Colloidal Structure Dictates Antimicrobial Efficacy in LL-37 Self-Assemblies With Glycerol Monooleate.

The antimicrobial peptide LL-37 is a promising alternative to conventional antibiotics to combat bacteria in suspension and biofilms. Its self-assembly with polar lipids is suggested to improve its potential for therapeutic applications with higher stability against degradation and bioavailability. This study investigates the self-assembly of LL-37 with glyceryl monooleate (GMO), establishing the link between colloidal structure and antimicrobial activity.

Nanostructured Fe-Doped NiS Electrocatalyst for the Oxygen Evolution Reaction with High Stability at an Industrially-Relevant Current Density.

A novel oxygen evolution reaction (OER) electrocatalyst was prepared by a synthesis strategy consisting of the solvothermal growth of NiS nanostructures on Ni foam, followed by hydrothermal incorporation of Fe species (Fe-NiS/Ni foam). This electrocatalyst displayed a low OER overpotential of 230 mV at 100 mA·cm, a low Tafel slope of 43 mV·dec, and constant performance at an industrially relevant current density (500 mA·cm) over 100 h in a 1.0 M KOH electrolyte, despite a minor loss of Fe in the process.

Lowest gelation concentration in a complex-coacervate-driven self-assembly system, achieved by redox-RAFT synthesis of high molecular weight block polyelectrolytes.

The objective of this work was to synthesize high molecular weight polyelectrolyte complex (PEC) micelles that are effective in controlling the rheology of aqueous solutions at low concentrations, paving the way for industrial applications of thickeners based on the principle of electrostatic self-assembly. Redox-initiated RAFT (reversible addition-fragmentation chain-transfer) polymerization was used to obtain anionic block polyelectrolytes based on poly(sodium 2-acrylamido-2-methylpropane sulfonate) and poly(acrylamide)-poly(AMPS)--poly(AM) (di-block) and poly(AMPS)--poly(AM)--poly(AMPS) (tri-block), with molecular weights of 237 kDa and 289 kDa and polydispersities of 1.29 and 1.

The Structure and Function of the Bacterial Osmotically Inducible Protein Y.

The ability to adapt to osmotically diverse and fluctuating environments is critical to the survival and resilience of bacteria that colonize the human gut and urinary tract. Environmental stress often provides cross-protection against other challenges and increases antibiotic tolerance of bacteria. Thus, it is critical to understand how E.

Aqueous Supramolecular Transformations of Motor Bola-Amphiphiles at Multiple Length-Scale.

Molecular motor amphiphiles have already been widely attempted for dynamic nanosystems across multiple length-scale for developments of small functional materials, including controlling macroscopic foam properties, amplifying motion as artificial molecular muscles, and serving as extracellular matrix mimicking cell scaffolds. However, limiting examples of bola-type molecular motor amphiphiles are considered for constructing macroscopic biomaterials. Herein, this work presents the designed two second generation molecular motor amphiphiles, motor bola-amphiphiles (MBAs).

The synthesis of fructose-based surfactants.

This study describes the synthesis of a new class of surfactants that is based on the bioderived building blocks fructose, fatty acid methyl esters (FAME), and hydroxy propionitrile (cyanoethanol, 3-HP). The synthesis is scalable, is carried out at ambient conditions, and does not require chromatography. The produced surfactants have excellent surfactant properties with critical micelle concentrations and Krafft points comparable to current glucose-based surfactants.

Light-Triggered Disassembly of Molecular Motor-based Supramolecular Polymers Revealed by High-Speed AFM.

Photoresponsive supramolecular polymers have a major potential for applications in responsive materials that are externally triggered by light with spatio-temporal control of their polymerisation state. While changes in macroscopic properties revealed the adaptive nature of these materials, it remains challenging to capture the dynamic depolymerisation process at the molecular level, which requires fast observation techniques combined with in situ irradiation. By implementing in situ UV illumination into a High-Speed Atomic Force Microscope (HS-AFM) setup, we have been able to capture the disassembly of a light-driven molecular motor-based supramolecular polymer.

Red-light-controlled supramolecular assemblies of indigo amphiphiles at multiple length scales.

Amphiphilic molecules functionalized with photoresponsive motifs have attractive prospects for applications in smart functional bio-material ranging from cell-material interfaces to drug delivery systems owing to the precisely controllable functionality of self-assembled hierarchical supramolecular structures in aqueous media by a non-invasive light stimulation with high temporal- and spatial-resolution. However, most of reported photoresponsive amphiphiles are triggered by bio-damaging UV-light, which greatly limits the potential in bio-related applications. Herein, we present newly designed red-light controlled N,N'-diaryl-substituted indigo amphiphiles (IA), exhibiting excellent photoswitchablity and photostability with dual red-/green-light in organic media.

Motorized Photomodulator: Making A Non-photoresponsive Supramolecular Gel Switchable by Light.

Introducing photo-responsive molecules offers an attractive approach for remote and selective control and dynamic manipulation of material properties. However, it remains highly challenging how to use a minimal amount of photo-responsive units to optically modulate materials that are inherently inert to light irradiation. Here we show the application of a light-driven rotary molecular motor as a "motorized photo-modulator" to endow a typical H-bond-based gel system with the ability to respond to light irradiation and create a reversible sol-gel transition.

Synthetic molecular motor activates drug delivery from polymersomes.

The design of stimuli-responsive systems in nanomedicine arises from the challenges associated with the unsolved needs of current molecular drug delivery. Here, we present a delivery system with high spatiotemporal control and tunable release profiles. The design is based on the combination of an hydrophobic synthetic molecular rotary motor and a PDMS--PMOXA diblock copolymer to create a responsive self-assembled system.

Role of Curvature-Sensing Proteins in the Uptake of Nanoparticles with Different Mechanical Properties.

