Construction method of novel abdominal approach mouse lumbar intervertebral disc degeneration model

Abstract

The invention discloses a construction method of a novel abdominal approach mouse lumbar intervertebral disc degeneration model, and relates to the field of biomedical experiments.The construction method comprises the steps that S1, preoperative preparation and positioning are conducted on an experimental mouse, and a preparation state is obtained; s2, establishing an abdominal approach channel in the abdomen of the experimental mouse to obtain a channel structure; s3, performing tissue separation and positioning treatment on the channel structure under microscopic amplification to obtain a target exposure structure; s4, performing controlled minimally invasive injury treatment on the target exposed structure to obtain a degeneration initial state; s5, obtaining a stable model state; s6, evaluating and calibrating the model at a postoperative preset time point by using imaging and histological methods to obtain model evaluation data; the degeneration model is constructed by accurately targeting the lumbar intervertebral disc through the abdominal approach, the diseased region of the degeneration model is highly matched with the clinical diseased region of human lumbar intervertebral disc degeneration, the degeneration model better fits the physiological anatomical characteristics of the human body, and a more reliable bridge is established for the conversion of scientific research achievements to clinic.

Description

Technical Field

[0001] This invention relates to the field of biomedical experiments, specifically to a method for constructing a novel mouse lumbar intervertebral disc degeneration model via an abdominal approach. Background Technology

[0002] Intervertebral disc degeneration is the core pathological basis for low back pain. Its pathogenesis is complex, and clinical treatment options are limited. Establishing animal models that closely match human pathophysiological characteristics is a crucial tool for advancing mechanistic research, drug screening, and clinical translation. Currently, mice are a commonly used model animal for intervertebral disc degeneration research due to their clear genetic background and ease of manipulation. However, existing modeling techniques still have many shortcomings that urgently need to be addressed:

[0003] For example, the precision and safety of the surgical procedure are not ideal. The traditional dorsal approach requires sharp dissection of the lumbar and posterior muscle groups, which not only causes greater tissue damage, but may also lead to deviation in the positioning of the target intervertebral disc due to limited field of vision, and carries a high risk of damage to adjacent nerves, blood vessels and other important structures. Even with modified approaches such as the anterior or lateral approach, there is often a lack of standardized visualization operation channels and support devices, the operation space is narrow and there is significant interference from abdominal organs, making it difficult to achieve precise exposure and minimally invasive treatment of the target intervertebral disc, and further affecting the reproducibility of model construction.

[0004] The aforementioned shortcomings make it difficult for existing models to meet the needs of precise and standardized scientific research, and there is an urgent need to develop a new modeling method that takes into account clinical relevance, operational safety and model stability. Summary of the Invention

[0005] The purpose of this invention is to provide a novel method for constructing a mouse lumbar intervertebral disc degeneration model via an abdominal approach, in order to solve the problems of poor precision and safety in existing surgical procedures.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for constructing a novel mouse lumbar intervertebral disc degeneration model via an abdominal approach, comprising the following steps:

[0007] S1. Perform preoperative preparation and localization on the experimental mice to establish a repeatable preoperative preparation state and determine the lumbar vertebral segment to be treated, thereby obtaining the preparation state.

[0008] S2. Based on the prepared state, an abdominal access channel is established in the abdomen of the experimental mouse to establish a visual operation channel in the abdominal cavity through a layer-by-layer pathway and to gather the abdominal contents to one side of the body cavity, thus obtaining the channel structure.

[0009] S3. Perform tissue separation and positioning under microscopic magnification on the channel structure to perform layered blunt separation within the channel structure tissue and expose the target lumbar intervertebral disc, so as to obtain visual exposure and positioning of the target intervertebral disc and obtain the target exposed structure.

[0010] S4. Perform controlled minimally invasive damage treatment on the target exposed structure to induce repeatable intervertebral disc degeneration characterization in the target segment and obtain the initial degeneration state;

[0011] S5. Based on the initial state of degeneration, the surgical wound was closed layer by layer and standard postoperative management and observation were implemented to maintain the physiological stability of the animal and ensure the continuity of the model, so as to obtain a stable model state.

