Drug screening method based on comprehensive survival index and application thereof

Abstract

The invention discloses a drug screening method based on a comprehensive survival index and application thereof, and belongs to the technical field of drug screening, and the drug screening method comprises the following steps: (1) constructing a disease experimental animal model, and obtaining the survival time, the survival rate, the tumor quality, the net body quality and the pulmonary nodule number of an experimental animal after the experimental animal is administered with a drug; (2) acquiring area data on a net body mass change rate curve according to the net body mass data; acquiring tumor control coefficient data according to the tumor quality and the net body quality; and (3) standardizing the data of the survival rate, the survival time, the area on the net body mass change rate curve and the number of pulmonary nodules by using a summation normalization method. The method provided by the invention can accurately judge the treatment effect of each medicine on diseases and the protection condition of each medicine on body health, objectively reflect the progress condition and prognosis effect of the diseases, screen out the medicine with a good comprehensive treatment effect, and provide more accurate data support for clinical and experimental research.

Description

Technical Field

[0001] The present invention belongs to the technical field of drug screening, and in particular relates to a drug screening method based on a comprehensive survival index. Background Art

[0002] During the drug development process, solid tumor models need to evaluate the efficacy of drugs through five evaluation indicators: tumor volume inhibition rate, net body weight, survival rate, survival time and number of lung metastasis nodules, such as breast cancer models, melanoma models and S180 sarcoma models.

[0003] Currently, tumor volume inhibition rate is often used as a key indicator for evaluating drug efficacy. However, in animal experiments, tumor cells not only proliferate in situ, causing tumor volume to increase, but also metastasize and colonize distally, further damaging other organs and even becoming infected by other pathogens in late-stage tumors. Therefore, solely focusing on changes in tumor size and relying on the tumor volume inhibition rate to evaluate drug efficacy has certain limitations and cannot fully reflect the drug's efficacy.

[0004] Net body weight changes in surviving tumor model animals are an important objective indicator for evaluating the results of animal experiments. The increase or decrease in net body weight of experimental animals often reflects multiple aspects of their health status, nutritional intake, and metabolic rate, and is therefore crucial in experimental design and result interpretation.

[0005] Survival rate and survival time are the ultimate pursuit of cancer treatment, and can directly reflect the therapeutic effect of drugs on tumors. However, survival rate and survival time are also affected by factors other than drugs, such as living environment, operator's technique, etc., so they cannot be used as indicators to comprehensively measure the effectiveness of drug treatment. The number of lung nodules can directly reflect the progress or inhibition of distant metastasis of tumor cells. The lungs are a common metastatic target organ for many solid tumors, such as breast cancer and melanoma. Most cancer patients die from metastasis rather than primary tumors, so measuring the number of lung nodules helps measure the inhibitory effect of drugs on tumor cell metastasis.

[0006] Currently, drug development typically focuses solely on indicators such as tumor size change, survival rate, survival time, net body mass change, and lung nodule count, which can be subject to significant subjective error. The challenge of integrating these data to conveniently and comprehensively evaluate drug efficacy against tumors, thereby improving the reliability and objectivity of drug evaluation results, has become a pressing technical challenge in this field. Summary of the Invention

[0007] In order to solve the above problems, the present invention provides a drug screening method based on the comprehensive survival index, which can accurately judge the therapeutic effect of each drug on the disease and the protection of the body's health, and screen out drugs with good comprehensive therapeutic effects.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] The present invention first designs and prepares a series of isotecan mesylate liposomes for subsequent drug screening. The raw materials for preparing the liposomes include isotecan mesylate (DXF), HSPC, CH, and SA-CH. Using encapsulation efficiency as an evaluation indicator, the drug-to-lipid ratio, phospholipid concentration, residence time of the blank liposomes on the ion exchange resin column, drug loading temperature, drug loading time, and drug loading gradient are optimized to obtain the optimal liposome preparation process.

