Method for establishing expansion line model
By suturing the fixing sheet and stud rotation on the back of rats, combined with drug intervention, we simulate excessive skin expansion, solving the problems of high safety risks and high cost in the prior art, and achieving the safe and effective establishment of the small animal expansion pattern model, verifying the feasibility of treating expansion pattern.
Patent Information
- Application Number
- CN202510454400.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-11
- Publication Date
- 2025-07-04
AI Technical Summary
The prior art has high safety risks and high cost when evaluating the therapeutic effect of expansion streaks, and it is difficult to safely and effectively establish an expansion streak model on small animals.
A specific device was used to slowly stretch the skin, and a swelling pattern model was established on the back of rats by suturing fixation sheets and stud rotation. Combined with the use of clobetasol propionate ointment and corticosterone solution, the skin hyperdistension process was simulated and collagen fiber fracture and red pattern characteristics were observed.
The successful establishment of a small animal expansion pattern model improves the simplicity and success rate of operation, and can safely and effectively verify the feasibility of instruments and drugs for treating expansion pattern.
Smart Images
Figure CN120241320A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of pathological models, and in particular to a method for establishing a striae distensae model. Background Art
[0002] Striae distensae (SD) generally appear in areas with more fat accumulation, such as the chest, lower abdomen, upper arms, underarms, buttocks, thighs, and back. They are the same for both men and women. The appearance problem of striae distensae has always existed and there are not many solutions. The growth and formation of striae distensae go through 4 stages: In the initial stage of injury, the dermal elastic fibers are damaged and torn, usually accompanied by an inflammatory reaction of blood vessel injury, presenting as red and purple raised stripes on the skin. At this stage, there will be a sense of itching in the area near the striae distensae, and the striae at this time are relatively easy to remove; In the late stage of injury, the dermal elastic fibers are broken, separated and missing, and there are depressions under the skin, and the skin loses its elasticity; In the initial stage of the body's self-repair, the tissue mechanism produces self-healing, showing an early scar-like repair, with strip-shaped atrophic and sunken skin-colored stripes of different lengths, widths and breadths; In the late stage of the body's self-repair, due to the body mechanism causing excessive scar repair, the stripes are filled with scar fibrotic tissue, and finally present as milky white inelastic stripes.
[0003] Currently, the evaluation of the treatment effect of striae distensae is applied to volunteers or large animals, which has certain safety risks and high costs. Designing a method to create striae distensae in small animals can overcome the existing bottlenecks and can more safely and effectively verify the feasibility of instruments and drugs for treating striae distensae. Summary of the Invention
[0004] The purpose of the present invention is to provide a method for establishing a striae distensae model with simple method, easy operation and high success rate.
[0005] To achieve the above purpose, the present invention provides a method for establishing a striae distensae model, which is characterized by including the following steps:
[0006] S1. Before rat modeling, perform hunger and thirst treatment for 24 ± 4 h, remove the hair on the back, and use depilatory cream to remove the excess fluff;
[0007] S2. Use a thread to suture and fix the fixing pieces 2 and 6 of the modeling mold on the back skin of the rat. The fixing pieces 2 and 6 are at the closest distance position, respectively located at symmetrical positions on both sides of the spine. When suturing, avoid damaging the subcutaneous tissue and nerves on the back of the rat. The suture passes through the small holes on the fixing pieces 2 and 6 of the modeling mold and is sutured to the depilated area on the back of the mouse;
[0008] S3. Every day, evenly apply clobetasol propionate ointment on the exposed back skin of the rat after suturing the modeling mold on the back, so as to evenly cover the skin of the modeling site, and continuously intervene for 14 ± 1 days; Apply it once a day;
[0009] S4. Rotate the stud of the modeling mold 0.5 - 3 turns every day; the pitch of the modeling mold is 0.5 - 1 mm;
[0010] S5. Remove the device 14 ± 1 days after modeling, and then rest for 7 - 14 days. During the rest period, feed the rats normally and observe the back of the rats; based on whether red streaks appear on the appearance and the results of Masson / HE staining analysis, whether the collagen fibers are broken; when it is observed that the characteristics of early red streaks of striae distensae appear, it indicates that the modeling is successful;
[0011] Starting from step S2, the daily drinking water of the rats is the rat drinking water, and they can drink it normally; the rat drinking water is prepared by dissolving corticosterone powder in 100% molecular - grade ethanol and then adding it to the drinking water; the final concentration is a 0.1% - 5% ethanol solution containing 10 - 200 μg / mL corticosterone.