[0012] S6. Based on the stable model state, the model is evaluated and calibrated using imaging and histological methods at predetermined postoperative time points. The evaluation data is obtained by quantifying and characterizing the degree of degeneration using imaging (e.g., magnetic resonance imaging, X-ray imaging) and histological staining (e.g., HE, SOFG).

[0013] Furthermore, the processing performed on the prepared state includes:

[0014] Identification of the segment to be treated and acquisition of baseline images are necessary to ensure consistency in preoperative localization and obtain baseline image data.

[0015] Furthermore, the processing performed on the channel structure includes:

[0016] By employing appropriate support devices and functional measures for intra-abdominal repositioning management, a stable operating window and channel structure can be formed without altering the integrity of the abdominal organs.

[0017] Furthermore, the processing performed on the target exposed structure includes:

[0018] Functional manipulations involving blunt dissection and exposure localization along anatomical gaps under magnified microscopic conditions are performed to reduce interference from adjacent tissues and obtain clear exposure of the target structure.

[0019] Furthermore, the controlled minimally invasive damage treatment performed on the initial degeneration state includes:

[0020] Apply controlled intensity of local structural destructive stimulation to the target intervertebral disc to induce a repeatable, graded degenerative response and obtain the initial degenerative state.

[0021] Furthermore, the standardized postoperative management and procedures for the layer-by-layer closure include:

[0022] Develop and implement a postoperative observation schedule and sample collection plan to obtain continuous postoperative records and postoperative data.

[0023] Furthermore, the imaging and histological evaluation processes include:

[0024] Postoperative imaging (including but not limited to magnetic resonance imaging and X-ray) and histological staining (including but not limited to HE and SOFG) were performed at multiple predetermined time points to conduct blinded semi-quantitative scoring in order to obtain comparable model evaluation data.

[0025] Compared with existing technologies, the present invention provides a novel method for constructing a mouse lumbar intervertebral disc degeneration model via an abdominal approach. By precisely targeting the lumbar intervertebral disc through an abdominal approach, the degeneration model is constructed. The lesion site is highly consistent with the clinical pathogenesis of human lumbar intervertebral disc degeneration, which is more in line with human physiological and anatomical characteristics, thus building a more reliable bridge for the translation of scientific research results into clinical practice.

[0026] By employing methods such as establishing a visual channel within the abdominal cavity and microsurgical blunt dissection, damage and interference to adjacent tissues are reduced. At the same time, degeneration is induced through a controllable minimally invasive injury method, which greatly improves the repeatability and stability of model construction and solves the problems of positioning deviation and large tissue damage in traditional approaches.

[0027] The construction process has formed a complete technical chain from preoperative positioning and intraoperative operation to postoperative multidimensional assessment. The resulting structural and characterization data can be directly used for blinded assessment, statistical analysis and various translational studies, providing a standardized and scalable experimental tool for scientific research such as exploring the mechanism of intervertebral disc degeneration and drug screening. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0029] Figure 1 A flowchart illustrating a novel mouse lumbar intervertebral disc degeneration model constructed via an abdominal approach, as provided in this embodiment of the invention. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] As attached Figure 1 As shown:

[0032] Example 1:

[0033] This invention provides a method for constructing a novel mouse lumbar intervertebral disc degeneration model via an abdominal approach, comprising the following steps:

[0034] S1. Perform preoperative preparation and localization on the experimental mice to establish a repeatable preoperative preparation state and determine the lumbar vertebral segment to be treated, thereby obtaining the preparation state.

[0035] Among them, the identification of the segment to be treated and the acquisition of baseline images are used to ensure the consistency of preoperative localization and to obtain baseline image data.

[0036] S2. Based on the prepared state, an abdominal access channel is established in the abdomen of the experimental mouse to establish a visual operation channel in the abdominal cavity through a layer-by-layer pathway and to gather the abdominal contents to one side of the body cavity, thus obtaining the channel structure.

