Read by QxMD icon Read

Self assembly

Junko Enomoto, Tatsuto Kageyama, Dina Myasnikova, Kisaki Onishi, Yuka Kobayashi, Yoko Taruno, Takahiro Kanai, Junji Fukuda
Self-assembled monolayers (SAMs) have been used to elucidate interactions between cells and material surface chemistry. Gold surfaces modified with oligopeptide SAMs exhibit several unique characteristics, such as cell-repulsive surfaces, micropatterns of cell adhesion and non-adhesion regions for control over cell microenvironments, and dynamic release of cells upon external stimuli under culture conditions. However, basic procedures for the preparation of oligopeptide SAMs, including appropriate cleaning methods of the gold surface before modification, have not been fully established...
January 15, 2018: Journal of Bioscience and Bioengineering
Neus Vilanova, Isja de Feijter, Abraham J P Teunissen, Ilja K Voets
To tailor the properties of colloidal materials, precise control over the self-assembly of their constituents is a prerequisite. Here, we govern the assembly of silica particles by functionalization with supramolecular moieties which interact with each other via directional and reversible hydrogen bonding. Through a generally applicable synthesis protocol, two different types of self-complementary hydrogen bonding moieties, BTA- and UPy-derivatives, are anchored to silica particles. Their self-assembly is initiated by the UV-induced removal of a photolabile protecting group, allowing the formation of hydrogen bonds between tethered molecules...
January 19, 2018: Scientific Reports
Mahya Hemmat, Brian T Castle, David J Odde
Microtubule self-assembly dynamics serve to facilitate many vital cellular functions, such as chromosome segregation during mitosis and synaptic plasticity. However, the detailed atomistic basis of assembly dynamics has remained an unresolved puzzle. A key challenge is connecting together the vast range of relevant length-time scales, events happening at time scales ranging from nanoseconds, such as tubulin molecular interactions (Å-nm), to minutes-hours, such as the cellular response to microtubule dynamics during mitotic progression (μm)...
January 16, 2018: Current Opinion in Cell Biology
Mingjun Huang, Kan Yue, Jiahao Huang, Chang Liu, Zhe Zhou, Jing Wang, Kan Wu, Wenpeng Shan, An-Chang Shi, Stephen Z D Cheng
This work reports the molecular design, synthesis, and systematic study on the bulk self-assembly behaviors of three series of polyhedral oligomeric silsesquioxanes (POSS)-based multi-headed giant surfactants XDPOSS-PSn (X = 2, 3 and 4), which are composed of two, three or four hydrophilic hydroxyl-group functionalized DPOSS cages attached via one junction point to a hydrophobic polystyrene (PS) chain. These series of hybrid polymeric amphiphiles with precisely defined chemical structure and controllable molecular architecture are synthesized by the sequential usage of "click" reactions...
January 19, 2018: ACS Nano
Yaqi Lv, Chaoran Xu, Xiangmei Zhao, Chenshi Lin, Xin Yang, Xiaofei Xin, Li Zhang, Chao Qin, Xiaopeng Han, Lei Yang, Wei He, Lifang Yin
The tumor microenvironment (TME) plays a critical role in tumor initiation, progression, invasion and metastasis. Therefore, a therapy that combines chemotherapeutic drugs with a TME modulator could be a promising route for cancer treatment. This paper reports a nanoplatform self-assembled from a hyaluronic acid (HA)-paclitaxel (PTX) (HA-PTX) prodrug and marimastat (MATT)-loaded thermosensitive liposomes (LTSLs) (MATT-LTSLs) for the dual targeting of the TME and cancer cells. Interestingly, the prodrug HA-PTX can self-assemble on both positively and negatively charged liposomes, forming hybrid nanoparticles (HNPs, 100 nm)...
January 19, 2018: ACS Nano
Jianting Zhang, Xiao Wang, Kun Zhou, Gang Chen, Qiangbin Wang
In this work, a typical cylinder-shaped tobacco mosaic virus coat protein (TMVCP) is employed as an anisotropic building block to assemble into triclinic and hexagonal close-packed (HCP) protein crystals by introducing cysteine residues at the 1 and 3 sites and four histidine residues at the C-terminal, respectively. The engineered functional groups of cysteine and histidine in the TMVCP and the self-assembly conditions determine the thermodynamics and kinetics in the self-assembly process for forming different crystal structures...
