A bilayer bioengineered patch with sequential dual-growth factor release to promote vascularization in bladder reconstruction.

Bladder tissue engineering holds promise for addressing bladder defects resulting from congenital or acquired bladder diseases. However, inadequate vascularization significantly impacts the survival and function of engineered tissues after transplantation. Herein, a novel bilayer silk fibroin (BSF) scaffold was fabricated with the capability of vascular endothelial growth factor (VEGF) and platelet derived growth factor-BB (PDGF-BB) sequential release. The outer layer of the scaffold was composed of compact SF film with waterproofness to mimic the serosa of the bladder. The inner layer was constructed of porous SF matrix incorporated with SF microspheres (MS) loaded with VEGF and PDGF-BB. We found that the 5% (w/v) MS-incorporated scaffold exhibited a rapid release of VEGF, whereas the 0.2% (w/v) MS-incorporated scaffold demonstrated a slow and sustained release of PDGF-BB. The BSF scaffold exhibited good biocompatibility and promoted endothelial cell migration, tube formation and enhanced endothelial differentiation of adipose derived stem cells (ADSCs) in vitro. The BSF patch was constructed by seeding ADSCs on the BSF scaffold. After in vivo transplantation, not only could the BSF patch facilitate the regeneration of urothelium and smooth muscle, but more importantly, stimulate the regeneration of blood vessels. This study demonstrated that the BSF patch exhibited excellent vascularization capability in bladder reconstruction and offered a viable functional bioengineered patch for future clinical studies.

Life disturbance and hospital visit experiences among Chinese patients with benign prostatic hyperplasia: a qualitative study.

BACKGROUND: The impact of lower urinary tract symptoms (LUTS) on the quality of life of patients with benign prostatic hyperplasia (BPH) has been rarely reported. Additionally, the challenges faced by these patients in seeking medical care have often been overlooked. In order to explore the personal struggles caused by LUTS and the difficulties or barriers experienced by Chinese patients with BPH when seeking help, we conducted a qualitative interview study. METHODS: Qualitative interviews were conducted among 46 patients with BPH who were hospitalized in three tertiary hospitals in China from July 2021 to November 2022. Grounded theory was adopted as the methodology for the qualitative study. After obtaining written informed consent from the study participants, semi-structured interviews were conducted according to the question guidelines. The interview process was audio-recorded; subsequently, the recordings were transcribed, coded, and thematically analyzed. RESULTS: The difficulties faced by Chinese patients with BPH were classified into seven main themes: (i) disturbed life, (ii) mental burden, (iii) disease cognition and communication, (iv) delayed treatment, (v) medication status, (vi) hospital visits barriers, and (vii) medical insurance issues. Further, each theme was subdivided into 2-5 sub-themes. CONCLUSIONS: LUTS have a certain effect on the life and spirit of patients with BPH. These patients face different degrees of difficulties in treatment and hospital visits. Therefore, better healthcare systems and additional social support are crucial for improving the current plight of these patients.

Chitin nanocrystal-assisted 3D bioprinting of gelatin methacrylate scaffolds.

In recent years, there has been an increasing focus on the application of hydrogels in tissue engineering. The integration of 3D bioprinting technology has expanded the potential applications of hydrogels. However, few commercially available hydrogels used for 3D biological printing exhibit both excellent biocompatibility and mechanical properties. Gelatin methacrylate (GelMA) has good biocompatibility and is widely used in 3D bioprinting. However, its low mechanical properties limit its use as a standalone bioink for 3D bioprinting. In this work, we designed a biomaterial ink composed of GelMA and chitin nanocrystal (ChiNC). We explored fundamental printing properties of composite bioinks, including rheological properties, porosity, equilibrium swelling rate, mechanical properties, biocompatibility, effects on the secretion of angiogenic factors and fidelity of 3D bioprinting. The results showed that adding 1% (w/v) ChiNC to 10% (w/v) GelMA improved the mechanical properties and printability of the GelMA hydrogels, promoted cell adhesion, proliferation and vascularization and enabled the printing of complex 3D scaffolds. This strategy of incorporating ChiNC to enhance the performance of GelMA biomaterials could potentially be applied to other biomaterials, thereby expanding the range of materials available for use. Furthermore, in combination with 3D bioprinting technology, this approach could be leveraged to bioprint scaffolds with complex structures, further broadening the potential applications in tissue engineering.

Injectable, stretchable, toughened, bioadhesive composite hydrogel for bladder injury repair.