[0012] Furthermore, in step S4, rotate the stud of the modeling mold 1 turn every day.
[0013] Furthermore, in step S4, the pitch of the modeling mold is 0.5 mm.
[0014] Furthermore, in the rat drinking water, the water contains a 2% ethanol solution with a final concentration of 150 μg / mL corticosterone.
[0015] The present invention simulates the process of short - term excessive skin expansion by slowly stretching the skin with a specific device, so as to achieve the purpose of establishing a striae distensae model for small animals; the device can closely fit the back, and at the same time, by twisting the screw rod, the distance between the two fixing pieces can be controlled to maintain sufficient tensile force, ensuring that the back skin is in a sufficiently strong tensile state. Brief Description of the Drawings
[0016] Figure 1 is the structural diagram of the modeling mold.
[0017] Figure 2 is Figure 1 the picture after the mold is fixed on the rat.
[0018] Figure 3 is the back picture of the rat after the modeling experiment is successful.
[0019] Figure 4 is the pathological section staining of the rat back after the modeling experiment is successful (HE staining & Masson staining). Detailed Embodiments
[0020] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention. For those technical or conditions not specified in the embodiments, they shall be carried out according to the techniques or conditions described in the literature in the art or according to the product specifications. For reagents or instruments whose manufacturers are not indicated, they are all conventional products that can be obtained through commercial purchase.
[0021] Example 1: Modeling of stretch marks on the back of small animals
[0022] Drinking water for rats: Dissolve corticosterone powder (Sigma C2505) in 100% molecular-grade ethanol, and then add it to the drinking water; make its final concentration an ethanol solution of corticosterone at 10 - 200 μg / mL (preferably 150 μg / mL) with 0.1% - 5% (preferably 2%). From the start of modeling, the daily drinking water for rats is the drinking water for rats, and they can drink it normally.
[0023] Modeling steps:
[0024] 1. Grouping: 3 rats in the control group and 3 rats in the experimental group. All 6 rats are SD rats, male, 6 - 8 weeks old, and weighing 180 - 250 g.
[0025] The rats in the control group are also subjected to hair removal treatment, and at the same time, the drinking water is the same, and the application method of clobetasol propionate ointment (clobetasol propionate ointment) is the same, except that the mold fixation treatment is not performed.
