It has been known that the successful reprogramming of differentiated human somatic cells into a pluripotent state would allow for the creation of cartilage cells. However, current virus‑mediated strategies to form induced pluripotent stem cells (iPSCs) are limited in their clinical application due to exogenous gene modification. In the present study, the piggyBac transposon system carrying corresponding genes (Oct3/4, Klf4, Sox2 and c‑Myc) was employed to reprogram rat embryonic fibroblasts (REFs) into iPSCs, and the transposon‑carried genes were successfully removed by a transposase system. Furthermore, the differentiation capacity of the iPSCs into chondrocytes was investigated in vitro. A typical chondrocyte marker, collagen‑II, was expressed following culture. In conclusion, rat iPSCs without genetic modification were obtained from REFs using the piggyBac transposon system and the transposase mPB system, and these cells possessed the capacity of chondrocyte differentiation, suggesting that this method may be an effective approach for the treatment of cartilage disorders in the future.

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Objective: To assess the factors associated with outcomes of arthroscopic surgical repair of rotator cuff tears (RCTs).Method: This prospective study recruited patients, at least 18 years old, who underwent arthroscopic rotator cuff repair for full-thickness RCTs at the First People's Hospital of Hangzhou Xiaoshan between July 2019 and October 2020. Patient demographics, lifestyle habits, and medical histories were collected preoperatively; RCT sizes and affected tendons were determined intraoperatively. Outcomes were assessed by shoulder range of motion (ROM) determinations 1.5 and 3 months postoperatively. The factors associated with ROM were determined using a binary logistic regression analysis, and the results were expressed as adjusted relative risks (RRs) and 95% confidence intervals (CIs).Results: A total of 132 patients with RCTs underwent arthroscopic surgery. Five were lost to follow-up, leaving 127 patients (mean age, 59 years; 58.3% women) who were included in the study analysis. The majority of the patients (54.5%) had RCTs that were classified as large or massive, and approximately 20% had tears involving multiple tendons; 80.3% of the patients had tears involving only a single tendon. Moreover, 29.9% of the patients had hypertension and 11.0% had diabetes. Among the patients, 23.0% were smokers and 34.6% drank alcohol. According to the multivariate analysis, none of the assessed factors were associated with shoulder ROM at the 1.5-month follow-up. At the 3-month follow-up, RCTs involving a single tendon demonstrated 3-fold better abduction (RR = 4.00; 95% CI, 1.30-12.33; P = 0.016) and 3.15-fold better internal rotation (RR = 3.15; 95% CI, 1.19-8.36; P = 0.021) than did RCTs involving multiple tendons. Patients who did not drink alcohol demonstrated 6.08-fold better anteflexion (RR = 7.08; 95% CI, 2.11-23.73; P = 0.002) and nearly 4-fold better abduction (RR = 4.97; 95% CI, 1.62-15.23; P = 0.005) than patients who drank alcohol. Conclusion:To improve outcomes, the results indicate that more targeted measures should be directed toward patients with multiple-tendon RCTs and that preoperative alcohol abstinence education is needed for patients with RCTs.