Optimization of Vascularized Intestinal Organoid Model.

Vasculature is crucial for maintaining organ homeostasis and metabolism. Although 3D organoids can mimic organ structures and patterns, they still lack vascular systems, limiting the recapitulation of physiological complexities. Although vascularization of organoids has been demonstrated by mixing Matrigel in fibrin, how the mixed gel niche affects endothelial cells (ECs) and organoids remains unclear. Existing protocols rely on fibroblasts to promote vascular network formation. This study explores how varying the ratio of Matrigel in fibrin-Matrigel co-gel affects vascular network formation and intestinal organoid growth. A fine-tuned hydrogel is developed by adding aprotinin and 15% Matrigel in fibrin. Medium for co-culturing ECs and organoids is modified with basic fibroblast growth factor (bFGF) and heparin. In combination with fine-tuned hydrogel and modified medium, vascular network formation and organoid vascularization are successfully generated in the absence of fibroblast. Furthermore, structural cues and pore architectures are critical for angiogenesis and vascularization. By incorporating engineered thick collagen fiber bundles into the system, vascular network formation is guided by bundle architectures, enhancing interactions between vascular networks and organoids. The results demonstrate an optimized system that advances tissue and organoid vascularization by combining fiber bundles with fine-tuned hydrogel and modified medium.

Instant Assembly of Collagen for Scaffolding, Tissue Engineering, and Bioprinting.

Controllable assembly of cells and tissues offers potential for advancing disease and development modeling and regenerative medicine. The body's natural scaffolding material is the extracellular matrix, composed largely of collagen I. However, challenges in precisely controlling collagen assembly limit collagen's applicability as a primary bioink or glue for biofabrication. Here, we introduce a set of biopatterning methods, termed Tunable Rapid Assembly of Collagenous Elements (TRACE), that enables instant gelation and rapid patterning of collagen I solutions with wide range of concentrations. Our methods are based on accelerating the gelation of collagen solutions to instantaneous speeds via macromolecular crowding, allowing versatile patterning of both cell-free and cell-laden collagen-based bioinks. We demonstrate notable applications, including macroscopic organoid engineering, rapid free-form 3D bioprinting, contractile cardiac ventricle model, and patterning of high-resolution (below 5 (m) collagen filament. Our findings enable more controllable and versatile applications for multi-scale collagen-based biofabrication.

Corrigendum: High follicle-stimulating hormone level associated with risk of rheumatoid arthritis and disease activity.

[This corrects the article DOI: 10.3389/fendo.2022.862849.].

Mesenchymal stem cells and their microenvironment.

Mesenchymal stem cells (MSCs), coming from a wide range of sources, have multi-directional differentiation ability. MSCs play vital roles in immunomodulation, hematopoiesis and tissue repair. The microenvironment of cells often refers to the intercellular matrix, other cells, cytokines and humoral components. It is also the place for cells' interaction. The stability of the microenvironment is pivotal for maintaining cell proliferation, differentiation, metabolism and functional activities. Abnormal changes in microenvironment components can interfere cell functions. In some diseases, MSCs can interact with the microenvironment and accelerate disease progression. This review will discuss the characteristics of MSCs and their microenvironment, as well as the interaction between MSCs and microenvironment in disease.

High Follicle-Stimulating Hormone Level Associated With Risk of Rheumatoid Arthritis and Disease Activity.

Background: The prevalence of rheumatoid arthritis (RA) has significant gender and age difference. The peak age of RA is consistent with the age of menopause, which is accompanied by a sharp increase in serum follicle-stimulating hormone (FSH) level. This study aims to identify the FSH levels in female RA patients and the relationship with diseases activity. Methods: In total, 79 female RA patients and 50 age-matched controls were included in our study. Serum sex hormones levels were measured using chemiluminescence. RA patients were grouped by FSH quartile. Disease activity and inflammatory marks were analyzed among groups. Results: Lower sex hormones and higher gonadotropin were found in RA patients. Serum FSH level was significantly higher in RA patients than in the age-match controls (57.58 ± 15.94 vs. 43.11 ± 19.46, p=0.025). Even after adjusting for age (OR: 1.071; 95%CI: 1.006-1.139; p = 0.031), luteinizing hormone (LH), estradiol (E), and testosterone (T) OR: 1.066; 95%CI: 1.003-1.133; p = 0.039), the OR were still more than one. RA patients in the higher quartiles had higher ESR, DAS28-ESR and DAS28-CRP (p<0.05) than the lowest quartile. Besides, menopause age was significantly related with onset age in post-menopause RA patients (r = 0.432, p =0.008). Conclusion: High FSH appears to be a risk factor for RA and is positively associated with their disease activity. Early menopause might be an essential factor of RA.