Browse
Submit Data
Databases
API
Help

Dataset Information

28 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Tuning the mechanical properties of self-assembled mixed-peptide tubes.

ABSTRACT: In this study, nano- and microscale fibrillar and tubular structures formed by mixing two aromatic peptides known to self-assemble separately, (diphenylalanine and di-D-2-napthylalanine) have been investigated. The morphology, mechanical strength and thermal stability of the tubular structures formed have been studied. The tubes are shown to consist of both peptides with some degree of nanoscale phase separation. The ability of the mixed peptides to form structures, which display variable mechanical properties dependent on the percentage composition of the peptides is presented. Such materials with tuneable properties will be required for a range of applications in nanotechnology and biotechnology.

SUBMITTER: Sedman VL

PROVIDER: S-EPMC3601425 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Tuning the mechanical properties of self-assembled mixed-peptide tubes.

Sedman V L VL Chen X X Allen S S Roberts C J CJ Korolkov V V VV Tendler S J B SJ

Journal of microscopy 20130111 3

In this study, nano- and microscale fibrillar and tubular structures formed by mixing two aromatic peptides known to self-assemble separately, (diphenylalanine and di-D-2-napthylalanine) have been investigated. The morphology, mechanical strength and thermal stability of the tubular structures formed have been studied. The tubes are shown to consist of both peptides with some degree of nanoscale phase separation. The ability of the mixed peptides to form structures, which display variable mechan ...[more]

PMID: 23305211

Similar Datasets

Modulating the mechanical properties of self-assembled peptide hydrogels via native chemical ligation.

Project description:Hydrogels produced from self-assembling peptides and peptide derivatives are being investigated as synthetic extracellular matrices for defined cell culture substrates and scaffolds for regenerative medicine. In many cases, however, they are less stiff than the tissues and extracellular matrices they are intended to mimic, and they are prone to cohesive failure. We employed native chemical ligation to produce peptide bonds between the termini of fibrillized beta-sheet peptides to increase gel stiffness in a chemically specific manner while maintaining the morphology of the self-assembled fibrils. Polymerization, fibril structure, and mechanical properties were measured by SDS-PAGE, mass spectrometry, TEM, circular dichroism, and oscillating rheometry; and cellular responses to matrix stiffening were investigated in cultures of human umbilical vein endothelial cells (HUVECs). Ligation led to a fivefold increase in storage modulus and a significant enhancement of HUVEC proliferation and expression of CD31 on the surface of the gels. The approach was also orthogonal to the inclusion of unprotected RGD-functionalized self-assembling peptides, which further increased proliferation. This strategy broadens the utility of self-assembled peptide materials for applications that require enhancement or modulation of matrix mechanical properties by providing a chemoselective means for doing so without significantly disrupting the gels' fibrillar structure.

| S-EPMC2330262 | biostudies-literature

Tuning the thermoelectrical properties of anthracene-based self-assembled monolayers.

Project description:It is known that the electrical conductance of single molecules can be controlled in a deterministic manner by chemically varying their anchor groups to external electrodes. Here, by employing synthetic methodologies to vary the terminal anchor groups around aromatic anthracene cores, and by forming self-assembled monolayers (SAMs) of the resulting molecules, we demonstrate that this method of control can be translated into cross-plane SAM-on-gold molecular films. The cross-plane conductance of SAMs formed from anthracene-based molecules with four different combinations of anchors are measured to differ by a factor of approximately 3 in agreement with theoretical predictions. We also demonstrate that the Seebeck coefficient of such films can be boosted by more than an order of magnitude by an appropriate choice of anchor groups and that both positive and negative Seebeck coefficients can be realised. This demonstration that the thermoelectric properties of SAMs are controlled by their anchor groups represents a critical step towards functional ultra-thin-film devices for future molecular-scale electronics.

| S-EPMC7504895 | biostudies-literature

Tuning self-assembled nanostructures through enzymatic degradation of a peptide amphiphile.

Project description:The enzymatic cleavage of a peptide amphiphile (PA) is investigated. The self-assembly of the cleaved products is distinct from that of the PA substrate. The PA C16-KKFFVLK is cleaved by ?-chymotrypsin at two sites leading to products C16-KKF with FVLK and C16-KKFF with VLK. The PA C16-KKFFVLK forms nanotubes and helical ribbons at room temperature. Both PAs C16-KKF and C16-KKFF corresponding to cleavage products instead self-assemble into 5-6 nm diameter spherical micelles, while peptides FVLK and VLK do not adopt well-defined aggregate structures. The secondary structures of the PAs and peptides are examined by FTIR and circular dichroism spectroscopy and X-ray diffraction. Only C16-KKFFVLK shows substantial ?-sheet secondary structure, consistent with its self-assembly into extended aggregates, based on PA layers containing hydrogen-bonded peptide headgroups. This PA also exhibits a thermoreversible transition to twisted tapes on heating.

| S-EPMC3678293 | biostudies-literature

Photophysical Properties of Fluorescent Self-Assembled Peptide Nanostructures for Singlet Oxygen Generation.

