Fibril motion improves peptide signaling Artificial scaffolds that bear the peptide-signaling sequences of proteins for tissue regeneration often have limited effectiveness. Álvarez et al . synthesized supramolecular fibril bearing two promote nerve regeneration, one reduces glial scarring and another promotes blood vessel formation (see Perspective by Wojciechowski Stevens). In a mouse model paralyzing human spinal cord injury, mutations in tetrapeptide domain outside regions improved...

Abstract Mechanical expansion and contraction of pores within photosynthetic organisms regulate a series processes that are necessary to manage light absorption, control gas exchange, water loss. These pores, known as stoma, allow the plant maximize output depending on environmental conditions such intensity, humidity, temperature by actively changing size stomal opening. Despite advances in artificial systems, little is about effect mechanical actuation synthetic materials where chemical...

We show that amorphous calcium carbonate (ACC) can be synthesized in phospholipid bilayer vesicles (liposomes). Liposome-encapsulated ACC nanoparticles are stable against aggregation, do not crystallize for at least 20 h, and ideally suited to investigate the influence of lipid chemistry, particle size, soluble additives on situ.

The realization of the full potential for polymeric nanocomposites to manifest their entitled property improvements relies, some properties, on ability achieve maximum particle–matrix interfacial area. Well-dispersed incorporating colloidal silica as filler can be realized in both polystyrene and poly(methyl methacrylate) matrices by exploiting charge stabilized nature nonaqueous solvents which act Bronsted bases. We demonstrate that dispersions dimethylformamide are stabilized, regardless...

Currently, carbon fibers (CFs) from the solution spinning, air oxidation, and carbonization of polyacrylonitrile impose a lower price limit ≈$10 per lb, limiting growth in industrial automotive markets. Polyethylene is promising precursor to enable high‐volume grade CF as it low cost, melt spinnable has high content. However, sulfonated polyethylene (SPE)‐derived CFs have thus far fallen short 200 GPa tensile modulus threshold for applicability. Here, graphitization process presented...

Over the past decade, a wealth of complexity has been reported in packing compositionally asymmetric, particle-forming diblock copolymer melts, beginning with discovery Frank–Kasper σ phase and continuing subsequent discoveries dodecagonal quasicrystal C14, C15, A15 phases. First identified by self-consistent mean-field theory (SCFT), blending copolymers proven to be useful strategy extending these packings new chemistries length scales. However, much immense space created on two remains...

Abstract Herein, phase transitions of a class thermally-responsive polymers, namely homopolymer, diblock, and triblock copolymer, were studied to gain mechanistic insight into nanoscale assembly dynamics via variable temperature liquid-cell transmission electron microscopy (VT-LCTEM) correlated with small angle X-ray scattering (VT-SAXS). We study thermoresponsive poly(diethylene glycol methyl ether methacrylate) (PDEGMA)-based block copolymers mitigate sample damage by screening flux...

Block copolymers (BCPs) self-assembled into 3D network phases are promising for designing useful materials with multiple properties that rely on domain continuity. However, access to potential applications has been limited because formation linear BCPs tends occur only over narrow compositional windows. Another constraint is slow self-assembly kinetics at higher molecular weights, which limits the unit cell dimensions and resulting material properties. Architecturally asymmetric,...

The functionality of supramolecular nanostructures can be expanded if systems containing multiple components are designed to either self-sort or mix into coassemblies. This is critical gain the ability craft self-assembling materials that integrate functions, and our understanding this process in its early stages. In work, we have utilized three different peptide amphiphiles with capacity form β-sheets within found binary others was measured using atomic force microscopy reveal nanoscale...

Surfactant vesicles containing monomers in the interior of bilayer were used to template hollow polymer nanocapsules. This study investigated formation surfactant/monomer assemblies by two loading methods, concurrent and diffusion loading. The assembly process resulting aggregates with dynamic light scattering, small angle neutron small-angle X-ray scattering. Acrylic formed a mixture cationic anionic surfactants broad range surfactant ratios. Regions predominant broader for compositions...

Colloidal crystal engineering with DNA has advanced beyond controlling the lattice symmetry and parameters of ordered crystals to now tuning habit size. However, predominately used slow-cooling procedure that enables faceted habits also limits control over size uniformity because nucleation growth cannot be separated. Here, we explore how sequence design can deliberately separate in a given crystallization process. Specifically, two batches complementary particles are created one batch...

