Tissue Sources Research Articles

Evaluation of mesenchymal stem cells as an in vitro model for inherited retinal diseases

Retinal pathologies are major causes of vision impairment and blindness in humans, and inherited retinal diseases (IRDs), such as retinitis pigmentosa, Leber congenital amaurosis, and Stargardt disease, greatly contribute to this problem. In vitro disease modeling can be used for understanding the development of pathology and for screening therapeutic pharmaceutical compounds. In the preclinical research phase, in vitro models complement in vivo models by reducing animal studies, decreasing costs, and shortening research timelines. Additionally, animal models may not always accurately replicate the human disease phenotype. This review examines the types of cells that can be used to create in vitro IRD models, including retina-specific cell lines, primary retinal cells, induced pluripotent stem cells (iPSCs), and more. Special attention is given to mesenchymal stem cells (MSCs), which are characterized by various isolation sources, relative ease of isolation, and straightforward differentiation. MSCs derived from bone marrow (BM), adipose tissue (AT), dental tissue (DT), umbilical cord (UC), and other sources can differentiate into retinal cells, including photoreceptor cells and retinal pigment epithelial (RPE) cells, dysfunction of which is most commonly associated with IRDs. Subsequent differentiation of MSCs into retinal cells can be carried out via various methods: culturing in induction media supplemented with certain growth factors, co-culturing with retinal cells or in their conditioned media, or regulating gene expression with viral vector-delivered transcription factors (TFs) or microRNAs (miRNAs). Compared to the popular iPSCs, for example, MSC-based models are significantly cheaper and faster to obtain, making them more feasible for large-scale drug screening. Nevertheless, the existing differentiation methods need further optimization for this promising platform to receive the success it deserves.

Molecular and cellular mechanisms of mitochondria transfer in models of central nervous system disease.

In the central nervous system (CNS), neuronal function and dysfunction are critically dependent on mitochondrial integrity and activity. In damaged or diseased brains, mitochondrial dysfunction reduces adenosine triphosphate (ATP) levels and impairs ATP-dependent neural firing and neurotransmitter dynamics. Restoring mitochondrial capacity to generate ATP may be fundamental in restoring neuronal function. Recent studies in animals and humans have demonstrated that endogenous mitochondria may be released into the extracellular environment and transported or exchanged between cells in the CNS. Under pathological conditions in the CNS, intercellular mitochondria transfer contributes to new classes of signaling and multifunctional cellular activities, thereby triggering deleterious effects or promoting beneficial responses. Therefore, to take full advantage of the beneficial effects of mitochondria, it may be useful to transplant healthy and viable mitochondria into damaged tissues. In this review, we describe recent findings on the mechanisms of mitochondria transfer and provide an overview of experimental methodologies, including tissue sourcing, mitochondrial isolation, storage, and modification, aimed at optimizing mitochondria transplantation therapy for CNS disorders. Additionally, we examine the clinical relevance and potential strategies for the therapeutic application of mitochondria transplantation.

Abstract A057: Cancer-induced epigenomic changes in circulating immune cells enable breast, colorectal and lung cancer detection