[0010] A model of advanced orthotopic breast cancer combined with sepsis was constructed as a drug screening model. The method for constructing the model of advanced orthotopic breast cancer combined with sepsis included: subcutaneously injecting 1.0×10 6 cell / mL of 4T1 cell suspension, and on the 28th day of tumor bearing, lipopolysaccharide (LPS) was injected into the peritoneal cavity of mice to establish an advanced orthotopic breast cancer combined with sepsis model.

[0011] Intraperitoneal injection of LPS is one of the ways to model sepsis. Injecting LPS on the 28th day simulates the acute inflammatory response caused by the body's reduced resistance to bacteria or pathogens due to low immune function in the late stage of tumor.

[0012] In the process of drug screening based on the constructed model of advanced in situ breast cancer combined with sepsis, the present invention introduces the concept of "net body mass change rate" in order to eliminate the differences between the initial levels of each experimental group, intuitively reflect the effect of drug treatment on net body mass, and make the comparison between groups more intuitive and scientific. The net body mass change rate refers to the ratio of the net body mass of the experimental animal to the initial net body mass. The initial net body mass of the experimental animal itself is used as the benchmark to make the experimental data more accurate and comparable. On this basis, the concept of "area on the net body mass change rate curve" is further proposed. The area on the net body mass change rate curve refers to a curve (curve I) that plots the net body mass change rate over time with different time points as the horizontal coordinate and the net body mass change rate of the experimental animal as the vertical coordinate; with the initial net body mass change rate as the baseline (Y=0), the area between curve I and the baseline is calculated, which is the area on the net body mass change rate curve.

[0013] Prior to the present invention, researchers usually used the "area under the curve" to evaluate changes in body mass. However, because the net body mass of tumor-bearing mice decreased after being attacked by LPS, the net body mass change rate of the mice was negative during the observation period. Using the area on the curve can use the X-axis as a reference line, while the area under the curve is a custom reference line, which is subject to human error. Therefore, the present invention introduces the "area on the net body mass change rate curve." When the curve is complete, the smaller the area on the net body mass change rate curve, the smaller the net body mass fluctuation of the experimental animal after drug treatment, indicating that the therapeutic effect of the drug is better. The curve of the net body mass change rate over time can be drawn using software commonly used in this field, including Graphpad.

[0014] In order to further improve the drug screening method of the present invention, the present invention also proposes the concept of "Tumor Control Coefficient" (TCC). The tumor control coefficient refers to the ratio of the final net body mass to the initial net body mass, which expresses the overdraft of the host's life resources by the tumor. The larger the value, the better the tumor inhibition effect and the smaller the threat to the host's health.

[0015] Furthermore, the present invention provides a drug screening method based on the comprehensive survival index, comprising:

[0016] (1) Construct a disease experimental animal model and obtain the survival time, survival rate, tumor mass, net body mass, and number of lung nodules of the experimental animals after drug administration;

[0017] (2) Obtaining the area on the net body mass change rate curve based on the net body mass data; obtaining the tumor control coefficient data based on the tumor mass and the net body mass;

[0018] (3) The data of survival rate, survival time, area under the curve of net body mass change rate, and number of lung nodules were normalized using the sum normalization method to construct a drug screening model. In order to eliminate the dimensional effects between different variables and make the data of different variables comparable, the present invention uses the sum normalization method to process the data of survival rate, survival time, area under the curve of net body mass change rate, and number of lung nodules before constructing the model.

[0019] Taking advanced tumors combined with sepsis as an example, the drug screening model is the therapeutic index model, and its formula is:

[0020]

[0021] CS indexis the comprehensive survival index; S is the survival rate data processed by the sum normalization method; T is the survival time data processed by the sum normalization method; TTC is the tumor control coefficient; L is the lung nodule data processed by the sum normalization method; A is the area on the net body mass change rate curve processed by the sum normalization method.

