Upconverting Nanoparticles Coated with Light-Breakable Mesoporous Silica for NIR-Triggered Release of Hydrophobic Molecules.

Upconverting nanoparticles (UCNPs) doped with Yb and Tm are near-infrared (NIR) to ultraviolet (UV) transducers that can be used for NIR-controlled drug delivery. However, due to the low quantum yield of upconversion, high laser powers and long irradiation times are required to trigger this drug release. In this work, we report the one-step synthesis of a nanocomposite consisting of a LiYbF:Tm@LiYF UCNP coated with mesoporous UV-breakable organosilica shells of various thicknesses.

Altered Foreign Body Response at the Posterior Surface Compared to the Anterior Surface of Human Silicone Breast Implants.

Soft implantable devices are crucial to optimizing form and function for many patients. However, periprosthetic capsule fibrosis is one of the major challenges limiting the use of implants. Currently, little is understood about how spatial and temporal factors influence capsule physiology and how the local capsule environment affects the implant structure.

Relationship between stream size, watershed land use, and pesticide concentrations in headwater streams.

A quantitative multiresidue study of current-use pesticides in multiple matrices was undertaken with field sampling at 32 headwater streams near Lac Saint-Pierre in Québec, Canada. A total of 232 samples were collected in five campaigns of stream waters and streambed sediments from streams varying in size and watershed land use. Novel multiresidue analytical methods from previous work were successfully applied for the extraction of pesticide residues from sediments via pressurized liquid extraction (PLE) and quantitative analysis using ultra high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) with online sample preparation on a hydrophilic-lipophilic balance (HLB) column.

Occurrence and removal of legacy plasticizers and flame retardants through a drinking water treatment plant.

The occurrence of thirty-four flame retardants and plasticizers throughout treatment steps in a drinking water treatment plant (DWTP) was analyzed to assess removal efficiencies of filtration, ultraviolet (UV) treatment, and chlorination. Legacy compounds and replacements were included to compare their presence and persistence. Twenty-four-hour composite sampling, offset to account for retention time, was performed at a direct filtration DWTP in Montreal, Canada over a three-day period.

ZAFG Method for Quantitative Characterization of Spherical Particles: Deriving a Universal Equation for Geometrical Correction.

This study introduces a universal equation to calculate the geometrical correction factor (G) as the fourth factor in the conventional ZAF method for quantifying spherical particles (specifically, NIST-K411 glass microspheres mounted on bulk carbon substrate). Note that the fluorescence correction factor (F) is not considered in this study. Our findings demonstrate that the G factor, as a function of the particle diameter (D) and the range of emitted X-rays in a bulk sample (Xe), provides the best model.

Multiresidue method for the fast and efficient analysis of current-use pesticides in streambed sediments using pressurized liquid extraction.

A multiresidue method for the fast and efficient analysis of current-use pesticides in streambed sediments is reported. The method employs pressurized liquid extraction (PLE) for the automated extraction of pesticide residues from small quantities (5 g) of lyophilized sediment samples. Various PLE parameters, including the extraction solutions and oven temperature, were optimized for thirty diverse current-use pesticides (CUPs) known to be commonly applied to corn and soybean monoculture crops.

pH-Responsive Reversible Granular Hydrogels Based on Metal-Binding Mussel-Inspired Peptides.

Taking advantage of their thixotropic behavior, microporosity, and modular properties, granular hydrogels formed from jammed hydrogel microparticles have emerged as an exciting class of soft, injectable materials useful for numerous applications, ranging from the production of biomedical scaffolds for tissue repair to the therapeutic delivery of drugs and cells. Recently, the annealing of hydrogel microparticles in situ to yield a porous bulk scaffold has shown numerous benefits in regenerative medicine, including tissue-repair applications. Current annealing techniques, however, mainly rely either on covalent connections, which produce static scaffolds, or transient supramolecular interactions, which produce dynamic but mechanically weak hydrogels.

An ultrasensitive FET biosensor based on vertically aligned MoS nanolayers with abundant surface active sites.

