Background: The plantarflexor muscles are important during walking. However, walking is not the only task that is used during daily life, and not much is known about the role of the plantarflexor muscles during other dynamic tasks. Insight into the demand of the plantarflexor muscles during different dynamic tasks might help to establish training or functional assessment for patients who experience plantarflexor weakness.
View Article and Find Full Text PDFThe cellular microenvironment is composed of a dynamic hierarchical fibrillar architecture providing a variety of physical and bioactive signals to the surrounding cells. This dynamicity, although common in biology, is a challenge to control in synthetic matrices. Here, responsive synthetic supramolecular monomers were designed that are able to assemble into hierarchical fibrous structures, combining supramolecular fiber formation via hydrogen bonding interactions, with a temperature-responsive hydrophobic collapse, resulting in cross-linking and hydrogel formation.
View Article and Find Full Text PDFIntracellular delivery of functional biomolecules by using supramolecular polymer nanostructures has gained significant interest. Here, various charged supramolecular ureido-pyrimidinone (UPy)-aggregates were designed and formulated a simple "mix-and-match" method. The cellular internalization of these UPy-aggregates in the presence or absence of serum proteins by phagocytic and non-phagocytic cells, , THP-1 derived macrophages and immortalized human kidney cells (HK-2 cells), was systematically investigated.
View Article and Find Full Text PDFBackground: Clubfoot patients show good-to-excellent foot correction after the Ponseti method. Nevertheless, underlying functional problems that limit motor abilities such as one-leg-standing and one-leg-hopping still persist. These restrictions have been proposed to arise due to problems with maintaining balance and the limited force-generating capacity of clubfoot patients.
View Article and Find Full Text PDFBackground: Being aware of possible gait impairments in Ponseti-treated clubfoot children might be useful for optimizing initial and additional treatment. Therefore, this systematic review and meta-analysis aimed to identify kinematic gait abnormalities in children with clubfoot treated with the Ponseti method (with and without relapse).
Methods: A systematic search was conducted.
Background: Functioning in children consists of different aspects, including their ability to execute activities and participate in life situations. Several studies on children with clubfeet showed limited motor abilities and walking capacity compared with healthy control children, while other studies showed comparable athletic abilities and gross motor development. Although participation in activities of daily life plays an important role in the development of children, this has not yet been investigated in children with clubfeet.
View Article and Find Full Text PDFBackground: Objective gait analysis that fully captures the multi-segmental foot movement of a clubfoot may help in early identification of a relapse clubfoot. Unfortunately, this type of objective measure is still lacking in a clinical setting and it is unknown how it relates to clinical assessment.
Research Question: The aim of this study was to identify differences in total gait and foot deviations between clubfoot patients with and without a relapse clubfoot and to evaluate their relationship with clinical status.
Background: Altered muscle-tendon properties in clubfoot patients could play a role in the occurrence of a relapse and negatively affect physical functioning. However, there is a lack of literature about muscle-tendon properties of clubfoot relapse patients.
Research Question: The aim of this study was to determine whether the muscle architecture of the medial gastrocnemius and the morphology of the Achilles tendon differ between typically developing children (TDC) and clubfoot patients with and without a relapse clubfoot and to determine the relationships between morphological and functional gait outcomes.
Background: Understanding the kinematic characteristics of relapse clubfoot compared to successfully treated clubfoot could aid early identification of a relapse and improve treatment planning. The usage of a multi segment foot model is essential in order to grasp the full complexity of the multi-planar and multi-joint deformity of the clubfoot.
Research Question: The purpose of this study was to identify differences in foot kinematics, using a multi-segment foot model, during gait between patients with Ponseti treated clubfoot with and without a relapse and age-matched healthy controls.
The interactions between and with nanostructures can only be fully understood when the functional group distribution on their surfaces can be quantified accurately. Here we apply a combination of direct stochastic optical reconstruction microscopy (dSTORM) imaging and probabilistic modelling to analyse molecular distributions on spherical nanoparticles. The properties of individual fluorophores are assessed and incorporated into a model for the dSTORM imaging process.
View Article and Find Full Text PDFRecent years have witnessed an increasing interest in hybrid molecular systems in which the programmability of DNA hybridization is used to introduce enhanced molecular control in synthetic systems. The first examples of DNA-functionalized supramolecular polymers have been reported only recently, but have already revealed structural and functional properties that are not easily obtained in either synthetic supramolecular polymers or DNA-only based systems. In this Topical Review, we provide an overview of the various forms of additional control offered by DNA hybridization for different types of supramolecular polymers and discuss how orthogonal supramolecular interactions in these hybrid systems can give rise to emergent structural and functional properties.
