] All data in this invention are expressed as mean ± standard deviation (SD). Statistical analysis and graphing were performed using GraphPad Prism 8 software. Differences between two groups were assessed using a two-tailed Student's t-test. For comparisons between three or more groups, one-way or two-way ANOVA was used, supplemented by multiple comparison tests by Tukey or Sidak as appropriate. Differences in animal survival rates were assessed using the Kaplan-Meier method, and p-values ​​were determined using a log-rank test. Statistical significance was defined as p < 0.05.

[0036] Example 1: Preparation and characterization of carbon dot MCDs from peony bark

[0037] The preparation method of peony bark carbon dots MCDs is consistent with previous studies (the specific preparation method and characterization results are consistent with Chinese patent application CN 119015343A). 5 g of peony bark (purchased from Anhui Huchuntang Traditional Chinese Medicine Pieces Co., Ltd., batch number: 240301, origin: Jiangsu) was ground into a fine powder using a pulverizer. The peony bark powder and water were added to a hydrothermal reactor at a mass-to-volume ratio of 1:10 g / mL, and the reaction was heated at 180℃ for 6 h. The heated product, after cooling overnight, was subjected to filtration, vacuum filtration through a 0.22 μm aqueous membrane, dialyzing through a 1000 D dialysis bag for 72 h, and vacuum freeze-drying at -50℃. The final product yield was 13%, and it was stored at -20℃ for a long period and named MCDs (…). Figure 1 (a) in the middle.

[0038] MCDs were observed using a transmission electron microscope (TEM, FEI Tecnai F20), and they exhibited a uniform size distribution with an average particle size of 4.8 ± 0.5 nm, showing a Gaussian distribution. Figure 1 (b) Furthermore, evaluation of optical performance indicates that MCDs possess a broad ultraviolet absorption peak ( Figure 1 (c) This proves the successful preparation of carbon dots. Meanwhile, the MCDs exhibit a maximum fluorescence excitation peak at 360 nm and a maximum emission peak at 450 nm ( Figure 1 c), the quantum yield (QY) is 8.5% ( Figure 1 (d) in the figure conforms to the photoluminescence property of carbon dots.

[0039] Example 2: Effects of MCDs on the cell viability of AML and normal cells

[0040] The cell lines used in this invention were derived from the Cell Resource Center of the Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, including HL-1 (normal mouse cardiomyocytes) and C1498 (small acute myeloid leukemia cells). HL-1 cells were cultured in Claycomb medium (Sigma, 51800C) supplemented with 100 μM adrenaline (abcam, 1236970) and 4 mM glutamine (abcam, G8540); C1498 cells were cultured in DMEM medium (Gibco, 10564045); all media were supplemented with 10% fetal bovine serum (HyClone), 100 units / mL penicillin (Thermo Fisher), and 100 μg / mL streptomycin (Thermo Fisher), and cultured at 37°C under 5% CO2 humidity.

[0041] Cell viability was assessed using a CCK-8 assay kit (Yeasen). The MCDs prepared in Example 1 were added to the corresponding culture media in 96-well plates to achieve final concentrations of 0, 1, 25, 50, and 100 μg / mL. HL-1 and C1498 cells (5 × 10⁻⁶ cells / well) were then cultured. 3 Cells were seeded into 96-well plates and cultured overnight. Then, they were treated with different concentrations of MCDs and cultured for 24 h, 48 h, and 72 h. At each time point, 10 μL of CCK-8 reagent was added to each well and incubated for 1 h. The absorbance was then measured at 450 nm using a BioTek microplate reader. The results are shown in Tables 1 and 2.

[0042] Table 1. Effects of different concentrations of MCDs on the viability of acute myeloid leukemia cells (C1498) (%)

[0043] Table 2. Effects of different concentrations of MCDs on the viability of normal cells (HL-1) (%)

[0044] As shown in Tables 1 and 2, MCDs significantly inhibited C1498 cell viability without affecting normal cells. After 72 h of incubation, 50 μg / mL of MCDs inhibited 50% of AML cell viability, and the higher the MCD concentration, the better the inhibitory effect. Furthermore, the longer the MCD treatment time for AML cells, the more pronounced the inhibitory effect (Table 1). More importantly, within 24 to 72 h, MCDs of 1–100 μg / mL had no effect on the cell viability of normal cells (Table 2).