Abstract Background: Epigenomic changes via the measurement of 5-hydroxymethylation cytosine (5hmC) in DNA have been shown to enable detection in a variety of cancers including pancreatic and ovarian cancer in plasma-derived cell-free DNA (cfDNA). Here, we investigated whether blood-based 5hmC profiling of genomic DNA (gDNA) derived from cells of the buffy coat (BC) possess signals that enable the detection of breast, colorectal and lung cancers. Method: Blood samples collected in Streck tubes from cancer patients or non-cancer controls were processed to obtain buffy coat and plasma samples. gDNA and cfDNA was isolated from buffy coat and plasma, respectively. gDNA or cfDNA was then subjected to 5hmC enrichment by click chemistry followed by preparation of sequencing libraries. Sequencing was performed to obtain genome-wide 5hmC profiles of buffy coat gDNA and cfDNA samples. Results: Differential hydroxymethylation analysis of BC gDNA revealed increased 5hmC over genes associated with myeloid lineage in breast, colorectal and lung cancers relative to non-cancer controls. Flow cytometry analysis confirmed increases in myeloid cells in cancer samples relative to non-cancer controls. 5hmC patterns in BC gDNA showed a larger number of cancer-associated changes compared to cfDNA, in particular this was found in early-stage disease. 5hmC features from BC gDNA or plasma-derived cfDNA were used to build prediction models that yielded cancer classification with overall sensitivity of 51.3% and 52.6% at 98% specificity, for BC or cfDNA, respectively. For early-stage cancer, the sensitivity at 98% specificity was 46.5% for the BC and 28.2% for cfDNA model. A final prediction model incorporating features from both tissue sources achieved superior classification (65.8% sensitivity) at 98% specificity, compared with using features from either tissue source alone, particularly for early-stage cancer which achieved 53.5% sensitivity of cancer detection. Conclusion: Our results demonstrate that cancer impacts the 5hmC profiles of buffy coat cells which can be leveraged for cancer detection using blood. Citation Format: Gulfem D Guler, Giuliana P Mognol, Yuhong Ning, Carolina Fraire, David Haan, Michael Kesling, Roger Malta, Melissa Peters, Anna Bergamaschi, Tierney Phillips, Shimul Chowdhury, Wayne Volkmuth, Samuel Levy. Cancer-induced epigenomic changes in circulating immune cells enable breast, colorectal and lung cancer detection [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A057.

Tissue source may affect the esophageal flora in patients with esophageal squamous cell carcinoma

Tissue source may affect the esophageal flora in patients with esophageal squamous cell carcinoma

Evaluation of a Novel Mechanical Device for the Production of Microfragmented Adipose Tissue for Veterinary Regenerative Medicine: A Proof-of-Concept.

Therapies based on mesenchymal stromal cells (MSCs) have become one of the most significant advancements in veterinary regenerative medicine. The isolation of MSCs is usually performed by enzymatic digestion and requires variable times for cell expansion. In addition, these procedures need to be performed in specialized laboratory facilities. An alternative approach to in vitro-expanded MSC therapy is the use of microfragmented adipose tissue (microfat), which is a rich source of cells and growth factors from the stromal vascular fraction. Recent clinical studies support its safety and efficacy in the treatment of musculoskeletal disorders and wound healing. The aim of the present work was to characterize the microfragmented adipose tissue obtained by a new mechanical device, which provides sterile tissue that is ready for use in the clinic by the veterinarian, avoiding the need for specialized laboratory facilities. Microfat-derived MSCs were compared with enzymatically isolated MSCs in terms of their phenotypic characterization, growth rate and differentiation potential. Conditioned medium derived from microfat culture was evaluated for its ability to promote MSC vitality. No differences were observed between MSCs obtained through mechanical fragmentation and those derived from collagenase digestion of adipose tissue, suggesting that the device could serve as a practical source of microfragmented adipose tissue for use in veterinary clinics.

Healthy but not osteoarthritic human meniscus-derived matrix scaffolds promote meniscus repair.

Meniscus tissue is commonly injured due to sports-related injuries and age-related degeneration and approximately 50% of individuals with a meniscus tear will develop post-traumatic osteoarthritis (PTOA). Given that the meniscus has limited healing potential, new therapeutic strategies are required to enhance meniscus repair. Porcine meniscus-derived matrix (MDM) scaffolds improve meniscus integrative repair, but sources of human meniscus tissue have not been investigated. Therefore, the objectives of this study were to generate healthy and osteoarthritic (OA) MDM scaffolds and to compare meniscus cellular responses and integrative repair. Meniscus cells showed high viability on both healthy and OA scaffolds. While DNA content was higher in cell-seeded OA scaffolds than cell-seeded healthy scaffolds, CCK-8, and both sGAG and collagen content were similar between scaffold types. After 28days in an ex vivo meniscus defect model, healthy and OA scaffolds had similar DNA, sGAG, and collagen content. However, the shear strength of repair was reduced in defects containing OA scaffolds compared to healthy scaffolds. In conclusion, healthy human allograft tissue is a useful source for generating MDM scaffolds that can support cellular growth, ECM production, and ex vivo integrative repair of the meniscus, highlighting the potential suitability for tissue engineering approaches to improve meniscus repair.