View Article and Find Full Text PDFIn biology, polymorphism is a well-known phenomenon by which a discrete biomacromolecule can adopt multiple specific conformations in response to its environment. The controlled incorporation of polymorphism into noncovalent aqueous assemblies of synthetic small molecules is an important step toward the development of bioinspired responsive materials. Herein, we report on a family of carboxylic acid functionalized water-soluble benzene-1,3,5-tricarboxamides (BTAs) that self-assemble in water to form one-dimensional fibers, membranes, and hollow nanotubes.
View Article and Find Full Text PDFDynamic DNA-based circuits represent versatile systems to perform complex computing operations at the molecular level. However, the majority of DNA circuits relies on freely diffusing reactants, which slows down their rate of operation substantially. Here we introduce the use of DNA-functionalized benzene-1,3,5-tricarboxamide (BTA) supramolecular polymers as dynamic scaffolds to template DNA-based molecular computing.
View Article and Find Full Text PDFNature uses dynamic molecular platforms for the recruitment of weakly associating proteins into higher-order assemblies to achieve spatiotemporal control of signal transduction. Nanostructures that emulate this dynamic behavior require features such as plasticity, specificity and reversibility. Here we introduce a synthetic protein recruitment platform that combines the dynamics of supramolecular polymers with the programmability offered by DNA-mediated protein recruitment.
View Article and Find Full Text PDFStructural and kinetic exchange properties of supramolecular polymers composed of mono- and bivalent ureidopyrimidinone-based monomers are investigated in aqueous solutions. It is shown that exchange dynamics can be controlled by mixing different types of monomers. This tunability widens the scope in their design as biomaterials.
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2016
Understanding the interaction between synthetic nanostructures and living cells is of crucial importance for the development of nanotechnology-based intracellular delivery systems. Fluorescence microscopy is one of the most widespread tools owing to its ability to image multiple colors in native conditions. However, due to the limited resolution, it is unsuitable to address individual diffraction-limited objects.
View Article and Find Full Text PDFThe interplay of Phe-Gly-Gly (FGG)-tagged proteins and bivalent FGG-tagged penta(ethylene glycol) as guest molecules with cucurbit[8]uril (Q8) hosts is studied to modulate the supramolecular assembly process. Ring structure formation of the bivalent guest molecule with Q8 leads to enhanced binding properties and efficient inhibition of protein assemblies.
View Article and Find Full Text PDFThe introduction of weak, hydrophobic interactions between fluorescent protein domains (FPs) can substantially increase the dynamic range (DR) of Förster resonance energy transfer (FRET)-based sensor systems. Here we report a comprehensive thermodynamic characterization of the stability of a range of self-associating FRET pairs. A new method is introduced that allows direct quantification of the stability of weak FP interactions by monitoring intramolecular complex formation as a function of urea concentration.
View Article and Find Full Text PDFEnterotoxigenic Escherichia coli (ETEC), which produces heat labile toxin (LT) and/or heat stable toxin (ST), is considered to be the most common known cause of travellers' diarrhoea (TD). Owing to the antigenic similarity between cholera toxin and LT, immunization with inactivated oral B-subunit/whole-cell cholera vaccine (BS-WC) offers short term (3 months) but significant (>67%) protection against TD caused by LT-related ETEC. Since it expresses the cholera toxin B (CTB) subunit, the live attenuated oral cholera vaccine strain CVD 103-HgR, may induce similar protection.
View Article and Find Full Text PDFTwo cases of Lassa fever have been reported in the Netherlands since viral haemorrhagic fevers became notifiable diseases in 1978. In 1980, an expatriate from Burkina Faso who was not seriously ill was confirmed by laboratory tests after his discharge from hospital. The second case occurred in 2000: the patient died on the 11th day of admission to hospital.
View Article and Find Full Text PDFThe interaction between tyramine and the new short-acting and reversible mono amine oxidase inhibitor moclobemide was investigated in a double-blind placebo-controlled study in six healthy volunteers. There were two consecutive study periods of 8 days during which the subjects received moclobemide three x 200 mg daily or placebo. On day 5 of each study period changes in systolic blood pressure (SBP) were determined after incremental intravenous bolus doses of tyramine and on days 6, 7 and 8 changes in SBP were determined after oral tyramine (100, 200 and 300 mg, respectively).
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