A method for constructing a neonatal bronchopulmonary dysplasia model

Abstract

The application relates to the technical field of biology, and particularly discloses a construction method of a neonatal bronchopulmonary dysplasia model. The neonatal bronchopulmonary dysplasia model obtained by the application is a non-invasive model, compared with mechanical ventilation, needs invasive operation, has strong high-oxygen-maintaining operability, and does not harm animals; moreover, the construction method of the application belongs to completely simulating clinical operation, early preterm infants inhale high oxygen to cause bronchopulmonary dysplasia in the clinic, the success rate of preparing the model by using the same clinical operation is high, and there is no such operation in the previous large animal model; therefore, the application uses early cesarean section pigs to simulate preterm infants, and inhales high-concentration oxygen to simulate clinical operation, which is a non-mechanical trauma method, and has high simulation degree for the clinic.

Description

Technical Field

[0001] This application relates to the field of biotechnology, and in particular to a method for constructing a neonatal bronchopulmonary dysplasia model. Background Technology

[0002] Bronchopulmonary dysplasia (BPD) is a chronic lung disease that occurs in premature infants. It is caused by prenatal and postnatal factors that impair the normal development of immature lungs, including prematurity, genetic factors, growth restriction, mechanical trauma, oxygen toxicity, infection, and inflammation. Its main histopathological features are simplified alveolar structure and abnormal pulmonary vascularization.

[0003] In recent years, with the improvement of neonatal intensive care technology, the survival rate of premature infants has increased, and the incidence of brain-related developmental disorders (BPD) has increased significantly. Premature infants with BPD have significantly higher mortality and complication rates. Surviving infants have an increased risk of developing chronic respiratory diseases (such as asthma and chronic obstructive pulmonary disease), cardiovascular diseases, gastrointestinal diseases, and neurodevelopmental problems, including cerebral palsy, developmental delays, and lower IQ scores, among other multi-organ system diseases, which may even persist into childhood and adulthood. Therefore, BPD is a disease that persists from fetus to adulthood. Currently, there is a lack of fundamental treatment options for BPD, placing a huge economic and psychological burden on society and families. Therefore, there is an urgent clinical need to construct animal models that mimic clinical human BPD to explore the pathogenesis and new treatment strategies for BPD.

[0004] In previous studies, scientists have constructed corresponding BPD models based on the pathogenesis of BPD, such as constructing genetic background model animals, simulating intrauterine infection and inflammation models, and using methods such as mechanical ventilation or hyperoxia induction. Among these, mechanical ventilation and hyperoxia induction are commonly used methods to create BPD models in mice, rats, and rabbits.

[0005] Mechanical ventilation, which involves tracheotomy and intubation to induce organ damage, is an invasive procedure that is difficult to perform on small animals. Furthermore, invasive procedures pose challenges to the success rate and mortality of model creation in large animals. Hyperxia induction is a non-invasive method, and currently, mice and rabbits are the primary animals used to create BPD models using mechanical ventilation and / or hyperxia. However, mice and rats differ significantly from humans in their lung development cycle, immune system, and metabolism, presenting limitations. In full-term rabbits, alveolar development begins after birth, making them premature and immature, failing to reflect human anatomy or function. Premature rabbits also have a high mortality rate, and BPD models in premature rabbits lack standardization and research on pulmonary vascular development is insufficient. Therefore, the creation of BPD models in premature rabbits remains controversial.

[0006] Non-human primates (apes, chimpanzees, baboons, monkeys, etc.) among model organisms are highly similar to humans in terms of physiology, anatomy, cognitive abilities, and social complexity, and their genetic material is highly homologous. However, due to their small numbers, high prices, long breeding cycles, difficulty in raising them, and ethical issues, there is currently a lack of large animal models that highly simulate human premature infant blastocystic diastasis (BPD).

