Congde Chen

Ureteral stent-associated urinary tract infections (UTIs) remain a significant clinical challenge, primarily due to bacterial adhesion and biofilm formation. To address this, we engineered a multifunctional antibacterial coating composed of co-assembled peptide–silver–manganese (PAMN) nanozymes for ureteral stent surface modification. This composite integrates silver nanoparticles (AgNPs), manganese dioxide (MnO ₂ ), and antimicrobial peptides (AMPs), achieving a synergistic enhancement of reactive oxygen species (ROS) generation and bactericidal activity. The PAMN coating effectively disrupts bacterial membranes, reduces protein adsorption, and inhibits bacterial adhesion. Compared to AMP-only coatings, PAMN-coated stents exhibited a 129% larger bacterial inhibition zone. Furthermore, PAMN surfaces demonstrated an approximately 40% reduction in protein adsorption, suggesting a lower potential for bacterial colonization. Bacterial viability assays and scanning electron microscopy (SEM) imaging further confirmed the decreased bacterial adhesion and elevated bactericidal efficacy of the coating. This nanozyme-enabled antibacterial coating offers a promising strategy to mitigate infection risks associated with ureteral stents and may be broadly applicable to other implantable medical devices requiring anti-biofilm functionality.

Background: In urethral reconstruction, autologous tissue grafts are subject to various limitations. Decellularized tissue has attracted significant interest in tissue engineering (TE) and regenerative medicine due to great biocompatibility and bioactivity. We investigated the effect of decellularized tilapia skin (DTS) in a rabbit urethral defect model to explore its feasibility and effectiveness as a TE construction for urethral reconstruction. Methods: Fresh tilapia skins were decellularized and verified through its residual deoxyribonucleic acid (DNA) content measurement. The physical properties and degradation profile of DTS were characterized as well. Finally, we established a rabbit urethral defect model and evaluated the effect of DTS on urethral defect healing through pathological examination and immunohistochemistry (IHC) staining. Results: The residual DNA content in the DTS was 32.94 ng/mg. Electron microscopy showed that the DTS retained its three-dimensional structure. In vitro, degradation experiments showed that DTS degraded at a faster rate than that of small intestinal submucosa (SIS). After implantation of the DTS, the penile tissue was well repaired. In the early stage of tissue repair, the tissue was gradually replaced by new collagen. In addition, smooth muscle content was significantly increased. No significant immune rejection was observed in the tissues during the repair process and the inflammatory response was significantly milder than other group. Nevertheless, angiogenesis markers, the numbers of blood vessels and blood vessel area in DTS intervention groups were the highest at 4 weeks post-implantation. Conclusions: DTS could degrade gradually during urethral reconstruction and demonstrated its better biocompatibility in terms of de novo tissue morphology, microanatomy of tissues, severity of inflammation, collagen deposition and angiogenesis in defect region vs. its match control groups. As an excellent TE material, it is expected to be used in clinical urethral reconstruction in future.

Background: The mammalian testicular interstitial cells are not well-defined. The present study characterized the interstitial cell types and their turnover dynamics in adult rats. Additionally, the heterogeneity of the mesenchymal population and the effects of Leydig cell elimination on interstitial homeostasis were further analyzed by scRNA-seq datasets and immunocytochemical techniques.Methods: Interstitial cells were defined at the transcriptomic level by scRNA-seq and then confirmed and quantified with protein markers. The dividing activity of the major cell types was determined by continuous EdU labeling of the animals for one week. Some of the rats were also treated with a dose of ethylenedimethylsulfonate (EDS) to examine how the loss of Leydig cells (LCs) could affect interstitial homeostasis for three weeks.Results: Seven interstitial cell types were identified, including cell types (percentage of the whole interstitial population) as follows: Leydig (44.6%), macrophage and dendritic (19.1%), lymphoid (6.2%), vascular endothelial (7.9%), smooth muscle (10.7%), and mesenchymal (11.5%) cells. The EdU experiment indicated that most cell types were dividing at relatively low levels (<9%) except for the mesenchymal cells (MCs, 17.1%). Further analysis of the transcriptome of MCs revealed 4 subgroups with distinct functions, including 1) glutathione metabolism and xenobiotic detoxification, 2) ROS response and AP-1 signaling, 3) extracellular matrix synthesis and binding, and 4) immune response and regulation. Stem LCs (SLCs) are primarily associated with subgroup 3, expressing ARG1 and GAP43. EDS treatment not only eliminated LCs but also increased subgroup 3 and decreased subgroups 1 and 2 of the mesenchymal population. Moreover, EDS treatment increased the division of immune cells by more than tenfold in one week.Conclusion: Seven interstitial cell types were identified and quantified for rat testis. Many may play more diversified roles than previously realized. The elimination of LCs led to significant changes in MCs and immune cells, indicating the importance of LCs in maintaining testicular interstitial homeostasis.

Purpose The objective of this study was to discern ferroptosis-related genes (FRGs) linked to non-obstructive azoospermia and investigate the associated molecular mechanisms. Method A dataset related to azoospermia was retrieved from the Gene Expression Omnibus database, and FRGs were sourced from GeneCards. Ferroptosis-related differentially expressed genes (FRDEGs) were discerned. Subsequently, these genes underwent analyses encompassing Gene Ontology and Kyoto Encyclopedia of Genes and Genomes, as well as protein–protein interaction (PPI) networks and assessments of functional similarity. Following the identification of hub genes, an exploration of immune infiltration, single-cell expression, diagnostic utility, and interactions involving hub genes, RNA-binding proteins (RBPs), transcription factors (TFs), microRNAs (miRNAs), and drugs was conducted. Results A total of 35 differentially expressed FRGs were discerned. These genes demonstrated enrichment in functions and pathways associated with ferroptosis. From the PPI network, eight hub genes were selected. Functional similarity analysis highlighted the potential pivotal roles of HMOX1 and GPX4 in azoospermia. Analysis of immune cell infiltration indicated a significant decrease in activated dendritic cells in the azoospermia group, with notable correlations between hub genes, particularly SAT1 and HMGCR, and immune cell infiltration. Unique expression patterns of hub genes across various cell types in the human testis were observed, with GPX4 prominently enriched in spermatid/sperm. Eight hub genes exhibited robust diagnostic value (AUC > 0.75). Lastly, a comprehensive hub gene-miRNA-TF-RBP-drug network was constructed. Conclusion In summary, our investigation unveiled eight FRDEGs associated with azoospermia, which hold potential as biomarkers for the diagnosis and treatment of azoospermia.