The Proliferation of Pre-Pubertal Porcine Spermatogonia in Stirred Suspension Bioreactors Is Partially Mediated by the Wnt/β-Catenin Pathway

Male survivors of childhood cancer are at risk of suffering from infertility in adulthood because of gonadotoxic chemotherapies. For adult men, sperm collection and preservation are routine procedures prior to treatment; however, this is not an option for pre-pubertal children. From young boys, a small biopsy may be taken before chemotherapy, and spermatogonia may be propagated in vitro for future transplantation to restore fertility. A robust system that allows for scalable expansion of spermatogonia within a controlled environment is therefore required. Stirred suspension culture has been applied to different types of stem cells but has so far not been explored for spermatogonia. Here, we report that pre-pubertal porcine spermatogonia proliferate more in bioreactor suspension culture, compared with static culture. Interestingly, oxygen tension provides an avenue to modulate spermatogonia status, with culture under 10% oxygen retaining a more undifferentiated state and reducing proliferation in comparison with the conventional approach of culturing under ambient oxygen levels. Spermatogonia grown in bioreactors upregulate the Wnt/ β-catenin pathway, which, along with enhanced gas and nutrient exchange observed in bioreactor culture, may synergistically account for higher spermatogonia proliferation. Therefore, stirred suspension bioreactors provide novel platforms to culture spermatogonia in a scalable manner and with minimal handling.

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Pediatric and Adolescent Oncofertility in Male Patients—From Alpha to Omega

Genes ◽

10.3390/genes12050701 ◽

2021 ◽

Vol 12 (5) ◽

pp. 701

Author(s):

Ovidiu Bîcă ◽

Ioan Sârbu ◽

Carmen Iulia Ciongradi

Keyword(s):

Fertility Preservation ◽

Gene Editing ◽

Genetic Diseases ◽

Reproductive Potential ◽

Molecular Techniques ◽

Male Population ◽

Male Survivors ◽

Male Patients ◽

Survivors Of Childhood Cancer

This article reviews the latest information about preserving reproductive potential that can offer enhanced prospects for future conception in the pediatric male population with cancer, whose fertility is threatened because of the gonadotoxic effects of chemotherapy and radiation. An estimated 400,000 children and adolescents aged 0–19 years will be diagnosed with cancer each year. Fertility is compromised in one-third of adult male survivors of childhood cancer. We present the latest approaches and techniques for fertility preservation, starting with fertility preservation counselling, a clinical practice guideline used around the world and finishing with recent advances in basic science and translational research. Improving strategies for the maturation of germ cells in vitro combined with new molecular techniques for gene editing could be the next scientific keystone to eradicate genetic diseases such as cancer related mutations in the offspring of cancer survivors.

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Ultrastructural Investigations of the Contractile Filaments of Amoebae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050950 ◽

1974 ◽

Vol 32 ◽

pp. 188-189

Author(s):

P.L. Moore

Keyword(s):

Cytoplasmic Streaming ◽

Three Dimensional ◽

Freeze Fracture ◽

Amoeboid Movement ◽

Different Types ◽

Chemical Conditions ◽

Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

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Recent Advances in Curcumin Nanocarriers for the Treatment of Different Types of Cancer with Special Emphasis on In Vitro Cytotoxicity and Cellular Uptake Studies

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681209666190417144126 ◽

2020 ◽

Vol 10 (5) ◽

pp. 577-590

Author(s):

Jai B. Sharma ◽

Shailendra Bhatt ◽

Asmita Sharma ◽

Manish Kumar

Keyword(s):

Cancer Cells ◽

Cellular Uptake ◽

Anticancer Agents ◽

Targeted Delivery ◽

In Vitro Cytotoxicity ◽

Curcumin Nanoparticles ◽

Cytotoxicity Studies ◽

Delivery Technique ◽

Different Types

Background: The potential use of nanocarriers is being explored rapidly for the targeted delivery of anticancer agents. Curcumin is a natural polyphenolic compound obtained from rhizomes of turmeric, belongs to family Zingiberaceae. It possesses chemopreventive and chemotherapeutic activity with low toxicity in almost all types of cancer. The low solubility and bioavailability of curcumin make it unable to use for the clinical purpose. The necessity of an effective strategy to overcome the limitations of curcumin is responsible for the development of its nanocarriers. Objective: This study is aimed to review the role of curcumin nanocarriers for the treatment of cancer with special emphasis on cellular uptake and in vitro cytotoxicity studies. In addition to this, the effect of various ligand conjugated curcumin nanoparticles on different types of cancer was also studied. Methods: A systematic review was conducted by extensively surfing the PubMed, science direct and other portals to get the latest update on recent development in nanocarriers of curcumin. Results: The current data from recent studies showed that nanocarriers of curcumin resulted in the targeted delivery, higher efficacy, enhanced bioavailability and lower toxicity. The curcumin nanoparticles showed significant inhibitory effects on cancer cells as compared to free curcumin. Conclusion: It can be concluded that bioavailability of curcumin and its cytotoxic effect to cancer cells can be enhanced by the development of curcumin based nanocarriers and it was found to be a potential drug delivery technique for the treatment of cancer.

