Soil colloids can significantly enhance spreading of polybromodiphenyl ethers in groundwater by serving as an effective carrier.

Polybromodiphenyl ethers (PBDEs), the widely used flame retardants, are common contaminants in surface soils at e-waste recycling sites. The association of PBDEs with soil colloids has been observed, indicating the potential risk to groundwater due to colloid-facilitated transport. However, the extent to which soil colloids may enhance the spreading of PBDEs in groundwater is largely unknown. Herein, we report the co-transport of decabromodiphenyl ester (BDE-209) and soil colloids in saturated porous media. The colloids released from a soil sample collected at an e-waste recycling site in Tianjin, China, contain high concentration of PBDEs, with BDE-209 being the most abundant conger (320 ± 30 mg/kg). The colloids exhibit relatively high mobility in saturated sand columns, under conditions commonly observed in groundwater environments. Notably, under all the tested conditions (i.e., varying flow velocity, pH, ionic species and ionic strength), the mass of eluted BDE-209 correlates linearly with that of eluted soil colloids, even though the mobility of the colloids varies markedly depending on the specific hydrodynamic and solution chemistry conditions involved. Additionally, the mass of BDE-209 retained in the columns also correlates strongly with the mass of retained colloids. Apparently, the PBDEs remain bound to soil colloids during transport in porous media. Findings in this study indicate that soil colloids may significantly promote the transport of PBDEs in groundwater by serving as an effective carrier. This might be the reason why the highly insoluble and adsorptive PBDEs are found in groundwater at some PBDE-contaminated sites.

Current Thoughts on Burn Resuscitation.

The optimal treatment of burn shock is still unresolved. The problem of "fluid creep" continues despite modern devices that fail to improve outcomes over hourly urine output. Colloids, especially albumin, reduce fluid requirements. Albumin can be used either immediately at the start of resuscitation, or as a "rescue" when crystalloid use is excessive. Several studies confirm that when crystalloid resuscitation is "out of control" the majority of caregivers will add albumin to reduce fluid rates. A multi-center trial is underway comparing crystalloids with albumin to confirm the benefit of colloids. The next question is whether albumin or plasma is as the better colloid choice.

Hydrocolloid-based fruit fillings: A comprehensive review on formulation, techno-functional properties, synergistic mechanisms, and applications.

This study offers a comprehensive review of current developments regarding the utilization of diverse hydrocolloids in formulating fruit fillings across different fruit types, their impact on textural attributes, rheological properties, thermal stability, syneresis, and nutritional advantages of fillings and optimization of its characteristics to align with consumer preferences. The review also focuses on the various factors influencing fruit fillings, including the selection of fruits, processing methodologies, the inherent nature and concentration of hydrocolloids, and their synergistic interactions. In depth, scientific work on the impact of the parameters such as pH, total soluble solids, and sugar content within the fruit fillings was also discussed. Additionally, this article focuses on the utilization of the diverse fruit fillings developed by using hydrocolloids in bakery products including pastry, tartlet, muffins, cookies, and so forth. The review establishes that hydrocolloids offer a spectrum of techno-functional attributes conducive to strengthening both the structural and thermal stability of fruit fillings, consequently extending their shelf life. It further establishes that incorporating of hydrocolloids facilitates the development of healthier food products by mitigating the necessity of excessive sugar or various other less favorable ingredients. The incorporation of fruit fillings in bakery products significantly increases the value proposition of these baked goods, contributing to their overall enhancement of quality and sensory value.

Methods for the Characterization of the Colloidal Properties of Bacterial Membrane Vesicles.

