Publications by authors named "Lingxiang Jiang"

30 Publications

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PCNA inhibition enhances the cytotoxicity of β-lapachone in NQO1-Positive cancer cells by augmentation of oxidative stress-induced DNA damage.

Cancer Lett 2021 Oct 27;519:304-314. Epub 2021 Jul 27.

Department of Radiation Oncology, Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indiana University School of Medicine, Indianapolis, IN, 46202, USA. Electronic address:

β-Lapachone is a classic quinone-containing antitumor NQO1-bioactivatable drug that directly kills NQO1-overexpressing cancer cells. However, the clinical applications of β-lapachone are primarily limited by its high toxicity and modest lethality. To overcome this side effect and expand the therapeutic utility of β-lapachone, we demonstrate the effects of a novel combination therapy including β-lapachone and the proliferating cell nuclear antigen (PCNA) inhibitor T2 amino alcohol (T2AA) on various NQO1 cancer cells. PCNA has DNA clamp processivity activity mediated by encircling double-stranded DNA to recruit proteins involved in DNA replication and DNA repair. In this study, we found that compared to monotherapy, a nontoxic dose of the T2AA synergized with a sublethal dose of β-lapachone in an NQO1-dependent manner and that combination therapy prevented DNA repair, increased double-strand break (DSB) formation and promoted programmed necrosis and G1 phase cell cycle arrest. We further determined that combination therapy enhanced antitumor efficacy and prolonged survival in Lewis lung carcinoma (LLC) xenografts model. Our findings show novel evidence for a new therapeutic approach that combines of β-lapachone treatment with PCNA inhibition that is highly effective in treating NQO1 solid tumor cells.
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http://dx.doi.org/10.1016/j.canlet.2021.07.040DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8403654PMC
October 2021

Astral hydrogels mimic tissue mechanics by aster-aster interpenetration.

Nat Commun 2021 07 13;12(1):4277. Epub 2021 Jul 13.

School of Molecular Science and Engineering, South China University of Technology, Guangzhou, China.

Many soft tissues are compression-stiffening and extension-softening in response to axial strains, but common hydrogels are either inert (for ideal chains) or tissue-opposite (for semiflexible polymers). Herein, we report a class of astral hydrogels that are structurally distinct from tissues but mechanically tissue-like. Specifically, hierarchical self-assembly of amphiphilic gemini molecules produces radial asters with a common core and divergently growing, semiflexible ribbons; adjacent asters moderately interpenetrate each other via interlacement of their peripheral ribbons to form a gel network. Resembling tissues, the astral gels stiffen in compression and soften in extension with all the experimental data across different gel compositions collapsing onto a single master curve. We put forward a minimal model to reproduce the master curve quantitatively, underlying the determinant role of aster-aster interpenetration. Compression significantly expands the interpenetration region, during which the number of effective crosslinks is increased and the network strengthened, while extension does the opposite. Looking forward, we expect this unique mechanism of interpenetration to provide a fresh perspective for designing and constructing mechanically tissue-like materials.
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http://dx.doi.org/10.1038/s41467-021-24663-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8277779PMC
July 2021

Enzyme-Responsive Molecular Assemblies Based on Host-Guest Chemistry.

Langmuir 2021 07 1;37(27):8348-8355. Epub 2021 Jul 1.

Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.

Recent years have witnessed a growing interest in the design of enzyme-responsive molecular assemblies that hold appealing applications in the fields of disease-related sensing, imaging, and drug delivery. Cyclodextrins (CDs) are amylase-cleavable host molecules that can associate with surfactants, alkanes, alkyl amines, fatty alcohols, and aromatic compounds to form diverse supramolecular structures. In this work, we report a versatile supramolecular platform to construct enzyme-responsive nanosystems via host-guest interactions, in which complexation between CDs and surfactants eventually leads to the formation of a variety of nanostructures such as vesicles and microtubes. These supramolecular structures are capable of loading water-soluble molecules or functional nanoparticles, which can be actively released on-demand in the presence of α-amylase. This universal strategy to fabricate enzyme-responsive supramolecular systems was further demonstrated with a range of surfactants with anionic, cationic, and nonionic headgroups. Our results highlight a versatile platform for the exploration of biologically responsive self-assembly with potential applications as controlled-release systems and microrobots.
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http://dx.doi.org/10.1021/acs.langmuir.1c01226DOI Listing
July 2021

Biomimetic self-assembly of subcellular structures.

Chem Commun (Camb) 2020 Jul;56(60):8342-8354

College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, China.