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Long-Term Severe In Vitro Hypoxia Exposure Enhances the Vascularization Potential of Human Adipose Tissue-Derived Stromal Vascular Fraction Cell Engineered Tissues

International Journal of Molecular Sciences ◽

10.3390/ijms22157920 ◽

2021 ◽

Vol 22 (15) ◽

pp. 7920

Author(s):

Myroslava Mytsyk ◽

Giulia Cerino ◽

Gregory Reid ◽

Laia Gili Sole ◽

Friedrich S. Eckstein ◽

...

Keyword(s):

Adipose Tissue ◽

Therapeutic Potential ◽

Stromal Vascular Fraction ◽

Human Adipose Tissue ◽

Bioreactor Culture ◽

Proliferating Cells ◽

Angiogenic Potential ◽

Engineered Tissues

The therapeutic potential of mesenchymal stromal/stem cells (MSC) for treating cardiac ischemia strongly depends on their paracrine-mediated effects and their engraftment capacity in a hostile environment such as the infarcted myocardium. Adipose tissue-derived stromal vascular fraction (SVF) cells are a mixed population composed mainly of MSC and vascular cells, well known for their high angiogenic potential. A previous study showed that the angiogenic potential of SVF cells was further increased following their in vitro organization in an engineered tissue (patch) after perfusion-based bioreactor culture. This study aimed to investigate the possible changes in the cellular SVF composition, in vivo angiogenic potential, as well as engraftment capability upon in vitro culture in harsh hypoxia conditions. This mimics the possible delayed vascularization of the patch upon implantation in a low perfused myocardium. To this purpose, human SVF cells were seeded on a collagen sponge, cultured for 5 days in a perfusion-based bioreactor under normoxia or hypoxia (21% and <1% of oxygen tension, respectively) and subcutaneously implanted in nude rats for 3 and 28 days. Compared to ambient condition culture, hypoxic tension did not alter the SVF composition in vitro, showing similar numbers of MSC as well as endothelial and mural cells. Nevertheless, in vitro hypoxic culture significantly increased the release of vascular endothelial growth factor (p < 0.001) and the number of proliferating cells (p < 0.00001). Moreover, compared to ambient oxygen culture, exposure to hypoxia significantly enhanced the vessel length density in the engineered tissues following 28 days of implantation. The number of human cells and human proliferating cells in hypoxia-cultured constructs was also significantly increased after 3 and 28 days in vivo, compared to normoxia. These findings show that a possible in vivo delay in oxygen supply might not impair the vascularization potential of SVF- patches, which qualifies them for evaluation in a myocardial ischemia model.

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Marginal Adaptation and Micropermeability of Class II Cavities Restored with Three Different Types of Resin Composites—A Comparative Ten-Month In Vitro Study

Polymers ◽

10.3390/polym13101660 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1660

Author(s):

Sevda Mihailova Yantcheva

Keyword(s):

Methylene Blue ◽

In Vitro Study ◽

Sem Analysis ◽

Marginal Adaptation ◽

Resin Composites ◽

Polymerization Shrinkage ◽

Gingival Margin ◽

Different Types ◽

Ageing Period

The development of composite materials is subject to the desire to overcome polymerization shrinkage and generated polymerization stress. An indicator characterizing the properties of restorative materials, with specific importance for preventing secondary caries, is the integrity and durability of marginal sealing. It is a reflection of the effects of polymerization shrinkage and generated stress. The present study aimed to evaluate and correlate marginal integrity and micropermeability in second-class cavities restored with three different types of composites, representing different strategies to reduce polymerization shrinkage and stress: nanocomposite, silorane, and bulk-fill composite after a ten-month ageing period. Thirty standardized class ΙΙ cavities were prepared on extracted human molars. Gingival margins were 1 mm apical to the cementoenamel junction. Cavities were randomly divided into three groups, based on the composites used: FiltekUltimate-nanocomposite; Filtek Silorane LS-silorane; SonicFill-bulk-fill composite. All specimens were subjected to thermal cycles after that, dipped in saline for 10-mounds. After ageing, samples were immersed in a 2% methylene blue. Thus prepared, they were covered directly with gold and analyzed on SEM for assessment of marginal seal. When the SEM analysis was completed, the teeth were included into epoxy blocks and cut longitudinally on three slices for each cavity. An assessment of microleakage on stereomicroscope followed. Results were statistically analyzed. For marginal seal evaluation: F.Ultimate and F.Silorane differ statistically with more excellent results than SonicFill for marginal adaptation to the gingival margin, located entirely in the dentin. For microleakage evaluation: F.Ultimate and F.Silorane differ statistically with less microleakage than SonicFill. Based on the results obtained: a strong correlation is found between excellent results for marginal adaptation to the marginal gingival ridge and micropermeability at the direction to the axial wall. We observe a more significant influence of time at the gingival margin of the cavities. There is a significant increase in the presence of marginal fissures (p = 0.001). A significant impact of time (p < 0.000) and of the material (p < 0.000) was found in the analysis of the microleakage.

