Research On Cartilage Derived Microcarriers Compounded Rats’ Chondrocytes To Rapier Rat Epiphyseal Plate Cartilage Defects

Objects:Research aim at building a large-size rat epiphyseal plate defect model and applying this model to evaluate repair of rat epiphyseal plate defect by using composite of cartilage derived microcarriers and rats’ chondrocytes.Methods:Use the locator to insert the rat epiphyseal cartilage central on the right proximal tibial, carefully scrape the medical semi-epiphyseal cartilage and finally build a large-size rat epiphyseal plate defect model. X ray assay, Micro-CT evaluation, histological evaluations are used to evaluate varus deformity formation and bone bridge tissue formation. PCR is used to evaluate the mechanism of bone bridge tissue formation. Cartilage derived microcarrier as a major material is used to combine with alginate hydrogels to form epiphyseal plate shape hydrogel scaffold. The scaffold is compounded with rat epiphyseal plate chondrocytes to repair rat epiphyseal plate defect. Several control groups are set up for comparison. Using gross morphology evaluation, X ray, histological staining to evaluate the efficiency of repair.Results:After medial proximal tibial epiphyseal plate injury, all rats appear varus deformity and can’t be rectified by themselves. The Locator can effectively protect the outer epiphyseal plate from damage. After 1-week injury, bone bridge tissues occur and varus deformity were been found. Bone bridge tissue have generated within the process involved in the formation of bone cartilage. Cartilage derived microcarriers combined with alginate hydrogels and then rat epiphyseal chondrocytes were seeded on the scaffold to repair defect. The combination can effectively form a large number of native-like epiphyseal cartilage in defect area. After 6 weeks, the combination can prevent varus deformity of bone tissue formation and reduce the bone bridge (P<0.05). However in 12 weeks, internal varus deformity correction are not obvious (P>0.05) Control groups show no or little newborn cartilage-like tissue formation.Conclusion:The Locator and scrape method can successfully established rat medial proximal tibial semi-epiphyseal plate injury model and can effectively protect the outer semi-epiphyseal cartilage from damage. The combination of cartilage derived microcarriers combined with alginate hydrogels and rat epiphyseal chondrocytes can effectively form a large number of native-like epiphyseal cartilage in defect area. Bone bridge tissue formation were prevented and varus deformity were reduced in 6 week. Further research and experiments were need for completely repair of angular deformity caused by epiphyseal plate damage. Cartilage derived microcarriers provide a new option for tissue engineering repair of epiphyseal plate defect.