Procter & Gamble (United Kingdom)

Abstract β-mannans are plant structural and storage polysaccharides prevalent in the human diet. Their degradation in the gastrointestinal tract is mediated by the human gut microbiota (HGM) through expression of a plethora of carbohydrate-active enzymes (CAZymes), although our understanding of the details of mannan breakdown is lacking. In this study, a prominent HGM member, Bacteroides cellulosilyticus , was found to be exceptionally efficient at utilising β-mannans, mediated by the expression of a single polysaccharide utilisation locus (PUL). Amongst the predicted surface CAZymes encoded in the PUL, we identified a family 26 glycoside hydrolase of an unusual molecular architecture. Bc WH2_GH26 contains a putative carbohydrate-binding module (CBM) directly intercalated into its catalytic domain, unlike classical CBMs which are located at the N- or C-termini of the catalytic domain. Phylogenetic and functional analyses of this internal CBM, and a homologue from another mannan user Bacteroides uniformis , revealed a narrow specificity for β-mannan and support their classification as a novel CBM family. To investigate the evolutionary basis for the unusual enzyme architecture, the effect of the CBM on the catalytic activity of the enzyme was assessed. No significant differences in the kinetic parameters were found between the full-length and CBM deletion constructs against both soluble and insoluble mannans. The potential role of the internal CBM in enzyme function is discussed in the context of the likely localisation of the Bc WH2_GH26 in the outer membrane utilisome encoded by the Bc mannan PUL.

The skin acts as an effective barrier against the uptake of hazardous chemicals and microorganisms as well as prevention of extensive water loss. These barrier functions are mainly assured by the outermost layer of the skin, the stratum corneum (SC). In conditions such as atopic dermatitis (AD)-a chronic inflammatory skin disease-these barrier functions can become impaired. Although AD is driven by environmental triggers and inflammation in the deeper skin layers, its effects are also evident in the SC, which is a lipid-corneocyte composite membrane. This study characterizes molecular dynamics of lipids and protein components in SC samples from the plantar heel region of AD patients aged 60-80 years, as well as healthy volunteers in the same age range and in the 20-30 age group. Using solid-state NMR, we show that, compared with age-matched healthy controls, lipids in the AD SC exhibit reduced mobility under dry conditions. With increasing hydration, mobility of both lipids and the protein keratin increases, with a stronger response observed in the AD SC. These molecular-level insights could provide further insight in the development of therapeutic strategies aimed at restoring properties of healthy skin.

The MS2 bacteriophage capsid serves as a model system for studying viral structure and function. Mature MS2 virus consists of 178 capsid proteins and a single maturation protein (MP), which is essential for host receptor binding and infection initiation. Despite its critical role, the dynamic behavior of the capsid with the MP remains poorly understood. To address this, we conducted 0.5 µs all-atom molecular dynamics (MD) simulations of the MS2 capsid with and without the MP, revealing key insights into its structural dynamics. Our simulations showed that MP exhibits high flexibility, particularly in the “tip” and “side-loop” regions, which undergo significant motions that likely enhance its ability to engage with the F-pilus receptor. Detailed analysis of MP conformational states revealed that loop rearrangements around H357 enable transient switching between “semi-closed” and “open” conformations, suggesting a conformational selection mechanism for pilus binding. Additionally, ion interaction analyses revealed distinct sodium and chloride binding patterns, where sodium ions were mostly found at the outer capsid shell, while chloride ions interacted with the basic residues on the RNA-facing side. We also found that the presence of the MP enhances salt-bridge interactions, contributing to increased capsid stability, yet it does not significantly alter the pore sizes of pentameric and hexameric units. Together, these findings provide new insights into the functional role of the MP, highlighting its contribution to capsid stability and host receptor engagement. This study offers a foundation for understanding capsid dynamics relevant to viral infectivity and may guide future rational strategies aimed at disrupting host-virus interactions.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-19036-0.