If there is a secret recipe that enables living cells to build themselves from individual molecules, it is likely to be hierarchical self-organization. Here, we summarize recent progress in synthetic self-assembly analogous to subcellular structures, including flattened sacs, crystalline membranes, reconfigurable coacervate droplets, semiflexible filaments, and asters. Simplicity is the key of these synthetic systems-they can reproduce the architecture and, sometimes, functions of seemingly complicated biological systems with surprisingly minimal constituents, underlying the overwhelming importance of fundamental physicochemical mechanisms over specific molecular details. Beyond molecular self-assembly on a microscale, we expect integration of the assembled structures to function in unison and synergy as the next step towards cell imitation.
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http://dx.doi.org/10.1039/d0cc01395aDOI Listing
July 2020

Hierarchically Chiral Lattice Self-Assembly Induced Circularly Polarized Luminescence.

ACS Nano 2020 Mar 10;14(3):3190-3198. Epub 2020 Mar 10.

CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology (NCNST), Beijing 100190, People's Republic of China.

Biomaterials in nature often exhibit hierarchical chiral structures with an intriguing mechanism involving hierarchical chirality transfer from molecular to supramolecular and the nano- or microscale level. To mimic the cross-level chirality transfer, we present here one kind of host-guest complex system built of β-cyclodextrin (β-CD), sodium dodecyl sulfate (SDS), and fluorescent dyes, which show multilevel chirality, including molecular chirality of β-CD, induced supramolecular chirality of β-CD/SDS host-guest complexes, a chiral lattice self-assembled nanosheet, mesoscopic chirality of an assembled helical tube, induced chirality of a dye-doped chiral tube. The hierarchical chirality involved a chiral lattice self-assembly process, which can be identified by small-angle X-ray scattering, optical studies, circular dichroism, and circularly polarized luminescence spectral measurements. Benefiting from the chiral lattice self-assembly, intense circularly polarized luminescence was observed from the achiral dye-doped complexes with a large dissymmetry factor up to +0.1. This work thus provides a feasible insight for developing hierarchical chiroptical materials based on the lattice self-assembly.
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http://dx.doi.org/10.1021/acsnano.9b08408DOI Listing
March 2020

Sex difference in the association of APOE4 with cerebral glucose metabolism in older adults reporting significant memory concern.

Neurosci Lett 2020 03 7;722:134824. Epub 2020 Feb 7.

Department of General Medicine, Taizhou First People's Hospital, Zhejiang, China. Electronic address:

There is accumulating evidence that the association of apolipoprotein E4 (APOE4) with the risk of developing Alzheimer's disease (AD) is modified by sex. However, the associations of APOE4 status and sex with AD-related markers in older adults with significant memory concern (SMC) remain elusive. Among individuals with SMC (n = 106), we investigated the associations of APOE4 status and sex with multiple AD-related markers, including verbal memory, hippocampal volumes, cerebral glucose metabolism and cortical amyloid burden. In individuals with SMC, we found a significant APOE4*sex interaction for cerebral glucose metabolism, but not verbal memory, hippocampal volumes or cortical amyloid burden. Specifically, female APOE4 carriers showed significantly higher cerebral glucose metabolism compared to female APOE4 non-carriers whereas male APOE4 carriers had lower cerebral glucose metabolism than male APOE4-noncarriers. In conclusion, the effect of APOE4 on cerebral glucose metabolism is altered by sex in individuals with SMC.
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http://dx.doi.org/10.1016/j.neulet.2020.134824DOI Listing
March 2020

Synthetic asters as elastic and radial skeletons.

Nat Commun 2019 10 31;10(1):4954. Epub 2019 Oct 31.

College of Chemistry and Materials Science, Jinan University, Guangzhou, 510632, China.

The radial geometry with rays radiated from a common core occurs ubiquitously in nature for its symmetry and functions. Herein, we report a class of synthetic asters with well-defined core-ray geometry that can function as elastic and radial skeletons to harbor nano- and microparticles. We fabricate the asters in a single, facile, and high-yield step that can be readily scaled up; specifically, amphiphilic gemini molecules self-assemble in water into asters with an amorphous core and divergently growing, twisted crystalline ribbons. The asters can spontaneously position microparticles in the cores, along the radial ribbons, or by the outer rims depending on particle sizes and surface chemistry. Their mechanical properties are determined on single- and multiple-aster levels. We further maneuver the synthetic asters as building blocks to form higher-order structures in virtue of aster-aster adhesion induced by ribbon intertwining. We envision the astral structures to act as rudimentary spatial organizers in nanoscience for coordinated multicomponent systems, possibly leading to emergent, synergistic functions.
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http://dx.doi.org/10.1038/s41467-019-13009-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6823511PMC
October 2019

Single-crosslink microscopy in a biopolymer network dissects local elasticity from molecular fluctuations.

Nat Commun 2019 07 25;10(1):3314. Epub 2019 Jul 25.

Center for Soft and Living Matter, Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea.