Free fatty acids and mortality among adults in the United States: a report from US National Health and Nutrition Examination Survey (NHANES)

Abstract Introduction Free fatty acids (FFAs) serve as vital energy sources in multiple body tissues and they have been associated with elevated cardiovascular disease risk and mortality. There is a scarcity of prospective studies examining the associations between specific FFAs and long-term health outcomes. Purpose To examine the correlation between different FFAs types and all-cause or cardiovascular mortality in a large, nationally representative sample of adults in the United States (US), and examine how different concentrations and types of FFAs may mediate this association. Methods This cohort study included 3719 and 3900 participants in the unsaturated fatty acids (USFAs) and saturated fatty acids (SFAs) populations, respectively, who participated in the US National Health and Nutrition Examination Survey (NHANES) from 2011-2014. Multiple model calibration was performed using univariate and multivariate cox regression analysis to explore the associations between circulating FFAs and all-cause or cardiovascular mortality. Results The UFAs (myristoleic acid (14:1 n-5), palmitoleic acid (16:1 n-7), cis-vaccenic acid (18:1 n-7), nervonic acid (24:1 n-9), eicosatrienoic acid (20:3 n-9), docosatetraenoic acid (22:4 n-6), and docosapentaenoic acid (22:5 n-6)) were associated with an elevated risk of all-cause mortality ((hazard ratio (HR) 1.02 [1.006-1.034]; P=0.004), (HR 1.001 [1.001–1.002]; P＜ 0.001), (HR 1.006 [1.003–1.009]; P＜ 0.001), (HR 1.007 [1.002–1.012]; P = 0.003), (HR 1.027 [1.009–1.046]; P= 0.003), (HR 1.024 [1.012–1.036]; P＜ 0.001) and (HR 1.019 [1.006–1.032]; P = 0.005), respectively), whereas docosahexaenoic acid (22:6 n-3) was linked to a lower risk (HR 0.998 [0.996–0.999]; P = 0.007). Among SFAs, palmitic acid 16:0 was associated with a higher all-cause risk (HR 1.00 [1.00–1.00]; P = 0.022), while tricosanoic acid (23:0) and lignoceric acid (24:0) were associated with lower risks (HR 0.975 [0.959–0.991]; P = 0.002) and (HR 0.992 [0.984–0.999]; P = 0.036). Kaplan–Meier survival curves according to FFAs quartiles shown the highest risk for all-cause mortality was observed in the group with the highest concentration, except serum 23:0. The association between FFAs concentration and cardiovascular mortality in the multivariate analysis indicated that only 22:6 n-3 (HR 0.997 [0.994-1.000]; P=0.035) had a lower risk of cardiovascular mortality in the USFAs group, while none of the SFAs was found to be associated with cardiovascular mortality. While, the relationship between 22:6 n-3, and cardiovascular mortality was characterized by neither a linear nor nonlinear association (P-linear = 0.215; P-nonlinear = 0.260). Conclusion In this cohort of US adults, the types and concentrations of FFAs exhibited significant associations with risk of all-cause mortality. Achieving optimal concentrations of specific FFAs effectively lowered this risk of all-cause mortality, but this benefit was not observed in regards to cardiovascular mortality.FFA and all-cause mortality

Development and intra-renal delivery of renal progenitor organoids for effective integration in vivo.

Renal progenitor organoids have been proposed as a source of tissue for kidney regeneration; however, their clinical translatability has not been demonstrated due to an inability to mass-produce comprehensive renal progenitor organoids and the lack of an effective intra-renal delivery platform that facilitates rapid integration into functionally meaningful sites. This study addresses these shortcomings. Human-induced pluripotent stem cells were differentiated into renal progenitor cells using an established protocol and aggregated using a novel assembly method to produce high yields of organoids. Organoids were encapsulated in collagen-based scaffolds for in vitro study and in vivo implantation into mouse renal cortex. In vitro, the organoids demonstrated sustained cell viability and renal structure maturation over time. In vivo delivered organoids showed rapid integration into host renal parenchyma while showing tubular and glomerular-like structure development and maturity markers. This proof-of-concept study presents many promising results, providing a system of renal organoid formation and delivery that may support the development of clinically translatable therapies and the advancement of in vitro renal organoid studies.

Emergence of the stromal vascular fraction and secretome in regenerative medicine.

