Zwitterionic Peptides Reduce Accumulation of Marine and Freshwater Biofilm Formers.

Zwitterionic peptides are facile low-fouling compounds for environmental applications as they are biocompatible and fully biodegradable as their degradation products are just amino acids. Here, a set of histidine (H) and glutamic acid (E), as well as lysine (K) and glutamic acid (E) based peptide sequences with zwitterionic properties were synthesized. Both oligopeptides (KE)K and (HE)H were synthesized in d and l configurations to test their ability to resist the nonspecific adsorption of the proteins lysozyme and fibrinogen.

Mode of Action of Condensed- and Gaseous-Phase Fire Retardation in Some Phosphorus-Modified Polymethyl Methacrylate- and Polystyrene-Based Bulk Polymers.

The aspects of fire retardation in some phosphorus-modified polymethyl methacrylate (PMMA) and polystyrene (PSt) polymers are reported in the present paper. Both and strategies were employed to obtain the desired level of loading of the phosphorus-bearing compound/moiety (2 wt.% of P in each case).

Agricultural application of microplastic-rich sewage sludge leads to further uncontrolled contamination.

Municipal sewage sludge has been shown to be high in microplastics (MP) and is applied to agricultural land as fertiliser in many countries. The authors recently proposed in a viewpoint article that MP applied to land in this way may well contaminate other areas in an uncontrolled way. This study examined experimental plots with known history of application of sewage sludge.

Determination of Strain Limits for Dimensioning Polyurethane Components.

Within the scope of this contribution, a method for the determination of a strain limit for designing components made of elastomeric polyurethane systems is presented. The knowledge of a material-specific strain limit is essential for the structural-mechanical calculation of plastic components in the context of component design. Compared to a commonly used component design, based on a simplified dimensioning approach taking only linear viscoelastic deformations into account, the strain limit determined in this study allows an improved utilisation of lightweight construction potential in the dimensioning of technical components made of polyurethanes through the consideration of permissible nonlinear viscoelastic deformations.

The innate immune response of self-assembling silk fibroin hydrogels.

Silk has a long track record of use in humans, and recent advances in silk fibroin processing have opened up new material formats. However, these new formats and their applications have subsequently created a need to ascertain their biocompatibility. Therefore, the present aim was to quantify the haemocompatibility and inflammatory response of silk fibroin hydrogels.

Poly(2-alkyl-2-oxazoline)-Heparin Hydrogels-Expanding the Physicochemical Parameter Space of Biohybrid Materials.

Poly(ethylene glycol) (PEG)-glycosaminoglycan (GAG) hydrogel networks are established as very versatile biomaterials. Herein, the synthetic gel component of the biohybrid materials is systematically varied by combining different poly(2-alkyl-2-oxazolines) (POx) with heparin applying a Michael-type addition crosslinking scheme: POx of gradated hydrophilicity and temperature-responsiveness provides polymer networks of distinctly different stiffness and swelling. Adjusting the mechanical properties and the GAG concentration of the gels to similar values allows for modulating the release of GAG-binding growth factors (VEGF165 and PDGF-BB) by the choice of the POx and its temperature-dependent conformation.

In situ identification and G4-PPI-His-Mal-dendrimer-induced reduction of early-stage amyloid aggregates in Alzheimer's disease transgenic mice using synchrotron-based infrared imaging.

Amyloid plaques composed of Aβ amyloid peptides and neurofibrillary tangles are a pathological hallmark of Alzheimer Disease. In situ identification of early-stage amyloid aggregates in Alzheimer's disease is relevant for their importance as potential targets for effective drugs. Synchrotron-based infrared imaging is here used to identify early-stage oligomeric/granular aggregated amyloid species in situ in the brain of APP/PS1 transgenic mice for the first time.

Bioresponsive starPEG-heparin hydrogel coatings on vascular stents for enhanced hemocompatibility.

Hydrogel coatings can improve the biocompatibility of medical devices. However, stable surface bonding and homogeneity of hydrogel coatings are often challenging. This study exploits the benefits of biohybrid hydrogels of crosslinked four-armed poly(ethylene glycol) and heparin to enhance the hemocompatibility of cobalt‑chromium (CoCr) vascular stents.