Bacterial membrane vesicles (BMVs) are extracellular vesicles secreted by either Gram-positive or Gram-negative bacteria. These BMVs typically possess a diameter between 20 and 250 nm. Due to their size, when these BMVs are suspended in another medium, they could be constituents of a colloidal system. It has been hypothesized that investigating BMVs as colloidal particles could help characterize BMV interactions with other environmentally relevant surfaces. Developing a more thorough understanding of BMV interactions with other surfaces would be critical for developing predictive models of their environmental fate. However, this bio-colloidal perspective has been largely overlooked for BMVs, despite the wealth of methods and expertise available to characterize colloidal particles. A particular strength of taking a more colloid-centric approach to BMV characterization is the potential to quantify a particle's attachment efficiency (α). These values describe the likelihood of attachment during particle-particle or particle-surface interactions, especially those interactions which are governed by physicochemical interactions (such as those described by DLVO and xDLVO theory). Elucidating the influence of physical and electrochemical properties on these attachment efficiency values could give insights into the primary factors driving interactions between BMVs and other surfaces. This chapter details methods for the characterization of BMVs as colloids, beginning with size and surface charge (i.e., electrophoretic mobility/zeta potential) measurements. Afterward, this chapter will address experimental design, especially column experiments, targeted for BMV investigation and the determination of α values.

Influence of chirality and sequence in lysine-rich lipopeptide biosurfactants and micellar model colloid systems.

Lipopeptides can self-assemble into diverse nanostructures which can be programmed to incorporate peptide sequences to achieve a remarkable range of bioactivities. Here, the influence of peptide sequence and chirality on micelle structure and interactions is investigated in a series of lipopeptides bearing two lysine or D-lysine residues and tyrosine or tryptophan residues, attached to a hexadecyl lipid chain. All molecules self-assemble into micelles above a critical micelle concentration (CMC). Small-angle x-ray scattering (SAXS) is used to probe micelle shape and structure from the form factor and to probe inter-micellar interactions via analysis of structure factor. The CMC is obtained consistently from surface tension and electrical conductivity measurements. We introduce a method to obtain the zeta potential from the SAXS structure factor which is in good agreement with directly measured values. Atomistic molecular dynamics simulations provide insights into molecular packing and conformation within the lipopeptide micelles which constitute model self-assembling colloidal systems and biomaterials.

Dielectrophoretic separation and purification: From colloid and biological particles to droplets.

It is indispensable to realize the high level of purification and separation, so that objective particles, such as malignant cells, harmful bacteria, and special proteins or biological molecules, could satisfy the high precise measurement in the pharmaceutical analysis, clinical diagnosis, targeted therapy, and food defense. In addition, this could reveal the intrinsic nature and evolution mechanisms of individual biological variations. Consequently, many techniques related to optical tweezers, microfluidics, acoustophoresis, and electrokinetics can be broadly used to achieve micro- and nano-scale particle separations. Dielectrophoresis (DEP) has been used for various manipulation, concentration, transport, and separation processes of biological particles owing to its early development, mature theory, low cost, and high throughput. Although numerous reviews have discussed the biological applications of DEP techniques, comprehensive descriptions of micro- and nano-scale particle separations feature less frequently in the literature. Therefore, this review summarizes the current state of particle separation attention to relevant technological developments and innovation, including theoretical simulation, microchannel structure, electrode material, pattern and its layout. Moreover, a brief overview of separation applications using DEP in combination with other technologies is also provided. Finally, conclusions, future guidelines, and suggestions for potential promotion are highlighted.

Formulation and Antimycotic Evaluation of Colloidal Itraconazole-Loaded Metered Dose Sprays for Treating Superficial Mycoses.

Commercial topical formulations containing itraconazole (poorly water soluble), for mycotic infections, have poor penetration to infection sites beneath the nails and skin thereby necessitating oral administration. To improve penetration, colloidal solutions of itraconazole (G1-G4) containing Poloxamer 188, tween 80, ethanol, and propylene glycol were prepared and incorporated into HFA-134-containing sprays. Formulations were characterized using particle size, drug content, and Fourier-transform infrared spectroscopy (FTIR). In vitro permeation studies were performed using Franz diffusion cells for 8 h. Antimycotic activity on Candida albicans and Trichophyton rubrum was performed using broth micro-dilution and flow cytometry, while cytotoxicity was tested on HaCaT cell lines. Particle size ranged from 39.35-116.80 nm. FTIR and drug content revealed that G1 was the most stable formulation (optimized formulation). In vitro release over 2 h was 45% for G1 and 34% for the cream. There was a twofold increase in skin permeation, fivefold intradermal retention, and a sevenfold increase in nail penetration of G1 over the cream. Minimum fungicidal concentrations (MFC) against C. albicans were 0.156 and 0.313 µg/mL for G1 and cream, respectively. The formulations showed optimum killing kinetics after 48 h. MFC values against T. rubrum were 0.312 and 0.625 µg/mL for the G1 and cream, respectively. Transmission electron microscopy revealed organelle destruction and cell leakage for G1 in both organisms and penetration of keratin layers to destroy T. rubrum. Cytotoxicity evaluation of G1 showed relative safety for skin cells. The G1 formulation showed superior skin permeation, nail penetration, and fungicidal activity compared with the cream formulation.

