Abstract: Objective To detect integrin αVβ3 expression in rat model of stage 2 pressure injury, and prepare arginineglycine-aspartic acid (RGD) - targeted ultrasound contrast agent (CA), thus exploring its targeting effect for skin lesions. Methods Thirty-six rats were randomly divided into experimental group and control group, with 18 rats in each group. Rats were established stage 2 pressure injury models by skin bridge method for experimental group, while rats of the control group did not do any treatment. After the model was formed, the pathological changes of skin tissue were observed by HE staining. The integrin αvβ3 was detected by immunohistochemistry. Then, the self-made RGD-targeted ultrasound CA and the blank counterpart were used to evaluate the wound in experimental group. Results HE staining showed that the damage reached the dermis layer in experimental group, and no damage was found in the control group. The expressions of integrin α Vβ3 were positive in the capillary endothelial cells and epidermal cells of the experimental group, and which were negative in the control group. The targeted adhesion value was significantly higher after injecting RGD-targeted ultrasound contrast agent in the experimental group than that of blank contrast agent group (P＜0.01). Conclusion The expression of integrin α Vβ3 is positive in the rat model of stage 2 pressure injury, suggesting that integrin αvβ3 can be used as a target site to prepare RGD-targeted ultrasound contrast agent. Integrin αVβ3 shows a good targeting effect and can be used as a new imaging method for diagnosing and treating pressure injury.

Key words: integrin αVβ3, contrast media, contrast-enhanced ultrasonography, pressure injury, RGD peptide