Highly Tunable Piezoresistive Behavior of Carbon Nanotube-Containing Conductive Polymer Blend Composites Prepared from Two Polymers Exhibiting Crystallization-Induced Phase Separation.

Conductive polymer composites (CPCs) are suitable as piezoresistive-sensing materials. When using CPCs for strain sensing, it is still a big challenge to simultaneously improve the piezoresistive sensitivity and linearity along with the electrical conductivity and mechanical properties. Here, highly tunable piezoresistive behavior is reported for multiwalled carbon nanotube (CNT)-filled CPCs based on blends of two semicrystalline polymers poly(vinylidene fluoride) (PVDF) and poly(butylene succinate) (PBS), which are miscible in the melt.

Kallikrein-Related Peptidase 6 Is Associated with the Tumour Microenvironment of Pancreatic Ductal Adenocarcinoma.

As cancer-associated factors, kallikrein-related peptidases (KLKs) are components of the tumour microenvironment, which represents a rich substrate repertoire, and considered attractive targets for the development of novel treatments. Standard-of-care therapy of pancreatic cancer shows unsatisfactory results, indicating the need for alternative therapeutic approaches. We aimed to investigate the expression of KLKs in pancreatic cancer and to inhibit the function of KLK6 in pancreatic cancer cells.

Amphiphilic Copolymers for Versatile, Facile, and In Situ Tunable Surface Biofunctionalization.

Precision surface engineering is key to advanced biomaterials. A new platform of PEGylated styrene-maleic acid copolymers for adsorptive surface biofunctionalization is reported. Balanced amphiphilicity renders the copolymers water-soluble but strongly affine for surfaces.

Electron-to Hole Transport Change Induced by Solvent Vapor Annealing of Naphthalene Diimide Doped with Poly(3-Hexylthiophene).

Herein we report on fabrication and properties of organic field-effect transistors (OFETs) based on the spray-coated films of N,N'-dioctyl naphthalene diimide (NDIC8) doped with 2.4 wt% of poly (3-hexylthiophene) (P3HT). OFETs with the untreated NDIC8:P3HT films revealed electron conductivity [μ* = 5 × 10 cm×(Vs)].

Understanding Beta-Lactam-Induced Lysis at the Single-Cell Level.

Mechanical rupture, or lysis, of the cytoplasmic membrane is a common cell death pathway in bacteria occurring in response to β-lactam antibiotics. A better understanding of the cellular design principles governing the susceptibility and response of individual cells to lysis could indicate methods of potentiating β-lactam antibiotics and clarify relevant aspects of cellular physiology. Here, we take a single-cell approach to bacterial cell lysis to examine three cellular features-turgor pressure, mechanosensitive channels, and cell shape changes-that are expected to modulate lysis.

Short Excited-State Lifetimes Mediate Charge-Recombination Losses in Organic Solar Cell Blends with Low Charge-Transfer Driving Force.

A blend of a low-optical-gap diketopyrrolopyrrole polymer and a fullerene derivative, with near-zero driving force for electron transfer, is investigated. Using femtosecond transient absorption and electroabsorption spectroscopy, the charge transfer (CT) and recombination dynamics as well as the early-time transport are quantified. Electron transfer is ultrafast, consistent with a Marcus-Levich-Jortner description.

3D Models for Ovarian Cancer.

The main reasons for the slow progress in improving survival outcomes for ovarian cancer are the 'one-size-fits-all' therapy and lack of clinically relevant experimental models that represent the advanced stages of the human disease. The interaction of tumour cells with their surrounding niche, the tumour microenvironment, influences the spread of ovarian cancer cells within the peritoneum and their responses to therapeutics. Scientists are increasingly using 3D cell culture models to dissect the role of the tumour microenvironment in cancer development and progression and the treatment of this disease.

Controlling Surface Wettability for Automated In Situ Array Synthesis and Direct Bioscreening.