[0037] Among them, a suitable support device and functional measures for intra-abdominal repositioning management are adopted to form a stable operating window and obtain a channel structure without changing the integrity of the abdominal organs.

[0038] S3. Perform tissue separation and positioning under microscopic magnification on the channel structure to perform layered blunt separation within the channel structure tissue and expose the target lumbar intervertebral disc, so as to obtain visual exposure and positioning of the target intervertebral disc and obtain the target exposed structure.

[0039] Among them, the functional operation of blunt dissection and exposure positioning along the anatomical gap under magnified microscopic conditions is used to reduce interference from adjacent tissues and obtain clear target exposed structures.

[0040] S4. Perform controlled minimally invasive damage treatment on the target exposed structure to induce repeatable intervertebral disc degeneration characterization in the target segment and obtain the initial degeneration state;

[0041] Among them, applying local structural destructive stimulation of controlled intensity at the target intervertebral disc is used to induce repeatable and graded degenerative responses and obtain the initial degenerative state.

[0042] S5. Based on the initial state of degeneration, the surgical wound was closed layer by layer and standard postoperative management and observation were implemented to maintain the physiological stability of the animal and ensure the continuity of the model, so as to obtain a stable model state.

[0043] Among these measures, a postoperative observation schedule and sample collection plan were developed and implemented to obtain continuous postoperative records and postoperative data.

[0044] S6. Based on the stable model state, the model is evaluated and calibrated using imaging and histological methods at predetermined postoperative time points. The degree of degeneration is quantified and characterized by imaging (e.g., magnetic resonance imaging, X-ray imaging) and histological staining (e.g., HE, SOFG) to obtain model evaluation data.

[0045] In this process, imaging (including magnetic resonance imaging and X-ray) and histological staining (including HE and SOFG) were used at multiple predetermined time points after surgery, and a blinded semi-quantitative scoring method was employed to obtain comparable model evaluation data.

[0046] As can be seen from the above, the degeneration model constructed by precisely targeting the lumbar intervertebral disc through the abdominal approach has a lesion site that closely matches the clinical pathogenesis of human lumbar intervertebral disc degeneration and is more in line with human physiological and anatomical characteristics, thus building a more reliable bridge for the translation of scientific research results into clinical practice.

[0047] Example 2:

[0048] Basic experimental setup:

[0049] 1. Laboratory animals:

[0050] SPF-grade male C57BL / 6 mice (8-10 weeks old, weighing 20-22g) were purchased from Beijing Vital River Laboratory Animal Technology Co., Ltd. After acclimatization for one week, experiments were conducted, with 12 mice in each group (n=12).

[0051] 2. Reagents and Instruments:

[0052] Anesthetic: Isoflurane (Sigma-Aldrich, USA);

[0053] Imaging equipment: 7.0T small animal MRI (Bruker, Germany), Micro-CT (SkyScan 1276, Belgium);

[0054] Histological reagents: HE staining kit, SOFG staining kit (Solarbio, China);

[0055] Surgical instruments: 3.0 / 3.2mm diameter small flaring stent (custom-made), 30G puncture needle (BD, USA), miniature mechanical probe (FemtoTools, Switzerland);

[0056] Analysis software: ImageJ 1.8.0 (NIH, USA), SPSS 26.0 (IBM, USA).

[0057] 3. Evaluation Indicators Explanation:

[0058] Preoperative localization accuracy: The percentage of the target lumbar vertebral segment (L4-L5) that is confirmed to be consistent with the preoperative markings during surgery;

[0059] Operation window stability: coefficient of variation of displacement during channel maintenance (CV = standard deviation / mean × 100%).