[0022] The net body mass of the experimental animal mentioned in the present invention refers to the difference between the body mass of the experimental animal and the tumor mass.

[0023] The initial net body weight mentioned in the present invention refers to the difference between the body weight of the mouse during LPS modeling (ie, the body weight of the mouse before intraperitoneal injection of LPS) and the tumor weight.

[0024] The terminal net body weight referred to in the present invention refers to the body weight of the mouse on day N after LPS modeling, or the body weight at the time of death during the N-day observation period, minus the terminal tumor weight. The terminal tumor weight refers to the tumor weight of the mouse on day N after LPS modeling, or the tumor weight of the mouse at the time of death during the N-day observation period.

[0025] In the present invention, the calculation formula of the survival rate is: survival rate % = number of surviving mice ÷ number of experimental mice × 100%.

[0026] The drug screened using the above-mentioned drug screening method based on the comprehensive survival index is sialic acid derivative-modified isotecan liposomes, the raw materials of which include: isotecan, phospholipids, cholesterol and sialic acid derivatives; wherein the mass ratio of isotecan to phospholipids is 1:(5-15); and the molar ratio of phospholipids, cholesterol and sialic acid derivatives is (40-60):(35-45):(2-10).

[0027] The sialic acid derivatives include at least one of sialic acid-cholesterol conjugate, sialic acid-tetradecylamine, sialic acid-hexadecylamine, sialic acid-octadecylamine, sialic acid methyl ester-hexadecanoic acid, sialic acid methyl ester-octadecanoic acid, sialic acid ethyl ester-hexadecanoic acid, sialic acid ethyl ester-octadecanoic acid, sialic acid-hexadecanoic acid, and sialic acid-octadecanoic acid; preferably, the sialic acid-cholesterol conjugate.

[0028] The phospholipids include: at least one of phosphatidylcholine, phosphatidylglycerol, phosphatidic acid, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, sphingomyelin, cardiolipin, hydrogenated soybean lecithin, hydroxyethyl phosphatidylcholine, distearoylphosphatidylcholine, and dipalmitoylphosphatidylcholine; preferably at least one of hydrogenated soybean lecithin, hydroxyethyl phosphatidylcholine, distearoylphosphatidylcholine, and dipalmitoylphosphatidylcholine; more preferably hydrogenated soybean lecithin.

[0029] Exitecan is a pharmaceutically acceptable salt of exitecan, preferably exitecan mesylate.

[0030] A method for preparing sialic acid derivative-modified isotecan liposomes, comprising:

[0031] (1) Dissolving phospholipids, cholesterol, and sialic acid derivatives in an organic solvent to obtain a membrane material solution, removing the organic solvent to obtain a membrane material concentrate, and mixing the membrane material concentrate with a gradient material solution to obtain a blank liposome initial product;

[0032] (2) Extruding the blank liposome sample through a filter membrane to obtain a liposome suspension modified with a sialic acid derivative;

[0033] (3) removing the gradient-building substance from the external aqueous phase of the liposome suspension modified with the sialic acid derivative to prepare a gradient liposome suspension;

[0034] (4) mixing the gradient liposome suspension with the isotecan solution to prepare isotecan liposomes modified with sialic acid derivatives;

[0035] Wherein, the gradient establishing substance is at least one of citric acid-sodium citrate, ammonium edetate, ammonium sulfate, ammonium citrate, and sucrose octasulfate ammonium; preferably ammonium sulfate; the concentration of the ammonium sulfate solution is 150mmol / L to 250mmol / L, preferably 200mmol / L to 250mmol / L.

[0036] The preparation method of the above-mentioned sialic acid derivative-modified exitecan liposomes specifically comprises:

[0037] (1) Dissolve phospholipids, cholesterol, and sialic acid derivatives in ethanol at 55°C to 70°C, remove the ethanol to prepare a membrane material, mix the membrane material with the gradient solution, and incubate at 55°C to 70°C with stirring for 10 min to 30 min to prepare a blank liposome.

