321 research outputs found

    Design and characterization of Squalene-Gusperimus nanoparticles for modulation of innate immunity

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    Immunosuppressive drugs are widely used for the treatment of autoimmune diseases and to prevent rejection in organ transplantation. Gusperimus is a relatively safe immunosuppressive drug with low cytotoxicity and reversible side effects. It is highly hydrophilic and unstable. Therefore, it requires administration in high doses which increases its side effects. To overcome this, here we encapsulated gusperimus as squalene-gusperimus nanoparticles (Sq-GusNPs). These nanoparticles (NPs) were obtained from nanoassembly of the squalene gusperimus (Sq-Gus) bioconjugate in water, which was synthesized starting from squalene. The size, charge, and dispersity of the Sq-GusNPs were optimized using the response surface methodology (RSM). The colloidal stability of the Sq-GusNPs was tested using an experimental block design at different storage temperatures after preparing them at different pH conditions. Sq-GusNPs showed to be colloidally stable, non-cytotoxic, readily taken up by cells, and with an anti-inflammatory effect sustained over time. We demonstrate that gusperimus was stabilized through its conjugation with squalene and subsequent formation of NPs allowing its controlled release. Overall, the Sq-GusNPs have the potential to be used as an alternative in approaches for the treatment of different pathologies where a controlled release of gusperimus could be required

    In Vitro Studies of Squalene-Gusperimus Nanoparticles in Islet-Containing Alginate Microcapsules to Regulate the Immune Response in the Immediate Posttransplant Period

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    Grafting of microencapsulated pancreatic islets has been proposed as an alternative to exogenous insulin for the treatment of type 1 diabetes mellitus. Microencapsulated islets are protected from direct contact with immune cells and larger immune‐active molecules such as immunoglobulins. Unfortunately, many islet cells in the microcapsules are lost in the immediate period after transplantation due to an early host immune response limiting long‐term function of the graft. Gusperimus has shown to reduce the inflammatory responses to grafted encapsulated islets, but it cannot be appropriately used because it is easily hydrolyzed leading to loss of activity. To temporarily modulate the inflammatory response directly after implantation and stabilize gusperimus, squalene‐gusperimus nanoparticles (Sq‐GusNPs) are developed and incorporated in human islets‐containing alginate‐based microcapsules. A prolonged and continuous release of gusperimus is achieved. This offers an anti‐inflammatory microenvironment in the vicinity of the microcapsules and a reduction of cytokine secretion by lipopolysaccharides‐activated human macrophages. Release of gusperimus from Sq‐GusNPs does not affect the in vitro viability or function of human pancreatic islets. The data illustrate that incorporation of Sq‐GusNPs in alginate microcapsules offers an opportunity to temporarily modulate the immediate immune response after the grafting procedure of encapsulated islets cells and reduce loss of islet cells

    In vitro determination of the immunosuppressive effect, internalization, and release mechanism of squalene-gusperimus nanoparticles for managing inflammatory responses

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    Gusperimus is an anti-inflammatory drug that has shown to be effective in managing autoimmunity and preventing graft rejection. This is unstable and easily broken down into cytotoxic components. We encapsulated gusperimus binding it covalently to squalene obtaining squalene-gusperimus nanoparticles (Sq-GusNPs). These nanoparticles enhanced the immunosuppressive effect of gusperimus in both mouse macrophages and T cells. The half-maximal inhibitory concentration in macrophages was 9-fold lower for Sq-GusNPs compared with the free drug. The anti-inflammatory effect of the Sq-GusNPs was maintained over time without cytotoxicity. By studying nanoparticles uptake by cells with flow cytometry, we demonstrated that Sq-GusNPs are endocytosed by macrophages after binding to low-density lipoprotein receptors (LDLR). In presence of cathepsin B or D release of gusperimus is increased demonstrating the participation of proteases in the release process. Our approach may allow the application of Sq-GusNPs for effective management of inflammatory disorders including autoimmunity and graft rejection

    Stable conditional expression and effect of C/EBPβ-LIP in adipocytes using the pSLIK system