The DNA gyrase negative supercoiling mechanism involves the assembly of a large gyrase/DNA complex and conformational rearrangements coupled to ATP hydrolysis. To establish arrangement that directs reaction towards supercoiling, bacterial complexes bound 137- or 217-bp fragments representing starting state catalytic cycle were characterized by sedimentation velocity small-angle X-ray scattering (SAXS) experiments. experiments revealed elongated with hydrodynamic radii 70–80 Å. Molecular...

The circadian clock in the cyanobacterium Synechococcus elongatus is composed of a post-translational oscillator (PTO) that can be reconstituted vitro from three different proteins presence ATP and transcription-translation feedback loop (TTFL). homo-hexameric KaiC kinase, phosphatase ATPase alternates between hypo- hyper-phosphorylated states over 24-h cycle, with KaiA enhancing phosphorylation, KaiB antagonizing promoting subunit exchange. SasA His kinase relays output signals PTO formed...

A good dispersion of carbon nanotube (CNT) in polyvinylidene fluoride (PVDF) is realized by using CNT and BaTiO3 (BT) hybrids (H-CNT-BT) with a special core–shell structure. Thus, high dielectric performance achieved for the composite (H-CNT-BT/PVDF). Carried BT, easy to connect each other thus more interface area may be created which helps achieve an extremely low percolation threshold (fc). Moreover, permittivity near fc increased than three times after thermal treatment while loss remains...

Reanalysis of an asymmetric poly(ethylene-alt-propylene)-block-polydimethylsiloxane (PEP-PDMS) diblock copolymer first investigated in 1999 has revealed a rich phase behavior including dodecagonal quasicrystal (DDQC), Frank–Kasper σ phase, and body-centered cubic (BCC) packing at high temperature adjacent to the disordered state. On subjecting sample large amplitude oscillatory shear well below σ-BCC order–order transition (TOOT), small-angle X-ray scattering evidenced emergence twinned BCC...

Peptide-brush polymers (PBPs), wherein every side-chain of the is peptidic, represent a new class proteomimetic with unusually high proteolytic resistance while maintaining bioactivity. Here, we sought to determine origin this behavior and assess its generality via combined theory experimental approach. A series PBPs various polymer backbone structures were prepared examined for their stability We discovered that an increase in hydrophobicity backbones predictive elevation peptides. Computer...

We report the sensitivity of diblock copolymer particle packing symmetry to ratio α = Nhomo/Ncore, where Nhomo and Ncore are respective homopolymer core-block degrees polymerization. Three poly(ethylene oxide)-b-poly(2-ethylhexyl acrylate) (OA) copolymers with O volume fractions fO 0.15, 0.16, 0.20 were blended homopolymers characterized by 0.23, 0.42, 0.80, 1.00. Small-angle X-ray scattering revealed rich phase behavior as a function α, overall core fraction (fcore), temperature. BCC, HCP,...

Biomineralizing organisms frequently precipitate minerals in small phospholipid bilayer-delineated compartments. We have established an vitro model system to investigate the effect of confinement attoliter femtoliter volumes on precipitation calcium carbonate. In particular, we analyze growth and stabilization liposome-encapsulated amorphous carbonate (ACC) nanoparticles using a combination situ techniques, cryo-transmission electron microscopy (Cryo-TEM), angle X-ray scattering (SAXS)....

We have applied small angle x-ray scattering and protein cross-linking coupled with mass spectrometry to determine the architectures of full-length HIV integrase (IN) dimers in solution. By blocking interactions that stabilize either a core-core domain interface or N-terminal intermolecular contacts, we show IN can form two dimer types. One is an expected dimer, characterized by between catalytic core domains. The other stabilized one monomer C-terminal second as well direct This...

The chemical interactions that lead to the emergence of hierarchical structures are often highly complex and difficult program. Herein, synthesis a series superlattices based upon 30 different structurally reconfigurable DNA dendrimers is reported, each which presents well-defined number single-stranded oligonucleotides (i.e., sticky ends) on its surface. Such building blocks assemble with complementary DNA-functionalized gold nanoparticles (AuNPs) yield five distinct crystal structures,...