Polypeptide-based multilayer nanoarchitectures: Controlled assembly on planar and colloidal substrates for biomedical applications.

Polypeptides have shown an excellent potential in nanomedicine thanks to their biocompatibility, biodegradability, high functionality, and responsiveness to several stimuli. Polypeptides exhibit high propensity to organize at the supramolecular level; hence, they have been extensively considered as building blocks in the layer-by-layer (LbL) assembly. The LbL technique is a highly versatile methodology, which involves the sequential assembly of building blocks, mainly driven by electrostatic interactions, onto planar or colloidal templates to fabricate sophisticated multilayer nanoarchitectures. The simplicity and the mild conditions required in the LbL approach have led to the inclusion of biopolymers and bioactive molecules for the fabrication of a wide spectrum of biodegradable, biocompatible, and precisely engineered multilayer films for biomedical applications. This review focuses on those examples in which polypeptides have been used as building blocks of multilayer nanoarchitectures for tissue engineering and drug delivery applications, highlighting the characteristics of the polypeptides and the strategies adopted to increase the stability of the multilayer film. Cross-linking is presented as a powerful strategy to enhance the stability and stiffness of the multilayer network, which is a fundamental requirement for biomedical applications. For example, in tissue engineering, a stiff multilayer coating, the presence of adhesion promoters, and/or bioactive molecules boost the adhesion, growth, and differentiation of cells. On the contrary, antimicrobial coatings should repel and inhibit the growth of bacteria. In drug delivery applications, mainly focused on particles and capsules at the micro- and nano-meter scale, the stability of the multilayer film is crucial in terms of retention and controlled release of the payload. Recent advances have shown the key role of the polypeptides in the adsorption of genetic material with high loading efficiency, and in addressing different pathways of the particles/capsules during the intracellular uptake, paving the way for applications in personalized medicine. Although there are a few studies, the responsiveness of the polypeptides to the pH changes, together with the inclusion of stimuli-responsive entities into the multilayer network, represents a further key factor for the development of smart drug delivery systems to promote a sustained release of therapeutics. The degradability of polypeptides may be an obstacle in certain scenarios for the controlled intracellular release of a drug once an external stimulus is applied. Nowadays, the highly engineered design of biodegradable LbL particles/capsules is oriented on the development of theranostics that, limited to use of polypeptides, are still in their infancy.

White Roman Goose Feather-Inspired Unidirectionally Inclined Conical Structure Arrays for Switchable Anisotropic Self-Cleaning.

White Roman goose (Anser anser domesticus) feathers, comprised of oriented conical barbules, are coated with gland-secreted preening oils to maintain a long-term nonwetting performance for surface swimming. The geese are accustomed to combing their plumages with flat bills in case they are contaminated with oleophilic substances, during which the amphiphilic saliva spread over the barbules greatly impairs their surface hydrophobicities and allows the trapped contaminants to be anisotropically self-cleaned by water flows. Particularly, the superhydrophobic behaviors of the goose feathers are recovered as well. Bioinspired by the switchable anisotropic self-cleaning functionality of white Roman geese, superhydrophobic unidirectionally inclined conical structures are engineered through the integration of a scalable colloidal self-assembly technology and a colloidal lithographic approach. The dependence of directional sliding properties on the shape, inclination angle, and size of conical structures is systematically investigated in this research. Moreover, their switchable anisotropic self-cleaning functionalities are demonstrated by Sudan blue II/water (0.01%) separation performances. The white Roman goose feather-inspired coatings undoubtedly offer a new concept for developing innovative applications that require directional transportation and the collection of liquids.