January 19, 2018: ACS Nano
Hongwei Cheng, Xiaoshan Fan, Xiaoyuan Wang, Enyi Ye, Xian Jun Loh, Zibiao Li, Yun-Long Wu
In this report, a new star-like copolymer -CD-g-(PNIPAAm-b-POEGA)x consisting of a -CD core, grafted with temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) and biocompatible poly(oligo(ethylene glycol) acrylate) (POEGA) in a block copolymer of the arms, was used to deliver chemotherapeutics to drug resistant cancer tumours. The first step of the self-assembly process involves the encapsulation of chemotherapeutics through host-guest inclusion complexation between the -cyclodextrin cavity and the anti-cancer drug...
January 19, 2018: Biomacromolecules
Changshun Hou, Shiqing Chen, Mengqi Wang
Herein, novel self-assembled red-emissive C-dots@Au nanoflowers were developed, and they demonstrated efficient photothermal properties under 750 nm laser irradiation. Moreover, C-dots@Au nanoflowers showed the ability of simultaneous photoacoustic and fluorescence imaging. Our study may provide a novel strategy for the efficient phototherapy of cancer cells based on C-dots.
January 19, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Whitney A Webre, Habtom B Gobeze, Shuai Shao, Paul A Karr, Katsuhiko Ariga, Jonathan P Hill, Francis D'Souza
A bis-crown ether-oxoporphyrinogen was newly synthesized and self-assembled concurrently with C60 alkyl ammonium cations at the crown ether sites and F- anions (through hydrogen bonding) at the oxoporphyrinogen core. Ultrafast photoinduced charge transfer processes within the donor-acceptor conjugate were promoted by fluoride ion binding and this was established using various spectroscopic methods and transient absorption studies.
January 19, 2018: Chemical Communications: Chem Comm
Shipeng Chen, Baohao Zhang, Nanxiang Zhang, Fengsheng Ge, Bao Zhang, Xiaoji Wang, Jian Song
Formation of supramolecular ionic liquid gels (ionogels) induced by low-molecular mass gelators (LMMGs) is an efficient strategy to confine ionic liquids and the negligible influence of LMMGs on the electrochemical properties of ionic liquids makes ionogels ideal quasi-solid electrochemical materials. Furthermore, the stimuli-responsive and self-healing characters of the supramolecular gel can be utilized for the potential development of smart electrochemical materials. However, the poor mechanical properties of supramolecular ionogel reported so far limit their practical applications...
January 19, 2018: ACS Applied Materials & Interfaces
Lin Feng, Danhua Xie, Binglei Song, Jiayu Zhang, Xiaomei Pei, Zhenggang Cui
Innovations in surfactant structure are a feasible way to probe molecular self-assembly principles. Herein, the solution behaviour of a newly synthesized Gemini surfactant derived from dehydroabietic acid, abbreviated R-(EO)-E-R, was investigated using surface tension, fluorescence, isothermal titration calorimetry (ITC), rheology, freeze-fracture transmission electron microscopy (FF-TEM) and cryogenic transmission electron microscopy (cryo-TEM) methods. R-(EO)-E-R has two large, rigid hydrophobic groups. At low concentrations, R-(EO)-E-R forms micelles with an aggregation number of approximately 10, which is smaller than those of Gemini surfactants containing flexible alkyl tails...
January 19, 2018: Soft Matter
Yuwei Cong, Haihua Xiao, Hejian Xiong, Zigui Wang, Jianxun Ding, Chan Li, Xuesi Chen, Xing-Jie Liang, Dongfang Zhou, Yubin Huang
Most of the current nanoparticle-based therapeutics worldwide failing in clinical trials face three major challenges: (i) lack of an optimum drug delivery platform with precise composition, (ii) lack of a method of directly monitoring the fate of a specific drug rather than using any other labelling molecules as a compromise, and (iii) lack of reliable cancer models with high fidelity for drug screen and evaluation. Here, starting from a PP2A inhibitor demethylcantharidin (DMC) and cisplatin, the design of a dual sensitive dual drug backboned shattering polymer (DDBSP) with exact composition at a fixed DMC/Pt ratio for precise nanomedicine is shown...
January 19, 2018: Advanced Materials
Katherine R Phillips, Tanya Shirman, Elijah Shirman, Anna V Shneidman, Theresa M Kay, Joanna Aizenberg
Inorganic microstructured materials are ubiquitous in nature. However, their formation in artificial self-assembly systems is challenging as it involves a complex interplay of competing forces during and after assembly. For example, colloidal assembly requires fine-tuning of factors such as the size and surface charge of the particles and electrolyte strength of the solvent to enable successful self-assembly and minimize crack formation. Co-assembly of templating colloidal particles together with a sol-gel matrix precursor material helps to release stresses that accumulate during drying and solidification, as previously shown for the formation of high-quality inverse opal (IO) films out of amorphous silica...