Recently, we read a mini-review published by Jeyaraman et al. The article explored the optimal methods for isolating mesenchymal stromal cells from adipose tissue-derived stromal vascular fraction (SVF). Key factors include tissue source, processing techniques, cell viability assessment, and the advantages/disadvantages of autologous vs allogeneic use. The authors emphasized the need for standardized protocols for SVF isolation, ethical and regulatory standards for cell-based therapy, and safety to advance mesenchymal stromal cell-based therapies in human patients. This manuscript shares our perspective on SVF isolation in canines. We discussed future directions to potentiate effective regenerative medicine therapeutics in human and veterinary medicine.

The environmental impact on aging: Insights from buccal mucosa and molecular biomarkers

Buccal epithelial cells serve as a primary barrier against the inhalation and ingestion of harmful substances, working alongside immune system cells such as natural killer cells to protect the body from health-damaging factors. These epithelial cells can also be used as an alternative tissue source for monitoring the genotoxic effects of external factors such as chemical exposure. This assessment can be performed using molecular biomarkers of aging, which reflect biological age and indicate cellular aging acceleration due to internal and external damage factors, such as environmental hazards. In contrast to chronological age, which merely reflects the passage of time, biological age accounts for individual variation in aging processes. Molecular biomarkers are crucial for distinguishing between normal and pathological processes in the body and for identifying the effects of external factors such as chemical exposures. The identification of specific biomarkers enhances the ability to detect and monitor adverse biological responses and accelerated aging. This review aims to highlight the routes through which environmental hazards enter the body, the application of buccal epithelial cells in assessing genetic modifications, and the introduction of potential molecular biomarkers. However, further research is necessary to elucidate the roles of these biomarkers in determining aging rates and individual variability. Understanding their implications may also help identify new therapeutic targets for preventing premature aging, treating age-related diseases, and developing potential treatments.

The role of DNA methylation in chondrogenesis of human iPSCs as a stable marker of cartilage quality

BackgroundLack of insight into factors that determine purity and quality of human iPSC (hiPSC)-derived neo-cartilage precludes applications of this powerful technology toward regenerative solutions in the clinical setting. Here, we set out to generate methylome-wide landscapes of hiPSC-derived neo-cartilages from different tissues-of-origin and integrated transcriptome-wide data to identify dissimilarities in set points of methylation with associated transcription and the respective pathways in which these genes act.MethodsWe applied in vitro chondrogenesis using hiPSCs generated from two different tissue sources: skin fibroblasts and articular cartilage. Upon differentiation toward chondrocytes, these are referred to as hFiCs and hCiC, respectively. Genome-wide DNA methylation and RNA sequencing datasets were generated of the hiPSC-derived neo-cartilages, and the epigenetically regulated transcriptome was compared to that of neo-cartilage deposited by human primary articular cartilage (hPAC).ResultsMethylome-wide landscapes of neo-cartilages of hiPSCs reprogrammed from two different somatic tissues were 85% similar to that of hPACs. By integration of transcriptome-wide data, differences in transcriptionally active CpGs between hCiC relative to hPAC were prioritized. Among the CpG-gene pairs lower expressed in hCiCs relative to hPACs, we identified genes such as MGP, GDF5, and CHAD enriched in closely related pathways and involved in cartilage development that likely mark phenotypic differences in chondrocyte states. Vice versa, among the CpG-gene pairs higher expressed, we identified genes such as KIF1A or NKX2-2 enriched in neurogenic pathways and likely reflecting off target differentiation.ConclusionsWe did not find significant variation between the neo-cartilages derived from hiPSCs of different tissue sources, suggesting that application of a robust differentiation protocol such as we applied here is more important as compared to the epigenetic memory of the cells of origin. Results of our study could be further exploited to improve quality, purity, and maturity of hiPSC-derived neo-cartilage matrix, ultimately to realize introduction of sustainable, hiPSC-derived neo-cartilage implantation into clinical practice.

Obesity Human Soluble Prorenin Receptor Expressed in Adipose Tissue Improves Insulin Sensitivity and Endothelial Function in Obese Female Mice.