Tailored Physicochemical Cues Direct Human Mesenchymal Stem Cell Differentiation through Epigenetic Regulation Using Colloidal Self-Assembled Patterns.

The extracellular matrix (ECM) shapes the stem cell fate during differentiation by exerting relevant biophysical cues. However, the mechanism of stem cell fate decisions in response to ECM-backed complex biophysical cues has not been fully understood due to the lack of versatile ECMs. Here, we designed two versatile ECMs using colloidal self-assembly technology to probe the mechanisms of their effects on mechanotransduction and stem cell fate regulation. Binary colloidal crystals (BCC) with a hexagonally close-packed structure, composed of silica (5 µm) and polystyrene (0.4 µm) particles as well as a polydimethylsiloxane-embedded BCC (BCCP), were fabricated. They have defined surface chemistry, roughness, stiffness, ion release, and protein adsorption properties, which can modulate the cell adhesion, proliferation, and differentiation of human adipose-derived stem cells (hASCs). On the BCC, hASCs preferred osteogenesis at an early stage but showed a higher tendency toward adipogenesis at later stages. In contrast, the results of BCCP diverged from those of BCC, suggesting a unique regulation of ECM-dependent mechanotransduction. The BCC-mediated cell adhesion reduced the size of the focal adhesion complex, accompanying an ordered spatial organization and cytoskeletal rearrangement. This morphological restriction led to the modulation of mechanosensitive transcription factors, such as c-FOS, the enrichment of transcripts in specific signaling pathways such as PI3K/AKT, and the activation of the Hippo signaling pathway. Epigenetic analyses showed changes in histone modifications across different substrates, suggesting that chromatin remodeling participated in BCC-mediated mechanotransduction. This study demonstrates that BCCs are versatile artificial ECMs that can regulate human stem cells' fate through unique biological signaling, which is beneficial in biomaterial design and stem cell engineering.

3D printable and biocompatible PEDOT:PSS-ionic liquid colloids with high conductivity for rapid on-demand fabrication of 3D bioelectronics.

3D printing has been widely used for on-demand prototyping of complex three-dimensional structures. In biomedical applications, PEDOT:PSS has emerged as a promising material in versatile bioelectronics due to its tissue-like mechanical properties and suitable electrical properties. However, previously developed PEDOT:PSS inks have not been able to fully utilize the advantages of commercial 3D printing due to its long post treatment times, difficulty in high aspect ratio printing, and low conductivity. We propose a one-shot strategy for the fabrication of PEDOT:PSS ink that is able to simultaneously achieve on-demand biocompatibility (no post treatment), structural integrity during 3D printing for tall three-dimensional structures, and high conductivity for rapid-prototyping. By using ionic liquid-facilitated PEDOT:PSS colloidal stacking induced by a centrifugal protocol, a viscoplastic PEDOT:PSS-ionic liquid colloidal (PILC) ink was developed. PILC inks exhibit high-aspect ratio vertical stacking, omnidirectional printability for generating suspended architectures, high conductivity (~286 S/cm), and high-resolution printing (~50 µm). We demonstrate the on-demand and versatile applicability of PILC inks through the fabrication of 3D circuit boards, on-skin physiological signal monitoring e-tattoos, and implantable bioelectronics (opto-electrocorticography recording, low voltage sciatic nerve stimulation and recording from deeper brain layers via 3D vertical spike arrays).

Role of Charge Heterogeneity on Physical Stability of Monoclonal Antibody Biotherapeutic Products.