Polymer networks are fundamental from cellular biology to plastics technology but their intrinsic inhomogeneity is masked by the usual ensemble-averaged measurements. Here, we construct direct maps of crosslinks-symbolic depiction of spatially-distributed elements highlighting their physical features and the relationships between them-in an actin network. We selectively label crosslinks with fluorescent markers, track their thermal fluctuations, and characterize the local elasticity and cross-correlations between crosslinks. Such maps display massive heterogeneity, reveal abundant anticorrelations, and may contribute to address how local responses scale up to produce macroscopic elasticity. Single-crosslink microscopy offers a general, microscopic framework to better understand crosslinked molecular networks in undeformed or strained states.
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http://dx.doi.org/10.1038/s41467-019-11313-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6658493PMC
July 2019

NQO1 targeting prodrug triggers innate sensing to overcome checkpoint blockade resistance.

Nat Commun 2019 07 19;10(1):3251. Epub 2019 Jul 19.

Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, 75235, USA.

Lack of proper innate sensing inside tumor microenvironment (TME) limits T cell-targeted immunotherapy. NAD(P)H:quinone oxidoreductase 1 (NQO1) is highly enriched in multiple tumor types and has emerged as a promising target for direct tumor-killing. Here, we demonstrate that NQO1-targeting prodrug β-lapachone triggers tumor-selective innate sensing leading to T cell-dependent tumor control. β-Lapachone is catalyzed and bioactivated by NQO1 to generate ROS in NQO1 tumor cells triggering oxidative stress and release of the damage signals for innate sensing. β-Lapachone-induced high mobility group box 1 (HMGB1) release activates the host TLR4/MyD88/type I interferon pathway and Batf3 dendritic cell-dependent cross-priming to bridge innate and adaptive immune responses against the tumor. Furthermore, targeting NQO1 is very potent to trigger innate sensing for T cell re-activation to overcome checkpoint blockade resistance in well-established tumors. Our study reveals that targeting NQO1 potently triggers innate sensing within TME that synergizes with immunotherapy to overcome adaptive resistance.
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http://dx.doi.org/10.1038/s41467-019-11238-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6642086PMC
July 2019

Diffusive Adhesives for Water-Rich Materials: Strong and Tunable Adhesion Beyond the Interface.

Chemistry 2019 Jun 20;25(34):8085-8091. Epub 2019 May 20.

College of Chemistry and Materials Science, Jinan University, Guangzhou, 510632, P.R. China.

It is notoriously difficult to adhere water-rich materials, such as hydrogels and biological tissues. Existing adhesives usually suffer from weak and nonadjustable adhesion strength, in part because the contact between the adhesive and substrate is largely restrained to the adhesive/substrate interface. In this study, we have attempted to overcome this shortcoming by developing a class of diffusive adhesives (DAs) that can extend adhesion deep into the substrate to maximize the adhesive/substrate contact. The DAs consist of hydrogel matrices and preloaded water-soluble monomers and crosslinkers that can diffuse extensively into the water-rich substrates after adhesive/substrate contact. Polymerization and crosslinking of the monomers are then triggered leading to a bridging network that interpenetrates the DA and substrate skeletons and topologically binds them together. This kind of adhesion, in the absence of adhesive/substrate covalent bonding, is of high strength and toughness, comparable to those of the best-performing natural and artificial adhesives. More importantly, we can precisely tune the adhesion strength on demand by manipulating the diffusion profile. It is envisioned that the DA family could be extended to include a large pool of hydrogel matrices and monomers, and that they could be particularly useful in biological and medical applications.
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http://dx.doi.org/10.1002/chem.201900606DOI Listing
June 2019

Steering Coacervation by a Pair of Broad-Spectrum Regulators.

ACS Nano 2019 02 4;13(2):2420-2426. Epub 2019 Feb 4.

College of Chemistry and Materials Science , Jinan University , Guangzhou 510632 , China.

Coacervation is liquid-liquid phase separation ubiquitous in industrial applications and cellular biology. Inspired by cellular manipulation of coacervate droplets such as P granules, we report here a regulatory strategy to manipulate synthetic coacervation in a spatiotemporally controllable manner. Two oppositely charged small molecules are shown to phase separate into coacervate droplets in water as a result of electrostatic attraction, hydrophobic effect, and entropy. We identify a down regulator, β-cyclodextrin, to disrupt the hydrophobic effect, thus dissolving the droplets, and an up regulator, amylase, to decompose β-cyclodextrin, thus restoring the droplets. The regulation kinetics is followed in real time on a single-droplet level, revealing diffusion-limited dissolution and reaction-limited condensation, respectively, taking ∼4 s and 2-3 min. Versatility of this strategy to manipulate the coacervation is demonstrated in two aspects: spatially distributed coacervation in virtue of amylase-grafted hydrogel frameworks and coacervate transportation across membranes and hydrogel networks via a disassemble-to-pass strategy. The current regulatory pairs and strategies are anticipated to be general for a wide variety of synthetic self-assembly systems.
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http://dx.doi.org/10.1021/acsnano.8b09332DOI Listing
February 2019

High internal phase water-in-oil emulsions stabilized by food-grade starch.