Molybdenum disulfide (MoS) nanolayers are one of the most promising two-dimensional (2D) nanomaterials for constructing next-generation field-effect transistor (FET) biosensors. In this article, we report an ultrasensitive FET biosensor that integrates a novel format of 2D MoS, vertically-aligned MoS nanolayers (VAMNs), as the channel material for label-free detection of the prostate-specific antigen (PSA). The developed VAMNs-based FET biosensor shows two distinctive advantages.

Fast and simplified quantitative multiresidue analytical method for pesticides in surface waters by UHPLC-MS/MS with online sample preparation.

A quantitative multiresidue analytical method for the simultaneous analysis of current-use agricultural pesticides in surface waters is reported. The method involves minimal sample manipulation and small sample collection volumes (for 1 mL and 5 mL injections) with online sample clean-up and analyte preconcentration on a hydrophilic-lipophilic balance (HLB) column. To our knowledge, this online approach with the use of an HLB column has not yet been reported for multiresidue pesticide analysis in surface waters.

Application of photocatalytic ozonation with a WO/TiO catalyst for PFAS removal under UVA/visible light.

This research evaluates photocatalytic ozonation for removing 5 PFAS (PFOA/PFHxS/PFBS/6:2 FTS/GenX) from water using a WO/TiO catalyst under UVA-visible radiation. Four catalysts of varying WO content (0/1/3/5 wt%) were synthesized by sol-gel and characterized by XRD, TEM, STEM-EDS, HAADF-STEM, adsorption/desorption N isotherms, and DRS-UV-vis. 5 wt% WO/TiO was the optimal composition based on physicochemical properties and photocatalytic activity tests with methylene blue.

The case for cancer-associated fibroblasts: essential elements in cancer drug discovery?

Although cancer-associated fibroblasts (CAFs) have gained increased attention for supporting cancer progression, current CAF-targeted therapeutic options are limited and failing in clinical trials. As the largest component of the tumor microenvironment (TME), CAFs alter the biochemical and physical structure of the TME, modulating cancer progression. Here, we review the role of CAFs in altering drug response, modifying the TME mechanics and the current models for studying CAFs.

A microfluidic field-effect transistor biosensor with rolled-up indium nitride microtubes.

Field-effect-transistor (FET) biosensors capable of rapidly detecting disease-relevant biomarkers have long been considered as a promising tool for point-of-care (POC) diagnosis. Rolled-up nanotechnology, as a batch fabrication strategy for generating three-dimensional (3D) microtubes, has been demonstrated to possess unique advantages for constructing FET biosensors. In this paper, we report a new approach combining the two fascinating technologies, the FET biosensor and the rolled-up microtube, to develop a microfluidic diagnostic biosensor.

Aluminum-free glass ionomer cements containing 45S5 Bioglass and its bioglass-ceramic.

Although the incorporation of bioactive glasses into glass ionomer cements (GICs) has led to promising results, using a bioactive glass as the only solid component of GICs has never been investigated. In this study, we developed an Al-free GIC with standard compressive strength using various combinations of 45S5 Bioglass and its glass-ceramic as the solid component. The glass-ceramic particles with 74% crystallinity were used for this purpose as they can best act as both remineralizing and reinforcing agents.

Bioprintable, Stiffness-Tunable Collagen-Alginate Microgels for Increased Throughput 3D Cell Culture Studies.

3D culture platforms with tunable stiffness have the potential to improve many applications, such as drug discovery, organoid studies, and stem cell differentiation. Both dimensionality and stiffness regulate crucial and relevant cellular processes. However, 3D culture models are often limited in throughput and difficult to adopt for widespread use.

An immune regulatory 3D-printed alginate-pectin construct for immunoisolation of insulin producing β-cells.

Different bioinks have been used to produce cell-laden alginate-based hydrogel constructs for cell replacement therapy but some of these approaches suffer from issues with print quality, long-term mechanical instability, and bioincompatibility. In this study, new alginate-based bioinks were developed to produce cell-laden grid-shaped hydrogel constructs with stable integrity and immunomodulating capacity. Integrity and printability were improved by including the co-block-polymer Pluronic F127 in alginate solutions.

Polymerization of Biobased Farnesene in Miniemulsions by Nitroxide-Mediated Polymerization.