[0038] (2) Extruding the blank liposomes through a filter membrane at 55°C to 70°C to obtain a liposome suspension modified with a sialic acid derivative;

[0039] (3) removing the gradient-building substance from the aqueous phase outside the liposome suspension modified with the sialic acid derivative to prepare a gradient liposome suspension;

[0040] (4) After mixing the gradient liposome suspension with the isotecan solution, the mixture was incubated at 55°C to 70°C for 15 min to 40 min to prepare the isotecan liposome modified with sialic acid derivatives.

[0041] Wherein, in step (4), the mixture is incubated at 60°C to 65°C for 20 min to 30 min.

[0042] The present invention also provides an application of a drug screening method based on the comprehensive survival index in the preparation of anti-tumor drugs.

[0043] The present invention also provides an application of a drug screening method based on the comprehensive survival index in constructing a drug screening model.

[0044] Considering that tumor is a systemic disease, we should not only pay attention to the tumor location. Therefore, the present invention integrates the survival status of mice, chronic invasion of tumors, acute infection and impact on major organs to obtain a comprehensive survival index, which can better reflect the long-term therapeutic effect of drugs on the disease and make the evaluation of drug efficacy more comprehensive and complete.

[0045] Beneficial effects of the present invention:

[0046] In the present invention, the larger the value of the comprehensive survival index is, the better the therapeutic effect of the drug is and the higher the safety is. index The value can accurately judge the therapeutic effect of each drug on the disease and the protection of the body's health, and screen out drugs with good comprehensive therapeutic effects.

[0047] The present invention combines five important evaluation indicators for drug efficacy experimental animal models: tumor size change, survival rate, survival time, net body mass change rate, and number of lung nodules. By cleverly converting net body mass data into area data on the net body mass change curve, and further standardizing it with survival rate, survival time, tumor size change, and number of lung nodules, a calculation formula for the therapeutic index is constructed for drug screening. The drug screening method of the present invention can organically combine survival rate and body mass data, objectively reflect the progression of the disease and prognosis, effectively amplify the effect differences between different drug treatment groups, and more accurately, conveniently, and comprehensively screen out drugs with excellent comprehensive effects, greatly reducing the development cost of new drugs, while also providing more accurate data support for clinical and experimental research. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a curve diagram of the survival rate of mice in different treatment groups in the examples of the present invention.

[0049] Figure 2 Comparison of the number of lung metastatic nodules in mice treated in different groups in the present invention. **** P<0.0001.

[0050] Figure 3 This is a curve diagram of the weight changes of mice in different treatment groups in the examples of the present invention.

[0051] Figure 4 Comparison of the comprehensive survival index of mice in different treatment groups in the examples of the present invention. DETAILED DESCRIPTION

[0052] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0053] Specific techniques or conditions not specified in the examples are all conventional methods or those described in the literature in this field, or according to the product instructions. Reagents and instruments used, for which the manufacturer is not specified, are all conventional products that can be purchased through regular channels.

[0054] Example 1

[0055] In this Example 1, different liposomes of exitecan mesylate were prepared. The composition of the blank liposome formula is shown in Table 1.

[0056] Table 1 Blank liposome formulation composition

[0057]

[0058] The preparation method is as follows:

[0059] According to Table 1, the prescribed amounts of hydrogenated soybean phospholipids (HSPC), cholesterol (CH), and SA-CH (sialic acid-cholesterol derivative) were accurately weighed and added to 500 μL of anhydrous ethanol. The mixture was heated and stirred in a 60°C water bath. After complete dissolution, the ethanol was evaporated. 5 mL of a hydration medium (200 mM ammonium sulfate solution) was added and the mixture was placed in a 60°C water bath for 20 min to obtain a preliminary liposome product. The preliminary liposome product was extruded through an extruder and sequentially passed through 0.4 μm, 0.2 μm, 0.1 μm, and 0.08 μm polycarbonate membranes nine times, nine times, 11 times, and nine times to obtain blank liposomes. The blank liposomes were then placed on anion and cation exchange resin columns, each retaining for 20 min to prepare gradient liposomes. Gradient liposomes were mixed with a solution of ixetine mesylate (DXF) at a drug-to-lipid ratio of 1:15 (w / w). Drug loading was performed at 60°C for 30 minutes, followed by a 2-minute ice-water bath to produce sialic acid-modified DXF liposomes (DXF-SAL). Conventional DXF liposomes (DXF-CL) were prepared using the same method, except that SA-CH was omitted. Both liposomes had an average particle size of 110 nm and an encapsulation efficiency greater than 90%.