[0060] Adjacent tissue damage rate: The proportion of samples with a muscle / fascia histological damage score ≥2 points (out of 5) at 24 hours postoperatively;

[0061] Degeneration induction success rate: the proportion of samples with a Pfirrmann score ≥2 at 28 days post-operation;

[0062] Imaging consistency: MRI T2 value, coefficient of variation (CV) of Micro-CT intervertebral disc height;

[0063] Histological consistency: HE staining Pfirrmann score, SOFG staining glycosaminoglycan (GAG) content coefficient of variation;

[0064] Blinded assessment concordance rate: The Kappa coefficient of the blinded assessment results by two independent observers is converted into a percentage;

[0065] Translational adaptability: The degree of matching between the model's degeneration process and the timeline of human lumbar intervertebral disc degeneration (1-4 points, 4 points being the best);

[0066] Puncture injury method:

[0067] Step S1: Preoperative preparation and positioning:

[0068] Anesthesia protocol: Isoflurane inhalation anesthesia (induction concentration 5%, maintenance concentration 2%, anesthesia time 20±3 min);

[0069] Localization method: The L4-L5 segment was determined by Micro-CT scan (voltage 50kV, current 500μA, resolution 10μm) before the operation. The segment was marked with methylene blue on the skin surface. The localization accuracy rate = (number of correctly localized segments out of 12 / 12) × 100% = 11 / 12 × 100% ≈ 91.7%.

[0070] Step S2: Establishment of the abdominal approach:

[0071] Incision parameters: The length of the midline abdominal incision is 1.5±0.1cm. The skin, subcutaneous tissue, and anterior rectus sheath are cut layer by layer to separate the rectus abdominis muscle.

[0072] Expansion and Closure: A small 3.0mm diameter exploratory stent was inserted into the incision to close the intestines and mesentery into the left side of the body cavity (closing area ≥ 80% of the abdominal cavity volume). The stability of the channel was determined by tracking displacement via intraoperative video. The CV was calculated as follows: CV = (displacement standard deviation / average displacement) × 100% = 0.12mm / 1.46mm × 100% ≈ 8.2%, thus obtaining the channel structure.

[0073] Step S3: Microscopic Separation and Target Exposure:

[0074] Magnification conditions: Operated under a 10x stereomicroscope (Olympus SZX16);

[0075] Dissection method: Blunt dissection (without sharp cutting) was performed along the intermuscular space between the posterior sheath of the rectus abdominis muscle and the lumbar and back muscles, with a dissection depth of 2.8±0.2 mm, exposing the L4-L5 intervertebral disc. The clarity of exposure was verified by histological sections (5-point score: 4.0±0.2 points) to obtain the target exposed structure.

[0076] Step S4: Minimally invasive damage-induced degeneration:

[0077] Damage parameters: 30G puncture needle (needle tip diameter 0.3mm), puncture depth 1.0±0.1mm, residence time 5s, damage pressure 0.3±0.05N (monitored by a miniature pressure sensor).

[0078] Degeneration induction: By controlling the puncture to destroy the annulus fibrosus of the intervertebral disc, the success rate of degeneration induction 28 days after the operation is (number of Pfirrmann scores ≥2 in 12 animals / 12) × 100% = 11 / 12 × 100% ≈ 91.7%, thus obtaining the initial state of degeneration.

[0079] Step S5: Postoperative management and observation:

[0080] Postoperative management: Set an observation schedule (1, 3, 7, 14, 28 days), record weight changes (weight recovered to 95.2±2.1% of preoperative weight 7 days after surgery), and behavioral scores (no limping, normal eating).

[0081] Sample collection: 28 days post-surgery, all patients were euthanized by cervical dislocation. L4-L5 intervertebral disc samples were separated, and the sample collection integrity rate was recorded as 100%, achieving a stable model state.

[0082] Step S6: Model Evaluation and Calibration

[0083] Evaluation time point: 28 days post-surgery;

[0084] Imaging examination:

[0085] MRI: T2-weighted imaging (TR=2000ms, TE=30ms), measuring the T2 value of the intervertebral disc (28 days: 68.3±4.2ms);

[0086] Micro-CT: Measured the intervertebral disc height and calculated the change rate = (postoperative height - preoperative height) / preoperative height × 100%. The preoperative height was 1.15 ± 0.08 mm, and the postoperative height was 0.94 ± 0.06 mm, with a change rate of -18.5 ± 3.1%.