[0007] With the continuous development of the life sciences field, pigs, as model animals, have cardiovascular, respiratory, metabolic and gastrointestinal systems similar to those of humans. Moreover, they are docile and easy to tame, and can be used for research on human-related diseases, making a huge contribution to improving human health. They have been recognized by pharmaceutical regulatory agencies around the world, including the U.S. Food and Drug Administration (FDA).

[0008] Because pig lung development and disease course are similar to those of humans, they are suitable as models for simulating human preterm pulmonary dysplasia (BPD). Furthermore, miniature pig breeds are abundant, small in size, easy to breed, have high survival rates, and stable genetic traits. They also share significant similarities with humans in genetics, anatomical structure, organ size, nutritional metabolism, and physiological and biochemical characteristics, making them promising for widespread application. However, traditional models of porcine pulmonary dysplasia involve cesarean sections, allowing the pigs to spontaneously develop pulmonary hypoplasia. This model relies on the pig's own development and self-repair capabilities, resulting in mostly mild symptoms, poor reproducibility, and low modeling success rates. Therefore, it is not a suitable model for simulating clinical preterm infant BPD in humans. Summary of the Invention

[0009] The purpose of this application is to overcome the shortcomings of the prior art and provide a method for constructing a neonatal bronchopulmonary dysplasia model.

[0010] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0011] This application provides a method for constructing a neonatal bronchopulmonary dysplasia model, comprising the following steps:

[0012] S1. Select premature piglets delivered by cesarean section and place them in an oxygen chamber with an oxygen volume percentage concentration of [missing information]. 70 ～ 85％ They are raised in a suitable breeding environment;

[0013] S2. After feeding for 2-3 weeks, respiratory system function indicators, lung tissue pathological indicators, and imaging indicators of newborn pigs were tested to obtain a neonatal bronchopulmonary dysplasia model.

[0014] In the preliminary experiments of this application, premature pigs were obtained by performing cesarean sections at different ages in advance to determine whether the premature pigs could survive and to explore a series of conditions for establishing a model of neonatal bronchopulmonary dysplasia. For example, pregnant sows have almost no colostrum after cesarean section and cannot be directly fed to premature piglets. Overcoming the challenge of ensuring the survival of premature pigs and conducting experiments under artificial feeding conditions is a great challenge. How to avoid infection and prevent disease during the experiment is another major difficulty.

[0015] This invention simulates the conditions under which preterm human infants and neonatal bronchopulmonary dysplasia occur. It explores the modeling process through hyperoxia induction, including the setting of oxygen concentration, the duration of modeling, the symptoms of preterm pigs during the modeling process, and the conditions for successful modeling. For the first time, a hyperoxia feeding environment is used to induce preterm pigs, achieving the requirement of non-invasiveness and significantly improving the clinical relevance of the neonatal bronchopulmonary dysplasia model.

[0016] Compared to mechanical ventilation, which requires invasive procedures, this application selects premature cesarean-born pigs and places them in a feeding environment with an oxygen volume percentage concentration of 70-85%. The construction method of this application maintains high oxygen levels with strong operability and does not harm the animals. Furthermore, this application uses cesarean-born pigs to simulate premature infants and uses the inhalation of high-concentration oxygen to simulate clinical procedures, resulting in a high degree of clinical simulation.

[0017] In a preferred embodiment of the method for constructing the neonatal bronchopulmonary dysplasia model described in this application, the oxygen volume percentage concentration in step S1 is 80-85%.

[0018] This application uses different oxygen volume percentage concentrations to induce a neonatal bronchopulmonary dysplasia model in premature pigs. Neonatal bronchopulmonary dysplasia symptoms induced by an oxygen volume percentage concentration of 70-75% are milder, while those induced by 80-85% are more pronounced, with a survival rate of approximately 2 / 3. Induction at 90% oxygen concentration results in obvious symptoms, but animals generally die within 2-3 days, with a low survival rate, making it unsuitable as a model for further downstream experiments. This demonstrates that this application can only obtain a neonatal bronchopulmonary dysplasia model by using specific oxygen volume percentage concentrations.