[0060] Note: SA-CH is a sialic acid-cholesterol derivative, which was prepared by referring to the preparation method of Neu5Ac-AE-AC-CH disclosed in Application No.: 201610533120.7, Patent Name: Synthesis of a Lipid Derivative Containing a Sialic Acid Group and Its Application in Pharmaceutical Preparations.

[0061] Example 2

[0062] In this Example 2, DXF liposomes were prepared according to the preparation method of Example 1, and a pharmacodynamic experiment was performed. The steps are as follows:

[0063] Balb / c female mice aged 6 to 8 weeks, weighing 18 g to 22 g, were randomly divided into 4 groups, 6 mice in each group, namely blank control group (5% glucose injection), DXF-S group (DXF solution), DXF-CL group and DXF-SAL group. The third pair of mammary pads of mice in each group were subcutaneously injected with 1.0×10 6 cell / mL of 4T1 cell suspension, when the tumor is 100 cm 3 At 4 days post-tumor growth, mice were injected with 5.0 mg / kg of each formulation via the tail vein. A blank control group received the same volume of 5% glucose solution every three days for five doses. On day 28 of tumor growth, mice were intraperitoneally injected with 2 mg / kg LPS. Tumor size, survival rate, and body weight were monitored and recorded for 10 days starting on day 8.

[0064] Net body mass data at different time points were converted into net body mass change rate (ratio of the experimental animal's net body mass to the initial net body mass). Graphpad software was used to plot a net body mass change rate over time curve (curve I), with the different time points as the horizontal axis and the experimental animal's net body mass change rate as the vertical axis. The initial net body mass change rate was used as the baseline (Y = 0), and the area on the net body mass change rate curve (i.e., the area between curve I and the baseline) was calculated. A survival curve was also plotted.

[0065] Tumor control coefficient data were obtained based on tumor mass and net body mass.

[0066] Then, the data on the area on the curves of survival time, survival rate, number of lung nodules and net body mass change rate were standardized using the sum normalization method to unify the data dimensions.

[0067] Sum normalization, also known as sum normalization, divides each data point by the sum of all data points. The advantages of sum normalization include: 1. Eliminating dimensionality: This method eliminates dimensionality, allowing data of different dimensions to be compared and analyzed without considering their units or dimensions. 2. Preserving relative data proportions: While normalizing data to the range [0, 1] preserves the relative size relationships of the data, sum normalization makes the relative proportions of data points more intuitive because the sum of all data points is 1. 3. Unaffected by extreme values: Compared to some normalization methods, such as min-max normalization, sum normalization is less sensitive to extreme values ​​because it normalizes based on the sum of the data points, rather than simply considering the maximum and minimum values. 4. Preserving data distribution: Sum normalization preserves the distribution of the original data because it simply scales the data by dividing by the sum, rather than transforming or offsetting the data. 5. Wide applicability: This method is applicable to various types of data, including numerical data, probability distribution, etc., so it has a wide range of applications in data analysis, machine learning and other fields.

[0068] Comprehensive survival index (CS) was calculated based on the standardized survival time, survival rate, area on the curve of lung nodule number and net body mass change rate data, as well as tumor control coefficient data. index ) to evaluate the therapeutic effects of different preparations.

