Establishment of a novel hypertrophic scar animal model by subcutaneous injection on the back of rabbits

ObjectiveTo explore the effects of anhydrous alcohol by subcutaneous injection on the appearance and morphology of skin, and establish a simple and repeatable animal model of scar.

MethodsTwenty-seven New Zealand white rabbits, weighing 1.5 kg, were randomly divided into the A group, B group and C group.The 99.5% alcohol was injected into the dorsal dermis of rabbits in A, B and C groups at the doses of 1, 2 and 3 mL/kg, respectively.The changes of injection sites at 7, 30 and 90 d were observed according to the POSAS scoring standard and microscopic appearance for finding out the best dose.

ResultsThe tissue similar to human hypertrophic scar in B group was found at 30 d of injection.The HE staining showed the epidermal layer significantly thickened, and the collagen fiber arrangement disorderedin the dermis.The results of type Ⅰ collagen fiber IHC staining showed that the type Ⅰ collagen was stained for brown, and the brown granules were found in the cytoplasm, and the number of type Ⅰ collagen fibers increased significantly under the microscope.

ConclusionsThe hypertrophic scar formed by 2 mL/kg anhydrous alcoholic by subcutaneous injection is similar to the human hypertrophic scar, and can be used as one of the animal models in studying the mechanism of hypertrophic scar and evaluating the treatment.