The bladder is exposed to constant internal and external mechanical forces due to its deformation and the dynamic environment in which it is placed, which can hamper its repair after an injury. Traditional hydrogel materials have limitations regarding their use in the bladder owing to their poor mechanical and tissue adhesion properties. In this study, a composite hydrogel composed of methacrylate gelatine, methacrylated silk fibroin, and Pluronic F127 diacrylate was developed, which combines the characteristics of natural and synthetic polymers. The mechanical properties of the novel hydrogel, such as stretchability, viscoelasticity, and toughness, were improved by virtue of a particular molecular design strategy whereby covalent and non-covalent bond interactions create a cross-linking effect. In addition, the composite hydrogel has important usability properties; it can be injected in liquid format and rapidly transformed into a gel via photo-initiated crosslinking. This was demonstrated on an isolated porcine bladder where the hydrogel closed arbitrarily-shaped tissue defects within 90 s of its application, verifying its effective bioadhesive and sealing properties. This composite hydrogel has great potential for application in bladder injury repair as a tissue-engineering scaffold.

A two-sample mendelian randomization analysis excludes causal relationships between non-alcoholic fatty liver disease and kidney stones.

Objectives: Non-alcoholic fatty liver disease (NAFLD) has been linked to an increased risk of kidney stones in prior observational studies, However, the results are inconsistent, and the causality remains to be established. We aimed to investigate the potential causal relationship between NAFLD and kidney stones using two-sample Mendelian randomization (MR). Methods: Genetic instruments were used as proxies for NAFLD. Summary-level data for the associations of exposure-associated SNPs with kidney stones were obtained from the UK Biobank study (6536 cases and 388,508 controls) and the FinnGen consortium (9713 cases and 366,693 non-cases). MR methods were conducted, including inverse variance weighted method (IVW), MR-Egger, weighted median, and MR-PRESSO. MR-Egger Regression Intercept and Cochran's Q test were used to assess the directional pleiotropy and heterogeneity. Results: cALT-associated NAFLD did not exhibit an association with kidney stones in the Inverse variance weighted (IVW) methods, in both the FinnGen consortium (OR: 1.02, 95%CI: 0.94-1.11, p = 0.632) and the UKBB study (OR: 1.000, 95%CI: 0.998-1.002, p = 0.852). The results were consistent in European ancestry (FinnGen OR: 1.05, 95%CI: 0.98-1.14, p = 0.144, UKBB OR: 1.000, 95%CI: 0.998-1.002, p = 0.859). IVW MR analysis also did not reveal a significant causal relationship between NAFLD and the risk of kidney stone for the other three NAFLD-related traits, including imaging-based, biopsy-confirmed NAFLD, and more stringent biopsy-confirmed NAFLD. The results remained consistent and robust in the sensitivity analysis. Conclusions: The MR study did not provide sufficient evidence to support the causal associations of NAFLD with kidney stones.

Developing the novel diagnostic model and potential drugs by integrating bioinformatics and machine learning for aldosterone-producing adenomas.

Background: Aldosterone-producing adenomas (APA) are a common cause of primary aldosteronism (PA), a clinical syndrome characterized by hypertension and electrolyte disturbances. If untreated, it may lead to serious cardiovascular complications. Therefore, there is an urgent need for potential biomarkers and targeted drugs for the diagnosis and treatment of aldosteronism. Methods: We downloaded two datasets (GSE156931 and GSE60042) from the GEO database and merged them by de-batch effect, then screened the top50 of differential genes using PPI and enriched them, followed by screening the Aldosterone adenoma-related genes (ARGs) in the top50 using three machine learning algorithms. We performed GSEA analysis on the ARGs separately and constructed artificial neural networks based on the ARGs. Finally, the Enrich platform was utilized to identify drugs with potential therapeutic effects on APA by tARGseting the ARGs. Results: We identified 190 differential genes by differential analysis, and then identified the top50 genes by PPI, and the enrichment analysis showed that they were mainly enriched in amino acid metabolic pathways. Then three machine learning algorithms identified five ARGs, namely, SST, RAB3C, PPY, CYP3A4, CDH10, and the ANN constructed on the basis of these five ARGs had better diagnostic effect on APA, in which the AUC of the training set is 1 and the AUC of the validation set is 0.755. And then the Enrich platform identified drugs tARGseting the ARGs with potential therapeutic effects on APA. Conclusion: We identified five ARGs for APA through bioinformatic analysis and constructed Artificial neural network (ANN) based on them with better diagnostic effects, and identified drugs with potential therapeutic effects on APA by tARGseting these ARGs. Our study provides more options for the diagnosis and treatment of APA.