Soluble prorenin receptor (sPRR) is a component of the renin-angiotensin system (RAS) identified as a plasma biomarker for human metabolic disease. However, what tissue source of sPRR is implicated in the modulation of metabolic function remains unclear. This study investigated the contribution of human sPRR (HsPRR) produced in the adipose tissue (Adi) on the metabolic and cardiovascular function of lean and obese male and female mice. Adi-HsPRR mice, generated by crossing human sPRR-Myc-tag and Adiponectin/Cre mice, were fed a low-fat or high-fat diet (10% and 60% kCal from fat, respectively) for 20 weeks. Obese Adi-HsPRR mice showed elevated sPRR levels in adipose tissue without affecting adipocyte size or fat depot weight. Despite plasma sPRR being similar between obese Adi-HsPRR and control female mice, a positive correlation between plasma sPRR and adiposity was present only in controls. Obese Adi-HsPRR male mice showed elevated plasma sPRR compared with controls, but no correlation with adiposity was found in either group. Nevertheless, Adi-HsPRR expression improved insulin sensitivity and endothelial function, reduced adipogenic genes mRNA abundance (PPARg, SEBP1C and CD36), and increased plasma Angiotensin 1-7 levels only in obese HsPPR female mice. Taken together, elevated HsPRR in adipose tissue improved metabolic and vascular function in obese female mice despite normal circulating levels of sPRR, whereas increased local and circulating levels of HsPRR did not influence metabolic and cardiovascular function in obese male mice. Our data suggest that increased plasma sPRR associated with metabolic disease could be produced by other tissues rather than adipocytes.

6816 The Estrogen Environment Characteristic of Endometriotic Lesion May Attenuate the Receptor γ-Mediated Antiproliferative Activity of Retinoids

Abstract Disclosure: M. Izawa: None. Y. Azuma: None. F. Taniguchi: None. Background: Endometriosis has been accepted as an estrogen-dependent disease, and the estrogen environment in endometriotic lesions has been proposed as a major background of the pathophysiology. Although the hormonal therapy targeting the reduction of estrogen has been employed to reduce endometriosis-associated symptoms, the limitation of therapy has been well recognized. How to overcome the limitation remains an urgent subject to be explored. [Objective:]We focused on retinoids, which have been known to induce an antiproliferative activity in tumors. Based on the retinoic acid receptor (RAR) expression profile in endometriotic lesions, we evaluated the antiproliferative activity of retinoids using endometriotic cells. Finally, we examined the effect of estrogen on antiproliferative activity. Methods: Endometriotic tissue and cells: Institutional Review Boards approved this project. The chocolate cyst lining in the ovaries of patients with endometriosis was the source of endometriotic tissue. Stromal cells collected from endometriotic tissues were used as endometriotic cells. RAR expression: RNAs were prepared from endometriotic tissues and cells, and single-stranded cDNAs were subjected to RT-PCR. Primers were designed using the UCSF genome browser. Protein expression was examined by Western blotting. Cell proliferation assay: Cells were treated with all-trans retinoic acid (ATRA), selective RAR modulators (sRARMs), BMS753, CD2314 and CD437, RARγ antagonist MM11253 and 17β-estradiol (E2). Viable cells were estimated using WST-8 assay. RNA-seq analysis: Cells were treated with retinoids and E2. RNA samples were used for polyA+ selected library and the strand-specific RNA-seq. Differentially expressed genes with p-values < 0.05 and log2 fold changes > 1 were extracted as responsive genes. Results: RAR expression: Transcripts of wild-type RARα, RARβ, and RARγ were demonstrated in arbitrary 10 regions of patient tissue, and in endometriotic cells. The expression of these RARs was almost at a comparable level. Effect of retinoids and/or estrogen on cell proliferation: Cell proliferation rate was significantly decreased in the presence of ATRA. Among sRARMs tested, only CD437 reduced the cell proliferation. The antiproliferative activity of ATRA was attenuated either in the presence of MM11253 or E2, respectively. ATRA- and/or E2-responsive gene expressions To explore gene expressions in response to retinoids and E2, RNA-seq analysis was performed. The results suggest the diversity of ATRA- and E2-responsive genes in endometriotic lesions.[Conclusion:]Endometriotic cell proliferation was significantly suppressed in response to retinoids through RARγ. The observation that the antiproliferative activity was attenuated in the presence of E2 suggests a suppressive environment against the activity of retinois in endometriotic legions. Presentation: 6/2/2024

Evaluation of enzymatic protocols to optimize efficiency of bovine adipose tissue-derived mesenchymal stromal cell isolation