PURPOSE: Chemical modifications in monoclonal antibodies can change hydrophobicity, charge heterogeneity as well as conformation, which eventually can impact their physical stability. In this study, the effect of the individual charge variants on physical stability and aggregation propensity in two different buffer conditions used during downstream purification was investigated. METHODS: The charge variants were separated using semi-preparative cation exchange chromatography and buffer exchanged in the two buffers with pH 6.0 and 3.8. Subsequently each variant was analysed for size heterogeneity using size exclusion chromatography and dynamic light scattering, conformational stability, colloidal stability, and aggregation behaviour under accelerated stability conditions. RESULTS: Size variants in each charge variant were similar in both pH conditions when analyzed without extended storage. However, conformational stability was lower at pH 3.8 than pH 6.0. All charge variants showed similar apparent melting temperature at pH 6.0. In contrast, at pH 3.8 variants A3, A5, B2, B3 and B4 display lower Tm, suggesting reduced conformational stability. Further, A2, A3 and A5 exhibit reduced colloidal stability at pH 3.8. In general, acidic variants are more prone to aggregation than basic variants. CONCLUSION: Typical industry practice today is to examine in-process intermediate stability with acidic species and basic species taken as a single category each. We suggest that perhaps stability evaluation needs to be performed at specie level as different acidic or basic species have different stability and this knowledge can be used for clever designing of the downstream process to achieve a stable product.

Development of injectable colloidal solution forming an in situ hydrogel for tumor ablation.

Ablation cancer therapy using percutaneous intra-tumoral injection of ethanol is a promising method for targeted and effective locoregional cancer therapy. Magnetic gelatin microsphere (MGM) colloidal ethanol solution is developed as a potential injectable tumor ablation agent. The MGM was fabricated by electrostatic interactions among gelatin, acrylic acid, and acrylic acid-coated iron oxide nanoparticles. The fabricated MGM was dispersed in ethanol solution to form injectable MGM colloidal ethanol solution. The MGM colloidal ethanol solution can be easily infused and undergo in situ gelation via solvent exchange from ethanol to water in an artificial tissue. Furthermore, the MGM colloidal ethanol solution allowed doxorubicin (Dox) chemo-agent loading and its sustained release upon the formation of a drug depot by in situ gelation in artificial tissues. Our in vitro study demonstrated that locally delivered ethanol and Dox with MGM colloidal ethanol solution promoted the anti-cancer therapeutic efficacy with a significantly suppressed cancer cell recovery rate. Overall, our developed injectable MGM colloidal ethanol solution that can be transformed to a hydrogel drug depot at the injection site holds clinical potential for a new class of chemo-ablation agents.

Based on Fe and Ni prepared organic colloidal materials as efficient oxide nanozymes for chemiluminescence detection of GSH and Hg(II) ions.

Metal-organic gels (MOGs) are a type of metal-organic colloid material with a large specific surface area, loose porous structure, and open metal active sites. In this work, FeNi-MOGs were synthesized by the simple one-step static method, using Fe(III) and Ni(II) as the central metal ions and terephthalic acid as the organic ligand. The prepared FeNi-MOGs could effectively catalyze the chemiluminescence of luminol without the involvement of H2O2, which exhibited good catalytic activity. Then, the multifunctional detected platform was constructed for the detection of GSH and Hg2+, based on the antioxidant capacity of GSH, and the strong affinity between mercury ion (Hg2+) and GSH which inactivated the antioxidant capacity of GSH. The experimental limits of detection (LOD) for GSH and Hg2+ were 76 nM and 210 nM, and the detection ranges were 2-100 µM and 8-4000 µM, respectively. The as-proposed sensor had good performance in both detection limit and detection range of GSH and Hg2+, which fully met the needs of daily life. Surprisingly, the sensor had low detection limits and an extremely wide detection range for Hg2+, spanning five orders of magnitude. Furthermore, the detection of mercury ions in actual lake water and GSH in human serum showed good results, with recovery rates ranging from 90.10 % to 105.37 %, which proved that the method was accurate and reliable. The as-proposed sensor had great potential as the platform for GSH and Hg2+ detection applications.

"One for two" strategy to construct an organic-inorganic polymer colloid for flame-retardant modification of flax fabric and rigid polyurethane foam.