[0087] Histological examination:

[0088] HE staining: Pfirrmann score (28 days: 2.8±0.3 points, scoring criteria: 1 point for normal, 4 points for severe degeneration);

[0089] SOFG staining: ImageJ was used to measure GAG ​​content (optical density OD value: 0.62±0.05);

[0090] Time series characteristics: Establish the degradation process curve (14 days → 28 days, T2 value decreases by 12.3%, Pfirrmann score increases by 0.5 points) to obtain model evaluation data.

[0091] Data statistics and verification:

[0092] Blinded assessment: Two observers blinded the evaluation of radiological / histological results, with a Kappa coefficient of 0.82, resulting in a concordance rate of 89.0%.

[0093] Statistical analysis: Independent samples t-test was used (α=0.05). The within-group CV of all indicators was <10%, which verified the repeatability.

[0094] Dataset: Includes localization accuracy, damage parameters, and imaging / histological data.

[0095] Example 3:

[0096] Local mechanical injury method:

[0097] Preoperative preparation and positioning:

[0098] Anesthesia protocol: Isoflurane inhalation anesthesia (induction concentration 4%, maintenance concentration 1.8%, anesthesia time 22±2 min);

[0099] Localization method: Micro-CT localization of L4-L5 segments, skin marking, localization accuracy = 12 / 12×100%=100%, achieving improved readiness.

[0100] Establishment of the abdominal approach:

[0101] Incision parameters: The length of the midline abdominal incision is 1.6 ± 0.1 cm, and the incision is made layer by layer;

[0102] Dilation and Closure: A 3.2mm diameter dilation stent was used to close the intestinal tract to the right side of the body cavity (closing area ≥85%). The channel displacement CV = 0.11mm / 1.39mm × 100% ≈ 7.9%, thus obtaining the channel structure.

[0103] Microscopic separation and target exposure:

[0104] Magnification conditions: Operated under a 15x stereo microscope;

[0105] Separation method: Bluntly separate the muscles and fascia of the lumbar and back sides along the anatomical gap, with a separation depth of 3.0±0.2mm and an exposure clarity score of 4.1±0.1 points, to obtain the target exposed structures.

[0106] Minimally invasive damage-induced degeneration:

[0107] Damage parameters: Miniature mechanical probe (diameter 0.4 mm), applied pressure 0.5 ± 0.05 N, damage time 8 s, damage area 0.12 mm²;

[0108] Degeneration induction: The success rate of degeneration induction 28 days after surgery = 12 / 12×100%=100%, achieving the initial degeneration state.

[0109] Postoperative management and observation:

[0110] Postoperative management: The observation schedule was the same as in Example 2. Seven days after the operation, the patient's weight recovered to 96.5±1.8% of the preoperative weight, and there were no abnormalities in behavior.

[0111] Sample collection: The model was sacrificed at 28 days, and the integrity rate of L4-L5 intervertebral disc samples was 100%, achieving a stable model state.

[0112] Model evaluation and calibration:

[0113] Evaluation time point: 28 days post-surgery;

[0114] Imaging examination:

[0115] MRI T2 value (28 days: 67.5±3.8ms);

[0116] Micro-CT intervertebral disc height: preoperative 1.20±0.07mm, postoperative 1.00±0.05mm, change rate = -17.8±2.9%;

[0117] Histological examination:

[0118] HE staining Pfirrmann score (28 days: 2.7±0.2 points);

[0119] SOFG staining GAG content (OD value: 0.64±0.04);

[0120] Time series characteristics: from 14 days to 28 days, the T2 value decreased by 11.7%, and the Pfirrmann score increased by 0.4 points, thus obtaining model evaluation data.

[0121] Data statistics and verification:

[0122] Blinded assessment consistency rate = Kappa coefficient 0.86 → 91.0%;

[0123] Statistical analysis: Within-group CV < 8%, replication validation passed;

[0124] Dataset: Can be used for drug intervention trials.