To perform a comprehensive statistical characterization of the Double Plate method (ISO 23675) as a potential invitro alternative to the invivo reference method (ISO 24444:2019) for determining the sun protection factor (SPF). Five qualified laboratories were involved in testing the Double Plate method, as part of a large-scale ring test conducted by the International Consortium 'ALT-SPF'. About 32 sunscreen products, reflecting diverse global formulations, were tested using both the invivo reference method and the Double Plate method. This method employs spectrophotometric measurements of sunscreen applied to UV-transparent plates with standardized robotic application to minimize the variability. A mathematical adjustment was introduced to address the initial bias compared to the reference method and further assessed in a follow-up ring test with 12 products, including ISO standards. The Double Plate method exhibited very high intra- and inter-laboratory reproducibility throughout the study, consistently meeting the precision criteria set by ISO/TC217/WG7. Following the mathematical adjustment, the accuracy significantly improved, demonstrating a close alignment with the reference method. The Double Plate method demonstrates excellent reproducibility and, following optimization, high accuracy for the SPF determination. These findings endorse the Double Plate method as a robust and ethical invitro alternative to the invivo reference method for SPF testing. This paved the way for its publication as a new ISO standard (ISO 23675), in December 2024, supporting consumer safety and informed product choices.

The industrial applications of surfactant solutions areboth numerousand extremely diverse, demonstrating the importance of these systemsin everyday life and driving the need for a systematic approach todesigning sustainable surfactant molecules adapted to the specificrequirements of each application. Given the very large space of possiblemolecules, the identification of candidate surfactants that achievea balance between the optimal physicochemical properties of the productand minimal environmental and health impacts is extremely challenging.In this work, a formulation and solution framework based on Computer-AidedMolecular Design is proposed for surfactant design. A novel multistagemethodology is developed based on the initial generation of promisingcandidates for the two constituents of a surfactant, the hydrophilichead and the hydrophobic tail, followed by the multiobjective optimizationof surfactant molecules. This decomposition results in an effectivesolution strategy. In addition to constraints that ensure the generationof feasible molecules, specific structural constraints can be incorporatedin the formulation, accelerating the discovery and optimization process.Data-driven predictive models for the most relevant surfactant properties,such as critical micelle concentration, Krafft point, surface tension,toxicity, and biodegradability, are developed and implemented in theoptimization formulation. Two case studies are tackled, successfullygenerating novel surfactant molecules. The proposed framework couldbe extended to more complex structures, such as two-headed or Geminisurfactants.

Abstract Although light microscopy has been used to examine the early trafficking of collagen within the cell, much of our understanding of the detailed organisation of cell deposited collagen is from static electron microscopy studies. To understand the dynamics of live cell collagen deposition and fibril organisation, we generated a bright photostable mNGCol1α2 fusion protein and employed a range of microscopy techniques to follow its intracellular transport and elucidate extracellular fibril formation. Our findings reveal the dynamics of fibril growth and the dynamic nature of collagen network interactions at the cellular level. Notably we observed molecular events that build network organisation, including fibril bundling, bifurcation, directionality along existing fibrils, and looping/intertwining behaviours. Strikingly, mNGCol1α2 fluorescence intensity maxima can mark a fibril before another growing collagen fibril intersects at this location. Our study shows that N-terminal protease site is not an absolute requirement for collagen fibril incorporation and is, to our knowledge, the first time that cell-directed collagen fibrillogenesis has been visualised at high resolution in real time. The approach paves the way for assessing the dynamic organisation and assembly of collagen into the extracellular matrix in skin models and other tissues during health, ageing and disease.

