Soft Matter最新文献

{"title":"Contact-induced molecular reorganisation in a model <i>Escherichia coli</i> lipid membrane.","authors":"Nicolo Tormena, Teuta Pilizota, Kislon Voïtchovsky","doi":"10.1039/d6sm00923a","DOIUrl":"10.1039/d6sm00923a","url":null,"abstract":"<p><p>The nanoscale composition, molecular organisation and mechanics of biological membranes underpins their function for cellular compartmentalisation, signalling, and mechanical integrity. Eukaryotic membranes can readjust their molecular content and structural organisation in response to specific interactions or changes in their environment, including through the formation of more ordered and solid-like nanodomains - lipid rafts. Recent studies have shown that bacterial membranes also possess significant lipid diversity and can form functional microdomains reminiscent of eukaryotic lipid rafts, despite lacking sterols and sphingolipids. In all cases, the role of biochemical interactions between lipids has long been recognized as determinant for the membrane molecular organisation and physical properties. In this study, we explore how non-specific physical contacts between a model lipid membrane mimicking the composition of the inner membrane of <i>Escherichia coli</i> and different substrates affect membrane molecular organisation and physical properties at the nanoscale. Using atomic force microscopy, we track the evolution of the membrane when kept a few degrees above its transition temperature. The sample is fully immersed in a solution mimicking the ionic composition of the standard <i>E. coli</i> growth media and placed in a sealed chamber to prevent changes in the interfacial hydration layer between the membrane and substrate. Aside from the expected role of the substrate on the lipid phase transition, we observe a slow substrate-dependent molecular reorganisation of the membrane following a spinodal-like behaviour. Over a period varying between minutes for rougher substrates to hours for atomically flat substrates, mechanically stiffer yet still fluid nanodomains emerge. Concomitant changes in height difference between lipid nanodomains are consistent with a substrate-biased lipid flip-flop mechanism resulting in compositional asymmetry between leaflets. The results support previous theoretical predictions and demonstrate that membrane-surface interactions may be sufficient to passively drive molecular reorganisation in bacterial membranes, with consequences for membrane function and mechanics, including in processes like osmotic pressure regulation.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13742302/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149356978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of linking groups on the liquid crystalline phases of a diphenylamine-based bow-shaped hexacatenar.","authors":"Hongxing Deng, Fen Wang, Jiawei Xu, Ruixue Li, Chunwei Ge, Fuqiong Wang, Xiaohong Cheng","doi":"10.1039/d6sm00792a","DOIUrl":"https://doi.org/10.1039/d6sm00792a","url":null,"abstract":"<p><p>A series of bow-shaped hexacatenar molecules based on a diphenylamine core are reported. By varying the linker groups (ether, ester, or amide) in the molecules, their mesophases can be precisely tuned. The ether-linked OD forms a highly symmetric Col_ss_qu/<i>P</i>4<i>mm</i> phase with <i>H</i>-aggregation; the ester-linked ED gives a less symmetric Col_rec/<i>P</i>2<i>mm</i> phase with <i>J</i>-aggregation; and the amide-linked AD forms a <i>P</i>4<i>mm</i> phase with <i>J</i>-aggregation. Notably, OD and AD exhibit fragmented and small-sized LC textures, whereas ED shows a much more well-developed texture, consistent with their gel morphologies. This distinction is rationalized by linker polarity and supramolecular interactions: the moderately polar ester group promotes LC formation and self-assembly; the weakly polar ether group provides insufficient dipole-dipole driving force, restricting the LC phase to a narrow low-temperature range; and the amide group introduces strong dipole-dipole interactions and hydrogen bonding, markedly elevating the melting point. Moreover, excessively strong hydrogen bonding and an insufficient aspect ratio can induce the formation of a monotropic liquid crystal. OD and AD show moderate fluorescence, and their HOMO levels below -5.0 eV suggest their potential as hole-transport materials. Finally, ion-recognition tests were performed using OD, which enables selective Fe³⁺ sensing <i>via</i> LMCT (ligand-to-metal charge transfer)-mediated quenching, with a detection limit of 4 × 10^-6 M and satisfactory anti-interference. This linker-engineering strategy provides a rational route for tuning columnar mesophases and sensing functions.