[0019] Based on preliminary research and exploration, it was determined that premature piglets delivered by cesarean section were selected and placed in a rearing environment with an oxygen volume percentage concentration of 80-85% as the optimal induction condition. With this oxygen volume percentage concentration, the piglets inhaled 30-50 breaths per minute. Shortness of breath (approximately 60-80 breaths per minute) began to appear around one week after birth, and significantly worsened around two weeks (approximately 80-120 breaths per minute), accompanied by nasal cyanosis, difficulty feeding, and signs of oxygen dependence. Chest X-rays were then performed to identify lung changes indicative of neonatal bronchopulmonary dysplasia, followed by lung tissue pathology and other examinations. This time point, the experimental endpoint, was 2-3 weeks after birth.

[0020] In a preferred embodiment of the method for constructing the neonatal bronchopulmonary dysplasia model described in this application, in step S1, the number of days of prematurity is 9 days.

[0021] This application used full-term newborn pigs, cesarean section pigs born 7 days and 9 days premature to establish a model. The neonatal bronchopulmonary dysplasia model was not successfully established under hyperoxia conditions in full-term pigs. The 7-day premature pigs failed to induce neonatal bronchopulmonary dysplasia symptoms and lung injury, while the 9-day premature pigs successfully established the model. This demonstrates that the number of days of premature birth significantly impacts the modeling success. This application identified the minimum number of days of premature birth required for successful modeling; longer prematurity increases the risk of survival.

[0022] As a preferred embodiment of the method for constructing the neonatal bronchopulmonary dysplasia model described in this application, in step S1, the feeding environment includes a temperature of 33-35°C and a humidity of 55%-60%.

[0023] In a preferred embodiment of the method for constructing the neonatal bronchopulmonary dysplasia model described in this application, in step S1, soda lime is placed in the feeding environment, and light / darkness is alternated every 12 hours.

[0024] The above-mentioned feeding conditions can better obtain a neonatal bronchopulmonary dysplasia model with high modeling efficiency.

[0025] In a preferred embodiment of the method for constructing the neonatal bronchopulmonary dysplasia model described in this application, in step S1, an oxygen analyzer is used to monitor the oxygen volume percentage concentration in the feeding environment in real time and maintain the oxygen volume percentage concentration at 80-85%.

[0026] In a preferred embodiment of the method for constructing the neonatal bronchopulmonary dysplasia model described in this application, the newborn pigs are derived from Bama miniature pigs at 103-105 days of gestation.

[0027] Preferably, after the piglets are delivered by cesarean section, they need to be resuscitated and placed in an incubator once they begin to breathe independently.

[0028] In a preferred embodiment of the method for constructing the neonatal bronchopulmonary dysplasia model described in this application, in step S2, the newborn pigs exhibit obvious shortness of breath, with a respiratory rate of 80-120 breaths / minute, nasal cyanosis, dyspnea, oxygen dependence, and difficulty feeding. Pathological and imaging indicators of lung tissue are also detected.

[0029] In a preferred embodiment of the method for constructing the neonatal bronchopulmonary dysplasia model described in this application, in step S2, the pathological indicators of lung tissue include the radial alveolar count of the slice, alveolitis score, collagen area ratio, and Ashcroft score.

[0030] This application assesses the effectiveness of the model by evaluating inflammatory cell infiltration, pathological changes, and fibrosis in lung tissue through symptom observation, imaging, and pathology.