J Colloid Interface Sci 2019 Jan 18;534:542-548. Epub 2018 Sep 18.

Unilever Research and Development Centre Shanghai, Shanghai 200335, PR China. Electronic address:

Water in oil emulsions would be prepared by silicones (SO), modified silicones (DC8500) and a food-grade stabilizer (starch 1). With increasing water contents, the emulsions turned from a liquid-like to gel-like behaviors with enhancing storage and loss modulus. When DC8500/SO was 1/17 with 10 wt% starch 1, a high internal phase emulsion can be obtained with 95 wt% water content. DC8500 and SO worked as efficient emulsifiers and possessed amphiphilic property to form emulsions with water in different ratios. A food-grade starch 1 was supplied as a stabilizer which can enhance both water content and strength of emulsion when added in a low concentration. Besides, it is indicated that the food-grade starches provided potential benefit on stabilizing emulsions in very low concentration.
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http://dx.doi.org/10.1016/j.jcis.2018.09.058DOI Listing
January 2019

Giant capsids from lattice self-assembly of cyclodextrin complexes.

Nat Commun 2017 06 20;8:15856. Epub 2017 Jun 20.

College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, China.

Proteins can readily assemble into rigid, crystalline and functional structures such as viral capsids and bacterial compartments. Despite ongoing advances, it is still a fundamental challenge to design and synthesize protein-mimetic molecules to form crystalline structures. Here we report the lattice self-assembly of cyclodextrin complexes into a variety of capsid-like structures such as lamellae, helical tubes and hollow rhombic dodecahedra. The dodecahedral morphology has not hitherto been observed in self-assembly systems. The tubes can spontaneously encapsulate colloidal particles and liposomes. The dodecahedra and tubes are respectively comparable to and much larger than the largest known virus. In particular, the resemblance to protein assemblies is not limited to morphology but extends to structural rigidity and crystallinity-a well-defined, 2D rhombic lattice of molecular arrangement is strikingly universal for all the observed structures. We propose a simple design rule for the current lattice self-assembly, potentially opening doors for new protein-mimetic materials.
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http://dx.doi.org/10.1038/ncomms15856DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5481833PMC
June 2017

Vector assembly of colloids on monolayer substrates.

Nat Commun 2017 06 8;8:15778. Epub 2017 Jun 8.

Center for Soft and Living Matter, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea.

The key to spontaneous and directed assembly is to encode the desired assembly information to building blocks in a programmable and efficient way. In computer graphics, raster graphics encodes images on a single-pixel level, conferring fine details at the expense of large file sizes, whereas vector graphics encrypts shape information into vectors that allow small file sizes and operational transformations. Here, we adapt this raster/vector concept to a 2D colloidal system and realize 'vector assembly' by manipulating particles on a colloidal monolayer substrate with optical tweezers. In contrast to raster assembly that assigns optical tweezers to each particle, vector assembly requires a minimal number of optical tweezers that allow operations like chain elongation and shortening. This vector approach enables simple uniform particles to form a vast collection of colloidal arenes and colloidenes, the spontaneous dissociation of which is achieved with precision and stage-by-stage complexity by simply removing the optical tweezers.
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http://dx.doi.org/10.1038/ncomms15778DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5472769PMC
June 2017

In situ observation of self-assembly of sugars and surfactants from nanometres to microns.

Soft Matter 2017 Mar;13(13):2421-2425

Van 't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute for Nanomaterials Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands. and Laboratory of Physical Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.

The hierarchical self-assembly of sugar and surfactant molecules into hollow tubular microstructures was characterized in situ with high resolution small-angle X-ray scattering spanning more than three orders of magnitude of spatial scales. Scattering profiles reveal that aqueous host-guest inclusion complexes self-assemble into multiple equally spaced curved bilayers forming a collection of concentric hollow cylinders. Scattering data can be described by a simple theoretical model of the microtubes. The interlamellar distance was found to be surprisingly large. Moreover, we report that the multi-walled structure of the microtubes swells as the concentration or the temperature is varied.
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http://dx.doi.org/10.1039/c7sm00109fDOI Listing
March 2017

Dynamic cross-correlations between entangled biofilaments as they diffuse.

Proc Natl Acad Sci U S A 2017 03 10;114(13):3322-3327. Epub 2017 Mar 10.