[0069] The calculation formula of the comprehensive survival index is:

[0070]

[0071] S is the survival rate data standardized by the sum normalization method, T is the survival time data standardized by the sum normalization method, L is the lung nodule data standardized by the sum normalization method, TCC is the tumor control coefficient, and A is the area on the net body mass change rate curve standardized by the sum normalization method.

[0072] The results are analyzed as follows:

[0073] Figures 1-4 The survival curves, area on the curve of net body mass change rate, number of lung nodules and comprehensive survival index (CS) of each group in the treatment of tumor combined with sepsis by different DXF liposomes in Example 2 are shown. index Table 2 shows the survival time and normalized data of mice in each group after infection, where T represents the survival time normalized by the sum normalization method.

[0074] Table 2 Survival time and normalized data of mice in each group after infection (n=6)

[0075]

[0076] Depend on Figure 1 As shown in Table 2, DXF liposomes showed a protective effect after LPS challenge, extending the average survival of mice to a certain extent. However, the average survival time of mice in the DXF solution group was shorter than that of the control group, suggesting that the DXF solution may have caused some damage to the body's health, weakening resistance and shortening survival when infected later. Survival time is also susceptible to extreme values, necessitating further analysis and comparison using survival rates. Table 3 shows the survival rates and normalized data for each group of mice after infection. S represents the survival rate normalized by the sum normalization method.

[0077] Table 3 Survival rate and normalized data of mice in each group after infection (n=6)

[0078]

[0079] Depend on Figure 1 As shown in Table 3, all mice in the Control and DXF-S groups had died by the end of observation. The survival rate of DXF-SAL was twice that of DXF-CL, which directly reflects the protective effect of the drug but does not reflect the overall survival during the observation period. Therefore, the survival rate is combined with the mean survival time to comprehensively reflect the survival trend and treatment benefit. Table 4 shows the lung nodule counts and normalized data for each group of mice before infection. L represents the number of lung nodules after normalization using the sum normalization method.

[0080] Table 4 Number of lung nodules and normalized data of mice in each group before infection (n=3)

[0081]

[0082] Depend on Figure 2 As shown in Table 4, the number of lung metastatic nodules in each group at the time of modeling was: Control > DXF-S > DXF-CL > DXF-SAL. This indicates that before infection, DXF-SAL was most effective in inhibiting tumor cell metastasis, delaying the progression of metastasis, reducing damage to distant organs such as the lungs, and enhancing resistance to infection. Table 5 shows the area under the net body mass change curve (AUC) and normalized data for each group of mice after infection. NBWLRC represents the area under the NUC; A represents the area under the NUC after normalization using the summation method.

[0083] Table 5 Area on the curve of net body mass change rate and normalized data of each group of mice after infection (n=6)

[0084]

[0085] Depend on Figure 3 As shown in Table 5, the areas on the net body mass change curves for each group are: DXF-CL > DXF-SAL > Control > DXF-S. The areas on the net body mass change curves represent the overall metabolic status of infected mice. A larger area on the net body mass change curve indicates a more disrupted metabolic state during the acute infection period. However, the areas on the net body mass change curves for Control and DXF-S are smaller than those for DXF-SAL because all mice in these two groups died within 3 days of infection. This suggests that a single survival rate or survival metric cannot fully reflect the therapeutic efficacy of a drug. A new index needs to be integrated to conduct a comprehensive analysis. Table 6 shows the tumor control coefficient data for each group of mice.

[0086] Table 6 Tumor control coefficient data of each group of mice (n=6)

[0087]

[0088] As shown in Table 6, the tumor control coefficients of each group were: DXF-SAL>DXF-CL>DXF-S>Control. In the tumor control coefficient, the "ratio of the final net body mass to the initial net body mass" represents the "overdraft ratio" of the tumor on the host's life resources. The larger the tumor control coefficient, the better the tumor control effect.