Abstract Introduction and aims The human hair follicle (HF) is a miniorgan in the skin that possesses a rich microenvironment composed of a complex assembly of sensory nerves that surround it. Recent studies have explored the effects of this perineural niche on the HF, but the influence of HF on the nervous system from a folliculocentric and skin-centric perspective remains underexplored. To explore the potential bidirectionality of the HF–nervous system connection in the context of nerve development, we asked whether the HF influences the differentiation and maturation of sensory neuron subtypes around it through the release of distinct neurotransmitters and neurotrophic factors. Methods To first identify which cell types might be involved in directing sensory neuron development, we reanalysed available skin and HF single-cell RNA sequencing (scRNA-Seq) datasets. Next, to evaluate neurotransmitter release from these cell types, we used fast-scan cyclic voltammetry (FSCV). Lastly, to interrogate the role of the HF on directing neuronal development in vitro, we used induced pluripotent stem cell-derived sensory neurons as a model for developing nerves. Results We found that a higher percentage of KRT14- (epithelial) and PDGFRA-expressing (mesenchymal) cells in the HF coexpressed genes encoding specific neurotrophic factors and enzymatic machinery for neurotransmitter production compared with equivalent cells in the skin, suggesting that the HF possesses a greater capacity to signal to the nervous system compared with interfollicular skin. Using FSCV, we then found that follicular outer root sheath and directionally selective cells are capable of releasing neurotransmitters such as serotonin and histamine. Conclusions We postulate that HF-derived neurotransmitters are important for aspects of sensory neuron development such as axonal growth, as serotonin has previously been shown to be an attractive guidance cue for neuronal growth cones. Overall, our work sheds light on the HF–nervous system connection and how the HF may regulate its microenvironment in the skin.

Erucamide is knownto play a critical role in modifying polymerfiber surface chemistry and morphology. However, its effects on fibercrystallinity and mechanical properties remain to be understood. Here,synchrotron nanofocused X-ray Diffraction (nXRD) revealed a bimodalorientation of the constituent polymer chains aligned along the fiberaxis and cross-section, respectively. Erucamide promoted crystallinityin the fiber, leading to larger and more numerous lamellae crystallites.The nXRD nanostructual characterization is complemented by single-fiberuniaxial tensile tests, which showed that erucamide significantlyaffected fiber mechanical properties, decreasing fiber tensile strengthand stiffness but enhancing fiber toughness, fracture strain, andductility. To correlate these single-fiber nXRD and mechanical testresults, we propose that erucamide mediated slip at the interfacesbetween crystallites and amorphous domains during stress-induced single-fibercrystallization, also decreasing the stress arising from the sheardisplacement of microfibrils and deformation of the macromolecularnetwork. Linking the single-fiber crystal structure with the single-fibermechanical properties, these findings provide the direct evidenceon a single-fiber level for the role of erucamide in enhancing fiber“softness”.

The Particle Shear and Impact tester has been developed to assess particle attrition in response to typical mechanical stresses prevailing in manufacturing plants. The particles are subjected to shear stresses by two counter-rotating rollers with an adjustable gap, and to repeated impacts through collisions at bends as they are recirculated in the tester. In this study, evaluation of the device performance and settings is described for attrition of enzyme granules. The extent of attrition of three different granule samples, subjected to impact alone, shear alone and coupled shear and impact tests is assessed and the sources of variability of the tester are investigated to determine its experimental repeatability. The mass collected in various parts of the tester is assessed both gravimetrically and by enzyme assay in order to investigate the device performance. Due to high sensitivity in enzyme dust analysis, adhesion of enzyme dust to surfaces influences the attrition variability. Three cleaning approaches are examined for removing enzyme dust deposited in the tester.

In September 2022, the 3rd International Workshop on pyrrolizidine alkaloids (PAs) and related phytotoxins was held on-line, entitled 'Toxins in botanical drugs and plant-derived food and feed - from science to regulation'. The workshop focused on new findings about the occurrence, exposure, toxicity, and risk assessment of PAs. In addition, new scientific results related to the risk assessment of alkenylbenzenes, a distinct class of herbal constituents, were presented. The presence of PAs and alkenylbenzenes in plant-derived food, feed, and herbal medicines has raised health concerns with respect to their acute and chronic toxicity but mainly related to the genotoxic and carcinogenic properties of several congeners. The compounds are natural constituents of a variety of plant families and species widely used in medicinal, food, and feed products. Their individual occurrence, levels, and toxic properties, together with the broad range of congeners present in nature, represent a striking challenge to modern toxicology. This review tries to provide an overview of the current knowledge on these compounds and indicates needs and perspectives for future research.