Bladder Acellular Matrix Prepared by a Self-Designed Perfusion System and Adipose-Derived Stem Cells to Promote Bladder Tissue Regeneration.

The bladder patch constructed with the bladder acellular matrix (BAM) and adipose-derived stem cells (ASCs) was incubated with the omentum for bladder reconstruction in a rat model of bladder augmentation cystoplasty. A self-designed perfusion system and five different decellularization protocols were used to prepare the BAM. Finally, an optimal protocol (group C) was screened out by comparing the cell nucleus residue, collagen structure preservation and biologically active components retention of the prepared BAM. ASCs-seeded (BAM-ASCs group) and unseeded BAM (BAM group) were incubated with the omentum for 7 days to promote neovascularization and then perform bladder reconstruction. Hematoxylin and eosin and Masson's trichrome staining indicated that the bladder patches in the BAM-ASCs group could better regenerate the bladder wall structure compared to the BAM group. Moreover, immunofluorescence analyses demonstrated that the ASCs could promote the regeneration of smooth muscle, neurons and blood vessels, and the physiological function (maximal bladder capacity, max pressure prior to voiding and bladder compliance) restoration in the BAM-ASCs group. The results demonstrated that the self-designed perfusion system could quickly and efficiently prepare the whole bladder scaffold and confirmed that the prepared BAM could be used as the scaffold material for functional bladder tissue engineering applications.

[Research advances of three-dimensional bioprinting technology in urinary system tissue engineering].

For the damage and loss of tissues and organs caused by urinary system diseases, the current clinical treatment methods have limitations. Tissue engineering provides a therapeutic method that can replace or regenerate damaged tissues and organs through the research of cells, biological scaffolds and biologically related molecules. As an emerging manufacturing technology, three-dimensional (3D) bioprinting technology can accurately control the biological materials carrying cells, which further promotes the development of tissue engineering. This article reviews the research progress and application of 3D bioprinting technology in tissue engineering of kidney, ureter, bladder, and urethra. Finally, the main current challenges and future prospects are discussed.

Bi-layer silk fibroin skeleton and bladder acellular matrix hydrogel encapsulating adipose-derived stem cells for bladder reconstruction.

A scaffold, constructed from a bi-layer silk fibroin skeleton (BSFS) and a bladder acellular matrix hydrogel (BAMH) encapsulated with adipose-derived stem cells (ASCs), was developed for bladder augmentation in a rat model. The BSFS, prepared from silk fibroin (SF), had good mechanical properties that allowed it to maintain the scaffold shape and be used for stitching. The prepared BAM was digested by pepsin and the pH was adjusted to harvest the BAMH that provided an extracellular environment for the ASCs. The constructed BSFS-BAMH-ASCs and BSFS-BAMH scaffolds were wrapped in the omentum to promote neovascularization and then used for bladder augmentation; at the same time, a cystotomy was used as the condition for the control group. Histological staining and immunohistochemical analysis confirmed that the omentum incubation could promote scaffold vascularization. Hematoxylin and eosin and Masson's trichrome staining indicated that the BSFS-BAMH-ASCs scaffold regenerated the bladder wall structure. In addition, immunofluorescence analyses confirmed that the ASCs could promote the regeneration of smooth muscle, neurons and blood vessels and the restoration of physiological function. These results demonstrated that the BSFS-BAMH-ASCs may be a promising scaffold for promoting bladder wall regeneration and the restoration of physiological function of the bladder in a rat bladder augmentation model.

A Preliminary Study on the Promotion of Canine Adipose-Derived Stem Cell Differentiation by Perfusion-Decellularized Ureter Matrix.

BACKGROUND: This study was to assess the possibility of the perfusing decellularized ureters (DUs) promoting the differentiation of the canine adipose stem cell (cASCs). METHODS: cASCs were isolated and cultured in different induction media to determine their multidirectional differentiation potential. The perfusion system was used to prepare the DUs, and the prepared DUs were systematically evaluated. The DU coating was prepared by enzymatic digestion for cell culture. The cASCs were seeded on the coverslips covered with DU coating and samples were collected on days 3, 7, and 10. Immunofluorescence staining and molecular biology testing were used to examine the differentiation of cASCs seeded on the DU coating. RESULTS: The cASCs were isolated and identified by flow cytometry. The prepared DUs removed the nuclear materials, and the 3-dimensional structure and biological compositions of the ureter were well preserved. Immunofluorescence staining showed the expression of anti-alpha smooth muscle actin (α-SMA). Western blot results suggested that the content of α-SMA in the experimental group was significantly higher than that in the control group at 3 different time points, and the mRNA expressions of α-SMA in the experimental group gradually increased with extended the culture time, whereas there was no significant change in the control group. CONCLUSION: The cASCs seeded on the coverslips of DU coating could differentiate into smooth muscle cells, and the number of differentiated cASCs increased significantly with extended incubation time.