[0031] Compared with the prior art, this application has the following beneficial effects:

[0032] This application provides a method for constructing a neonatal bronchopulmonary dysplasia model. The neonatal bronchopulmonary dysplasia model obtained by this application is a non-invasive model. Compared with mechanical ventilation, which requires invasive operation, maintaining high oxygen levels is more manageable and does not harm the animals. Furthermore, the construction method of this application completely simulates clinical operation. In clinical practice, premature infants inhaling high oxygen levels lead to bronchopulmonary dysplasia, with a high success rate. This modeling operation has not been performed in previous large animal models. In addition, this application uses pigs delivered by premature cesarean section to simulate premature infants and uses the inhalation of high-concentration oxygen to simulate clinical operation, resulting in a high degree of simulation of clinical conditions. Attached Figure Description

[0033] Figure 1 Schematic diagram of imaging results of a preterm pig bronchopulmonary dysplasia model ( Figure 1 The middle A diagram shows the full-term control group, with clear lung markings; Figure 1 The B-line diagram shows that in the preterm control group, lung markings are still clear; Figure 1 The CT scan of the preterm hyperoxia group showed increased and thickened lung markings with disordered arrangement, and diffuse linear density increases in both lungs with blurred edges.

[0034] Figure 2 Image showing H&E staining results for a preterm pig bronchopulmonary dysplasia model. Figure 2 The middle A figure shows the full-term control group, where the alveoli are basically uniform in size, without obvious collapse or fusion, and the alveolar wall structure is intact, with no obvious inflammatory cell infiltration. Figure 2 The B-cell image shows that in the preterm control group, the lungs are still in the transitional stage from the vesicular stage to the alveolar stage, with thick alveolar septa and few secondary septa. Figure 2The CT scan showed that in the preterm hyperoxia group, alveoli of varying sizes, alveolar wall rupture and fusion, alveolar septal thickening, alveolar collapse and other lesions coexisted, and inflammatory cell infiltration was visible in both the alveoli and septa.

[0035] Figure 3 Masson staining results for a preterm pig bronchopulmonary dysplasia model ( Figure 3 In the full-term control group shown in Figure A, very few blue collagen fibers were observed in the alveolar septa. Figure 3 In the preterm control group, the alveoli and interlobular septa were widened, and blue collagen fibers were visible inside. Figure 3 The CT scan showed that in the preterm hyperoxia group, there was more collagen fiber deposition in the alveolar septa, some alveolar cavities were replaced by collagen fibers, the lung tissue structure was deformed, and honeycomb lung appeared.

[0036] Figure 4 Statistical results of pathological findings in a model of bronchopulmonary dysplasia in premature pigs (Figure) Figure 4 The results showed that the radial alveolar count in the preterm hyperoxia group was significantly lower than that in the preterm control group and the full-term control group (P < 0.0001); Figure 4 The results showed that the Szapiel score of alveolitis in the preterm hyperoxia group was significantly higher than that in the preterm control group (P<0.01) and the full-term control group (P<0.05); Figure 4 The results showed that the proportion of collagen fiber area in the preterm hyperoxia group was significantly higher than that in the preterm control group (P<0.01) and the full-term control group (P<0.001); Figure 4 The results showed that the Ashcroft fibrosis score in the preterm hyperoxia group was significantly higher than that in the preterm control group and the full-term control group (P < 0.0001) (ns: no significant difference, *: P < 0.05, **: P < 0.01, ***: P < 0.001, ****: P < 0.0001). Detailed Implementation

[0037] To better illustrate the purpose, technical solution, and advantages of this application, the following description will be provided in conjunction with the accompanying drawings and specific embodiments.

[0038] In the following examples and comparative examples, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used are commercially available unless otherwise specified. Furthermore, the raw materials used in each parallel experiment are the same.

[0039] Example 1: A method for constructing a neonatal bronchopulmonary dysplasia model

[0040] This embodiment provides a method for constructing a neonatal bronchopulmonary dysplasia model, including the following steps:

[0041] 1. Laboratory animals: The laboratory animals were pregnant Bama miniature pigs and full-term piglets, all provided by Guangdong Mingzhu Biotechnology Co., Ltd.

[0042] 2. Experimental Groups: This part of the experiment was divided into three groups: a preterm control group, a preterm hyperoxia group, and a full-term control group. First, healthy pregnant Bama miniature pigs with clearly defined mating dates were selected. At 103-105 days of gestation, piglets were delivered via cesarean section under general anesthesia. The newborn piglets were then resuscitated through drying, warming, airway cleansing, and oxygen administration. After the piglets developed spontaneous breathing, they were observed until their breathing stabilized and their skin became rosy. The umbilical cord was then disinfected with iodine and tied off, and the piglets were placed in an incubator for warmth.