IBS Center for Soft and Living Matter, Ulsan National Institute of Science and Technology, Ulju-gun, Ulsan 689-789, South Korea

Entanglement in polymer and biological physics involves a state in which linear interthreaded macromolecules in isotropic liquids diffuse in a spatially anisotropic manner beyond a characteristic mesoscopic time and length scale (tube diameter). The physical reason is that linear macromolecules become transiently localized in directions transverse to their backbone but diffuse with relative ease parallel to it. Within the resulting broad spectrum of relaxation times there is an extended period before the longest relaxation time when filaments occupy a time-averaged cylindrical space of near-constant density. Here we show its implication with experiments based on fluorescence tracking of dilutely labeled macromolecules. The entangled pairs of aqueous F-actin biofilaments diffuse with separation-dependent dynamic cross-correlations that exceed those expected from continuum hydrodynamics up to strikingly large spatial distances of ≈15 µm, which is more than 10 times the size of the solvent water molecules in which they are dissolved, and is more than 50 times the dynamic tube diameter, but is almost equal to the filament length. Modeling this entangled system as a collection of rigid rods, we present a statistical mechanical theory that predicts these long-range dynamic correlations as an emergent consequence of an effective long-range interpolymer repulsion due to the de Gennes correlation hole, which is a combined consequence of chain connectivity and uncrossability. The key physical assumption needed to make theory and experiment agree is that solutions of entangled biofilaments localized in tubes that are effectively dynamically incompressible over the relevant intermediate time and length scales.
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http://dx.doi.org/10.1073/pnas.1620935114DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5380065PMC
March 2017

Real-Space, in Situ Maps of Hydrogel Pores.

ACS Nano 2017 01 8;11(1):204-212. Epub 2016 Dec 8.

IBS Center for Soft and Living Matter and UNIST, Ulsan 689-798, South Korea.

We characterize the porosity of hydrogels by imaging the displacement trajectories of embedded tracer particles. This offers the possibility of characterizing the size and projected shape of individual pores as well as direct, real-space maps of heterogeneous porosity and its distribution. The scheme shows that when fluorescent spherical particles treated to avoid specific adsorption are loaded into the gel, their displacement trajectories from Brownian motion report on the size and projected shape in which the pore resides, convoluted by the particle size. Of special interest is how pores and their distribution respond to stimuli. These ideas are validated in agarose gels loaded with latex particles stabilized by adsorbed bovine serum albumin. Gels heated from room temperature produced an increasingly more monodisperse pore size distribution because increasing temperature preferentially enlarges smaller pores, but this was irreversible upon cooling, and shearing agarose gels beyond the yield point destroyed larger pores preferably. The method is considered to be generalizable beyond the agarose system presented here as proof of concept.
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http://dx.doi.org/10.1021/acsnano.6b04468DOI Listing
January 2017

Correlated two-particle diffusion in dense colloidal suspensions at early times: Theory and comparison to experiment.

Phys Rev E Stat Nonlin Soft Matter Phys 2015 Nov 6;92(5):052304. Epub 2015 Nov 6.

Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801, USA.

The spatially resolved diffusive dynamic cross correlations of a pair of colloids in dense quasi-two-dimensional monolayers of identical particles are studied experimentally and theoretically at early times where motion is Fickian. In very dense systems where strong oscillatory equilibrium packing correlations are present, we find an exponential decay of the dynamic cross correlations on small and intermediate length scales. At large separations where structure becomes random, an apparent power law decay with an exponent of approximately -2.2 is observed. For a moderately dense suspension where local structural correlations are essentially absent, this same apparent power law decay is observed over all probed interparticle separations. A microscopic nonhydrodynamic theory is constructed for the dynamic cross correlations which is based on interparticle frictional effects and effective structural forces. Hydrodynamics enters only via setting the very short-time single-particle self-diffusion constant. No-adjustable-parameter quantitative predictions of the theory for the dynamic cross correlations are in good agreement with experiment over all length scales. The origin of the long-range apparent power law is the influence of the constraint of fixed interparticle separation on the amplitude of the mean square force exerted on the two tagged particles by the surrounding fluid. The theory is extended to study high-packing-fraction 3D hard sphere fluids. The same pattern of an oscillatory exponential form of the dynamic cross correlation function is predicted in the structural regime, but the long-range tail decays faster than in monolayers with an exponent of -3.
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http://dx.doi.org/10.1103/PhysRevE.92.052304DOI Listing
November 2015

Strigolactones spatially influence lateral root development through the cytokinin signaling network.

J Exp Bot 2016 Jan 31;67(1):379-89. Epub 2015 Oct 31.