Sustainable food provision for a continuously growing human population is one of the major challenges for the next decades. Cultured meat represents one of the alternatives which is currently extensively explored. Yet, the most appropriate cell type, capable of long-term proliferation and myogenic differentiation, remains to be identified. Bovine mesenchymal stromal cells (MSCs) are considered as a promising cell source. Within the context of cultured meat production, it is mandatory to maximize cell yield per tissue source. Although many enzymatic methods to isolate MSCs from adipose tissue (AT) have been described, cell yield has never been compared. In this study, we evaluate 32 isolation conditions including four enzyme mixtures (Collagenase type I, Collagenase type I + Trypsin, LiberaseTM and Collagenase type IV) at varying concentrations and incubation times, regarding their efficiency to isolate MSCs from bovine subcutaneous AT. The highest cell yield in combination with a low population doubling time was obtained using LiberaseTM at a concentration of 0.1% for 3 h. MSC identity of the cells was confirmed by tri-lineage differentiation potential and cell surface marker expression. Subsequently, isolated cells were myogenically differentiated using 5-aza-2’-deoxycytidine and galectin-1. mRNA levels of the myogenic regulatory factors (MRF) myogenic factor 5 (MYF5), myogenic differentiation 1 (MYOD1), MYF6, and myogenin (MYOG) were increased, while less paired box 3 (PAX3) mRNA expression was observed when compared to undifferentiated MSCs. The presence of desmin (DES), tropomyosin (TM), and myosin heavy chain (MyHC) in myogenically differentiated bovine AT-MSCs was confirmed using immunofluorescence stainings. When considering MSCs from bovine AT as potential cell source to produce cultured meat, it is recommended to use 0.1% LiberaseTM for 3 h to ensure a high cell yield.

Functional outcome of cell seeded tracheal scaffold after mechanical stress in vitro

Tracheal tissue engineering is still facing major challenges: realization of efficient vascularization and mechanical properties comparable to native trachea need to be achieved. In this study, we present a strategy for the manufacturing of a construct for tracheal tissue engineering by conditioning through cell seeding followed by mechanical stimulation in vitro. Scaffolds derived from porcine trachea decellularized with supercritical carbon dioxide were seeded with stem cells of different tissue sources and cultured in a bioreactor for 21 days under mechanical stimulation. Enhanced chondrogenic development was demonstrated, with improved sulphated glycosaminoglycan secretion and cellular alignment which resulted in mechanical properties resembling native trachea. This method may provide a useful addition to tracheal tissue engineering strategies aimed at optimizing cartilage formation.

Influence of native thin filament type on the regulation of atrial and ventricular myosin motor activity

Ca2+-mediated activation of thin filaments is a crucial step in initiating striated muscle contraction. To gain mechanistic insight into this regulatory process, thin filament (TF) components and myosin motors from diverse species and tissue sources are often combined in minimal in vitro systems. The contribution of tissue-specific TF composition with native myosin motors in generating contraction speed remains unclear. To examine TF-mediated regulation, we established a procedure to purify native TFs (nTF) and myosin motors (M-II) from the same cardiac tissue samples as low as 10 mg and investigated their influence on gliding speeds and Ca2+ sensitivity. The rabbit atrial and ventricular nTFs and M-II were assessed in in vitro nTF motility experiments under varying Ca2+ concentrations. The speed-pCa relationship yielded a maximum TF speed of 2.58 μm/s for atrial (aM-II) and 1.51 μm/s for ventricular myosin (vM-II), both higher than the respective unregulated actin filament gliding speeds. The Ca2+ sensitivity was different for both protein sources. After swapping the nTFs, the ventricular TFs increased their gliding speed on atrial myosin, while the atrial nTFs reduced their gliding speed on ventricular myosin. Swapping of the nTFs decreased the calcium sensitivity for both vM-II and aM-II, indicating a strong influence of the thin filament source. These studies suggest that the nTF-myosin combination is critical to understanding the Ca2+ sensitivity of the shortening speed. Our approach is highly relevant to studying precious human cardiac samples, i.e., small myectomy samples, to address the alteration of contraction speed and Ca2+ sensitivity in cardiomyopathies.

