Influence of particle parameters on deposition onto healthy and damaged human hair.

Objective: This research investigates how particle parameters, such as zeta potential, size, functional group, material composition, and hydrophobicity affect their affinity and deposition of particles onto hair.

Methods: Streaming potential was used as the technique for analysis. The streaming potential data obtained was then converted to surface coverage data.

Extracellular Vesicles and Their Mimetics: A Comparative Study of Their Pharmacological Activities and Immunogenicity Profiles.

Extracellular vesicles (EVs), which are miniaturised carriers loaded with functional proteins, lipids, and nucleic acid material, are naturally secreted by cells and show intrinsic pharmacological effects in several conditions. As such, they have the potential to be used for the treatment of various human diseases. However, the low isolation yield and laborious purification process are obstacles to their translation for clinical use.

Immuno-Modulatory Effects of Microparticles Formulated from Degradable Polystyrene Analogue.

Environmental accumulation of non-degradable polystyrene (PS) microparticles from plastic waste poses potential adverse impact on marine life and human health. Herein, microparticles from a degradable PS analogue (dePS) are formulated and their immuno-modulatory characteristics are comprehensively evaluated. Both dePS copolymer and microparticles are chemically degradable under accelerated hydrolytic condition.

Backbone degradable poly(acrylic acid) analogue via radical ring-opening copolymerization and enhanced biodegradability.

Degradable poly(acrylic acid) has been prepared via free radical ring-opening copolymerization of tert-butyl acrylate and 2-methylene-1,3-dioxepane followed by tert-butyl deprotection, under acidic conditions. The resulting degradable poly(acrylic acid) analogue possesses ester groups within the backbone, which facilitate environmental hydrolysis into short chain oligomers, which subsequently undergo biodegradation. The degradable poly(acrylic acid) reported displays a significant degree of biodegradability (27.

Elucidating the Role of Interfacial Hydrogen Bonds on Glass Transition Temperature Change in a Poly(Vinyl Alcohol)/SiO Polymer-Nanocomposite by Noncovalent Interaction Characterization and Atomistic Molecular Dynamics Simulations.

A thorough experimental investigation of polymer-glass transition temperature (T ) is performed on poly(vinyl alcohol) (PVA) and fumed silica nanoparticle (SiNP) composite. This is done together with atomistic molecular dynamics simulations of PVA systems in contact with bare and fully hydroxylated silica. Experimentally, PVA-SiNP composites are prepared by simple solution casting from aqueous solutions followed by its characterization using Fourier-transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), and dynamic scanning calorimetry (DSC).

A general strategy for degradable single-chain nanoparticles via cross-linker mediated chain collapse of radical copolymers.

Radical ring-opening copolymerization (rROP) between 2-methylene-1,3-dioxepane (MDO) and methacrylic acid N-hydroxysuccinimide ester (NHSMA) furnishes a reactive polyester-based linear copolymer precursor. Subsequent cross-linker mediated chain collapse affords degradable single-chain nanoparticles (DSCNPs). This methodology is an experimentally robust and straightforward route to main-chain degradable polymeric nanoparticles in the sub-30 nm size range.

Unraveling the History and Revisiting the Synthesis of Degradable Polystyrene Analogues via Radical Ring-Opening Copolymerization with Cyclic Ketene Acetals.

Degradable analogues of polystyrene are synthesized via radical ring-opening (co)polymerization (rROP) between styrene and two cyclic ketene acetals, namely 2-methylene-1,3-dioxepane (MDO) and 5,6-benzo-2-methylene-1,3-dioxepane (BMDO). This approach periodically inserts ester bonds throughout the main chain of polystyrene, imparting a degradation pathway via ester hydrolysis. We discuss the historical record of this approach, with careful attention paid to the conflicting findings previously reported.

Nanoparticle-Hydrogel Composites: Concept, Design, and Applications of These Promising, Multi-Functional Materials.