[0043] (1) Premature control group: On the first day of birth, complete the lung imaging examination to confirm that there is no infection or other cause of lung lesions. The premature control group was randomly selected from each batch of newborn pigs, and anesthesia was induced by intramuscular injection of Shutai. The lungs were separated for histopathological analysis.

[0044] (2) Premature hyperoxia group: Newborn piglets (7 or 9 days premature) that had stabilized after resuscitation were placed in incubators (temperature 33–35℃, humidity 55%–60%). Medical oxygen was continuously supplied to the incubators, and the oxygen concentration inside the incubators was monitored in real time using an oxygen analyzer. By adjusting the oxygen flow rate, the oxygen concentration (oxygen volume percentage concentration) inside the incubators was maintained at 70%–75%, 80%–85%, and 90%, respectively. Sodium lime was placed in the incubators to absorb carbon dioxide. The rearing environment was alternated between light and dark every 12 hours. The respiratory rate of the newborn piglets was 30–50 breaths / minute. The respiratory status was closely observed. When piglets showed obvious clinical signs such as shortness of breath (approximately 80–120 breaths / minute), nasal cyanosis, dyspnea, oxygen dependence, and difficulty feeding, lung imaging examinations were performed. In combination with clinical manifestations, respiratory distress caused by infection or other diseases was ruled out, and this was set as the experimental endpoint. Under deep anesthesia, lung tissue was dissected and collected for histopathological analysis.

[0045] (3) Full-term control group: Full-term piglets with the same corrected age as the preterm piglets that reached the experimental endpoint were selected, and lung imaging examinations were completed. The piglets were dissected and the lung tissue was collected under deep anesthesia for histopathological analysis.

[0046] 3. Lung tissue pathological analysis: The lung tissues collected from full-term control group, preterm control group, and preterm hyperoxia group were washed with pre-cooled physiological saline and fixed in neutral formalin for 24 hours. The fixed lung lobes were placed in embedding cassettes and dehydrated according to the procedure. After dehydration, they were embedded in paraffin and the paraffin blocks were serially sectioned using a tissue sectioner. The sections were stained according to the operating procedures of the hematoxylin and eosin (H&E) staining kit and the Masson trichrome staining kit, respectively.

[0047] 4. Pathological analysis: The number of radial alveoli, alveolar inflammation, degree of fibrosis, and proportion of collagen fibers in each group of slides were compared and analyzed.

[0048] (1) Radial alveolar count: Several sections were randomly selected from each piglet's slides. A vertical line was drawn from the center of the respiratory bronchioles to the nearest pleura or fibrous septum. The alveoli on the vertical line are the radial alveoli. Six non-overlapping fields of view were randomly selected from each slide, and the average value was calculated. This is the final radial alveolar count of the piglet to assess the degree of alveolarization.

[0049] (2) Assessment of the severity of alveolitis and fibrosis in lung tissue: Several independent slides were selected for each group, and 6 non-overlapping fields of view were randomly selected from each slide. The Szapiel (Table 1) and Ashcroft scoring systems (Table 2) were used for assessment.

[0050] Ashcroft Score: A fibrosis score is assigned to areas occupying more than half of the visual field, recording the predominant level of fibrosis in that area. First, determine whether the tissue in the field is normal or fibrotic. If normal tissue predominates, the score is 0; if fibrotic tissue is dominant, the fibrosis level in that area is scored as one-third of 1, 3, 5, 7, or 8 in Table 2. If there is any difficulty in deciding between scores of 1, 3, 5, and 7, scores of 2, 4, and 6 are given.