[0026] The rats are starved and thirsty for 24 h before modeling. Use an electric hair clipper to remove the hair on the back, and use 0.5 ml of Veet hair removal cream to remove the excess fluff (the usage method of the hair removal cream is to apply it evenly on the area to be depilated, let it stand for 5 - 10 min, then wipe off the hair removal cream, and rinse the remaining hair removal cream on the depilated area with pure water);
[0027] 2. Use nylon thread to Figure 1 The fixing pieces (fixing pieces 2 and 6) of the modeling mold in Figure 1 are sutured and fixed on the back skin of the rats. The model number of the nylon thread used as the suture is 5 - 0; when suturing, assemble the mold according to Figure 2 After completion, the two fixing pieces are in the position of the closest distance, and are respectively located at symmetric positions on both sides of the spine. When suturing, pass the suture needle through the back skin of the mouse (note that the suture depth should be under the epidermis and above the subcutaneous tissue) to avoid damaging the subcutaneous tissue and nerves on the back of the mouse. The nylon thread is sutured to the depilated area on the back of the mouse through the small holes on the fixing pieces 2 and 6 of the modeling mold (there are multiple small holes on the fixing pieces 2 and 6 respectively). The back of the sutured rat is as shown in
[0028] 3. After suturing the modeling mold on the back of the rats every day, evenly apply 0.2 ml - 0.3 ml of 0.05% clobetasol propionate ointment on the exposed back skin (to evenly cover the skin at the modeling site), and continuously intervene for 14 days; apply it once a day;
[0029] 4. Rotate the stud of the modeling mold 0.5 - 3 turns (preferably 1 turn) every day; the pitch of the modeling mold is 0.5 - 1 mm (preferably 0.5 mm);
[0030] The working principle of the modeling mold is: Rotate the wing nut 7. The rotation of the wing nut only stays in place, driving the stud 5 to rotate. The wing nut 7 does not move its position. At the same time, close to the fixing piece 6 of the wing nut, the nuts 3 and 4 do not move, and the fixing piece 2 moves upward, increasing the distance between the two fixing pieces.
[0031] 5. After 14 days of modeling, remove the device, and then rest for 7 - 14 days. During the rest period, feed the rats normally (except for using the above-mentioned drinking water for rats for drinking water, the rest is normal), and observe the back of the rats; based on whether red streaks appear in appearance and the results of Masson / HE staining analysis, whether the collagen fibers are broken; when it is observed that the characteristics of early red streaks of striae distensae appear (see Figure 3 and Figure 4 ), it indicates that the modeling is successful.
[0032] 6. When one of the following situations occurs in the experimental animals, immediately terminate the experiment:
[0033] (1) Weight loss: Rapidly lose 15 - 20% of the original weight (such as within 24 hours), or growing animals continuously show no weight gain, or the weight is not monitored but the animals show cachexia and persistent muscle wasting.
[0034] (2) Loss of appetite: Completely lose appetite for 24 hours or have poor appetite (less than 50% of the normal amount) for 3 days.
[0035] (3) Weakness: Unable to eat and drink on its own, unable to stand for 24 hours or can only stand with great difficulty. It is necessary to first rule out whether it is the recovery period of the animals after anesthesia, and then evaluate whether the animals are weak due to diseases or experiments and other factors.
[0036] (4) Infection of body organs: Presenting physical indicators and abnormal blood test values, showing no good response to drug treatment and continuously evolving into a systemic disease.
[0037] The following lists some abnormal indicators. If there is one of them, it is determined as abnormal;
[0038] 1. Physical indicators
[0039] Fever: A common symptom of infection, with an increase in body temperature.
[0040] Pain: Pain or tenderness may occur at the site of infection.
[0041] Redness and swelling: Local infections are often accompanied by redness, swelling and heat.
[0042] Discharge: Such as pus, mucus, etc.
[0043] Fatigue: Systemic infections are often accompanied by fatigue and weakness.
[0044] Shortness of breath: Lung infections may cause rapid breathing.
[0045] Frequent urination or urgency: Common symptoms of urinary tract infections.
[0046] 2. Abnormal blood test values
[0047] White blood cell count (WBC):
[0048] Elevated: Common in bacterial infections.
[0049] Decreased: May be caused by certain viral infections.
[0050] C-reactive protein (CRP):
[0051] Elevated: A sensitive indicator of inflammation or infection.
[0052] Erythrocyte sedimentation rate (ESR):
[0053] Elevated: An indicator of inflammation or infection.
[0054] Procalcitonin (PCT):
[0055] Elevated: An indicator of severe bacterial infection or sepsis.
[0056] Platelet count:
[0057] Elevated: Inflammatory response.
[0058] Decreased: Severe infection or sepsis.
[0059] Liver function indicators:
[0060] Elevated ALT / AST: Liver infection or inflammation.