[0125] As can be seen from the above, the use of intra-abdominal visualization channel establishment and micro-blunt dissection reduces damage and interference to adjacent tissues. At the same time, the controlled minimally invasive damage method induces degeneration, which greatly improves the repeatability and stability of model construction and solves the problems of positioning deviation and large tissue damage in traditional approaches.

[0126] Comparative example:

[0127] A mouse model of intervertebral disc degeneration was constructed using a traditional dorsal approach. Except for the "surgical approach" and "exposure method," the other experimental conditions (animals, reagents, instruments, and evaluation indicators) were the same as in Example 2. The specific steps are as follows:

[0128] Preoperative localization of the L4-L5 segment yielded an accuracy rate of approximately 91.7% (11 / 12 × 100%).

[0129] A midline back incision of 1.8 ± 0.1 cm was made without a flaring support, and the erector spinae muscles were directly dissected. The channel stability CV = 0.32 mm / 2.24 mm × 100% ≈ 14.3%.

[0130] The erector spinae muscles were sharply dissected under a 10x microscope to expose the L4-L5 intervertebral disc, with a clarity score of 3.2 ± 0.3 points.

[0131] With a 30G puncture needle (1.0mm depth), the success rate of degeneration induction is approximately 91.7% (11 / 12 × 100%).

[0132] Seven days after surgery, the patient's weight recovered to 90.3 ± 2.5% of the pre-operative weight, and the sample collection completeness rate was 100%.

[0133] 28-day MRI T2 value = 75.6±6.8ms, intervertebral disc height change rate = -25.3±5.4%, Pfirrmann score = 3.2±0.5 points, SOFG staining GAG content = 0.51±0.07 OD;

[0134] Blinded assessment concordance rate = Kappa coefficient 0.72 → 78.0%, within-group CV > 15%.

[0135] Data calculation instructions:

[0136] 1. Rate of change in intervertebral disc height:

[0137] Formula: Change rate = (Postoperative height - Preoperative height) / Preoperative height × 100%;

[0138] Example 1: (0.94-1.15) / 1.15×100%≈-18.5%;

[0139] Example 2: (1.00-1.20) / 1.20×100%≈-17.8%;

[0140] Comparative example: (0.90-1.21) / 1.21×100%≈-25.3%.

[0141] 2. Coefficient of Variation (CV):

[0142] CV = (Standard deviation of indicator / Mean of indicator) × 100%

[0143] Example 1: MRI T2 value CV: 4.2 / 68.3×100%≈6.1%;

[0144] Comparative MRI T2 value CV: 6.8 / 75.6×100%≈9.0%.

[0145] 3. Consistency rate of blinded assessment:

[0146] Formula: Consistency rate = (Number of completely consistent samples + 0.5 × Number of partially consistent samples) / Total number of samples × 100%;

[0147] Example 2: (10 + 0.5×2) / 12×100%≈91.0%.

[0148] A comprehensive comparison of Examples 2, 3, and the comparative examples is shown in Table 1 below:

[0149] Table 1

[0150] Evaluation indicators Example 2 (Puncture Injury) Example 3 (Mechanical Damage) Comparative example (traditional back approach) Improvement potential of this plan (vs. comparative) Preoperative localization accuracy rate (%) 91.7 100.0 91.7 8.3 percentage points (Example 3) Operation window stability CV (%) 8.2 7.9 14.3 42.0%-44.7% Percentage of adjacent tissue damage (%) 8.3（1 / 12） 0.0（0 / 12） 33.3（4 / 12） 75.1%-100.0% Degeneration induction success rate (%) 91.7 100.0 91.7 8.3 percentage points (Example 3) MRI T2 value (28 days, ms) 68.3±4.2 67.5±3.8 75.6±6.8 The T2 value is more stable (CV decreased by 32.2%). Intervertebral space height change rate (%) -18.5±3.1 -17.8±2.9 -25.3±5.4 The rate of return and change is controllable (the decline decreased by 26.9%). Pfirrmann rating (28 days) 2.8±0.3 2.7±0.2 3.2±0.5 The ratings were more consistent (CV decreased by 54.0%). SOFG staining GAG content (OD) 0.62±0.05 0.64±0.04 0.51±0.07 GAG retention rate improved by 21.6%-25.5%. Consistency rate of blinded assessment (%) 89.0 91.0 78.0 14.1%-16.7% Transformation suitability score (1-4 points) 3.6 3.8 2.5 44.0%-52.0%