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    Murine 3T3-L1 adipocytes are widely used as a cellular model of obesity. However, whereas transfection of 3T3-L1 preadipocytes is straightforward, ectopic gene expression in mature 3T3-L1 adipocytes has proved challenging. Here, we used the pSLIK vector system to generate stable doxycycline-inducible expression of the liver-enriched inhibitor protein isoform of CCAAT/enhancer binding protein (C/EBP) {beta} (C/EBP{beta}-LIP) in fully differentiated 3T3-L1 adipocytes. Because overexpression of C/EBP{beta}-LIP impairs adipocyte differentiation, the C/EBP{beta}-LIP construct was first integrated in 3T3-L1 preadipocytes but expression was induced only when adipocytes were fully differentiated. Increased C/EBP{beta}-LIP in mature adipocytes down-regulated C/EBP{beta} target genes including 11{beta}-hydroxysteroid dehydrogenase type 1, phosphoenolpyruvate carboxykinase and fatty acid binding protein 4, but had no effect on asparagine synthetase, demonstrating that transcriptional down-regulation by C/EBP{beta}-LIP in 3T3-L1 adipocytes is not a general effect. Importantly, these genes were modulated in a similar manner in adipose tissue of mice with genetically increased C/EBP{beta}-LIP levels. The use of the pSLIK system to conditionally express transgenes in 3T3-L1 cells could be a valuable tool to dissect adipocyte physiology

    Tethering Cells via Enzymatic Oxidative Crosslinking Enables Mechanotransduction in Non-Cell-Adhesive Materials

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    Cell–matrix interactions govern cell behavior and tissue function by facilitating transduction of biomechanical cues. Engineered tissues often incorporate these interactions by employing cell-adhesive materials. However, using constitutively active cell-adhesive materials impedes control over cell fate and elicits inflammatory responses upon implantation. Here, an alternative cell–material interaction strategy that provides mechanotransducive properties via discrete inducible on-cell crosslinking (DOCKING) of materials, including those that are inherently non-cell-adhesive, is introduced. Specifically, tyramine-functionalized materials are tethered to tyrosines that are naturally present in extracellular protein domains via enzyme-mediated oxidative crosslinking. Temporal control over the stiffness of on-cell tethered 3D microniches reveals that DOCKING uniquely enables lineage programming of stem cells by targeting adhesome-related mechanotransduction pathways acting independently of cell volume changes and spreading. In short, DOCKING represents a bioinspired and cytocompatible cell-tethering strategy that offers new routes to study and engineer cell–material interactions, thereby advancing applications ranging from drug delivery, to cell-based therapy, and cultured meat

    Implementation of laparoscopic hysterectomy for endometrial cancer over the past decade

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    Background: Laparoscopic hysterectomy (LH) for the treatment of early-stage endometrial carcinoma/cancer (EC) has demonstrated to be safe in several randomized controlled trials. Yet, data on implementation of LH in clinical practice are limited. In the present study, implementation of LH for EC was evaluated in a large oncology network in the Netherlands. Results: Retrospectively, a total of 556 EC patients with FIGO stage I-II were registered in the selected years. The proportion of LH gradually increased from 11% in 2006 to 85% in 2015. LH was more often performed in patients with low-grade EC and was not related to the studied patient characteristics. The introduction of TLH was frequently preceded by LAVH. Patients treated in teaching hospitals were more likely to undergo a LH compared to patients in non-teaching hospitals. The conversion rate was 7.7%, and the overall complication rates between LH and AH were comparable, but less postoperative complications in LH. Conclusions: Implementation of laparoscopic hysterectomy for early-stage EC increased from 11 to 85% in 10 years. Implementation of TLH was often preceded by LAVH and was faster in teaching hospitals

    EuroDia: a beta-cell gene expression resource

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    Type 2 diabetes mellitus (T2DM) is a major disease affecting nearly 280 million people worldwide. Whilst the pathophysiological mechanisms leading to disease are poorly understood, dysfunction of the insulin-producing pancreatic beta-cells is key event for disease development. Monitoring the gene expression profiles of pancreatic beta-cells under several genetic or chemical perturbations has shed light on genes and pathways involved in T2DM. The EuroDia database has been established to build a unique collection of gene expression measurements performed on beta-cells of three organisms, namely human, mouse and rat. The Gene Expression Data Analysis Interface (GEDAI) has been developed to support this database. The quality of each dataset is assessed by a series of quality control procedures to detect putative hybridization outliers. The system integrates a web interface to several standard analysis functions from R/Bioconductor to identify differentially expressed genes and pathways. It also allows the combination of multiple experiments performed on different array platforms of the same technology. The design of this system enables each user to rapidly design a custom analysis pipeline and thus produce their own list of genes and pathways. Raw and normalized data can be downloaded for each experiment. The flexible engine of this database (GEDAI) is currently used to handle gene expression data from several laboratory-run projects dealing with different organisms and platforms
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