The in situ synthesis of biomolecules on glass surfaces for direct bioscreening can be a powerful tool in the fields of pharmaceutical sciences, biomaterials, and chemical biology. However, it is still challenging to 1) achieve this conventional multistep combinatorial synthesis on glass surfaces with small feature sizes and high yields and 2) develop a surface which is compatible with solid-phase syntheses, as well as the subsequent bioscreening. This work reports an amphiphilic coating of a glass surface on which small droplets of polar aprotic organic solvents can be deposited with an enhanced contact angle and inhibited motion to permit fully automated multiple rounds of the combinatorial synthesis of small-molecule compounds and peptides.

Corrigendum to "A Versatile Surface Bioengineering Strategy Based on Mussel-Inspired and Bioclickable Peptide Mimic".

[This corrects the article DOI: 10.34133/2020/7236946.].

Field-Induced Transversely Isotropic Shear Response of Ellipsoidal Magnetoactive Elastomers.

Magnetoactive elastomers (MAEs) claim a vital place in the class of field-controllable materials due to their tunable stiffness and the ability to change their macroscopic shape in the presence of an external magnetic field. In the present work, three principal geometries of shear deformation were investigated with respect to the applied magnetic field. The physical model that considers dipole-dipole interactions between magnetized particles was used to study the stress-strain behavior of ellipsoidal MAEs.

Nanoparticles for Directed Immunomodulation: Mannose-Functionalized Glycodendrimers Induce Interleukin-8 in Myeloid Cell Lines.

New therapeutic strategies for personalized medicine need to involve innovative pharmaceutical tools, for example, modular nanoparticles designed for direct immunomodulatory properties. We synthesized mannose-functionalized poly(propyleneimine) glycodendrimers with a novel architecture, where freely accessible mannose moieties are presented on poly(ethylene glycol)-based linkers embedded within an open-shell maltose coating. This design enhanced glycodendrimer bioactivity and led to complex functional effects in myeloid cells, with specific induction of interleukin-8 expression by mannose glycodendrimers detected in HL-60 and THP-1 cells.

Analysis of microplastics in drinking water and other clean water samples with micro-Raman and micro-infrared spectroscopy: minimum requirements and best practice guidelines.

Microplastics are a widespread contaminant found not only in various natural habitats but also in drinking waters. With spectroscopic methods, the polymer type, number, size, and size distribution as well as the shape of microplastic particles in waters can be determined, which is of great relevance to toxicological studies. Methods used in studies so far show a huge diversity regarding experimental setups and often a lack of certain quality assurance aspects.

Preclinical Testing of New Hydrogel Materials for Cartilage Repair: Overcoming Fixation Issues in a Large Animal Model.

Reinforced hydrogels represent a promising strategy for tissue engineering of articular cartilage. They can recreate mechanical and biological characteristics of native articular cartilage and promote cartilage regeneration in combination with mesenchymal stromal cells. One of the limitations of models for testing the outcome of tissue engineering approaches is implant fixation.

Tuning the network charge of biohybrid hydrogel matrices to modulate the release of SDF-1.

The delivery of chemotactic signaling molecules via customized biomaterials can effectively guide the migration of cells to improve the regeneration of damaged or diseased tissues. Here, we present a novel biohybrid hydrogel system containing two different sulfated glycosaminoglycans (sGAG)/sGAG derivatives, namely either a mixture of short heparin polymers (Hep-Mal) or structurally defined nona-sulfated tetrahyaluronans (9s-HA4-SH), to precisely control the release of charged signaling molecules. The polymer networks are described in terms of their negative charge, i.

Silk Hydrogel Substrate Stress Relaxation Primes Mesenchymal Stem Cell Behavior in 2D.

Tissue-mimetic silk hydrogels are being explored for diverse healthcare applications, including stem cell delivery. However, the impact of stress relaxation of silk hydrogels on human mesenchymal stem cell (MSC) biology is poorly defined. The aim of this study was to fabricate silk hydrogels with tuned mechanical properties that allowed the regulation of MSC biology in two dimensions.

How Influenza's Spike Motor Works.

While often believed to be a passive agent that merely exploits its host's metabolism, the influenza virus has recently been shown to actively move across glycan-coated surfaces. This form of enzymatically driven surface motility is currently not well understood and has been loosely linked to burnt-bridge Brownian ratchet mechanisms. Starting from known properties of influenza's spike proteins, we develop a physical model that quantitatively describes the observed motility.