Department of Plant Systems Biology, VIB, 9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium

Strigolactones are important rhizosphere signals that act as phytohormones and have multiple functions, including modulation of lateral root (LR) development. Here, we show that treatment with the strigolactone analog GR24 did not affect LR initiation, but negatively influenced LR priming and emergence, the latter especially near the root-shoot junction. The cytokinin module ARABIDOPSIS HISTIDINE KINASE3 (AHK3)/ARABIDOPSIS RESPONSE REGULATOR1 (ARR1)/ARR12 was found to interact with the GR24-dependent reduction in LR development, because mutants in this pathway rendered LR development insensitive to GR24. Additionally, pharmacological analyses, mutant analyses, and gene expression analyses indicated that the affected polar auxin transport stream in mutants of the AHK3/ARR1/ARR12 module could be the underlying cause. Altogether, the data reveal that the GR24 effect on LR development depends on the hormonal landscape that results from the intimate connection with auxins and cytokinins, two main players in LR development.
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http://dx.doi.org/10.1093/jxb/erv478DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4682444PMC
January 2016

Self-assembly of ultralong polyion nanoladders facilitated by ionic recognition and molecular stiffness.

J Am Chem Soc 2014 Feb 23;136(5):1942-7. Epub 2014 Jan 23.

Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University , Chengfu Road 202, Beijing 100871, China.

It is hard to obtain spatially ordered nanostructures via the polyion complexation process due to the inherent flexibility of polymers and isotropicity of ionic interactions. Here we report the formation of polyion assemblies with well-defined, periodically regular internal structure by imparting the proper stiffness to the molecular tile. A stiff bisligand TPE-C4-L2 was designed which is able to form a negatively charged supramolecular polyelectrolyte with transition metal ions. This supramolecular polyelectrolyte slowly self-assembled into polydispersed flat sheets with cocoon-like patterns. Upon the addition of an oppositely charged ordinary polyelectrolyte, the polydispersed cocoons immediately transformed into ultralong, uniform nanoladders as a result of matched ionic density recognition. The supramolecular polyelectrolytes assembled side-by-side, and the negative charges aligned in an array. This structure forced the positively charged polymers to lie along the negative charges so that the perpendicular arrangement of the oppositely charged chains was achieved. Such precise charge recognition will provide insight into the design of advanced materials with hierarchical self-assembled structures.
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http://dx.doi.org/10.1021/ja410443nDOI Listing
February 2014

Alterations of angiopoietin-related growth factor (Angptl6) during pregnancy and in pre-eclampsia.

J Obstet Gynaecol Res 2013 Jun 30;39(6):1137-41. Epub 2013 May 30.

Shaoxing Women and Children's Hospital, Shaoxing, Zhejiang, China.

Aim: The aim of this study was to clarify the alterations of angiopoietin-related growth factor (AGF, also known as Angptl6/ARP5) in the serum of normally pregnant women and pre-eclamptic women and to explore the role of AGF in pre-eclampsia.

Material And Methods: Thirty healthy non-pregnant women, 118 normally pregnant women (30 at 6-12 gestational weeks, 30 at 13-28 weeks and 58 at 29-40 weeks, respectively) and 46 pre-eclamptic women were recruited. Fasting blood samples were obtained from all subjects. Fifteen women of healthy pregnant women provided their blood samples at 24 and 48 h after cesarean section, respectively. Enzyme-linked immunosorbent assay was used to determine the serum level of AGF.

Results: Serum levels of AGF were significantly higher in normally pregnant women than non-pregnant women (P < 0.001 of all). Although serum AGF of the first trimester was significantly higher than that of the second trimester (P = 0.033), there were no significant differences of serum AGF in the comparison between the first and third trimester (P = 0.064) and between the second and third trimester (P = 0.546). Serum AGF significantly decreased after delivery (P < 0.05). There were no significant differences in AGF of maternal serum between pre-eclamptic women and normally pregnant control women (P = 0.285). There were no significant differences in circulating AGF concentration between non-pregnant women and postpartum groups (P = 0.052 for 24 h after delivery and P = 0.083 for 48 h after delivery).

Conclusion: The serum level of AGF was elevated in normal pregnancy compared with non-pregnant women, suggesting that placenta is an important source of circulating AGF during pregnancy.
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http://dx.doi.org/10.1111/jog.12039DOI Listing
June 2013

Helical colloidal sphere structures through thermo-reversible co-assembly with molecular microtubes.

Angew Chem Int Ed Engl 2013 Mar 25;52(12):3364-8. Epub 2013 Feb 25.

Van't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute for NanoMaterials Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.

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http://dx.doi.org/10.1002/anie.201209767DOI Listing
March 2013

Enzyme-triggered model self-assembly in surfactant-cyclodextrin systems.

Chem Commun (Camb) 2012 Jul 23;48(59):7347-9. Epub 2012 May 23.

Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.