[0151] As shown in the table above, the stability of the abdominal approach (CV<8.2%) is significantly better than that of the traditional dorsal approach (14.3%), reducing intraoperative tissue traction damage;

[0152] Degeneration consistency (Pfirrmann score CV < 11%) is better than that of the control group (CV > 15%), which is beneficial for research replication;

[0153] The conversion adaptability of the target lumbar spine site (3.6-3.8 points) is much higher than that of the traditional model (2.5 points), which is more in line with the clinical scenario of human lumbar spine degeneration.

[0154] As can be seen from the above, the construction process forms a complete technical chain from preoperative positioning and intraoperative operation to postoperative multidimensional assessment. The structural and characterization data produced can be directly used for blinded assessment, statistical analysis and various translational studies, providing a standardized and scalable experimental tool for scientific research such as exploring the mechanism of intervertebral disc degeneration and drug screening.

[0155] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for constructing a novel mouse model of lumbar intervertebral disc degeneration by abdominal approach, characterized in that, The method comprises the following steps: S1, preoperative preparation and positioning of the experimental mouse is performed to establish a repeatable preoperative preparation state and determine the lumbar segment to be treated, obtaining a preparation state; S2, an abdominal access channel is established in the abdomen of the experimental mouse based on the preparation state, to establish an intraperitoneal visualization operation channel by layer-by-layer access and to gather the intraperitoneal contents to one side of the body cavity, obtaining a channel structure; S3, the channel structure is subjected to microscopic magnification-based tissue separation and positioning treatment, to perform hierarchical blunt separation in the channel structure tissue and expose the target lumbar intervertebral disc, to obtain visual exposure and positioning of the target intervertebral disc, obtaining a target exposure structure; S4, the target exposure structure is subjected to controlled minimally invasive damage treatment to induce a repeatable intervertebral disc degeneration feature at the target segment, obtaining a degeneration initial state; S5, based on the degeneration initial state, the surgical wound is closed layer by layer and standard postoperative management and observation are implemented to maintain animal physiological stability and ensure model sustainability, obtaining a stable model state; S6, based on the stable model state, the model is evaluated and calibrated at a predetermined postoperative time point using imaging and histological methods, to quantify and characterize the degree of degeneration by imaging and histological staining, obtaining model evaluation data.

2. The method according to claim 1, wherein, The treatment of the preparation state comprises: Identification and baseline image acquisition of the segment to be treated to ensure preoperative positioning consistency and obtain baseline image data.

3. The method according to claim 1, wherein, The treatment of the channel structure comprises: Adopting an appropriate support device and functional measures for intraperitoneal homing management to form a stable operation window without changing the integrity of the abdominal organs and obtain the channel structure.

4. The method according to claim 1, wherein, The treatment of the target exposure structure comprises: Performing a functional operation of blunt separation and exposure positioning along the anatomical gap under magnifying microscopic conditions to reduce adjacent tissue interference and obtain a clear target exposure structure.

5. The method according to claim 1, wherein, The controlled minimally invasive damage treatment of the degeneration initial state comprises: Applying a controllable intensity of local structural destructive stimulation at the target intervertebral disc to induce a repeatable and gradable degeneration response and obtain the degeneration initial state.

6. The method according to claim 1, wherein, The layer-by-layer closure and implementation of standardized postoperative management treatment comprises: Developing and implementing a postoperative observation schedule and sample collection plan to obtain continuous postoperative records and obtain postoperative record data.

7. The method according to claim 1, wherein, The imaging and histological evaluation treatment comprises: Using imaging and histological staining and performing blind semi-quantitative scoring at a predetermined plurality of postoperative time points to obtain comparable model evaluation data.

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