Sustainable Removal of Microplastics and Natural Organic Matter from Water by Coagulation-Flocculation with Protein Amyloid Fibrils.

Water contamination is a global threat due to its damaging effects on the environment and human health. Water pollution by microplastics (MPs), dissolved natural organic matter (NOM), and other turbid particles is ubiquitous in water treatment. Here, we introduce lysozyme amyloid fibrils as a novel natural bio-flocculant and explore their ability to flocculate and precipitate the abovementioned undesired colloidal objects. Thanks to their positively charged surface in a very broad range of pH, lysozyme amyloid fibrils show an excellent turbidity removal efficiency of 98.2 and 97.9% for dispersed polystyrene MPs and humic acid (HA), respectively. Additionally, total organic carbon measurements confirm these results by exhibiting removal efficiencies of 93.4 and 61.9% for purifying water from dispersed MPs and dissolved HA, respectively. The comparison among amyloid fibrils, commercial flocculants (FeCl3 and polyaluminumchloride), and native lysozyme monomers points to the superiority of amyloid fibrils at the same dosage and sedimentation time. Furthermore, the turbidity of pristine and MP-spiked wastewater and lake water decreased after the treatment by amyloid fibrils, validating their coagulation-flocculation performance under natural conditions. All these results demonstrate lysozyme amyloid fibrils as an appropriate natural bio-flocculant for removing dispersed MPs, NOM, and turbid particles from water.

Amyloid Fibril-Templated High-Performance Conductive Aerogels with Sensing Properties.

Amyloid fibrils have garnered increasing attention as viable building blocks for functional material design and synthesis, especially those derived from food and agricultural wastes. Here, amyloid fibrils generated from ß-lactoglobulin, a by-product from cheese industries, have been successfully used as a template for the design of a new class of high-performance conductive aerogels with sensing properties. These mechanically stable aerogels with three-dimensional porous architecture have a large surface area (≈159 m2 g-1), low density (≈0.044 g cm-3), and high electrical conductivity (≈0.042 S cm-1). A pressure sensing device is developed from these aerogels based on their combined electrical conductivity and compressible properties. More interestingly, these aerogels can be employed to design novel enzyme sensors by exploiting the proteinaceous nature of amyloid fibrils. This study expands the scope of structured amyloid fibrils as scaffolds for in situ polymerization of conducting polymers, offering new opportunities to design materials with multiple functionalities.

Lipidic Mesophase-Embedded Palladium Nanoparticles: Synthesis and Tunable Catalysts in Suzuki-Miyaura Cross-Coupling Reactions.

Lipidic cubic phases (LCPs) can reduce Pd2+ salts to palladium nanoparticles (PdNPs) of ∼5 nm size in their confined water channels under mild conditions. The resulting PdNP-containing LCPs were used as nanoreactor scaffolds to catalyze Suzuki-Miyaura cross-coupling reactions in the aqueous channels of the mesophase. To turn on catalysis, PdNP-containing LCPs were activated by swelling the aqueous channels of the lipidic framework, thereby enabling diffusion of the water-soluble substrates to the catalysts. The mesophases play a threefold role: they act as reducing agents for Pd2+, as limiting templates for their growth, and as support. The system was characterized and investigated by small-angle X-ray scattering (SAXS), cryo-transmission electron microscopy, dynamic light scattering, and nuclear magnetic resonance. Bulk LCPs and three dispersed palladium/lipid hybrid nanoparticle types were applied in the catalysis. The latter-liposomes, hexosomes, and cubosomes-can be obtained by design through combination of lipids and additives. The Suzuki-Miyaura cross-coupling of 5-iodo-2'-deoxyuridine and phenylboronic acid was used as a model reaction to study these systems. Bulk Pd-LCPs deliver the Suzuki-Miyaura product in 24 h in conversions up to 98% at room temperature, whereas with palladium/lipid dispersions at 40 °C, 68% of the starting material was transformed to the product after 72 h.

Selective and Efficient Removal of Fluoride from Water: In Situ Engineered Amyloid Fibril/ZrO2 Hybrid Membranes.

We report a new strategy for efficient removal of F- from contaminated water streams, and it relies on carbon hybrid membranes made of amyloid fibril/ZrO2 nanoparticles (<10 nm). These membranes exhibit superior selectivity for F- against various competitive ions, with a distribution coefficient (Kd ) as high as 6820 mL g-1 , exceeding commercial ion-exchange resins (IRA-900) by 180 times and outdoing the performance of most commercial carbon-activated aluminum membranes. At both low and high (ca. 200 mg L-1 ) F- concentrations, the membrane efficiency exceeds 99.5 % removal. For real untreated municipal tap water (ca. 2.8 mg L-1 ) under continuous operating mode, data indicates that about 1750 kg water m-2 membrane can be treated while maintaining drinking water quality, and the saturated membranes can be regenerated and reused several times without decrease in performance. This technology is promising for mitigating the problem of fluoride water contamination worldwide.

Rapid Structure Determination of Microcrystalline Molecular Compounds Using Electron Diffraction.

Chemists of all fields currently publish about 50 000 crystal structures per year, the vast majority of which are X-ray structures. We determined two molecular structures by employing electron rather than X-ray diffraction. For this purpose, an EIGER hybrid pixel detector was fitted to a transmission electron microscope, yielding an electron diffractometer. The structure of a new methylene blue derivative was determined at 0.9 Šresolution from a crystal smaller than 1×2 µm2 . Several thousand active pharmaceutical ingredients (APIs) are only available as submicrocrystalline powders. To illustrate the potential of electron crystallography for the pharmaceutical industry, we also determined the structure of an API from its pill. We demonstrate that electron crystallography complements X-ray crystallography and is the technique of choice for all unsolved cases in which submicrometer-sized crystals were the limiting factor.