[0045] Example 3: Therapeutic effect of MCDs on AML mice

[0046] 1. AML mouse experimental protocol

[0047] By injecting 1×10 into the tail vein of male C57BL / 6J mice 6 An AML mouse model was established by inducing the use of C1498 cells. Eight-week-old male C57BL / 6J mice were randomly divided into three groups: PBS (10 mM, pH 7.4) (healthy group), C1498 (model group), and MCDs (treatment group) (n=6 per group). On day 0, C1498 cells were injected into the tail vein of mice in the C1498 and MCDs groups to establish the AML model, while the PBS group was injected with 100 μL of PBS as a healthy control. On days 10, 12, and 14, mice in the MCDs group received MCDs (MCDs prepared in Example 1 were dissolved in PBS to prepare an MCDs solution, which was intravenously injected, MCDs 25 mg / kg mice) for treatment, while mice in the PBS and C1498 groups were injected with 100 μL of PBS. The weight changes of mice were monitored daily during the experiment. On day 20, blood samples were collected, and mice were subsequently sacrificed and tissues such as heart, liver, spleen, lung, kidney, and bone marrow cells were removed. The collected tissues were stained with H&E, and bone marrow cells were subjected to DCFH staining, Wright-Giemsa staining, and immunofluorescence (IF) analysis of STAT3 and p-STAT3. In addition, a parallel experiment was conducted to investigate the effect of MCDs on the survival time of AML mice. The experiment consisted of three groups: a PBS group (control group), a C1498 group (model group), and an MCDs group (treatment group) (n=10 in each group) to assess mouse survival outcomes and record survival time. Mice whose body weight decreased by more than 20% compared to pre-treatment levels were euthanized.

[0048] 2. Immunofluorescence (IF) detection experiment

[0049] After fixing bone marrow nucleated cells, specific primary antibodies against STAT3 (Abcam, ab68153, 1:200) and p-STAT3 (Abcam, ab76315, 1:500) were added, and the cells were incubated overnight at 4°C. Subsequently, the cells were washed three times with TBST for 5 min each time. Next, secondary antibodies were added under light-protected conditions: either Alexa Fluor 647-labeled secondary antibody (Abcam, ab300101, 1:100, for STAT3 detection) or Alexa Fluor 488-labeled secondary antibody (Abcam, ab150077, 1:500, for p-STAT3 detection), and incubation continued. After incubation, the cells were washed three more times with TBST for 5 min each time, followed by staining with DAPI (Beyotime, C1005). After incubation at room temperature for 5 min, the staining solution was removed, and the cells were washed three more times with TBST for 5 min each time. Finally, the samples were directly observed and analyzed under a fluorescence microscope.

[0050] 3. ELISA testing

[0051] The following kits were used: TNF-α ELISA kit (Absin, abs520010), IL-6 ELISA kit (Absin, abs520004), and MDA ELISA kit (Absin, abs554411). The experimental procedure was as follows: Following the kit instructions, bone marrow nucleated cells were collected by centrifugation at 1000 rpm for 5 min, and 500 μL of lysis buffer (thermo, 89900) was added to lyse the cells. 100 μL of standard solution, control samples (bone marrow nucleated cell lysates from healthy and model mice), and experimental samples (bone marrow nucleated cell lysates from treatment mice) were added in triplicate to pre-coated 96-well microplates. The plates were then incubated at 37°C. After incubation, the liquid was removed, the plates were washed with the provided washing buffer, and then the detection antibody solution was added. The following steps are: re-incubation, washing, addition of enzyme conjugate, washing to remove unbound enzyme conjugate, addition of substrate solution for color development, and finally stopping the reaction with stop solution. Once the standard wells show an appropriate color gradient, immediately measure the absorbance at 450 nm using a microplate reader.

[0052] 4. Hematoxylin and eosin (H&E) and Wright-Giemsa staining experiments

[0053] H&E staining of heart, liver, spleen, lung, kidney, and colon tissues was performed as follows: After dewaxing and rehydration, sections were stained with hematoxylin for 5 min, differentiated with hydrochloric acid ethanol, and then blued again with ammonia. Eosin staining was then performed for 3 min, followed by dehydration, clearing, and mounting. Under a light microscope, cell nuclei appeared blue-purple, while the cytoplasm and extracellular matrix appeared pink. For Wright-Giemsa staining of nucleated bone marrow cells, after air-drying the cell smear, Wright-Giemsa staining was performed for 5 min, diluted with buffer, and stained for another 10 min. The smears were then rinsed and air-dried again. Under a microscope, cell nuclei appeared purplish-blue, while the cytoplasm ranged from pink to blue depending on the cell type.