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Antioxidant and Hypolipidemic Activity of Açai Fruit Makes It a Valuable Functional Food

Antioxidants ◽

10.3390/antiox10010040 ◽

2020 ◽

Vol 10 (1) ◽

pp. 40

Author(s):

Anna Virginia Adriana Pirozzi ◽

Paola Imbimbo ◽

Antonella D’Agostino ◽

Virginia Tirino ◽

Rosario Finamore ◽

...

Keyword(s):

Functional Food ◽

Subcutaneous Fat ◽

Cell Models ◽

Alcoholic Fatty Liver ◽

Hypoxic Conditions ◽

Tnf Α ◽

Different Types ◽

Vitro Model ◽

Alcoholic Fatty Liver Disease

Several plant extracts are acquiring increasing value because of their antioxidant activity and hypolipidemic properties. Among them, great interest has been recently paid to açai fruit as a functional food. The aim of this study was to test the ability of açai extract in reducing oxidative stress and modulating lipid metabolism in vitro using different cell models and different types of stress. In fact, lipid peroxidation as evaluated in a HepG2 model was reduced five-fold when using 0.25 µg/mL of extract, and it was further reduced (20-fold) with the concentration increase up to 2.5 µg/mL. With the non alcoholic fatty liver disease (NAFLD)in vitro model, all concentrations tested showed at least a two-fold reduced fat deposit. In addition, primary adipocytes challenged with TNF-α under hypoxic conditions to mimic the persistent subcutaneous fat, treated with açai extract showed an approximately 40% reduction of fat deposit. Overall, our results show that açai is able to counteract oxidative states in all the cell models analysed and to prevent the accumulation of lipid droplets. No toxic effects and high stability overtime were highlighted at the concentrations tested. Therefore, açai can be considered a suitable support in the prevention of different alterations of lipid and oxidative metabolism responsible for fat deposition and metabolic pathological conditions.

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Engineering nucleosomes for generating diverse chromatin assemblies

Nucleic Acids Research ◽

10.1093/nar/gkab070 ◽

2021 ◽

Author(s):

Zenita Adhireksan ◽

Deepti Sharma ◽

Phoi Leng Lee ◽

Qiuye Bao ◽

Sivaraman Padavattan ◽

...

Keyword(s):

Dynamic Properties ◽

Dna Nanostructures ◽

Macromolecular Assemblies ◽

Maximum Resolution ◽

Different Types ◽

Chromatin Structural ◽

Dna Fragment

Abstract Structural characterization of chromatin is challenging due to conformational and compositional heterogeneity in vivo and dynamic properties that limit achievable resolution in vitro. Although the maximum resolution for solving structures of large macromolecular assemblies by electron microscopy has recently undergone profound increases, X-ray crystallographic approaches may still offer advantages for certain systems. One such system is compact chromatin, wherein the crystalline state recapitulates the crowded molecular environment within the nucleus. Here we show that nucleosomal constructs with cohesive-ended DNA can be designed that assemble into different types of circular configurations or continuous fibers extending throughout crystals. We demonstrate the utility of the method for characterizing nucleosome compaction and linker histone binding at near-atomic resolution but also advance its application for tackling further problems in chromatin structural biology and for generating novel types of DNA nanostructures. We provide a library of cohesive-ended DNA fragment expression constructs and a strategy for engineering DNA-based nanomaterials with a seemingly vast potential variety of architectures and histone chemistries.

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Stem cells and exosomes: promising candidates for necrotizing enterocolitis therapy

Stem Cell Research & Therapy ◽

10.1186/s13287-021-02389-4 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Ruijie Zeng ◽

Jinghua Wang ◽

Zewei Zhuo ◽

Yujun Luo ◽

Weihong Sha ◽

...