Robot-assisted radical cystectomy with intracorporeal Mainz â ¡ rectosigmoid pouch for muscle-invasive bladder cancer.

BACKGROUND: To report the surgical techniques and results of robot-assisted radical cystectomy (RARC) with intracorporeal Mainz Ⅱ rectosigmoid pouch at our centre. METHODS: Two female patients were treated with this procedure. Construction of the pouch was divided into four main steps: incision of the rectum and sigmoid colon, closure of the posterior wall of the pouch, reimplantation of the ureters at the bottom of pouch in an anti-reflux manner, and closure of the anterior wall. Surgical results and perioperative complications were assessed. RESULTS: The operations were performed completely intracorporeally. No perioperative complications were observed. Postoperatively, high-grade invasive urothelial carcinoma was detected. On postoperative day 60, no bilateral ureteral dilation was detected. Two patients demonstrated total continence. Clinical recurrence was not observed during the follow-up period. CONCLUSIONS: With careful patient selection, robot-assisted intracorporeal Mainz Ⅱ rectosigmoid pouch might be a simple minimally invasive surgical technique to be evaluated in repeated applications.

Novel perfusion-decellularized method to prepare decellularized ureters for ureteral tissue-engineered repair.

As the endoscopic technique is widely used in the diagnosis and treatment of diseases, the incidence of ureteral injuries increases annually. The classical surgical therapies are not always satisfactory. With the constant development of the tissue engineering technology in the field of urinary reconstruction, the ureteral reconstruction has become possible technology. In this study, a novel perfusion-decellularized protocol, which combined a perfusion system with the commonly used physical and chemical methods, was used to prepare the decellularized ureters for ureteral reconstruction and the urinary tract-derived cells (UDCs) were seeded on the surface of the perfusion-decellularized ureters (PDUs) in order to observe the cells survival, adhesion, proliferation and distribution. The data of H&E staining, DAPI staining, and the agarose gel electrophoresis demonstrated that the cellular components of PDUs were removed, and the decellularized time was shorter than previous study. In addition, compared with the native ureters, the DNA content of the PDUs was significantly decreased just two percent residue (P<0.05). Scanning electron microscopy, collagen and glycosaminoglycan content assay showed that the three-dimensional (3D) ultrastructure and the compositions of the extracellular matrix (ECM) of PDUs were well preserved. When the UDCs were seeded onto the PDUs, the UDCs formed multilayer structure on the surface of the PDUs, infiltrated into the deep layer of the decellularized ureters and then formed laminated structure. In conclusion, the decellularized ureters prepared by the novel perfusion-decellularized method may be the potential surrogate for ureteral tissue-engineered repair.

[A perfusion system for preparing canine ureteral acellular matrix].

OBJECTIVE: To explore the feasibility of preparing ureteral acellular matrix (UAM) using perfusion systems. METHODS: Using the luminal structure of the ureter, the UAM was prepared by perfusing canine ureter with SDS, TritonX-100, or both. The residual nuclei in the UAM were evaluated using HE staining, DAPI staining, DNA quantification, and agarose gel electrophoresis. The three-dimensional ultrastructure and the bioactive components were evaluated by Masson's trichrome staining, Alcian Blue staining, collagen quantification, GAG quantification, scanning electron microscopy (SEM), and toxicity detection. RESULTS: HE staining and DAPI staining showed the absence of obvious nuclear materials in the combined group, which was further confirmed by DNA quantification and agarose gel electrophoresis. Masson's trichrome staining, Alcian Blue staining, collagen quantification and GAG quantification all verified that the ultrastructure and the bioactive components were well preserved in the combined group. SEM showed a large amount of porous structure on the surface of the UAM prepared by combined perfusion, and toxicity assay confirmed that the prepared UAM was nontoxic. CONCLUSION: Perfusion of canine ureter with SDS and TritonX-100 is feasible to prepare UAM for ureteral reconstruction.