Stimuli-Responsive Phosphate Hydrogel: A Study on Swelling Behavior, Mechanical Properties, and Application in Expansion Microscopy.

Phosphorus-based stimuli-responsive hydrogels have potential in a wide range of applications due to their ionizable phosphorus groups, biocompatibility, and tunable swelling capacity utilizing hydrogel design parameters and external stimuli. In this study, poly(2-methacryloyloxyethyl phosphate) (PMOEP) hydrogels were synthesized via aqueous activators regenerated by electron transfer atomic transfer radical polymerization using ascorbic acid as the reducing agent. Swelling and deswelling behaviors of PMOEP hydrogels were examined in different salt solutions, pH conditions, and temperatures.

Solution and Film Self-Assembly Behavior of a Block Copolymer Composed of a Poly(ionic Liquid) and a Stimuli-Responsive Weak Polyelectrolyte.

Cu(0)-mediated atom transfer radical polymerization was used to synthesize a poly(ionic liquid), poly[4-vinylbenzyl-3-butylimidazolium bis(trifluoromethylsulfonyl)imide] (PVBBImTfN), a stimuli-responsive polyelectrolyte, poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA), and a novel block copolymer formed from these two polymers. The synthesis of the block copolymer, poly[2-(dimethylamino) ethyl methacrylate]--[poly(4-vinylbenzyl-3-butylimidazolium bis(trifluoromethylsulfonyl)imide] (PDMAEMA--PVBBImTfN), was examined to evaluate the control of "livingness" polymerization, as indicated by molecular weight, characterizations of degree of polymerization, and HNMR spectroscopy. 2D DOSY NMR measurements revealed the successful formation of block copolymer and the connection between the two polymer blocks.

Chemically Edge-Carboxylated Graphene Enhances the Thermal Conductivity of Polyetherimide-Graphene Nanocomposites.

In this work, we demonstrate that edge oxidation of graphene can enable larger enhancement in thermal conductivity () of graphene nanoplatelet (GnP)/polyetherimide (PEI) composites relative to oxidation of the basal plane of graphene. Edge oxidation offers the advantage of leaving the basal plane of graphene intact, preserving its high in-plane thermal conductivity ( > 2000 W m K), while, simultaneously, the oxygen groups introduced on the graphene edge enhance interfacial thermal conductance through hydrogen bonding with oxygen groups of PEI, enhancing the overall polymer composite thermal conductivity. Edge oxidation is achieved in this work by oxidizing graphene in the presence of sodium chlorate and hydrogen peroxide, thereby introducing an excess of carboxyl groups on the edge of graphene.

Mesoporous Silica Nanoparticles: Properties and Strategies for Enhancing Clinical Effect.

Due to the theragnostic potential of mesoporous silica nanoparticles (MSNs), these were extensively investigated as a novel approach to improve clinical outcomes. Boasting an impressive array of formulations and modifications, MSNs demonstrate significant in vivo efficacy when used to identify or treat myriad malignant diseases in preclinical models. As MSNs continue transitioning into clinical trials, a thorough understanding of the characteristics of effective MSNs is necessary.

Chemical and Microstructural Characterization of pH and [Ca] Dependent Sol-Gel Transitions in Mucin Biopolymer.

Mucus is responsible for controlling transport and barrier function in biological systems, and its properties can be significantly affected by compositional and environmental changes. In this study, the impacts of pH and CaCl were examined on the solution-to-gel transition of mucin, the primary structural component of mucus. Microscale structural changes were correlated with macroscale viscoelastic behavior as a function of pH and calcium addition using rheology, dynamic light scattering, zeta potential, surface tension, and FTIR spectroscopic characterization.

Computational and experimental approach to understanding the structural interplay of self-assembled end-terminated alkanethiolates on gold surfaces.

