动物模型 z-bo 2020-08-10 597

　　(1) Method of replication 4 to 5 months old New Zealand rabbits are anesthetized by intraperitoneal ketamine at a dose of 50 mg/kg body weight, and then fixed on the operating plate; routinely sterile sterilized operating area, make an incision on the animal's patella to expose the distal femur End the articular cartilage on the patella surface, and then use a hand drill to create a full-thickness cartilage defect with a diameter of 4-6mm on the surface of the articular cartilage. One side of the defect site was filled with the test substance as the experimental group, and the other side was filled with collagen gel as the control group. After the operation, the experimental rabbits were routinely raised in rabbit cages and moved freely. After surgery, observe whether the animal’s knee joints have contractures, adhesions and new organisms, and whether the model animals have joint pain, stiffness, and functional dysfunction. The model animals were sacrificed 1 to 24 weeks after the operation, and the samples were taken for histopathological observation. The specimens were made into routine pathological sections, stained with toluidine blue and HE, and placed under a light microscope for histological observation. Observe whether the animal’s knee joints have contractures, adhesions, slow and progressive degeneration of articular cartilage, synovial edema, hyperemia, and color.

　　(2) Model characteristics This model is mostly used in a new field of biomedical science development in recent years: tissue engineering to repair articular cartilage defects, that is, a science of preparing new tissues to replace defective tissues. Articular cartilage is hyaline cartilage with low tissue metabolic activity. Cartilage damage or defects caused by trauma and surgery are difficult to repair or replace with fibrocartilage and fibrous tissue. The application of tissue engineering methods to repair articular cartilage defects has a profound impact. The animal model of traumatic articular cartilage injury established by this method can be used to observe the effect of tissue engineering restorations on animal articular cartilage cells.

　　(3) Comparative Medicine It is well known that the difference in cartilage thickness between humans and animals exists in all areas of the joints, and the thickness of the hyaline cartilage layer of the human medial femoral condyle is 5-8 times that of adult rabbits. Although the size of cartilage cells in human and rabbit articular cartilage is not significantly different from each other, the amount of matrix in a single cartilage cell in the human radial layer is 7-8 times that of rabbits; the content of proteoglycan in the anterior articular cartilage of human femur is higher than that of the posterior side. Articular cartilage, while the situation in rabbits is just the opposite of that in humans; differences in cartilage mechanical characteristics lead to differences in the repair of cartilage after cartilage damage; inherent differences in structure and mechanical characteristics will also affect the evaluation of the research results, thus enabling animal model experiments The results are difficult to apply to the human body, or the experimental results are difficult to repeat, or the same experimental factor is applied to different animal models, and different results will appear. Therefore, only a comprehensive understanding of the biological and structural characteristics of human and animal articular cartilage can replicate a more ideal experimental model.