Figure 1.

Construction and validation of a rat model of knee OA. (A) Establishment of OA model in rats by ALCT method. (a) The hair around the knee was removed to expose the surgical incision site. (b) After disinfection, the skin and various subcutaneous tissues were sequentially incised using a scalpel. (c) The knee joint capsule was exposed laterally. (d) The anterior cruciate ligament was cut. (e) The muscles, fascia, and skin were sequentially sutured. (B) The screening flow for the differentially available miRNAs between the circulating EVs of the control (healthy rats) and the model (OA rats) groups. The circulating EVs were extracted from serum using differential centrifugation, and TEM, NTA, and WB were used to identify the EVs. Then, miRNA sequencing was performed on these EVs. (C) Morphological observation. After the skin and subcutaneous tissues surrounding the knee, the knee joints were removed layer by layer. (a) The skin on the knee surface was opened. (b) Then, the joint cavity was opened, and the SM was exposed. (D) Histological observation. The entire knee joints were stained using HE.