New technologies rely on the development of new materials, and these may simply be the innovative combination of known components. The structural combination of a polymer hydrogel network with a nanoparticle (metals, non-metals, metal oxides, and polymeric moieties) holds the promise of providing superior functionality to the composite material with applications in diverse fields, including catalysis, electronics, bio-sensing, drug delivery, nano-medicine, and environmental remediation. This mixing may result in a synergistic property enhancement of each component: for example, the mechanical strength of the hydrogel and concomitantly decrease aggregation of the nanoparticles.

Nanoparticle cluster arrays for high-performance SERS through directed self-assembly on flat substrates and on optical fibers.

We demonstrate template-guided self-assembly of gold nanoparticles into ordered arrays of uniform clusters suitable for high-performance SERS on both flat (silicon or glass) chips and an optical fiber faucet. Cluster formation is driven by electrostatic self-assembly of anionic citrate-stabilized gold nanoparticles (~11.6 nm diameter) onto two-dimensionally ordered polyelectrolyte templates realized by self-assembly of polystyrene-block-poly(2-vinylpyridine).

Inherently reproducible fabrication of plasmonic nanoparticle arrays for SERS by combining nanoimprint and copolymer lithography.

We present an inherently reproducible route to realizing high-performance SERS substrates by exploiting a high-throughput top-down/bottom-up fabrication scheme. The fabrication route employs self-assembly of amphiphilic copolymers to create high-resolution molds for nanoimprint lithography (NIL) spanning entire 100 mm Si wafers. The nanoporous polymer templates obtained upon NIL are subjected to galvanic displacement reactions to create gold nanorod arrays.

Effect of polyvinylpyrrolidone on the interaction of chlorin e6 with plasma proteins and its subcellular localization.

A photophysical study describing the effects of the polymer polyvinylpyrrolidone (PVP), on the binding interaction between chlorin e6 (Ce6) with bovine serum albumin (BSA) and human plasma proteins such as very low-density lipoprotein (VLDL), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) was performed using a steady-state fluorescence technique. Combined Ce6-PVP was found to have very stable photostability at three different temperatures (4°C, 21°C and 37°C) when dissolved in an aqueous solution containing 5% and 10% fetal calf serum. The partition coefficient of combined Ce6-PVP was relatively more hydrophilic than that of Ce6 alone.

Combinatorial synthesis of a triphenylmethine library and their application in the development of surface enhanced Raman scattering (SERS) probes.

The first synthesis of a triphenylmethine (TM) library of compounds and screening of their Surface Enhanced Raman Scattering (SERS) capability was carried out to identify novel Raman reporters with high sensitivity. We identified three novel SERS reporters (B2, B7, and C7) with higher signal intensity than that of commonly used crystal violet (CV). These reporters may find potential applications in developing sensitive SERS based biosensors.

Continuous glucose sensing with fluorescent thin-film hydrogels. 2. Fiber optic sensor fabrication and in vitro testing.

Background: There continues to be a need for better sensors for continuous glucose monitoring. We are working on a two-component sensing system based on a viologen boronic acid and a fluorescent dye, which are immobilized in a hydrogel. This system has the potential for further development into a real-time glucose-monitoring device.

The interaction of boronic acid-substituted viologens with pyranine: the effects of quencher charge on fluorescence quenching and glucose response.

The fluorescence sensing of several monosaccharides using boronic acid-substituted viologen quenchers in combination with the fluorescent dye pyranine (HPTS) is reported. In this two-component sensing system, fluorescence quenching by the viologen is modulated by monosaccharides to provide a fluorescence signal. A series of viologen quenchers with different charges were prepared and tested for their ability both to quench the fluorescence of HPTS and to sense changes in glucose concentration in aqueous solution at pH 7.

Optical glucose detection across the visible spectrum using anionic fluorescent dyes and a viologen quencher in a two-component saccharide sensing system.

A very general system is described in which anionic fluorescent dyes possessing a wide range of absorbance and emission wavelengths are used in combination with a boronic acid-modified viologen quencher to sense glucose at pH 7.4 in buffered aqueous solution. The present study demonstrates this capability with the use of eleven anionic fluorescent dyes of various structural types.