[0089] Furthermore, the therapeutic index CS was calculated according to the above-mentioned calculation formula of the comprehensive survival index. index , the results are shown in Table 7.

[0090] Table 7 Comprehensive survival index (CS) of mice in each group after infection index ):

[0091]

[0092] Depend on Figure 4 As shown in Table 7, the CS of DXF-SAL index The value is 12.1 times that of DXF-CL, CS index The larger the value, the higher the degree of weight recovery, the longer the survival time and the higher the survival rate of the mice, which means the better the quality of life of the mice. This result suggests that DXF-SAL makes an important contribution to improving the quality of life and maintaining the health of mice with advanced breast cancer and sepsis.

[0093] CS index The difference in the therapeutic effects of DXF-SAL and DXF-CL for tumor combined with sepsis was clearly revealed, confirming the CS indexThis result emphasizes that the use of SA-modified DXF liposomes may be a more effective treatment strategy for the treatment of tumor complications and has the greatest development value. This is of great significance for the development of more effective drugs for the treatment of sepsis and provides a new option for clinical treatment.

Claims

1. A drug screening method based on comprehensive survival index, characterized in that: include: (1) Construct a disease experimental animal model and obtain the survival time, survival rate, tumor mass, net body mass, and number of lung nodules of the experimental animals after drug administration; (2) Obtaining the area on the net body mass change rate curve based on the net body mass data; obtaining the tumor control coefficient data based on the tumor mass and the net body mass; (3) The data of survival rate, survival time, area on the net body mass change rate curve, and number of lung nodules were standardized using the sum normalization method.

2. A drug screening method based on comprehensive survival index according to claim 1, characterized in that: Methods for establishing disease experimental animal model: 1.0×10 6 cell / mL of 4T1 cell suspension, and on the 28th day of tumor bearing, lipopolysaccharide was injected into the peritoneal cavity of mice to obtain an advanced in situ breast cancer combined with sepsis model.

3. The drug screening method based on comprehensive survival index according to claim 2, characterized in that: Net body mass includes the net body mass and initial net body mass of experimental animals; The net body mass of the experimental animals refers to the difference between the body mass of the experimental animals and the tumor mass; Initial net body weight refers to the difference between the body weight of the mouse before intraperitoneal injection of lipopolysaccharide minus the tumor weight; Calculation method of the area on the net mass change rate curve: Net body mass change rate = ratio of the net body mass of the experimental animal to the initial net body mass; A curve showing the change in net body mass rate over time was drawn with different time points as the abscissa and the net body mass change rate of the experimental animals as the ordinate, which was recorded as curve I. The initial net body mass change rate was used as the baseline, and the area between curve I and the baseline was calculated, which was the area on the net body mass change rate curve.

4. The drug screening method based on comprehensive survival index according to claim 2, characterized in that: The formula for calculating the survival rate is: survival rate % = number of surviving mice ÷ number of experimental mice × 100%; The tumor control coefficient is the ratio of the final net body mass to the initial net body mass; The final net body weight refers to the body weight of the mouse on the Nth day after lipopolysaccharide modeling or the body weight at the time of death during the N-day observation period minus the final tumor weight; wherein, the final tumor weight refers to the tumor weight of the mouse on the Nth day after lipopolysaccharide modeling or the tumor weight of the mouse at the time of death during the N-day observation period; Initial net body weight refers to the difference between the mouse body weight before intraperitoneal injection of lipopolysaccharide and the tumor weight.

5. The drug screening method based on comprehensive survival index according to claim 2, characterized in that: The data of survival rate, survival time, area under the curve of net body mass change rate, and number of lung nodules were processed by sum normalization method before model construction and calculation of comprehensive survival index. CS index is the comprehensive survival index, S is the survival rate data processed by the sum normalization method, T is the survival time data processed by the sum normalization method, TTC is the tumor control coefficient, L is the lung nodule data processed by the sum normalization method, and A is the area on the net body mass change rate curve processed by the sum normalization method.