[0061] Kidney function indicators:
[0062] Elevated creatinine and blood urea nitrogen: Kidney infection or impaired function.
[0063] The structural schematic diagram of the specific device for striae distensae modeling is as Figure 1 shown, consisting of a nut, a stud, and a fixing piece, which is fixed on the back of the mouse as Figure 2 shown; after the entire test cycle, asFigure 3 As shown, Figure 3 Obvious red lines can be seen on the back of the mouse in A and B. After HE staining and Masson staining, the subcutaneous condition was observed. The results are as follows Figure 4 As shown: In the stretch mark model group, the epidermis was significantly thickened (black arrow), the dermis was infiltrated with scattered inflammatory cells (blue arrow), and the collagen fibers were broken and the scars were hyperplastic (red arrow).
[0064] From the appearance observation and pathological section analysis, it is consistent with the characteristics of early expansion lines - red lines:
[0065] 1. Red stripes on the surface
[0066] 2. Slightly raised;
[0067] 3. Collagen fibers are disordered and broken.
[0068] The above situation did not occur in the three rats in the control group.
[0069] In summary, the present invention provides a method for manufacturing a stretch mark model on the back of a small animal. After verification by animal experiments, it is clear that a small animal stretch mark model can be established, and the feasibility of instruments and drugs for treating stretch marks can be verified more safely and effectively.
[0070] Example 2: Modeling of small animal back expansion lines
[0071] According to the method of Example 1, a control group of 5 mice and a test group of 10 mice were set up, and finally 8 mice in the test group were successful. The 5 rats in the control group were the same as those in Example 1.
[0072] It is proved that the method of the present invention is feasible and can be implemented repeatedly with a high success rate.
[0073] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.
Claims
1. A method for establishing a stretch mark model, characterized in that It includes the following steps: S1. Before modeling the rats, they are starved and thirsty for 24 ± 4 h, the back hair is removed, and superfluous fluff is removed with depilatory cream. S2. Use a thread to suture and fix the fixing pieces 2 and 6 of the modeling mold on the back skin of the rat. The fixing pieces 2 and 6 are in the position of the closest distance and are symmetrically located on both sides of the spine. Avoid damaging the subcutaneous tissue and nerves on the back of the rat during suturing. The suture passes through the small holes on the fixing pieces 2 and 6 of the modeling mold and is sutured to the depilated area on the back of the mouse. S3. Every day, apply Clobetasol Propionate Ointment evenly on the exposed back skin after suturing the modeling mold on the back of the rat until the skin of the modeling site is evenly covered, and continuously intervene for 14 ± 1 days; apply it once a day. S4. Rotate the stud of the modeling mold 0.5 - 3 turns every day; the pitch of the modeling mold is 0.5 - 1 mm. S5. After 14 ± 1 days of modeling, remove the device, and then let it rest for 7 - 14 days. During the rest period, raise it normally and observe the back condition of the rat; based on whether red streaks appear in appearance and the analysis of the Masson / HE staining results, whether the collagen fibers are broken. When it is observed that the characteristics of early red streaks of striae distensae appear, it indicates that the modeling is successful. Starting from step S2, the daily drinking water of the rats is the drinking water for rats, and they can drink it normally; the drinking water for rats is to dissolve corticosterone powder in 100% molecular-grade ethanol, and then add it to the drinking water; make its final concentration be a 0.1% - 5% ethanol solution containing 10 - 200 μg / mL corticosterone.
2. The method for establishing a striae distensae model according to claim 1, wherein, In step S4, rotate the stud of the modeling mold 1 turn every day.
3. The method for establishing a striae distensae model according to claim 1, characterized in that, In step S4, the pitch of the modeling mold is 0.5 mm.
4. The method for establishing a striae distensae model according to claim 1, wherein In the drinking water for rats, the water contains a 2% ethanol solution with a final concentration of 150 μg / mL corticosterone.