Publications by authors named "Naaijkens B"

In most pre-clinical animal studies investigating stem cell therapy in acute myocardial infarction (AMI), the administered stem cells are isolated from healthy donors. In clinical practice, however, patients who suffer from AMI will receive autologous cells, for example using adipose-derived stem cells (ASC). During AMI, inflammation is induced and we hypothesized that this might affect characteristics of ASC.

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Introduction: Administration of mesenchymal stem cells (MSCs) represents a promising treatment option for patients suffering from immunological and degenerative disorders. Accumulating evidence indicates that the healing effects of MSCs are mainly related to unique paracrine properties, opening opportunities for secretome-based therapies. Apart from soluble factors, MSCs release functional small RNAs via extracellular vesicles (EVs) that seem to convey essential features of MSCs.

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Adipose tissue-derived stromal cells (ASC) form a rich source of autologous cells for use in regenerative medicine. In vitro induction of an endothelial phenotype may improve performance of ASCs in cardiovascular repair. Here, we report on an in vitro strategy using direct reprogramming of ASCs by means of ectopic expression of the endothelial-specific transcription factor SRY (sex determining region Y)-box18 (SOX18).

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The use of stem cells for the repair of damaged cardiac tissue after a myocardial infarction holds great promise. However, a common finding in experimental studies is the low number of cells delivered at the area at risk. To improve the delivery, we are currently investigating a novel delivery platform in which stem cells are conjugated with targeted microbubbles, creating echogenic complexes dubbed StemBells.

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The majority of patients survive an acute myocardial infarction (AMI). Their outcome is negatively influenced by post-AMI events, such as loss of viable cardiomyocytes due to a post-AMI inflammatory response, eventually resulting in heart failure and/or death. Recent pre-clinical animal studies indicate that mesenchymal stem cells derived from adipose tissue (ASC) are new promising candidates that may facilitate cardiovascular regeneration in the infarcted myocardium.

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The Wistar rat is a commonly used strain for experimental animal models. Recently it was shown that results vary between studies using Wistar rats of different suppliers. Therefore we studied whether Wistar rats obtained from Harlan Laboratories (Ha, n=24) and Charles River (CR, n=22) had a different outcome in an acute myocardial infarction (AMI) model.

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Inadequate healing following acute myocardial infarction (AMI) can lead to the development of heart failure. The ischemic myocardium triggers an inflammatory response that clears cell debris and initiates the onset of scar tissue formation. The duration and intensity of this inflammatory response have been linked to the cardiac functioning post-AMI.

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Context: C1-esterase inhibitor (C1-inh) therapy is currently administered to patients with C1-inh deficiency through intravenous injections. The possibility of subcutaneous administration is currently being explored since this would alleviate need for hospitalization and increase mobility and well-being of patients. Recently, it was observed in pigs that C1-inh indeed can effectively be applied by subcutaneous injection.

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In this study, we investigated the effect of secondary Bjerknes forces on targeted microbubbles using high-speed optical imaging. We observed that targeted microbubbles attached to an underlying surface and subject to secondary Bjerknes forces deform in the direction of their neighboring bubble, thereby tending toward a prolate shape. The deformation induces an elastic restoring force, causing the bubbles to recoil back to their equilibrium position; typically within 100 μs after low-intensity ultrasound application.

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Adipose tissue-derived stem cells (ASCs) are promising candidates for regenerative therapy, like after myocardial infarction. However, when transplanted into the infarcted heart, ASCs are jeopardized by the ischemic environment. Interestingly, it has been shown that multidrug resistance (MDR) proteins like the breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp) have a protective effect in haematopoietic stem cells.

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Adipose-derived stromal cells (ASC) are promising candidates for cell therapy, for example to treat myocardial infarction. Commonly, fetal bovine serum (FBS) is used in ASC culturing. However, FBS has several disadvantages.

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Although mesenchymal stromal cells (MSCs) have been applied clinically to treat cardiac diseases, it is unclear how and to which extent transplanted MSCs exert their beneficial effects. To address these questions, pre-clinical MSC administrations are needed for which pigs appear to be the species of choice. This requires the use of porcine cells to prevent immune rejection.

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Stem cell therapy is a promising tool to improve outcome after acute myocardial infarction (AMI), but needs to be optimized since results from clinical applications remain ambiguous. A potent source of stem cells is the stromal vascular fraction of adipose tissue (SVF), which contains high numbers of adipose derived stem cells (ASC). We hypothesized that: 1) intravenous injection can be used to apply stem cells to the heart.

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Mesenchymal stem cells (MSCs) of human and nonhuman mammalian species are often studied for various applications in regenerative medicine research. These MSCs can be derived from human bone marrow (BM) and identified by their ability to form fibroblast-like colony forming units that develop into stromal like cells when expanded in culture. These cells are characterized by their spindle-shaped morphology, their characteristic phenotype (CD73(+), CD90(+), CD105(+), CD45⁻, and CD34⁻), and their ability to differentiate into cells of the osteogenic, adipogenic, and chondrogenic lineages.

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The HIV-1 envelope glycoprotein complex (Env) is the focus of vaccine development aimed at eliciting humoral immunity. Env's extensive and heterogeneous N-linked glycosylation affects folding, binding to lectin receptors, antigenicity and immunogenicity. We characterized recombinant Env proteins and virus particles produced in mammalian cells that lack N-acetylglucosaminyltransferase I (GnTI), an enzyme necessary for the conversion of oligomannose N-glycans to complex N-glycans.

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