We present here a host-guest approach to construct enzyme-triggered assembly systems on the basis of surfactant-cyclodextrin complexes and α-amylase. We realized enzyme-responsive model self-assembly systems including monolayers, micelles, and vesicles. The host-guest approach is expected to be extended to more complicated assembly systems with widespread applications.
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http://dx.doi.org/10.1039/c2cc32533kDOI Listing
July 2012

Versatility of cyclodextrins in self-assembly systems of amphiphiles.

Adv Colloid Interface Sci 2011 Nov 27;169(1):13-25. Epub 2011 Jul 27.

Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.

Recently, cyclodextrins (CDs) were found to play important yet complicated (or even apparently opposite sometimes) roles in self-assembly systems of amphiphiles or surfactants. Herein, we try to review and clarify the versatility of CDs in surfactant assembly systems by 1) classifying the roles played by CDs into two groups (modulator and building unit) and four subgroups (destructive and constructive modulators, amphiphilic and unamphiphilic building units), 2) comparing these subgroups, and 3) analyzing mechanisms. As a modulator, although CDs by themselves do not participate into the final surfactant aggregates, they can greatly affect the aggregates in two ways. In most cases CDs will destroy the aggregates by depleting surfactant molecules from the aggregates (destructive), or in certain cases CDs can promote the aggregates to grow by selectively removing the less-aggregatable surfactant molecules from the aggregates (constructive). As an amphiphilic building unit, CDs can be chemically (by chemical bonds) or physically (by host-guest interaction) attached to a hydrophobic moiety, and the resultant compounds act as classic amphiphiles. As an unamphiphilic building unit, CD/surfactant complexes or even CDs on their own can assemble into aggregates in an unconventional, unamphiphilic manner driven by CD-CD H-bonds. Moreover, special emphasis is put on two recently appeared aspects: the constructive modulator and unamphiphilic building unit.
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http://dx.doi.org/10.1016/j.cis.2011.07.002DOI Listing
November 2011

Unveil the potential function of CD in surfactant systems.

Phys Chem Chem Phys 2011 May;13(20):9074-82

Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.

CDs may have promising functions in surfactant systems far beyond simply being disadvantageous to the formation of micelles. In this paper we review the recent literature and our work on the interesting effect of CDs on amphiphilic systems, especially on the concentrated single surfactant systems and catanionic surfactant mixed systems, both of them have been scarcely focused upon in the literature. In concentrated single surfactant systems, the 2:1 surfactant-CD inclusion complexes may form hierarchical self-assemblies such as lamellae, microtubes, and vesicles which are driven by hydrogen bonding. In nonstoichiometrically mixed catanionic surfactant systems, CDs behave as a stoichiometry booster that always selectively binds to the excess component so as to shift the mixing ratio to electro-neutral in the aggregates. In this way, CDs reduce the electrorepulsion in the aggregates and trigger their growth. Upon analysis of literature work and our own results, we expect that a new era focusing on the new function of CDs on surfactant systems will come.
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http://dx.doi.org/10.1039/c0cp02651dDOI Listing
May 2011

Effects of inorganic and organic salts on aggregation behavior of cationic gemini surfactants.

J Phys Chem B 2010 Nov 28;114(46):14955-64. Epub 2010 Oct 28.

Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Colloid and Interface Science, Institute of Chemistry, Chinese Academy of Sciences, China.

All salts studied effectively reduce critical micelle concentration (CMC) values of the cationic gemini surfactants. The ability to promote the surfactant aggregation decreases in the order of C(6)H(5)COONa > p-C(6)H(4)(COONa)(2) > Na(2)SO(4)> NaCl. Moreover, only C(6)H(5)COONa distinctly reduces both the CMC values and the surface tension at CMC. For 12-4-12 solution, the penetration of C(6)H(5)COO(-) anions and charge neutralization induce a morphology change from micelles to vesicles, whereas the other salts only slightly increase the sizes of micelles. The 12-4(OH)(2)-12 solution changes from the micelle/vesicle coexistence to vesicles with the addition of C(6)H(5)COONa, whereas the other salts transfer the 12-4(OH)(2)-12 solution from the micelle/vesicle coexistence to micelles. As compared with 12-4-12, the two hydroxyls in the spacer of 12-4(OH)(2)-12 promote the micellization of 12-4(OH)(2)-12 and reduce the amounts of C(6)H(5)COONa required to induce the micelle-to-vesicle transition.
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http://dx.doi.org/10.1021/jp106031dDOI Listing
November 2010

General rules for the scaling behavior of linear wormlike micelles formed in catanionic surfactant systems.

J Colloid Interface Sci 2010 Aug 28;348(2):491-7. Epub 2010 Apr 28.

Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China.