[0054] 4. Experimental Results

[0055] Inspired by our MCDs cell experiments, we explored the therapeutic effects and mechanisms of MCDs on AML mice. We established a mouse AML model by intravenous injection of C1498 cells, and the experiment was divided into three groups: PBS (healthy group), C1498 (model group), and MCDs (treatment group). Figure 2 (a) After treatment with MCDs, the AML cell infiltration and inflammatory damage observed in the spleen and liver of mice were significantly reduced, approaching the levels observed in the PBS group ( Figure 2 (b) Compared with the C1498 group, the MCDs group showed significantly reduced splenomegaly and hepatomegaly ( Figure 2 c). Analysis of nucleated cells in mouse bone marrow showed a significant reduction in leukemia cells in the MCDs treatment group ( Figure 2 In addition, the results of detecting intracellular ROS levels in bone marrow cells showed that DCFH staining and quantitative analysis revealed a significant decrease in intracellular ROS levels after MCDs treatment. Figure 2 (e and f in the text), this result is also supported by MDA content analysis ( Figure 2 (g in the original text). Subsequently, we investigated the effect of MCDs on STAT3 regulation in AML cells. Immunofluorescence analysis and quantification showed that MCDs significantly inhibited the expression of STAT3 and p-STAT3 (g in the original text). Figure 2 h and Figure 3 (a) Decreased STAT3 and ROS levels are associated with suppressed expression of pro-inflammatory cytokines TNF-α and IL-6, thereby alleviating systemic inflammation induced by AML. Figure 2 (i). Notably, MCDs treatment significantly prolonged the survival time of AML mice ( Figure 3 (b) In addition, MCDs also restored blood parameters and serum biochemical indicators in AML mice to normal ( Figure 3(c and d in the text). In summary, MCDs demonstrated the ability to alleviate systemic inflammation induced by AML, halt the progression of AML, and prolong the lifespan of AML mice by regulating STAT3, p-STAT3, and ROS levels.

[0056] Example 4: In vivo safety experiment of MCDs

[0057] 1. Safety test protocol

[0058] In the safety assessment, 8-week-old female BALB / c mice were randomly assigned to two groups (PBS group and MCDs group, n = 10). Mice received intravenous injections of either PBS (100 μL) or MCDs (MCDs prepared in Example 1 were dissolved in PBS to prepare the MCDs solution, MCDs 25 mg / kg mice). Body weight was monitored daily. On day 60, mice were sacrificed, and blood and serum samples were collected for complete blood cell counts and serum biochemical analysis. Tissues from the heart, liver, spleen, lungs, and kidneys were collected for H&E staining. Whole blood was analyzed using a Mindray Veterinary Automated Hematology Analyzer to measure red blood cells (RBC), white blood cells (WBC), platelets (PLT), and hemoglobin (HGB). Serum samples were prepared by incubating whole blood at room temperature for 2 h, followed by centrifugation at 300 rpm at 4°C for 15 min. The supernatant was immediately analyzed using an automated biochemical analyzer.

[0059] 2. Blood compatibility test

[0060] Blood compatibility assessment of MCDs was performed using 1 mL of mouse blood. Red blood cells were separated by repeated centrifugation. Subsequently, 50 μL of red blood cell suspension was mixed with 450 μL of MCDs at different concentrations (MCDs prepared in Example 1 were dissolved in PBS to prepare MCD solutions with final concentrations of 1, 5, 10, 20, 50, 100, and 500 μg / mL) and incubated at 37°C for 3 h. Red blood cells treated with PBS and water were used as controls. After centrifugation of the mixture, the absorbance of the supernatant at 570 nm was measured to determine the hemolysis rate.