Keyword(s):

Stem Cells ◽

Necrotizing Enterocolitis ◽

Therapeutic Effects ◽

Beneficial Effects ◽

Pediatric Diseases ◽

Gastrointestinal Conditions ◽

Different Types ◽

Novel Therapeutic Strategies

AbstractNecrotizing enterocolitis (NEC) is a devastating disease predominately affecting neonates. Despite therapeutic advances, NEC remains the leading cause of mortality due to gastrointestinal conditions in neonates. Stem cells have been exploited in various diseases, and the application of different types of stem cells in the NEC therapy is explored in the past decade. However, stem cell transplantation possesses several deficiencies, and exosomes are considered potent alternatives. Exosomes, especially those derived from stem cells and breast milk, demonstrate beneficial effects for NEC both in vivo and in vitro and emerge as promising options for clinical practice. In this review, the function and therapeutic effects of stem cells and exosomes for NEC are investigated and summarized, which provide insights for the development and application of novel therapeutic strategies in pediatric diseases. Further elucidation of mechanisms, improvement in preparation, bioengineering, and administration, as well as rigorous clinical trials are warranted.

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Impact of Chronic Tetracycline Exposure on Human Intestinal Microbiota in a Continuous Flow Bioreactor Model

Antibiotics ◽

10.3390/antibiotics10080886 ◽

2021 ◽

Vol 10 (8) ◽

pp. 886

Author(s):

Youngbeom Ahn ◽

Ji Young Jung ◽

Ohgew Kweon ◽

Brian T. Veach ◽

Sangeeta Khare ◽

...

Keyword(s):

Molecular Analysis ◽

Intestinal Microbiota ◽

Continuous Flow ◽

Antimicrobial Drug ◽

Bioreactor Culture ◽

Analysis Techniques ◽

Human Intestinal Microbiota ◽

Traditional Cultures ◽

The Impact

Studying potential dietary exposure to antimicrobial drug residues via meat and dairy products is essential to ensure human health and consumer safety. When studying how antimicrobial residues in food impact the development of antimicrobial drug resistance and disrupt normal bacteria community structure in the intestine, there are diverse methodological challenges to overcome. In this study, traditional cultures and molecular analysis techniques were used to determine the effects of tetracycline at chronic subinhibitory exposure levels on human intestinal microbiota using an in vitro continuous flow bioreactor. Six bioreactor culture vessels containing human fecal suspensions were maintained at 37 °C for 7 days. After a steady state was achieved, the suspensions were dosed with 0, 0.015, 0.15, 1.5, 15, or 150 µg/mL tetracycline, respectively. Exposure to 150 µg/mL tetracycline resulted in a decrease of total anaerobic bacteria from 1.9 × 107 ± 0.3 × 107 down to 2 × 106 ± 0.8 × 106 CFU/mL. Dose-dependent effects of tetracycline were noted for perturbations of tetB and tetD gene expression and changes in acetate and propionate concentrations. Although no-observed-adverse-effect concentrations differed, depending on the traditional cultures and the molecular analysis techniques used, this in vitro continuous flow bioreactor study contributes to the knowledge base regarding the impact of chronic exposure of tetracycline on human intestinal microbiota.

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Melatonin in Cancer Treatment: Current Knowledge and Future Opportunities

Molecules ◽

10.3390/molecules26092506 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2506

Author(s):

Wamidh H. Talib ◽

Ahmad Riyad Alsayed ◽

Alaa Abuawad ◽

Safa Daoud ◽

Asma Ismail Mahmod

Keyword(s):

Clinical Trials ◽

Current Knowledge ◽

Biological Activities ◽

Experimental Studies ◽

Therapeutic Effects ◽

Cell Proliferation Inhibition ◽

Different Types ◽

Solid Foundation

Melatonin is a pleotropic molecule with numerous biological activities. Epidemiological and experimental studies have documented that melatonin could inhibit different types of cancer in vitro and in vivo. Results showed the involvement of melatonin in different anticancer mechanisms including apoptosis induction, cell proliferation inhibition, reduction in tumor growth and metastases, reduction in the side effects associated with chemotherapy and radiotherapy, decreasing drug resistance in cancer therapy, and augmentation of the therapeutic effects of conventional anticancer therapies. Clinical trials revealed that melatonin is an effective adjuvant drug to all conventional therapies. This review summarized melatonin biosynthesis, availability from natural sources, metabolism, bioavailability, anticancer mechanisms of melatonin, its use in clinical trials, and pharmaceutical formulation. Studies discussed in this review will provide a solid foundation for researchers and physicians to design and develop new therapies to treat and prevent cancer using melatonin.

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