Biobased farnesene (Far) was polymerized by nitroxide-mediated polymerization in miniemulsions using two different alkoxyamine initiators, the SG1-based and succinimidyl-modified BlocBuilder (NHS-BB) and Dispolreg 007 (D7). Stable emulsions were observed after 30 h of reaction at 90 °C, where NHS-BB-initiated systems resulted in smaller particles (∼300 nm) than using D7 (∼400 nm). Successful chain extension of the poly(Far) macroinitiators (24,500-39,700 g mol) with styrene were achieved using 15 wt % surfactant relative to monomer concentration.

Injectable, strong and bioadhesive catechol-chitosan hydrogels physically crosslinked using sodium bicarbonate.

Fast-gelling chitosan thermosensitive hydrogels have proven to be excellent matrices for targeted drug-delivery and cell therapy. In this work, we demonstrate the possibility of designing injectable bioadhesive hydrogels with a high gelation rate by modifying chitosan with catechol (cat-CH) and using sodium bicarbonate (SHC) as a gelling agent. Cat-CH/SHC hydrogels gel under 5 min at 37 °C and reach a high secant modulus after 24 h (E = 90 kPa at 50% strain).

Accessible dynamic micropatterns in monolayer cultures via modified desktop xurography.

Micropatterned cell cultures provide an important tool to understand dynamic biological processes, but often require specialized equipment and expertise. Here we present subtractive bioscribing (SuBscribing), a readily accessible and inexpensive technique to generate dynamic micropatterns in biomaterial monolayers on-the-fly. We first describe our modifications to a commercially available desktop xurographer and demonstrate the utility and limits of this system in creating micropatterned cultures by mechanically scribing patterns into a brittle, non-adhesive biomaterial layer.

Extraction of 3D quantitative maps using EDS-STEM tomography and HAADF-EDS bimodal tomography.

Electron tomography has been widely applied to three-dimensional (3D) morphology characterization and chemical analysis at the nanoscale. A HAADF-EDS bimodal tomographic (HEBT) reconstruction technique has been developed to extract high resolution element-specific information. However, the reconstructed elemental maps cannot be directly converted to quantitative compositional information.

Polymer-Free Emulsion-Templated Graphene-Based Sponges for Contaminant Removal.

An emulsion-templated porous material can be formed by polymerizing the continuous phase of high internal phase Pickering emulsions (HIPEs). Although polymerization is a key step to maintain the pore size and integrity of the final sponge, it lowers the effective specific surface area of the final sponge as the continuous phase makes up at least half of the HIPE's volume. Hence, eliminating the need of polymerization not only eases the material processing but also leads to a greater specific surface area.

Inverse modeling for quantitative X-ray microanalysis applied to 2D heterogeneous materials.

Current quantitative X-ray microanalysis methods are only available for homogeneous materials. This paper presents a newly developed inverse modeling algorithm to determine both the structure and composition of two-dimensional (2D) heterogeneous materials from a series of X-ray intensity measurements under different beam energies and beam positions. It utilizes an iterative process of forward modeling to determine the optimal specimen to minimize the relative differences between the simulated and experimental characteristic X-ray intensities.

Secondary Fluorescence of 3D Heterogeneous Materials Using a Hybrid Model.

In electron probe microanalysis or scanning electron microscopy, the Monte Carlo method is widely used for modeling electron transport within specimens and calculating X-ray spectra. For an accurate simulation, the calculation of secondary fluorescence (SF) is necessary, especially for samples with complex geometries. In this study, we developed a program, using a hybrid model that combines the Monte Carlo simulation with an analytical model, to perform SF correction for three-dimensional (3D) heterogeneous materials.

Controlled clustering enhances PDX1 and NKX6.1 expression in pancreatic endoderm cells derived from pluripotent stem cells.

Pluripotent stem cell (PSC)-derived insulin-producing cells are a promising cell source for diabetes cellular therapy. However, the efficiency of the multi-step process required to differentiate PSCs towards pancreatic beta cells is variable between cell lines, batches and even within cultures. In adherent pancreatic differentiation protocols, we observed spontaneous local clustering of cells expressing elevated nuclear expression of pancreatic endocrine transcription factors, PDX1 and NKX6.

A review of bubble break-up.

The coalescence and break-up of bubbles are important steps in many industrial processes. To date, most of the literature has been focussed on the coalescence process which has been studied using high speed cinematographic techniques. However, bubble break-up is equally important and requires further research.