Project description:In this work, a drug delivery system for perillyl alcohol based on the peptide self-assembly containing 3-(2-benzothiazolyl)-7-(diethylamino)coumarin (C6) as a fluorescent additive is obtained, and its photophysical characteristics as well as its release dynamics were studied by steady-state and time-resolved fluorescence spectroscopy. Results proved the dynamics of drug release from the peptide nanostructures and showed that the system formed by the self-assembled peptide and C6, along with perillyl alcohol, presents unique photophysical properties that can be exploited to generate singlet oxygen (1O2) upon irradiation, which is not achieved by the sole components. Through epifluorescence microscopy combined with time-correlated single photon counting fluorescence spectroscopy, the release mechanism was proven to occur upon peptide structure interconversion, which is controlled by environmental changes.

| S-EPMC7178805 | biostudies-literature

Self-Assembled Polyvinyl Alcohol-Tannic Acid Hydrogels with Diverse Microstructures and Good Mechanical Properties.

Project description:Fabrication of hydrogels with unique microstructures and better mechanical properties through the self-assembly of commercially available synthetic polymers and small molecules is of great scientific and practical importance. A type of physical hydrogels is prepared by the self-assembly of polyvinyl alcohol (PVA) and tannic acid (TA) in aqueous solution with a low PVA-TA concentration (0.5-6.0 wt %) at room temperature. With the increase of the PVA-TA concentration, the water content of the hydrogels increases, and the content of TA in the hydrogels decreases from 23.1 to 6.4%. The driving force for the self-assembly is proven to be the hydrogen bonding between PVA and TA, which also induces the crystallization of PVA chains. The self-assembled PVA-TA hydrogels have diverse morphologies that change from microspheres to oriented porous structures with the increase of the PVA-TA concentration, and these structures are all composed of nanosized particles, fibers, and/or sheets. Most of the self-assembled PVA-TA hydrogels show good mechanical properties. The highest tensile strength and elastic modulus of the PVA-TA hydrogel prepared with 1.0 wt % PVA-TA concentration are about 84 and 30 kPa, respectively. This self-assembly method would lead to the fabrication of more hydrogels with unique microstructures and properties for practical applications.

| S-EPMC6645311 | biostudies-literature

Self-Assembled DNA Tubes Forming Helices of Controlled Diameter and Chirality.

Project description:Multihelical DNA bundles could enhance the functionality of nanomaterials and serve as model architectures to mimic protein filaments on the molecular and cellular level. We report the self-assembly of micrometer-sized helical DNA nanotubes with widely controllable helical diameters ranging from tens of nanometers to a few micrometers. Nanoscale helical shapes of DNA tile tubes (4-, 6-, 8-, 10-, and 12-helix tile tubes) are achieved by introducing discrete amounts of bending and twist through base pair insertions and/or deletions. Microscale helical diameters, which require smaller amounts of twist and bending, are achieved by controlling the intrinsic "supertwist" present in tile tubes with uneven number of helices (11-, 13-, and 15-helix tile tubes). Supertwist fine-tuning also allows us to produce helical nanotubes of defined chirality.

| S-EPMC6544521 | biostudies-literature

Fluorine-Containing, Self-Assembled Graft Copolymer for Tuning the Hydrophilicity and Antifouling Properties of PVDF Ultrafiltration Membranes.

Project description:Neat poly(vinylidene fluoride) (PVDF) ultrafiltration (UF) membranes exhibit poor water permeance and surface hydrophobicity, resulting in poor antifouling properties. Herein, we report the synthesis of a fluorine-containing amphiphilic graft copolymer, poly(2,2,2-trifluoroethyl methacrylate)-g-poly(ethylene glycol) behenyl ether methacrylate (PTFEMA-g-PEGBEM), hereafter referred to as PTF, and its effect on the structure, morphology, and properties of PVDF membranes. The PTF graft copolymer formed a self-assembled nanostructure with a size of 7-8 nm, benefiting from its amphiphilic nature and microphase separation ability. During the nonsolvent-induced phase separation (NIPS) process, the hydrophilic PEGBEM chains were preferentially oriented towards the membrane surface, whereas the superhydrophobic PTFEMA chains were confined in the hydrophobic PVDF matrix. The PTF graft copolymer not only increased the pore size and porosity but also significantly improved the surface hydrophilicity, flux recovery ratio (FRR), and antifouling properties of the membrane. The membrane performance was optimal at 5 wt.% PTF loading, with a water permeance of 45 L m-2 h-1 bar-1, a BSA rejection of 98.6%, and an FRR of 83.0%, which were much greater than those of the neat PVDF membrane. Notably, the tensile strength of the membrane reached 6.34 MPa, which indicated much better mechanical properties than those reported in the literature. These results highlight the effectiveness of surface modification via the rational design of polymer additives and the precise adjustment of the components for preparing membranes with high performance and excellent mechanical properties.

