Alginate (Alg) is a versatile biopolymer for scaffold engineering and a bioink component widely used for direct cell printing. However, due to a lack of intrinsic cell-binding sites, Alg must be functionalized for cellular adhesion when used as a scaffold. Moreover, direct cell-laden ink 3D printing requires tedious disinfection procedures and cell viability is compromised by shear stress.
View Article and Find Full Text PDFLiver diseases represent a considerable burden to patients and healthcare systems. Hydrogels play an important role in the engineering of soft tissues and may be useful for embedding hepatocytes for different therapeutic interventions or the development of in vitro models to study the pathogenesis of liver diseases or testing of drugs. Here, we developed two types of hydrogels by crosslinking hydrazide-functionalized gelatin with either oxidized dialdehyde hyaluronan or alginate through the formation of hydrazone bonds.
View Article and Find Full Text PDFThe outcome of three-dimensional (3D) bioprinting heavily depends, amongst others, on the interaction between the developed bioink, the printing process, and the printing equipment. However, if this interplay is ensured, bioprinting promises unmatched possibilities in the health care area. To pave the way for comparing newly developed biomaterials, clinical studies, and medical applications (i.
View Article and Find Full Text PDFEngineered neural tissues serve as models for studying neurological conditions and drug screening. Besides observing the cellular physiological properties, in situ monitoring of neurochemical concentrations with cellular spatial resolution in such neural tissues can provide additional valuable insights in models of disease and drug efficacy. In this work, we demonstrate the first three-dimensional (3D) tissue cultures with embedded optical dopamine (DA) sensors.
View Article and Find Full Text PDFHepatocellular adenomas (HCAs) are benign liver tumors associated with bleeding or malignant transformation. Data on the indication for surgery are scarce. We analyzed indications and outcome of patients operated for HCAs < 50 mm compared to HCAs ≥ 50 mm.
View Article and Find Full Text PDFMetal ions are important effectors of protein and cell functions. Here, polyelectrolyte multilayers (PEMs) made of chitosan (Chi) and alginate (Alg) were doped with different metal ions (Ca, Co, Cu, and Fe), which can form bonds with their functional groups. Ca and Fe ions can be deposited in PEM at higher quantities resulting in more positive ζ potentials and also higher water contact angles in the case of Fe.
View Article and Find Full Text PDFThere are limits to the use of cardioplegic arrest during complex cardiac surgical procedures, especially in patients with severe left ventricular dysfunction. In the current report, we graphically present the detailed surgical strategy and technique for beating-heart aortic root replacement with concomitant coronary bypass grafting, for patients otherwise deemed inoperable. With support of cardiopulmonary bypass (CPB), beating-heart bypass surgery is realized, after which the bypass grafts can selectively be connected to the CPB, preserving coronary flow.
View Article and Find Full Text PDFBackground: The position of the specialist nurse profession varies across the European Union. Action is required to address the challenges to promote mobility and the contribution of specialist nurses to quality of care. The purpose of the study is to identify the interfaces of the specialist nurse profession across the European Union.
View Article and Find Full Text PDFBioengineering (Basel)
December 2021
Hemocompatibility of biomaterials in contact with the blood of patients is a prerequisite for the short- and long-term applications of medical devices such as cardiovascular stents, artificial heart valves, ventricular assist devices, catheters, blood linings and extracorporeal devices such as artificial kidneys (hemodialysis), extracorporeal membrane oxygenation (ECMO) and cardiopulmonary bypass. Although lower blood compatibility of materials and devices can be handled with systemic anticoagulation, its side effects, such as an increased bleeding risk, make materials that have a better hemocompatibility highly desirable, particularly in long-term applications. This review provides a short overview on the basic mechanisms of blood coagulation including plasmatic coagulation and blood platelets, as well as the activation of the complement system.
View Article and Find Full Text PDFThe human foot is uniquely adapted to bipedal locomotion and has a deformable arch of variable stiffness. Intrinsic foot muscles regulate arch deformation, making them important for foot function. In this study we explore the hypothesis that normal daily activity in minimal footwear, which provides little or no support, increases foot muscle strength.
View Article and Find Full Text PDFBackground: Pain is a common problem in elite athletes. This exploratory study compares goal orientations towards sport, fear of failure, self-handicapping and pain catastrophizing between active young elite athletes with and without chronic pain (CP) complaints (longer than three months). It examines the associations between chronic pain, fear of failure, goal orientations, self-handicapping and pain catastrophizing in young elite athletes.
View Article and Find Full Text PDFCellulose and chitosan are excellent components for the fabrication of bioactive scaffolds, as they are biocompatible and abundantly available. Their derivatives Ocarboxymethyl chitosan (CMChi) and oxidized cellulose sulfate (oxCS) can form in situ gelling, bioactive hydrogels, due to the formation of imine bonds for crosslinking. Here the influence of the degrees of sulfation (DS), oxidation (DO), and the molecular weight of oxCS on intrinsic and rheological properties of such hydrogels and their ability to support the survival and growth of human-adipose-derived stem cells (hADSC) is investigated.
View Article and Find Full Text PDFPolysaccharides are widely used as building blocks of scaffolds and hydrogels in tissue engineering, which may require their chemical modification to permit crosslinking. The goal of this study was to generate a library of oxidized alginate (oALG) and oxidized hyaluronic acid (oHA) that can be used for in situ gelling hydrogels by covalent reaction between aldehyde groups of the oxidized polysaccharides (oPS) and amino groups of carboxymethyl chitosan (CMC) through imine bond formation. Here, we studied the effect of sodium periodate concentration and reaction time on aldehyde content, molecular weight of derivatives and cytotoxicity of oPS towards 3T3-L1 fibroblasts.