Polymeric materials such as fabric and foam have high flammability which limits their application in the field of fire protection. To this end, an organic-inorganic polymer colloid constructed from carboxymethyl chitosan and ammonium polyphosphate was used to improve the flame retardancy of flax fabric (FF) and rigid polyurethane foam (RPUF) based on a "one for two" strategy. The modification processes of FF and RPUF relied on pad-dry-cure method and UV-curing technology, respectively, and the modified FF and RPUF were severally designated as CMC/APP-FF and RFR-RPUF. Flame retardancy studies showed that CMC/APP-FF and RFR-RPUF exhibited limiting oxygen index values as high as 39.4 % and 42.6 %, respectively, and both achieved self-extinguishing behavior when external ignition source was removed. Thermogravimetric analysis and cone calorimetry test confirmed that CMC/APP-FF and RFR-RPUF had good charring ability and demonstrated reduced peak heat release rate values of 90.1 % and 10.8 %, respectively, distinct from before they were modified. In addition, condensed phase analysis showed that after burning, CMC/APP-FF became an integration char structure, whereas RFR-RPUF turned into a sandwiched char structure. In summary, the "one for two" strategy reported in this work provides a new insight into the economical fabrication of flame-retardant polymeric materials.

Influence of natural organic matter on the aggregation dynamics of biochar colloids derived from various feedstocks.

Abundant biochar colloids (BCs) produced from a wide range of feedstocks, resulting from forest fires, agricultural production, and environmental restoration, exhibit varying aggregation behaviors influenced by feedstock type and natural organic matter. However, the impact of natural organic matter on the colloidal stability of BCs derived from different feedstocks remains poorly understood. In this study, six selected biochars were derived from various feedstocks as follows: sewage sludge (SS), rice husk (RH), oil seed rape straw pellets (OSR), wheat straw pellets (WS), miscanthus straw pellets (MS) and softwood pellets (SW). The colloidal stability of BCs, with the exogenous addition of organic matter, was further determined. The order of critical coagulation concentrations (CCCs) of BCs with the presence of humic acid (HA) was as follows: RH (989.48 mM) < MS (1084.69 mM) < SS (1149.76 mM) < WS (1338.99 mM) < OSR (2402.98 mM) < SW (3151.32 mM). This order was significantly positively correlated with the specific surface area and negatively correlated with the ash content of the bulk biochar. Compared to HA, bovine serum albumin (BSA) more effectively inhibited the aggregation behavior of BCs due to steric hindrance. The initial aggregation rate constant (k) of BCs at 3000 mM NaCl was as follows: MS (0.238 nm/s) > OSR (0.142 nm/s) > WS (0.128 nm/s) > SS (0.126 nm/s) > RH (0.118 nm/s) > SW (0.112 nm/s). The stabilizing effects of BSA on biochar colloids were independent of the physicochemical properties of bulk biochar. In the presence of BSA, a thin layer of protein corona significantly enhanced the stability of biochar colloids, particularly the BCs derived from MS. Our results underscore the importance of considering feedstock resources and natural organic matter type when assessing the aggregation and potential risks of BCs in aquatic systems.

Boosting the Accuracy and Chemical Space Coverage of the Detection of Small Colloidal Aggregating Molecules Using the BAD Molecule Filter.

The ability to conduct effective high throughput screening (HTS) campaigns in drug discovery is often hampered by the detection of false positives in these assays due to small colloidally aggregating molecules (SCAMs). SCAMs can produce artifactual hits in HTS by nonspecific inhibition of the protein target. In this work, we present a new computational prediction tool for detecting SCAMs based on their 2D chemical structure. The tool, called the boosted aggregation detection (BAD) molecule filter, employs decision tree ensemble methods, namely, the CatBoost classifier and the light gradient-boosting machine, to significantly improve the detection of SCAMs. In developing the filter, we explore models trained on individual data sets, a consensus approach using these models, and, third, a merged data set approach, each tailored for specific drug discovery needs. The individual data set method emerged as most effective, achieving 93% sensitivity and 90% specificity, outperforming existing state-of-the-art models by 20 and 5%, respectively. The consensus models offer broader chemical space coverage, exceeding 90% for all testing sets. This feature is an important aspect particularly for early stage medicinal chemistry projects, and provides information on applicability domain. Meanwhile, the merged data set models demonstrated robust performance, with a notable sensitivity of 79% in the comprehensive 10-fold cross-validation test set. A SHAP analysis of model features indicates the importance of hydrophobicity and molecular complexity as primary factors influencing the aggregation propensity. The BAD molecule filter is readily accessible for the public usage on https://molmodlab-aau.com/Tools.html. This filter provides a new, more robust tool for aggregate prediction in the early stages of drug discovery to optimize hit rates and reduce associated testing and validation overheads.