6. The drug screening method based on comprehensive survival index according to claim 1, characterized in that: The screened drug is sialic acid derivative-modified isotecan liposomes, the raw materials of which include: isotecan, phospholipid, cholesterol and sialic acid derivative; wherein the mass ratio of isotecan to phospholipid is 1:(5-15); and the molar ratio of phospholipid, cholesterol and sialic acid derivative is (40-60):(35-45):(2-10); The sialic acid derivatives include at least one of sialic acid-cholesterol conjugate, sialic acid-tetradecylamine, sialic acid-hexadecylamine, sialic acid-octadecylamine, sialic acid methyl ester-hexadecanoic acid, sialic acid methyl ester-octadecanoic acid, sialic acid ethyl ester-hexadecanoic acid, sialic acid ethyl ester-octadecanoic acid, sialic acid-hexadecanoic acid, and sialic acid-octadecanoic acid; preferably, the sialic acid-cholesterol conjugate; The phospholipids include: at least one of phosphatidylcholine, phosphatidylglycerol, phosphatidic acid, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, sphingomyelin, cardiolipin, hydrogenated soybean lecithin, hydroxyethyl phosphatidylcholine, distearoylphosphatidylcholine, and dipalmitoylphosphatidylcholine; preferably at least one of hydrogenated soybean lecithin, hydroxyethyl phosphatidylcholine, distearoylphosphatidylcholine, and dipalmitoylphosphatidylcholine; more preferably hydrogenated soybean lecithin; The isotecan is a pharmaceutically acceptable salt of isotecan, preferably isotecan mesylate.

7. The drug screening method based on comprehensive survival index according to claim 6, characterized in that: The preparation method of the sialic acid derivative-modified exitecan liposomes comprises: (1) Dissolving phospholipids, cholesterol, and sialic acid derivatives in an organic solvent to obtain a membrane material solution, removing the organic solvent to obtain a membrane material concentrate, and mixing the membrane material concentrate with a gradient material solution to obtain a blank liposome initial product; (2) Extruding the blank liposome sample through a filter membrane to obtain a liposome suspension modified with a sialic acid derivative; (3) removing the gradient-building substance from the aqueous phase outside the liposome suspension modified with the sialic acid derivative to prepare a gradient liposome suspension; (4) mixing the gradient liposome suspension with the isotecan solution to prepare isotecan liposomes modified with sialic acid derivatives; Wherein, the gradient establishing substance is at least one of citric acid-sodium citrate, ammonium edetate, ammonium sulfate, ammonium citrate, and sucrose octasulfate ammonium; preferably ammonium sulfate; the concentration of the ammonium sulfate solution is 150mmol / L to 250mmol / L, preferably 200mmol / L to 250mmol / L.

8. The drug screening method based on comprehensive survival index according to claim 7, characterized in that: include: (1) Dissolve phospholipids, cholesterol, and sialic acid derivatives in ethanol at 55°C to 70°C, remove the ethanol to prepare a membrane material, mix the membrane material with the gradient solution, and incubate at 55°C to 70°C with stirring for 10 min to 30 min to prepare a blank liposome. (2) Extruding the blank liposomes through a filter membrane at 55°C to 70°C to obtain a liposome suspension modified with a sialic acid derivative; (3) removing the gradient-building substance from the aqueous phase outside the liposome suspension modified with the sialic acid derivative to prepare a gradient liposome suspension; (4) After mixing the gradient liposome suspension with the isotecan solution, the mixture was incubated at 55°C to 70°C for 15 min to 40 min to prepare the isotecan liposome modified with sialic acid derivatives.

9. The drug screening method based on comprehensive survival index according to claim 8, characterized in that: In step (4), incubate at 60°C to 65°C for 20 min to 30 min.

10. Use of the drug screening method based on the comprehensive survival index according to any one of claims 1 to 9 in the preparation of anti-tumor drugs and in the construction of drug screening models.

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