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149339902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction: Residual cells and nutrient availability guide wound healing in bacterial biofilms.","authors":"Yusong Ye, Mnar Ghrayeb, Sarah Miercke, Sania Arif, Susann Müller, Thorsten Mascher, Liraz Chai, Vasily Zaburdaev","doi":"10.1039/d6sm90173e","DOIUrl":"https://doi.org/10.1039/d6sm90173e","url":null,"abstract":"<p><p>Correction for 'Residual cells and nutrient availability guide wound healing in bacterial biofilms' by Yusong Ye <i>et al.</i>, <i>Soft Matter</i>, 2024, <b>20</b>, 1047-1060, https://doi.org/10.1039/d3sm01032e.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149331733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Collective behaviors of self-pulsing particles in graded circular obstacles under colored noise.","authors":"Bing Wang, Zixiang Zhang","doi":"10.1039/d6sm00880a","DOIUrl":"https://doi.org/10.1039/d6sm00880a","url":null,"abstract":"<p><p>The collective behaviors of self-pulsing particles confined in a graded circular obstacle subjected to Gaussian colored noise are investigated. Translational and rotational colored noises impose complex amplitude-dependent effects on the system. For different values of pulsation amplitude <i>λ</i>, the average velocity 〈<i>V</i>〉, average synchronization parameter 〈<i>P</i>〉, and average packing fraction 〈<i>Φ</i>〉 display different variation trends with increasing translational noise intensity, self-correlation time of translational noise, rotational noise intensity, and self-correlation time of rotational noise. An appropriate rotation frequency facilitates the directed motion and phase ordering of pulsating particles. At <i>λ</i> = 0.15, the average particle area increases with rising frequency and eventually saturates. For <i>λ</i> = 0.30 and <i>λ</i> = 0.45, the average particle area exhibits a maximum as the driving frequency increases. As the pulsation amplitude <i>λ</i> increases, the average velocity reaches a peak, while the synchronization order parameter and packing fraction decrease monotonically. Larger noise intensities (translational and rotational) and larger pulsation amplitudes both favor diffusion. Rapid alternation of deformation induced by high-frequency pulsation suppresses particle diffusion.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149316251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlinear elasticity of phantom networks: from cross-link fluctuations to affine deformation.","authors":"Andrey V Dobrynin","doi":"10.1039/d6sm00844e","DOIUrl":"https://doi.org/10.1039/d6sm00844e","url":null,"abstract":"<p><p>We develop a self-consistent theory of the nonlinear elasticity of phantom networks that accounts for both finite strand extensibility and rigidity. Network strands are represented by Toeplitz chains whose Kuhn length is controlled by a bond-correlation parameter <i>g</i> describing mutual orientation of the bond vectors. A self-consistent constraint on the mean-square bond length produces finite chain extensibility. Integrating over the internal chain modes at fixed end-to-end vector results in a non-Gaussian chain free energy governed by an effective spring constant. This spring constant is used to derive a theory of phantom networks by representing each strand deformation as a sum of the mean strand end-to-end vector and its fluctuations coupled to cross-link fluctuations. Applying Foster's theorem, which connects the numbers of nodes and edges of a graph with its network-averaged effective resistance, shows that network topology, including connectivity defects and loops, enters the macroscopic elasticity through the node-to-edge ratio <i>η</i>_NE of the elastically active graph. This eliminates the need for detailed enumeration of loops in predicting the network elastic response. For flexible strands at small deformations, the theory recovers the classical phantom network result, <i>G</i>_ph/<i>G</i>_aff = 1 - <i>η</i>_NE, with <i>η</i>_NE = 2/<i>f</i> for an ideal, defect-free <i>f</i>-functional network. However, the model predicts progressive suppression of cross-link fluctuations as strands become stiffer or approach their finite extensibility limit, resulting in a continuous crossover to affine network behavior.