[0061] 3. Pharmacokinetics and Biodistribution

[0062] To assess the in vivo blood metabolism and distribution of MCDs, a functionalized fluorescent probe Cy5.5-NH2 (MCE, HY-D1540) was conjugated to MCDs. 2 mg of the MCDs prepared in Example 1 were dissolved in 2 mL of MES buffer (MCE, HY-D0858). 5 mg of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (Sigma, E7750) and 5 mg of N-hydroxysuccinimide (Sigma, 130672) were added, and the reaction was stirred at room temperature for 30 min. The activated carbon dot solution was dialyzed for 24 h (1000 D), and 0.2 mg of Cy5.5-NH2 was added. The reaction was carried out under light-protected conditions with magnetic stirring for 12 h. After completion, the reaction solution was dialyzed for another 24 h (1000 D), and finally freeze-dried at -50 °C to obtain Cy5.5-conjugated MCDs. Healthy BALB / c mice (n = 3) were intravenously injected with PBS (100 μL) or MCDs conjugated with Cy5.5 (25 mg / kg). Blood samples (100 μL) were collected from the orbital vein at specified time points (1, 2, 4, 6, 8, 10, 12, 24, and 48 h) and dissolved in PBS (anticoagulant) containing 10 mM EDTA. Fluorescence in these blood samples was measured to determine the blood metabolism and half-life of the MCDs. To assess biodistribution, mice (n = 3) in both the PBS and MCDs groups were sacrificed at different time points (4, 12, 24, and 48 h) after injection. Major organs (heart, liver, lungs, spleen, and kidneys) were harvested, homogenized, and MCD concentrations were determined by fluorescence analysis. Results are expressed as a percentage of the injected dose per gram of tissue (%ID / g).

[0063] 4. Experimental Results

[0064] To assess the in vivo safety of these carbon dots, we performed a tail vein injection test on healthy mice. The study was conducted in two groups: the PBS group (healthy group) and the MCDs group (treatment group). Figure 4 (a) Long-term monitoring of mouse body weight showed that MCDs had no significant effect on mice ( Figure 4 (b) Furthermore, the hemolysis assay further demonstrates the good in vivo safety of MCDs ( Figure 4 (c in the text)

[0065] Blood circulation analysis in mice over 48 hours showed that the plasma half-life of MCDs was 1.87 hours, and the blood concentration of MCD decreased to 5.2% at 48 hours. Figure 4 (d in the text). Tissue biodistribution analysis showed that MCDs mainly accumulated in mouse liver, with concentrations remaining around 30% over 48 hours. Figure 4(e). After 60 days of MCDs administration, H&E staining of major mouse tissues showed that the MCDs had minimal toxicity to the heart, liver, spleen, lungs, and kidneys. Figure 4 (f in the text). Furthermore, no significant differences were observed in blood parameters and serum biochemical indicators between the MCD treatment group and the PBS control group mice (f in the text). Figure 4 g and Figure 4 (h in the text). These results indicate that MCDs have excellent in vivo safety and have potential application prospects in translational research for anti-inflammatory applications.

Claims

1. Application of peony bark-derived carbon dots in drugs for the treatment of acute myeloid leukemia.

2. The application according to claim 1, characterized in that, The peony bark-derived carbon dots are prepared from the traditional Chinese medicine peony bark through a one-step hydrothermal method.

3. The application according to claim 1, characterized in that, The one-step hydrothermal method specifically includes the following steps: (1) Grind the peony bark into a fine powder and dissolve it in ultrapure water to obtain a mixture. The mass-volume ratio of the finely ground peony bark powder to pure water is 1:5 g / mL to 1:50 g / mL. (2) Place the mixture in a hydrothermal reactor and react at a temperature of 160~300℃. (3) After cooling, further processing by filtration, vacuum filtration, dialysis and vacuum freeze drying yields the most peony bark-derived carbon dots.

4. The application according to claim 1, characterized in that, The average particle size of the carbon dots derived from peony bark is 4.8 ± 0.5 nm.

5. The application according to claim 1, characterized in that, The concentration of carbon dots derived from peony bark is 1~100 µg / mL.

6. The application according to claim 1, characterized in that, The dosage forms of the drug include liquid preparations, tablets, capsules, or dry suspensions.

7. The application according to claim 1, characterized in that, The drug can inhibit the activity of acute myeloid leukemia cells but does not affect normal cells.

8. The application according to claim 1, characterized in that, The drug can reduce oxidative damage to acute myeloid leukemia cells and inhibit the activation of the STAT3 signaling pathway.

9. The application according to claim 1, characterized in that, The drug can significantly inhibit the infiltration of acute myeloid leukemia cells in the liver, spleen and bone marrow, and greatly prolong the survival of mice with acute myeloid leukemia.

10. The application according to claim 1, characterized in that, The dosage of the peony bark-derived carbon dots is 1~100 mg / kg.

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