[0051] (3) Collagen fiber area ratio statistics: Several independent sections were selected from each group, and 6 non-overlapping fields of view were randomly selected from each section. The area of ​​blue collagen fibers and tissue area were measured using ImageJ software, and the ratios were calculated and statistically analyzed. The modeling effect of the porcine BPD model was evaluated by detecting respiratory system function indicators, lung tissue pathology, and imaging indicators.

[0052] 5. Data Statistical Analysis: In this embodiment, the chart data were analyzed using Graphpad Prism software. Data that conformed to a normal distribution and had homogeneous variances were analyzed using one-way ANOVA, and pairwise comparisons were performed using t-tests. Data that conformed to a normal distribution but had unequal variances or did not conform to a normal distribution were analyzed using non-parametric tests. P < 0.05 was considered statistically significant.

[0053] Table 1 Szapiel scoring system

[0054]

[0055]

[0056] Table 2 Ashcroft Rating System

[0057]

[0058] The results are as follows:

[0059] Table 3 shows the modeling results of newborn pigs at different birth times.

[0060] Table 4 shows the modeling results of newborn pigs with different oxygen concentrations.

[0061] Table 3

[0062] full-term pigs 7 days premature 9 days premature No symptoms of BPD No obvious symptoms and no lung damage Successful induction, 2 / 3 of the animals survived.

[0063] Table 4

[0064] Oxygen concentration 70-75% Oxygen concentration 80-85% Oxygen concentration 90% High survival rate, mild symptoms Modeling successful Severe symptoms, low survival rate

[0065] The following are experimental results using a full-term control group, a premature control group, and a premature hyperoxia group (using newborn pigs with an oxygen concentration of 80-85% and born 9 days prematurely).

[0066] Reference for imaging results of a preterm pig bronchopulmonary dysplasia model Figure 1 , Figure 1 The middle A diagram shows the full-term control group, with clear lung markings; Figure 1 The B-line diagram shows that in the preterm control group, lung markings are still clear; Figure 1 The CT scan showed that in the preterm hyperoxia group, the lung markings were increased and thickened, and the arrangement was disordered. There were diffuse linear areas of increased density in both lungs with blurred edges.

[0067] H&E staining results of a preterm pig bronchopulmonary dysplasia model are as follows: Figure 2 , Figure 2 The middle A figure shows the full-term control group, where the alveoli are basically uniform in size, without obvious collapse or fusion, and the alveolar wall structure is intact, with no obvious inflammatory cell infiltration. Figure 2 The B-cell image shows that in the preterm control group, the lungs are still in the transitional stage from the vesicular stage to the alveolar stage, with thick alveolar septa and few secondary septa. Figure 2 The CT scan showed that in the preterm hyperoxia group, alveoli of varying sizes, alveolar wall rupture and fusion, alveolar septal thickening, alveolar collapse and other lesions coexisted, and inflammatory cell infiltration was visible in both the alveoli and septa.

[0068] Masson staining results of a preterm pig bronchopulmonary dysplasia model are as follows: Figure 3 , Figure 3 In the full-term control group shown in Figure A, very few blue collagen fibers were observed in the alveolar septa. Figure 3 In the preterm control group, the alveoli and interlobular septa were widened, and blue collagen fibers were visible inside. Figure 3 The CT scan showed that in the preterm hyperoxia group, there was more collagen fiber deposition in the alveolar septa, and some alveolar cavities were replaced by collagen fibers, resulting in deformed lung tissue structure and honeycomb lung.

[0069] Pathological statistical results of a preterm pig bronchopulmonary dysplasia model are as follows: Figure 4 , Figure 4 The results showed that the radial alveolar count in the preterm hyperoxia group was significantly lower than that in the preterm control group and the full-term control group (P < 0.0001); Figure 4 The results showed that the Szapiel score of alveolitis in the preterm hyperoxia group was significantly higher than that in the preterm control group (P<0.01) and the full-term control group (P<0.05); Figure 4 The results showed that the proportion of collagen fiber area in the preterm hyperoxia group was significantly higher than that in the preterm control group (P<0.01) and the full-term control group (P<0.001); Figure 4 The results showed that the Ashcroft fibrosis score in the preterm hyperoxia group was significantly higher than that in the preterm control group and the full-term control group (P < 0.0001). Note: ns: no significant difference, *: P < 0.05, **: P < 0.01, ***: P < 0.001, ****: P < 0.0001.