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149316253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Buckling of stretched and twisted rubber rods.","authors":"Majed N Saadawi, Yue Luna Zheng, Christopher W Barney","doi":"10.1039/d6sm00812g","DOIUrl":"https://doi.org/10.1039/d6sm00812g","url":null,"abstract":"<p><p>The coupled nature of the normal load and torque when twisting a cylinder has been a subject of interest to experimentalists and theoreticians since the early measurements of Poynting. When investigating such deformations in soft solids, it is well-documented that sufficient twisting causes a cylinder to deform through a torsional instability. Although many works have investigated these instabilities, their approach often assumes kinking while overlooking the preceding buckling. Here the impact of cylinder aspect ratio and loading conditions on the onset of the buckling are experimentally probed. These measurements are used as a means to examine several criteria for the onset of the torsional instability. It is observed that modeling buckling is essential as the sample becomes shorter. Additionally, cyclic loading measurements show that the buckling point results in a signature path-dependent mechanical response during loading. This result suggests that buckling may be sensed through this mechanical signature. Finally, discussion of the data highlights strategies for probing torsional failure without observing buckling.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149316250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ring sliding dynamics of single- and double-threaded cyclodextrin-polyethylene glycol polyrotaxane slide-ring polymers under tension.","authors":"Luna Ramirez, Yufei Chen, Chenfeng Ke, Andrew L Ferguson","doi":"10.1039/d6sm00602g","DOIUrl":"https://doi.org/10.1039/d6sm00602g","url":null,"abstract":"<p><p>Slide-ring materials comprising polyrotaxanes are an emerging class of soft materials composed of mechanically interlocked polymer strands threaded by macrocyclic rings. Double-threaded γ-cyclodextrin-based slide-rings in which two polymer chains are threaded through the same ring give rise to materials with exceptional extensibility and toughness that can overcome the elasticity-toughness trade-off inherent to traditional polymer architectures. However, a fundamental molecular-level understanding of how tension, ring chemistry, and threading geometry govern ring mobility remains lacking. In this work, we employ all-atom molecular dynamics simulations to model the thermodynamics and sliding dynamics of single and pairs of native and permethylated α- and γ-cyclodextrin rings on single- and double-threaded polyethylene glycol (PEG) polyrotaxanes as a function of applied tension. Double-threaded configurations, permethylated rings, and rings with stronger binding energies show consistently lower diffusivities than their single-threaded, native, and weakly bound counterparts. The 3D diffusivity of single- and double-threaded native and permethylated cyclodextrin monomers and dimers monotonically decreases with applied tension due to a reduction in the amplitude of the thermal fluctuations. Similar monotonic trends are generally preserved for 1D diffusivity along the PEG chain contour, but less sterically-constrained single-threaded native cyclodextrins in both the monomer and dimer state can exhibit non-monotonic trends due to the interplay of tension-dependent thermal fluctuations that promote mobility and the presence of backbone dihedral <i>gauche</i> defects that serve as a barrier to ring sliding.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149316254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A soft penetrable sphere colloid model for the description of charge and excluded volume interactions in antibody solutions.","authors":"Peter Schurtenberger, Marco Polimeni, Sophia Marzouk, Robin Curtis, Emanuela Zaccarelli, Anna Stradner","doi":"10.1039/d6sm00591h","DOIUrl":"https://doi.org/10.1039/d6sm00591h","url":null,"abstract":"<p><p>Colloid models have frequently been used to successfully describe the influence of protein-protein interactions on antibody solution properties, but they suffer from inherent problems due to the anisotropic shape of the particles. The net charge required to describe electrostatic interactions is an effective quantity that cannot directly be obtained from the known molecular structure of an antibody, and the solution structure caused by excluded volume interactions is strongly overestimated at high concentrations due to the assumption of hard sphere interactions. As a result, these models have descriptive rather than predictive power. Here, we present an improved, soft penetrable sphere model based on analogies