Objective To investigate the feasibility of urethral reconstruction by using stretched electrospun silk fibroin matrices.Methods Stretched electrospun silk fibroin matrix was prepared,and the structure of the material was assessed by electron microscopy.Canine urothelial cells were isolated,expanded and seeded onto the material for 1 week to obtain a tissue-engineered graft.The tissue-engineered graft was assessed using HE staining and electron microscopy scanning.A dorsal urethral mucosa defect was created in 9 female beagle dogs.In the experimental group,tissue-engineered mucosa was used to repair urethral mucosa defects in 6 dogs.No substitute was used in the 3 dogs of the control group.Retrograde urethrography was performed at 1,2 and 6 months after grafting.The urethral grafts were analyzed grossly and histologically.Results Electron microscopy scanning revealed that the material had a 3 dimensional porous structure.Urothelial cells grew on the material and showed good biocompatibility with the stretched silk fibroin matrices.Canines implanted with tissue-engineered mucosa voided without difficulty.Retrograde urethrography revealed no signs of stricture,and histological staining showed gradual epithelial cell development and stratified epithelial layers at 1,2 and 6 months.The canines in the control group showed difficulty in voiding.Retrograde urethrography showed urethral stricture,and histological staining showed that no or only one layer of epithelial cells developed.A severe inflammatory reaction was also observed in the control group.Conclusion Stretched electrospun silk fibroin matrices have good biocompatibility with urothelial cells,and could be a potential material for urethral reconstruction.

Objective Circular RNAs (circRNAs) are non-coding RNAs (ncRNA) circularized without a 3' polyadenylation [poly-(A)] tail or a 5' cap, resulting in a covalently closed loop structure. circRNAs were first discovered in RNA viruses in the 1970s, but only a small number of circRNAs were discovered at that time due to limitations in traditional polyadenylated transcriptome analyses. With the development of specific biochemical and computational methods, recent studies have shown the presence of abundant circRNAs in eukaryotic transcriptomes. circRNAs play vital roles in many physiological and pathological processes, such as acting as miRNA sponges, binding to RNA-binding proteins (RBPs), acting as transcriptional regulatory factors, and even serving as translation templates. Current evidence has shown that circRNAs can be potentially used as excellent biomarkers for diagnosis, therapeutic effect evaluation, and prognostic assessment of a variety of diseases, and they may also provide effective therapeutic targets due to their stability and tissue and development-stage specificity. This review focuses on the properties of circRNAs and their immune relationship to disease, and explores the role of circRNAs in immune-related diseases and the directions of future research.
Biomarkers ; MicroRNAs/genetics* ; RNA, Circular ; Transcriptome