Effects of five tissue sources of silver carp by-products on the structure, physicochemical and emulsifying properties of gelatin

Effects of five tissue sources of silver carp by-products on the structure, physicochemical and emulsifying properties of gelatin

Fifty free flaps from the ear

Reconstruction of facial and intraoral defects is often challenging. Local pedicled flaps may not always be available and distant free flaps usually have suboptimal color match and texture for the facial area. The aim of this study was to assess whether auricular free flaps are a valid reconstructive option. Clinical data and outcomes of patients who underwent reconstruction with microsurgical flaps from the ear between 2011 and 2021 were analyzed. Patient demographic data, type of flaps, etiology, location and size of the defect, features of the pedicle and recipient vessels, complications, and additional surgeries were reviewed. Overall, 48 patients with 50 microsurgical flaps were identified. Thirty-one patients (65%) were men and 17 were (35%) women. The median age was 62 years. Among the 50 flaps, 26 (52%) were helix flaps, 20 (40%) were temporal artery posterior auricular skin flaps, and 4 (8%) were extended helix flaps. The nose was the most frequently reconstructed region (n=32, 64%), followed by the tongue (n=6, 12%), floor of the mouth (n=5%), lower eyelid (n=2%), and in one (2%) patient each, restoration of the upper eyelid, ear, larynx, esophagus, lower lip, and palate. The median follow-up was 74 months. Three flaps (6%) were lost, and the overall rate of complications was 46%. Surgical intervention was required in 7 (14%) cases. All cases healed with acceptable cosmesis. The ear is a valuable source of tissue for complex reconstructions of the face and intraoral regions. However, this technique is surgically demanding and should be reserved for selected cases.

Chicken embryo cultures in the dorsal-upward orientation for the manipulation of epiblasts.

Chicken embryos have many advantages in the study of amniote embryonic development. In particular, culture techniques developed for early-stage embryos have promoted the advancement of modern developmental studies using chicken embryos. However, the standard technique involves placing chicken embryos in the ventral-upward (ventral-up) orientation, limiting manipulation of the epiblast at the dorsal surface, which is the primary source of ectodermal and mesodermal tissues. To circumvent this limitation, we developed chicken embryo cultures in the dorsal-up orientation and exploited this technique to address diverse issues. In this article, we first review the history of chicken embryo culture techniques to evaluate the advantages and limitations of the current standard technique. Then, the dorsal-up technique is discussed. These technological discussions are followed by three different examples of experimental analyses using dorsal-up cultures to illustrate their advantages: (1) EdU labeling of epiblast cells to assess potential variation in the cell proliferation rate; (2) migration behaviors of N1 enhancer-active epiblast cells revealed by tracking cells with focal fluorescent dye labeling in dorsal-up embryo culture; and (3) neural crest development of mouse neural stem cells in chicken embryos.

Comparative Analysis of Commercially Available Extracellular Matrix Soft Tissue Bioscaffolds.

Decellularized extracellular matrix (dECM) products are widely established for soft tissue repair, reconstruction and reinforcement. These regenerative biomaterials mimic native tissue ECM with respect to structure and biology and are produced from a range of tissue sources and species. Optimal source tissue processing requires a balance between removal of cellular material and the preservation of structural and biological properties of tissue ECM. Despite the wide-spread clinical use of dECM products there is a lack of comparative information on these products Structurally, some dECM products showed a well-preserved collagen architecture with a broad porosity distribution, while others showed a significantly altered structure compared with native tissue. Decellularization varied across the products. Some materials surveyed (OFMm, PPN, PPC, OFMo, UBM, SISz, ADM, PADM and BADM) were essentially devoid of nuclear bodies (mean count of <5 cells per high powered field (HPF)), whereas others (SISu and SISb) demonstrated an abundance of nuclear bodies (>50 cells per HPF). Pathology assessment of the products demonstrated that OFMm, OFMo and PADM had the highest qualitative assessment score for collagen fiber orientation and arrangement, matrix porosity, decellularization efficiency, and residual vascular channels scoring 10.5±0.8, 12.8±1.0, and 9.7±0.7 out of a maximum total score of 16, respectively This analysis of commercially available dECM products in terms of their structure and cellularity includes 12 different commercial materials The findings highlight the variability of the products in terms of matrix structure and the efficacy of decellularization.