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Computational methods to understand interactions in bio-complex systems are however limited to time-scales typically much shorter than in Nature. For example, on the nanoscale level, interactions between nanoparticles (NPs)/molecules/peptides and membranes are central in complex biomolecular processes such as membrane-coated NPs or cellular uptake. This can be remedied by the application of e.g. J

The contributions from anions and cations from salt are inseparable in their perturbation of molecular systems by experimental and computational methods, rendering it difficult to dissect the effects exerted by the anions and cations individually. Here we investigate the solvation of a small molecule, caffeine, and its perturbation by monovalent salts from various parts of the Hofmeister series. U

Enzymes have come into use for many new applications outside their natural biological environment, taking advantage of their high efficiency and selectivity as biocatalysts. Such new application often requires encapsulation to preserve the structure and activity of the enzyme, but also to regulate and control the activity. Here, we will discuss two types of encapsulation, soft matrices consisting

Looking at globular proteins with the eyes of a colloid scientist has a long tradition, in fact a significant part of the early colloid literature was focused on protein solutions. However, it has also been recognized that proteins are much more complex than the typical hard sphere-like synthetic model colloids. Proteins are not perfect spheres, their interaction potentials are in general not isot

The addition of polyelectrolytes (PEs) to suspensions of charged colloids, such as nanoplatelets (NPs), is of great interest due to their specific feature of being either a stabilizing or a destabilizing agent. Here, the complexation between a PE and oppositely charged NPs is studied utilizing coarse-grained molecular dynamics simulations based on the continuum model. The complex formation is eval

Histatin 5 is a histidine-rich, intrinsically disordered, multifunctional saliva protein known to act as a first line of defense against oral candidiasis caused by Candida albicans. An earlier study showed that, upon interaction with a common model bilayer, a protein cushion spontaneously forms underneath the bilayer. Our hypothesis is that this effect is of electrostatic origin and that the obser

The bioactivity, biological fate and cytotoxicity of nanomaterials when they come into contact with living organisms are determined by their interaction with biomacromolecules and biological barriers. In this context, the role of symmetry/shape anisotropy of both the nanomaterials and biological interfaces in their mutual interaction, is a relatively unaddressed issue. Here, we study the interacti

NrdR is a bacterial transcriptional repressor consisting of a zinc (Zn)-ribbon domain followed by an ATP-cone domain. Understanding its mechanism of action could aid the design of novel antibacterials. NrdR binds specifically to two “NrdR boxes” upstream of ribonucleotide reductase operons, of which Escherichia coli has three: nrdHIEF, nrdDG and nrdAB, in the last of which we identified a new

Simple models based on isotropic interparticle attractions often fail to capture experimentally observed structures of colloidal gels formed through spinodal decomposition and subsequent arrest: the resulting gels are typically denser and less branched than their experimental counterparts. Here, we simulate gels formed from soft particles with directional attractions ("patchy particles"), designed

We report on the structural properties of ionic microgel particles subjected to alternating electric fields, using small-angle neutron scattering. The experiments were performed under so-called zero average contrast conditions, which cancel the structure factor contribution to the scattered intensity, allowing us to obtain direct information on the single particle size and structure as particles a

A simple Pickering emulsion route has been developed for the assembly of temperature-responsive poly(N-isopropylacrylamide) (PNIPAM) microgel particles into colloidal molecules comprising a small number of discrete microgel interaction sites on a central oil emulsion droplet. Here, the surface activity of the microgels serves to drive their assembly through adsorption to growing polydimethylsiloxa

We present a scheme for transferring conformational degrees of freedom from all-atom (AA) simulations of an intrinsically disordered protein (IDP) to coarse-grained (CG) Monte Carlo (MC) simulations using conformational swap moves. AA simulations of a single histatin 5 peptide in water were used to obtain a structural ensemble, which is reweighted in a CGMC simulation in the presence of a negative

In this article, it is shown that by exposing commonly used lipids for biomembrane mimicking studies, to a solution containing the histidine-rich intrinsically disordered protein histatin 5, a protein cushion spontaneously forms underneath the bilayer. The underlying mechanism is attributed to have an electrostatic origin, and it is hypothesized that the observed behavior is due to proton charge f

Better understanding of the local deformation of the bone network around metallic implants subjected to loading is of importance to assess the mechanical resistance of the bone-implant interface and limit implant failure. In this study, four titanium screws were osseointegrated into rat tibiae for 4 weeks and screw pullout was conducted in situ under x-ray microtomography, recording macroscopic me

When a biomaterial is inserted into the body, proteins rapidly adsorb onto its surface, creating a conditioning protein film that functions as a link between the implant and adhering cells. Depending on the nano-roughness of the surface, proteins will adsorb in different amounts, with different conformations and orientations, possibly affecting the subsequent attachment of cells to the surface. Th

Hybrid anisotropic microgels were synthesised using mesoporous silica as core particles. By finely controlling the synthesis conditions, the latter can be obtained with different shapes such as platelets, primary particles or rods. Using the core particles as seeds for precipitation polymerisation, a crosslinked poly(N-isopropylacrylamide) (PNIPAM) microgel shell could be grown at the surface, con

In this article, we demonstrate a method for inducing reversible crystal-to-crystal transitions in binary mixtures of soft colloidal particles. Through a controlled decrease of salinity and increasingly dominating electrostatic interactions, a single sample is shown to reversibly organize into entropic crystals, electrostatic attraction-dominated crystals, or aggregated gels, which we quantify usi

Intrinsically disordered proteins (IDPs) adopt heterogeneous conformational ensembles in solution. The properties of the conformational ensemble are dependent upon the solution conditions, including the presence of ions, temperature, and crowding, and often directly impact biological function. Many in vitro investigations focus on the properties of IDPs under dilute conditions, rather than the cro

Stimuli-responsive microgels have attracted much interest for their use as vehicles for drug delivery or as the building blocks of adaptive materials. Ionic microgel particles, including popular poly(NIPAM-co-acrylic acid), show strong mechanical responsiveness to many external stimuli, including changes in ionic strength or acidity. In this work, we demonstrate that combining multiple ionic stimu