Nanoparticles of different properties, such as size, charge, and rigidity, are used for drug delivery. Upon interaction with the cell membrane, because of their curvature, nanoparticles can bend the lipid bilayer. Recent results show that cellular proteins capable of sensing membrane curvature are involved in nanoparticle uptake; however, no information is yet available on whether nanoparticle mechanical properties also affect their activity.

Molecular Engineering of the Kinetic Barrier in Seeded Supramolecular Polymerization.

Seeded supramolecular polymerization (SSP) is a method that enables the controlled synthesis of supramolecular structures. SSP often relies on structures that are capable of self-assembly by interconverting between intramolecular and intermolecular modes of hydrogen bonding, characterized by a given kinetic barrier that is typically low. The control of the polymerization process is thus limited by the propensity of the hydrogen bonds to interconvert between the intramolecular and intermolecular modes of binding.

New insights in polydopamine formation via surface adsorption.

Polydopamine is a biomimetic self-adherent polymer, which can be easily deposited on a wide variety of materials. Despite the rapidly increasing interest in polydopamine-based coatings, the polymerization mechanism and the key intermediate species formed during the deposition process are still controversial. Herein, we report a systematic investigation of polydopamine formation on halloysite nanotubes; the negative charge and high surface area of halloysite nanotubes favour the capture of intermediates that are involved in polydopamine formation and decelerate the kinetics of the process, to unravel the various polymerization steps.

Temperature-responsive and biocompatible nanocarriers based on clay nanotubes for controlled anti-cancer drug release.

Administration of temperature-responsive drug carriers that release anticancer drugs at high temperatures can benefit hyperthermia therapies because of the synergistic effect of anticancer drug molecules and high temperature on killing the cancer cells. In this study, we design and characterize a new temperature-responsive nanocarrier based on a naturally occurring and biocompatible clay mineral, halloysite nanotubes. Poly(-isopropylacrylamide) brushes were grown on the surface of halloysite nanotubes using a combination of mussel-inspired dopamine polymerization and surface-initiated atom transfer radical polymerization.

The effect of biomolecular corona on adsorption onto and desorption from a model lipid membrane.

The current lack of insight into nanoparticle-cell membrane interactions hampers smart design strategies and thereby the development of effective nanodrugs. Quantitative and methodical approaches utilizing cell membrane models offer an opportunity to unravel particle-membrane interactions in a detailed manner under well controlled conditions. Here we use total internal reflection microscopy for real-time studies of the non-specific interactions between nanoparticles and a model cell membrane at 50 ms temporal resolution over a time course of several minutes.

Run-and-halt motility of droplets in response to light.

Microscopic motility is a property that emerges from systems of interacting molecules. Unraveling the mechanisms underlying such motion requires coupling the chemistry of molecules with physical processes that operate at larger length scales. Here, we show that photoactive micelles composed of molecular switches gate the autonomous motion of oil droplets in water.

Responsive Pickering Emulsions Stabilized by Frozen Complex Coacervate Core Micelles.

Frozen complex coacervate core micelles (C3Ms) were developed as a class of particle stabilizers for Pickering emulsions. The C3Ms are composed of a core of electrostatically interacting weak polyelectrolytes, poly(acrylic acid) (pAA) and poly(dimethylaminopropylacrylamide) (pDMAPAA), surrounded by a corona of water-soluble and surface active poly(-isopropylacrylamide) (pNiPAM). Mixing parameters of the two polymer solutions, including pH, mixing method, charge ratio, and salinity of the medium, were carefully controlled, leading to monodisperse, colloidally stable C3Ms.

Cryogenic TEM imaging of artificial light harvesting complexes outside equilibrium.

The energy transport in natural light-harvesting complexes can be explored in laboratory conditions via self-assembled supramolecular structures. One such structure arises from the amphiphilic dye C8S3 molecules, which self-assemble in an aqueous medium to a double-wall cylindrical nanotube reminiscent of natural light-harvesting complexes found in green sulphur bacteria. In this paper, we report a way to investigate the structure of inner nanotubes (NTs) alone by dissolving the outer NTs in a microfluidic setting.

Dynamic Control of a Multistate Chiral Supramolecular Polymer in Water.

Natural systems transfer chiral information across multiple length scales through dynamic supramolecular interaction to accomplish various functions. Inspired by nature, many exquisite artificial supramolecular systems have been developed, in which controlling the supramolecular chirality holds the key to completing specific tasks. However, to achieve precise and non-invasive control and modulation of chirality in these systems remains challenging.

Moxifloxacin Liposomes: Effect of Liposome Preparation Method on Physicochemical Properties and Antimicrobial Activity against .

The aim of this study was the development of optimal sustained-release moxifloxacin (MOX)-loaded liposomes as intraocular therapeutics of endophthalmitis. Two methods were compared for the preparation of MOX liposomes; the dehydration-rehydration (DRV) method and the active loading method (AL). Numerous lipid-membrane compositions were studied to determine the potential effect on MOX loading and retention in liposomes.

Photoactuating Artificial Muscles of Motor Amphiphiles as an Extracellular Matrix Mimetic Scaffold for Mesenchymal Stem Cells.

Mimicking the native extracellular matrix (ECM) as a cell culture scaffold has long attracted scientists from the perspective of supramolecular chemistry for potential application in regenerative medicine. However, the development of the next-generation synthetic materials that mimic key aspects of ECM, with hierarchically oriented supramolecular structures, which are simultaneously highly dynamic and responsive to external stimuli, remains a major challenge. Herein, we present supramolecular assemblies formed by motor amphiphiles (), which mimic the structural features of the hydrogel nature of the ECM and additionally show intrinsic dynamic behavior that allow amplifying molecular motions to macroscopic muscle-like actuating functions induced by light.