Colloidal Aggregation Confounds Cell-Based Covid-19 Antiviral Screens.

Colloidal aggregation is one of the largest contributors to false positives in early drug discovery. Here, we consider aggregation's role in cell-based infectivity assays in Covid-19 drug repurposing. We investigated the potential aggregation of 41 drug candidates reported as SARs-CoV-2 entry inhibitors. Of these, 17 formed colloidal particles by dynamic light scattering and exhibited detergent-dependent enzyme inhibition. To evaluate the impact of aggregation on antiviral efficacy in cells, we presaturated the colloidal drug suspensions with BSA or spun them down by centrifugation and measured the effects on spike pseudovirus infectivity. Antiviral potencies diminished by at least 10-fold following both BSA and centrifugation treatments, supporting a colloid-based mechanism. Aggregates induced puncta of the labeled spike protein in fluorescence microscopy, consistent with sequestration of the protein on the colloidal particles. These observations suggest that colloidal aggregation is common among cell-based antiviral drug repurposing and offers rapid counter-screens to detect and eliminate these artifacts.

Characterizing the Stoichiometry of Individual Metal Sulfide and Phosphate Colloids in Soils, Sediments, and Industrial Processes by Inductively Coupled Plasma Time-of-Flight Mass Spectrometry.

Size and purity of metal phosphate and metal sulfide colloids can control the solubility, persistence, and bioavailability of metals in environmental systems. Despite their importance, methods for detecting and characterizing the diversity in the elemental composition of these colloids in complex matrices are missing. Here, we develop a single-particle inductively coupled plasma time-of-flight mass spectrometry (sp-icpTOF-MS) approach to characterize the elemental compositions of individual metal phosphate and sulfide colloids extracted from complex matrices. The stoichiometry was accurately determined for particles of known composition with an equivalent spherical diameter of ≥∼200 nm. Assisted by machine learning (ML), the new method could distinguish particles of the copper sulfides covellite (CuS), chalcocite (Cu2S), and chalcopyrite particles (CuFeS2) with 75% (for Cu2S) to 99% (for CuFeS2) accuracy. Application of the sp-icpTOF-MS method to particles recovered from natural samples revealed that iron sulfide (FeS) particles in lake sediment contained ∼4% copper and zinc impurities, whereas pure pyrite (FeS2) was identified in hydraulic fracturing wastewater and confirmed by selected area electron diffraction. Colloidal mercury in an offshore marine sediment was present as pure mercury sulfide (HgS), whereas geogenic HgS recovered from an industrial process contained ∼0.08 wt % silver per Hg, enabling source apportionment of these colloids using ML. X-ray absorption spectroscopy confirmed that Hg was predominantly present as metacinnabar (ß-HgS) in the industrial process sample. The determination of impurities in individual colloids, such as zinc and copper in FeS, and silver in HgS may enable improved assessment of their origin, reactivity, and bioavailability potential.

Colloidal and interfacial properties of spray dried pulse protein-blueberry polyphenol particles in model dispersion systems.

The phytochemical composition and physicochemical attributes of polyphenol-enriched protein particle ingredients produced with pulse proteins (e.g. chickpea protein, pea protein, and a chickpea-pea protein blend) and polyphenols recovered from wild blueberry pomace were investigated for colloidal and interfacial properties. Anthocyanins were the major polyphenol fraction (27.74-36.47 mg C3G/g) of these polyphenol-rich particles (44.95-62.08 mg GAE/g). Dispersions of pea protein-polyphenol particles showed a superior phase stability before and after heat treatment compared to the chickpea pea protein-polyphenol system. This observation was independent of the added amount of NaCl in the dispersion. In general, at quasi equilibrium state, pulse protein-polyphenol particles and parental pulse protein ingredients showed similar oil-water interfacial tension. However, pea protein-polyphenol particles demonstrated a reduced diffusion-driven oil-water interfacial adsorption rate constant compared to the parental pea protein ingredient. Overall, the obtained results suggest application potential of pea protein-polyphenol particles as a functional food/beverage ingredient.