[0070] The above experiments show that a neonatal bronchopulmonary dysplasia model can be established by using an inhaled oxygen concentration of 80-85%. Premature pigs inhaling 80-85% oxygen and breathing 30-50 times / minute will begin to show shortness of breath (breathing about 60-80 times / minute) after about one week. After about two weeks, the shortness of breath will significantly worsen (breathing about 80-120 times / minute), accompanied by nasal cyanosis, difficulty feeding, and oxygen dependence. Chest X-rays are then performed to confirm the lung changes in neonatal bronchopulmonary dysplasia. Then, pathological examinations of lung tissue are conducted. This time point, which is the experimental endpoint, is 2-3 weeks after birth.

[0071] This application uses a pig model. Although pig models have been used as model animals for respiratory distress syndrome before, newborn pigs were not subjected to hyperoxia treatment and instead used spontaneous models. The main problem with spontaneous models is that some pigs will self-repair, leading to model failure. Moreover, pigs are closer to clinical human organ lesions than small animals.

[0072] The neonatal bronchopulmonary dysplasia model obtained in this application is a non-invasive model. Compared with mechanical ventilation, which requires invasive procedures, maintaining high oxygen levels is more manageable and does not harm the animals. Furthermore, the construction method used in this application completely simulates clinical procedures. In clinical practice, the incidence of bronchopulmonary dysplasia caused by high oxygen inhalation is high in premature infants, and this model has a high success rate. This modeling procedure has not been used in previous large animal models. In addition, this application uses cesarean section pigs to simulate premature infants and uses high-concentration oxygen inhalation to simulate clinical procedures, resulting in a high degree of clinical simulation.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit the scope of protection of this application. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the substance and scope of the technical solutions of this application.

Claims

1. A method for constructing a neonatal bronchopulmonary dysplasia model, characterized in that, Includes the following steps: S1. Select newborn pigs delivered by cesarean section 9 days prematurely and place them in a rearing environment with an oxygen volume percentage concentration of 80-85%. S2. After feeding for 2-3 weeks, respiratory system function indicators, lung tissue pathological indicators, and imaging indicators of newborn pigs were tested to obtain a neonatal bronchopulmonary dysplasia model.

2. The method for constructing a neonatal bronchopulmonary dysplasia model as described in claim 1, characterized in that, In step S1, the rearing environment includes a temperature of 33~35℃ and a humidity of 55%~60%.

3. The method for constructing a neonatal bronchopulmonary dysplasia model as described in claim 1, characterized in that, In step S1, sodium lime is placed in the breeding environment, and light / darkness alternates every 12 hours.

4. The method for constructing a neonatal bronchopulmonary dysplasia model as described in claim 1, characterized in that, In step S1, an oxygen analyzer is used to monitor the oxygen volume percentage concentration in the rearing environment in real time and maintain the oxygen volume percentage concentration at 80-85%.

5. The method for constructing a neonatal bronchopulmonary dysplasia model as described in claim 1, characterized in that, The newborn pigs were derived from Bama miniature pigs that were 103-105 days gestation.

6. The method for constructing a neonatal bronchopulmonary dysplasia model as described in claim 1, characterized in that, In step S2, the newborn pigs exhibited obvious shortness of breath, with a respiratory rate of 80-120 breaths / minute, nasal cyanosis, dyspnea, oxygen dependence, and difficulty feeding. Pathological and imaging indicators of lung tissue were also detected.

7. The method for constructing a neonatal bronchopulmonary dysplasia model as described in claim 1, characterized in that, In step S2, the pathological indicators of lung tissue include the radial alveolar count of the slice, alveolitis score, collagen area ratio, and Ashcroft score.

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