January 19, 2018: Advanced Materials
Sergey V Pyrlin, Nicholas D M Hine, Arjan W Kleij, Marta M D Ramos
The recently-observed self-assembly of certain salphen-based compounds into neuron-like networks of microrings interconnected with nano-thin strings may suggest a new highly-potent tool for nanoscale patterning. However, the mechanism behind such phenomena needs to be clarified before they can be applied in materials design. Here we show that, in contrast with what was initially presumed, the emergence of a "rings-and-rods" pattern is unlikely to be explained by merging, collapse and piercing of vesicles as in previously reported cases of nanorings self-assembly via non-bonding interactions...
January 19, 2018: Soft Matter
Martina Banchelli, Marella de Angelis, Cristiano D'Andrea, Roberto Pini, Paolo Matteini
An advanced optofluidic system for protein detection based on Raman signal amplification via dewetting and molecular gathering within temporary mesoscale assemblies is presented. The evaporation of a microliter volume of protein solution deposited in a circular microwell precisely follows an outward-receding geometry. Herein the combination of liquid withdrawal with intermolecular interactions induces the formation of self-assembled molecular domains at the solid-liquid interface. Through proper control of the evaporation rate, amplitude of the assemblies and time for spectral collection at the liquid edge are extensively raised, resulting in a local enhancement and refinement of the Raman response, respectively...
January 18, 2018: Scientific Reports
Enzo Kopperger, Jonathan List, Sushi Madhira, Florian Rothfischer, Don C Lamb, Friedrich C Simmel
The use of dynamic, self-assembled DNA nanostructures in the context of nanorobotics requires fast and reliable actuation mechanisms. We therefore created a 55-nanometer-by-55-nanometer DNA-based molecular platform with an integrated robotic arm of length 25 nanometers, which can be extended to more than 400 nanometers and actuated with externally applied electrical fields. Precise, computer-controlled switching of the arm between arbitrary positions on the platform can be achieved within milliseconds, as demonstrated with single-pair Förster resonance energy transfer experiments and fluorescence microscopy...
January 19, 2018: Science
Kyungtae Kim, Akash Arora, Ronald M Lewis, Meijiao Liu, Weihua Li, An-Chang Shi, Kevin D Dorfman, Frank S Bates
Cooling disordered compositionally asymmetric diblock copolymers leads to the formation of nearly spherical particles, each containing hundreds of molecules, which crystallize upon cooling below the order-disorder transition temperature (TODT). Self-consistent field theory (SCFT) reveals that dispersity in the block degrees of polymerization stabilizes various Frank-Kasper phases, including the C14 and C15 Laves phases, which have been accessed experimentally in low-molar-mass poly(isoprene)-b-poly(lactide) (PI-PLA) diblock copolymers using thermal processing strategies...
January 18, 2018: Proceedings of the National Academy of Sciences of the United States of America
Elsen Tjhung, Ludovic Berthier
Tracking experiments in dense biological tissues reveal a diversity of sources for local energy injection at the cell scale. The effect of cell motility has been largely studied, but much less is known about the effect of the observed volume fluctuations of individual cells. We consider a microscopic model of "actively deforming" particles where local fluctuations of the particle size constitute a unique source of motion. We demonstrate that collective motion can emerge under the sole influence of such active volume fluctuations...
November 2017: Physical Review. E
Nathan Rebello, Vaidyanathan Sethuraman, Gregory Blachut, Christopher J Ellison, C Grant Willson, Venkat Ganesan
Single chain in mean-field Monte Carlo simulations were employed to study the self-assembly of block copolymers (BCP) in thin films that use trapezoidal guidelines to direct the orientation and alignment of lamellar patterns. The present study explored the influence of sidewall interactions and geometry of the trapezoidal guidelines on the self-assembly of perpendicularly oriented lamellar morphologies. When both the sidewall and the top surface exhibit preferential interactions to the same block of the BCP, trapezoidal guidelines with intermediate taper angles were found to result in less defective perpendicularly orientated morphologies...
November 2017: Physical Review. E
Mudi Wang, Chunyin Qiu, Shenwei Zhang, Runzhou Han, Manzhu Ke, Zhengyou Liu
Here we report an experimental observation of the self-organization effect of polystyrene particles formed by acoustically induced interaction forces. Two types of stable configurations are observed experimentally: one is mechanically equilibrium and featured by nonzero interparticle separations, and the other corresponds to a closely packed assembly, which is created by strong attractions among the aggregated particles. For the former case involving two or three particles, the most probable interparticle separations (counted for numerous independent initial arrangements) agree well with the theoretical predictions...
November 2017: Physical Review. E
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"