Objective To investigate the effects of platelet-rich plasma-derived exosomes(PRP-Exos)on the proliferation and migration of tendon stem/progenitor cell(TSPC).Methods PRP-Exos were extracted through the combination of polymer-based precipitation and ultracentrifugation.The morphology,concentration,and particle size of PRP-Exos were identified by transmission electron microscopy and nanoparticle tracking analysis.The expression levels of surface marker proteins on PRP-Exos and platelet membrane glycoproteins were deter-mined by Western blot analysis.Rat TSPC was extracted and cultured,and the expression of surface marker mol-ecules on TSPC was detected using flow cytometry and immunofluorescence staining.The proliferation of TSPC in-fluenced by PRP-Exos was evaluated using CCK-8 assay and EdU assay.The effect of PRP-Exos on the migration of TSPC was evaluated by cell scratch assay and Transwell assay.Results The extracted PRP-Exos exhibit typi-cal saucer-like structures,with a concentration of 4.9 ×1011 particles/mL,an average particle size of(132.2±56.8)nm,and surface expression of CD9,CD63 and CD41.The extracted TSPC expressed the CD44 pro-tein.PRP-Exos can be taken up by TSPC,and after co-cultured for 48 h,concentrations of 50 and 100 μg/mL of PRP-Exos significantly promoted the proliferation of TSPC(both P＜0.001),with no statistical difference be-tween the two concentrations(P=0.283).Additionally,after co-cultured for 24 h,50 μg/mL of PRP-Exos significantly promoted the migration of TSPC(P＜0.001).Conclusion Under in vitro culture conditions,PRP-Exos significantly promote the proliferation and migration of rat TSPC.

Purpose To predict the 2015 American thyroid association(ATA)recurrence risk stratification based on ultrasonographic features and Hashimoto's thyroiditis(HT)-specific antibody status of papillary thyroid carcinoma(PTC)in the context of HT.Materials and Methods A retrospective analysis was conducted on the ultrasonographic and clinical data of 479 patients with coexisting PTC and HT,who underwent their first thyroid surgery at the First Medical Center of Chinese PLA General Hospital from January 2017 to December 2019.All patients were divided in chronological order into a training group(n=327)and a validation group(n=152).Multivariate Logistic regression analysis was utilized to identify independent factors associated with high recurrence risk stratification according to the ATA guidelines.Predictive models were constructed and screened,and the efficacy of these models was evaluated using the area under the curve,calibration curves and Brier scores.Results Multivariate Logistic regression analysis identified the following as independent predictive factors for high recurrence risk stratification:multifocal malignancy of nodules(OR=3.812,95％CI 1.275-11.397,P=0.017),nodule contact with the capsule(OR=8.012,95％CI 1.647-38.972,P=0.010),microcalcifications(OR=4.220,95％CI 1.302-13.678,P=0.016),an aspect ratio＞1(OR=4.017,95％CI 1.286-12.548,P=0.017),abundant nodule vascularity(OR=6.120,95％CI 2.225-16.832,P＜0.001),maximum nodule diameter ≥1 cm(OR=4.784,95％CI 1.360-16.833,P=0.015),a glandular echo characteristic of typical HT(OR=0.114,95％CI 0.039-0.330,P＜0.001),and anti-thyroid peroxidase antibody monopositivity(OR=0.088,95％CI 0.006-1.299,P=0.077).The predictive model demonstrated strong performance,as evidenced by the area under the curve of 0.942(95％CI 0.911-0.972)in the training set and 0.933(95％CI 0.878-0.990)in the validation set.Both groups exhibited well-fitting calibration curves.The Brier scores were 0.054 and 0.058 for the training and validation sets,respectively,indicating excellent predictive efficacy of the model.Conclusion The preoperative prediction model,based on ultrasonographic features combined with antibody status,demonstrates good efficacy in assessing ATA recurrence risk stratification for coexisting PTC and HT patients,which can assist clinicians in formulating treatment plans.