Oil transfer converts phosphatidylcholine vesicles into nonlamellar lyotropic liquid crystalline particles.

There is a need for the development of low-energy dispersion methods tailored to the formation of phospholipid-based nonlamellar lyotropic liquid crystalline (LLC) particles for delivery system applications. Here, facile formation of nonlamellar LLC particles was obtained by simple mixing of a phosphatidylcholine (PC) liposome solution and an oil-in-water emulsion, with limonene or isooctane as an oil. The internal structure of the particles was controlled by the PC-to-oil ratio, consistently with the sequence observed in bulk phase. For the first time, reverse micellar cubosomes with Fm3̅m inner structure were produced. The size, morphology, and inner structure of the particles were characterized by small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), and freeze-fracture cryo scanning electron microscopy (cryo-SEM). These findings pave the way to new strategies in low-energy formulation of LLC delivery systems.

Fibrillar networks of glycyrrhizic acid for hybrid nanomaterials with catalytic features.

Self-assembly of the naturally occurring sweetening agent, glycyrrhizic acid (GA) in water is studied by small-angle X-ray scattering and microscopic techniques. Statistical analysis on atomic force microscopy images reveals the formation of ultralong GA fibrils with uniform thickness of 2.5 nm and right-handed twist with a pitch of 9 nm, independently of GA concentration. Transparent nematic GA hydrogels are exploited to create functional hybrid materials. Two-fold and three-fold hybrids are developed by introducing graphene oxide (GO) and in situ-synthesized gold nanoparticles (Au NPs) in the hydrogel matrix for catalysis applications. In the presence of GO, the catalytic efficiency of Au NPs in the reduction of p-nitrophenol to p-aminophenol is enhanced by 2.5 times. Gold microplate single crystals are further synthesized in the GA hydrogel, expanding the scope of these hybrids and demonstrating their versatility in materials design.

Facile dispersion and control of internal structure in lyotropic liquid crystalline particles by auxiliary solvent evaporation.

Submicron sized, structured lyotropic liquid crystalline (LLC) particles, so-called hexosomes and cubosomes, are generally obtained by high energy input dispersion methods, notably ultrasonication and high-pressure emulsification. We present a method to obtain dispersions of such LLC particles with a significantly reduced energy input, by evaporation of an auxiliary volatile solvent immiscible with water, e.g. cyclohexane or limonene. The inner structure of the particles can be precisely controlled by the addition of a nonvolatile oil, such as α-tocopherol or tetradecane consistently with bulk phase diagrams,. Two different lyotropic surfactants were employed, industrial grade monolinoleine (MLO) and soy bean phosphatidylcholine (PC). The lyotropic surfactant and oil phase modifier were first dissolved in the volatile solvent to give a liquid reverse micellar (L2) phase, which requires significantly less energy input to be dispersed in an aqueous solution of secondary emulsifier compared to the corresponding gel-like bulk mesophase. The auxiliary volatile solvent was then removed from the emulsion by evaporation at room temperature, yielding LLC particles of the desired inner structure, Pn3̅m, H2, or Fd3̅m. The obtained particles were characterized by small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), and cryogenic transmission electron microscopy (cryo-TEM). Our method enables fine-tuning of the final particle size through the volatile-to-nonvolatile volume ratio and processing conditions.

Amyloid fibrils enhance transport of metal nanoparticles in living cells and induced cytotoxicity.

Amyloid protein fibrils occur in vivo as pathological agents, in the case of neurodegenerative diseases, or as functional amyloids, when playing biologically vital roles. Here we show how amyloid fibrils generated from a food protein, ß-lactoglobulin, can be used as nanoreactors for the synthesis of metal nanoparticles and demonstrate that the resulting hybrids can play a central role in the internalization of nanoparticles into living cells, with up to 3-fold-enhanced transport properties over pristine nanoparticles. We conjugate gold, silver, and palladium nanoparticles onto amyloid fibrils by chemical reduction, and we study their effect on dendritic and MCF7 breast cancer cells. Transmission electron microscopy indicates localization of nanoparticles inside vesicles of the cells. Flow cytometry reveals that silver nanoparticle-amyloid hybrids are cytotoxic, while gold and palladium nanoparticle-amyloid hybrids produce no notable effect on cell viability and activation status.

Structural and mechanical anisotropy in plant-based meat analogues.

The rising demand for plant-based meat analogues as alternatives to animal products has sparked interest in understanding the complex interplay between their structural and mechanical properties. The ability to manipulate the processing parameters and protein blend composition offers fundamental insights into the texturization process and holds economic and sustainable implications for the food industry. Consequently, the correlation between mechanical and structural properties in meat analogues is crucial for achieving consumer satisfaction and successful market penetration, providing comprehensive insights into the textural properties of meat analogues and their potential to mimic traditional animal produce. Our study delves into the relationship between structural and mechanical anisotropy in meat analogues produced using high moisture extrusion cooking, which involves blending protein, water, and other ingredients, followed by a controlled heating and cooling process to achieve a fibrous texture akin to traditional meat. By employing techniques such as scanning small-angle X-ray scattering, scanning electron microscopy, and mechanical testing we investigate the fibrous structure and its impact on the final texture of meat analogues. We show that textural and structural anisotropy is reflected on the mechanical properties measured using tensile and dynamic mechanical techniques. It is demonstrated that the calculated anisotropy indexes, a measure for the degree of textural and structural anisotropy, increase with increasing protein content. Our findings have significant implications for the understanding and development of plant-based meat analogues with structures that can be tuned to closely resemble the animal meat textures of choice, thereby enabling consumers to transition to more sustainable dietary choices while preserving familiar eating habits.