Applications of self-assembled monolayers (SAMs) on surfaces are prevalent in modern technologies and drives the need for a better understanding of the surface domain architecture of SAMs. To explore structural interaction at the interface between gold surfaces and a hydroxyl-terminated alkanethiol, 11-hydroxy-1-undecanethiol, (C11TH) we have employed a combined computational and experimental approach. Density functional theory (DFT) calculations were carried out on the thiol-gold interface using both the Perdew-Burke-Ernzerhof (PBE) and van der Waals (optB86b) density functionals.

Constant pH simulations of pH responsive polymers.

Polyacidic polymers can change structure over a narrow range of pH in a competition between the hydrophobic effect, which favors a compact state, and electrostatic repulsion, which favors an extended state. Constant pH molecular dynamics computer simulations of poly(methacrylic acid) reveal that there are two types of structural changes, one local and one global, which make up the overall response. The local structural response depends on the tacticity of the polymer and leads to different cooperative effects for polymers with different stereochemistries, demonstrating both positive and negative cooperativities.

Bioluminescent magnetic nanoparticles as potential imaging agents for mammalian spermatozoa.

Background: Nanoparticles have emerged as key materials for developing applications in nanomedicine, nanobiotechnology, bioimaging and theranostics. Existing bioimaging technologies include bioluminescent resonance energy transfer-conjugated quantum dots (BRET-QDs). Despite the current use of BRET-QDs for bioimaging, there are strong concerns about QD nanocomposites containing cadmium which exhibits potential cellular toxicity.

Fetuin-A adsorption and stabilization of calcium carbonate nanoparticles in a simulated body fluid.

Fetuin-A is a serum glycoprotein identified as a calcification inhibitor, and a key player in bone formation and human metabolic processes. A study on binding mechanisms of Fetuin-A with calcium carbonate nanoparticles in a simulated body fluid (DMEM) environment is presented. Observed interactions between Fetuin-A and the CaCO nanoparticles reveal an initial adsorption process, followed by a stabilization stage, and then a solubilization period for the Fetuin-A/CaCO complex.

SILAC-based quantitative proteomic analysis of human lung cell response to copper oxide nanoparticles.

Copper (II) oxide (CuO) nanoparticles (NP) are widely used in industry and medicine. In our study we evaluated the response of BEAS-2B human lung cells to CuO NP, using Stable isotope labeling by amino acids in cell culture (SILAC)-based proteomics and phosphoproteomics. Pathway modeling of the protein differential expression showed that CuO NP affect proteins relevant in cellular function and maintenance, protein synthesis, cell death and survival, cell cycle and cell morphology.

Janus magnetic nanoparticles with a bicompartmental polymer brush prepared using electrostatic adsorption to facilitate toposelective surface-initiated ATRP.

Utilizing the inherent negative charge of mica surfaces, amine-functionalized magnetic nanoparticles (Fe3O4/NH2) were electrostatically adsorbed onto the mica such that surface-initiated ATRP could be used to grow poly(n-isopropylacrylamide) (PNIPAM) from the exposed hemisphere. By reducing the solution pH, a positive charge generated on the mica was used to release the nanoparticles from the substrate. A second ATRP reaction was carried out to grow poly(methacrylic acid) (PMAA) from the initiated surfaces.

The effects of water and microstructure on the mechanical properties of bighorn sheep (Ovis canadensis) horn keratin.

The function of the bighorn sheep horn prompted quantification of the various parametric effects important to the microstructure and mechanical property relationships of this horn. These parameters included analysis of the stress-state dependence with the horn keratin tested under tension and compression, the anisotropy of the material structure and mechanical behavior, the spatial location along the horn, and the wet-dry horn behavior. The mechanical properties of interest were the elastic moduli, yield strength, ultimate strength, failure strain and hardness.

XPS study on the use of 3-aminopropyltriethoxysilane to bond chitosan to a titanium surface.

Chitosan, a biopolymer found in the exoskeletons of shellfish, has been shown to be antibacterial, biodegradable, osteoconductive, and has the ability to promote organized bone formation. These properties make chitosan an ideal material for use as a bioactive coating on medical implant materials. In this study, coatings made from 86.