View Article and Find Full Text PDFIn hemodialysis, vascular access is a key issue. The preferred access is an arteriovenous fistula on the non-dominant lower arm. If the natural vessels are insufficient for such access, the insertion of a synthetic vascular graft between artery and vein is an option to construct an arteriovenous shunt for punctures.
View Article and Find Full Text PDFThermoresponsive polymers hold great potential in the biomedical field, since they enable the fabrication of cell sheets, in situ drug delivery and 3D-printing under physiological conditions. In this review we provide an overview of several thermoresponsive polymers and their application, with focus on poly(N-isopropylacrylamide)-surfaces for cell sheet engineering. Basic knowledge of important processes like protein adsorption on surfaces and cell adhesion is provided.
View Article and Find Full Text PDFFreestanding multilayer films prepared by layer-by-layer technique have attracted interest as promising materials for wound dressings. The goal is to fabricate freestanding films using chitosan (CHI) and alginate (ALG) including subsequent crosslinking to improve the mechanical properties of films while maintaining their biocompatibility. Three crosslinking strategies are investigated, namely use of calcium ions for crosslinking ALG, 1-ethyl-3-(-3-dimethylaminopropyl) carbodiimide combined with N-hydroxysuccinimide for crosslinking ALG with CHI, and Genipin for crosslinking chitosan inside the films.
View Article and Find Full Text PDFBackground: Pulse oximetry-derived oxygen saturation is typically >97% in normoxia and hyperoxia, limiting its clinical use. The new Oxygen Reserve Index (ORi), a relative indicator of the partial pressure of oxygen dissolved in arterial blood (PaO2) in the range of 100-200 mm Hg, may allow additional monitoring of oxygen status.
Methods: In this prospective validation intervention study, 20 healthy volunteers were breathing standardized oxygen concentrations ranging from mild hypoxia (fraction of inspired oxygen = 0.
Preclinical and clinical studies support that Notch signaling may play an important oncogenic role in cancer, but there is scarce information for pituitary tumors. We therefore undertook a functional study to evaluate Notch participation in pituitary adenoma growth. Tumors generated in Nude mice by subcutaneous GH3 somatolactotrope cell injection were treated in vivo with DAPT, a γ-secretase inhibitor, thus inactivating Notch signaling.
View Article and Find Full Text PDFEpilepsies are a common and chronic neurological disorder characterized by sustained risk of recurrent seizures. Because of paroxysmal and often unpredictable occurrence of seizures, patients with uncontrolled epilepsy are subject to disease-specific restrictions in daily life, such as their career choice or specific work limitations. According to German law and many other European and international guidelines, driving is strictly prohibited in patients with uncontrolled epilepsy so as to increase active and passive safety in public road traffic.
View Article and Find Full Text PDFWe investigated the genetic role of sortilin (SORT1) in frontotemporal dementia (FTD). SORT1 is the neuronal receptor for granulin, encoded by the progranulin gene (GRN), a major causal gene for inherited FTD. In Belgian cohorts of 636 FTD patients and 1066 unaffected control individuals, we identified 5 patient-only nonsynonymous rare variants in SORT1.
View Article and Find Full Text PDFStud Health Technol Inform
April 2018
A report written as a personal communication based on the experience gathered by developing and delivery of a international professional master course. The organization of the curriculum consists of 16 modules. Using a framework of the user centered design and development cycle students receive domain knowledge related to user-orientation, business, innovation and implementation.
View Article and Find Full Text PDFThis study examined mostly lower-middle-income Latino (37%) and African American (33%) adolescents' (N = 90, Mage = 15.90) conceptions of how U.S.
View Article and Find Full Text PDFImportance: Patients carrying a C9orf72 repeat expansion leading to frontotemporal dementia and/or amyotrophic lateral sclerosis have highly variable ages at onset of disease, suggesting the presence of modifying factors.
Objective: To provide clinical-based evidence for disease anticipation in families carrying a C9orf72 repeat expansion by analyzing age at onset, disease duration, and age at death in successive generations.
Design, Setting, And Participants: This cohort study was performed from June 16, 2000, to June 1, 2016, in 36 extended Belgian families in which a C9orf72 repeat expansion was segregating.
Objectives: This study investigates biomechanical implications of walking with indigenous "Kolhapuri" footwear compared to barefoot walking among a population of South Indians.
Materials And Methods: Ten healthy adults from South India walked barefoot and indigenously shod at voluntary speed on an artificial substrate. The experiment was repeated outside, on a natural substrate.
We investigated the mutation spectrum of the TANK-Binding Kinase 1 (TBK1) gene and its associated phenotypic spectrum by exonic resequencing of TBK1 in a cohort of 2,538 patients with frontotemporal dementia (FTD), amyotrophic lateral sclerosis (ALS), or FTD plus ALS, ascertained within the European Early-Onset Dementia Consortium. We assessed pathogenicity of predicted protein-truncating mutations by measuring loss of RNA expression. Functional effect of in-frame amino acid deletions and missense mutations was further explored in vivo on protein level and in vitro by an NFκB-induced luciferase reporter assay and measuring phosphorylated TBK1.
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