We report in this work on the scaling behavior of wormlike micelles formed in a series of mixed systems of oppositely charged surfactants, including sodium decanote (SD)/hexadecyltrimethylammonium bromide (CTAB), sodium laurate (SL)/hexadecyltrimethylammonium bromide, sodium didecaminocystine (SDDC)/hexadecyltrimethylammonium bromide, and sodium dilauraminocystine (SDLC)/hexadecyltrimethylammonium bromide. Steady and dynamic rheological measurements were performed to characterize these wormlike micelles. The scaling behavior for these systems at various mixing ratios was systematically investigated and was compared with that given by the Cates model. It was found that the Cates law can be applied in these systems simply by manipulating the mixing ratio or the surfactant structure. Energetic analysis demonstrates that the scaling behavior of wormlike micelles in nonequimolar mixed cationic and anionic surfactant systems can be close to that predicted by the Cates model, if the electrostatic contribution is below a threshold value.
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http://dx.doi.org/10.1016/j.jcis.2010.04.065DOI Listing
August 2010

Selectivity and stoichiometry boosting of beta-cyclodextrin in cationic/anionic surfactant systems: when host-guest equilibrium meets biased aggregation equilibrium.

J Phys Chem B 2010 Feb;114(6):2165-74

Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.

Cationic surfactant/anionic surfactant/beta-CD ternary aqueous systems provide a platform for the coexistence of the host-guest (beta-CD/surfactant) equilibrium and the biased aggregation (monomeric/aggregated surfactants) equilibrium. We report here that the interplay between the two equilibria dominates the systems as follows. (1) The biased aggregation equilibrium imposes an apparent selectivity on the host-guest equilibrium, namely, beta-CD has to always selectively bind the major surfactant (molar fraction > 0.5) even if binding constants of beta-CD to the pair of surfactants are quite similar. (2) In return, the host-guest equilibrium amplifies the bias of the aggregation equilibrium, that is, the selective binding partly removes the major surfactant from the aggregates and leaves the aggregate composition approaching the electroneutral mixing stoichiometry. (3) This composition variation enhances electrostatic attractions between oppositely charged surfactant head groups, thus resulting in less-curved aggregates. In particular, the present apparent host-guest selectivity is of remarkably high values, and the selectivity stems from the bias of the aggregation equilibrium rather than the difference in binding constants. Moreover, beta-CD is defined as a "stoichiometry booster" for the whole class of cationic/anionic surfactant systems, which provides an additional degree of freedom to directly adjust aggregate compositions of the systems. The stoichiometry boosting of the compositions can in turn affect or even determine microstructures and macroproperties of the systems.
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http://dx.doi.org/10.1021/jp911092yDOI Listing
February 2010

Special effect of beta-cyclodextrin on the aggregation behavior of mixed cationic/anionic surfactant systems.

J Phys Chem B 2009 May;113(21):7498-504

Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China.

Controllable aggregate transitions are achieved in this work by adding due amounts of beta-cyclodextrin (beta-CD) to mixed cationic/anionic surfactant aqueous solutions. In contrast to its "aggregate breaking" effect in single surfactant systems, aggregate growth is observed in nonstoichiometrical mixed cationic/anionic surfactant systems upon addition of beta-CD. The aggregate growth typically undergoes a micellar elongation and a following micelle-to-vesicle transition, which in turn greatly influences the viscosity and absorbance of the solutions. A possible mechanism of this beta-CD-induced aggregate growth is proposed. In mixed cationic/anionic surfactant systems, the surfactants strongly tend to reach electroneutral equilibrium in aggregates. In the present case, added beta-CD is found to greatly facilitate the equilibrium by transferring the "major" component (whose molar fraction>0.5) of a cationic/anionic surfactant mixture from the aggregates to beta-CD cavities. Consequently, the surfactants in the aggregates approach electroneutral mixing, in favor of low-curved aggregates such as vesicles. This work shows that beta-CD provides an additional degree of freedom to control microstructures and macroproperties for the whole class of mixed cationic/anionic surfactant systems.
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http://dx.doi.org/10.1021/jp811455fDOI Listing
May 2009

Bile salt-induced vesicle-to-micelle transition in catanionic surfactant systems: steric and electrostatic interactions.

Langmuir 2008 May 18;24(9):4600-6. Epub 2008 Mar 18.

Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.

The vesicle-to-micelle transition (VMT) was realized in catanionic surfactant systems by the addition of two kinds of bile salts, sodium cholate (SC) and sodium deoxycholate (SDC). It was found that steric interaction between the bile salt and catanionic surfactant plays an important role in catanionic surfactant systems that are usually thought to be dominated by electrostatic interaction. The facial amphiphilic structure and large occupied area of the bile salt are crucial to the enlargement of the average surfactant headgroup area and result in the VMT. Moreover, bile salts can also induce a macroscopic phase transition. Freeze-fracture transmission electron microscopy, dynamic light scattering, isothermal titration calorimetry, and absorbance measurements were used to follow the VMT process.
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http://dx.doi.org/10.1021/la7035554DOI Listing
May 2008
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