| S-EPMC10490059 | biostudies-literature

The electronic structure of mixed self-assembled monolayers.

Project description:The electronic structure of mixed self-assembled monolayers (SAMs) on Au(111) surfaces is modeled using slab-type density-functional theory calculations. The studied molecules have a dipolar character induced by polar and electron donating or accepting tail-group substituents. The resulting electronic structure of mixed layers is found to differ qualitatively from a simple superposition of those of the respective pure layers. Specifically, the positions of the frontier electronic states are shifted relative to the metal Fermi level, with the sign and magnitude of that shift depending on the dipole moment of the molecules and the mixing ratio in the film. This appears counterintuitive considering previous investigations, in which it has been shown that, for densely packed layers, tail-group substituents have no impact on the interfacial energy-level alignment. The seeming contradiction can be lifted by considering the local electrostatic interactions within the films in both mixed and homogeneous monolayers. Beyond that, we show that mixed SAMs provide an efficient tool for continuously tuning substrate work functions over a range that far exceeds that accessible by merely changing the coverage of homogeneous layers, with the net effect depending linearly on the mixing ratio in agreement with recent experimental findings.

| S-EPMC3011841 | biostudies-other

Non-destructive detection of matrix stabilization correlates with enhanced mechanical properties of self-assembled articular cartilage.

Project description:Tissue engineers rely on expensive, time-consuming, and destructive techniques to monitor the composition, microstructure, and function of engineered tissue equivalents. A non-destructive solution to monitor tissue quality and maturation would greatly reduce costs and accelerate the development of tissue-engineered products. The objectives of this study were to (a) determine whether matrix stabilization with exogenous lysyl oxidase-like protein-2 (LOXL2) with recombinant hyaluronan and proteoglycan link protein-1 (LINK) would result in increased compressive and tensile properties in self-assembled articular cartilage constructs, (b) evaluate whether label-free, non-destructive fluorescence lifetime imaging (FLIm) could be used to infer changes in both biochemical composition and biomechanical properties, (c) form quantitative relationships between destructive and non-destructive measurements to determine whether the strength of these correlations is sufficient to replace destructive testing methods, and (d) determine whether support vector machine (SVM) learning can predict LOXL2-induced collagen crosslinking. The combination of exogenous LOXL2 and LINK proteins created a synergistic 4.9-fold increase in collagen crosslinking density and an 8.3-fold increase in tensile strength as compared with control (CTL). Compressive relaxation modulus was increased 5.9-fold with addition of LOXL2 and 3.4-fold with combined treatments over CTL. FLIm parameters had strong and significant correlations with tensile properties (R2 = 0.82; p < 0.001) and compressive properties (R2 = 0.59; p < 0.001). SVM learning based on FLIm-derived parameters was capable of automating tissue maturation assessment with a discriminant ability of 98.4%. These results showed marked improvements in mechanical properties with matrix stabilization and suggest that FLIm-based tools have great potential for the non-destructive assessment of tissue-engineered cartilage.

| S-EPMC6461514 | biostudies-literature

Tuning whispering gallery mode lasing from self-assembled polymer droplets.

Project description:Optical microcavities are important for both fundamental studies of light-matter interaction and applications such as microlasers, optical switches and filters etc... Tunable microresonators, in which resonant modes can be manipulated, are especially fascinating. Here we demonstrate a unique approach to mechanically tuning microresonators formed by polymer droplets with varying sizes. The droplets are self-assembly inside an elastic medium. By incorporating different dye molecules into the droplets, optically pumped lasing with selective wavelengths in a range of about 100 nm are achieved. Lasing action is ascribed to whispering gallery modes, verified by rigorous characterizations. Single longitudinal mode lasing is obtained when the droplet diameter is reduced to about 14 μm. Tuning lasing modes are clearly demonstrated by mechanical deformation. Our finding provides an excellent platform for exploring flexible and tunable microlasers for plastic optoelectronic devices.

| S-EPMC3584906 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data