to soft colloids and star polyelectrolytes that takes into account the Y-shaped antibody form and the corresponding charge and ion distribution. The model not only correctly describes the concentration and ionic strength dependence of thermodynamic and collective dynamics quantities such as the osmotic compressibility and the apparent hydrodynamic radius, but also reproduces the center-of-mass static structure factor obtained in computer simulations using a weakly coarse-grained model, in which the antibody is described at an amino acid level. We demonstrate that this soft penetrable sphere model quantitatively reproduces experimental data from static and dynamic light scattering at low and high ionic strength for two well-characterized monoclonal antibodies (mAbs) when using the net charges and the overall mAb dimensions directly obtained from their molecular structure.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149316237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tunable shear thickening in active frictional non-Brownian suspensions.","authors":"Bhanu Prasad Bhowmik, Christopher Ness","doi":"10.1039/d6sm00615a","DOIUrl":"https://doi.org/10.1039/d6sm00615a","url":null,"abstract":"<p><p>We study tunable shear thickening in active suspensions of non-Brownian, repulsive, frictional grains using particle-based simulation, finding that activity augments the rheology beyond the friction-mediated shear thickening paradigm. Specifically, up to a crossover activity strength, increasing particle self-propulsion drives a viscosity-reducing 'dethickening' of the system at large stresses, where the material would otherwise be in a thickened, highly viscous state. Above this crossover activity strength, the system enters a thickening regime. Self-propulsion introduces additional isotropic dynamics to the particles, which compete with the flow-driven formation of frictional contacts. The degree of dethickening can thus be tuned by varying a suitably-defined dimensionless active stress that quantifies this competition. Recognising the parallels between self-propulsion and other contemporary routes to dethickening, we demonstrate that our data, within the dethickening regime, are consistent with a recently proposed universal scaling framework, offering a route to tuning the rheology of dense suspensions. Moreover, using the obtained scaling relation, we infer how the shear-jamming and shear-thickening regimes can be tuned by choosing an appropriate self-propulsion strength, and partially validate these inferences with targeted simulations.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149316255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical response of colloidal clusters under uniaxial tension.","authors":"Yanhui Yang, Jiawei Kang, Yao Li, Xiaoguang Ma","doi":"10.1039/d6sm00587j","DOIUrl":"https://doi.org/10.1039/d6sm00587j","url":null,"abstract":"<p><p>Despite extensive studies of equilibrium conformations of colloidal clusters, little is known about their mechanical response. Here, we investigate the tensile behavior of a quasi-two-dimensional colloidal cluster subjected to uniaxial tension up to fracture. The sample is a ribbon-shaped assembly of 16 colloidal beads bound by short-range depletion attraction. Using multiple optical tweezers, we clamp the cluster at both ends and perform a tensile test along its long axis. Combining video microscopy with particle tracking, we measure the tensile stress, strain, and particle configurations during deformation. We observe diverse mechanical response behaviors, including elastic, plastic, and soft-mode deformation, with fracture occurring at a strain near 10%. To explain these behaviors, we construct a spring-mass frame model with breakable elastic bonds. We perform canonical Monte Carlo simulations on the full model with 32 degrees of freedom and compute the statistical distributions of mechanical observables using a simplified model with only 7 degrees of freedom. Both the simulations and the theoretical calculations accurately reproduce the experimental stress-strain curves. Moreover, the configuration distributions predicted by the simplified model agree well with both experiment and simulation in the elastic and soft-mode regimes, with only minor discrepancies in the plastic regime. This work demonstrates the capability of optical-tweezers-enabled mechanical measurements to unravel the rich mechanical response properties of colloidal clusters.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149316252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}