Translocation of particles and inflammatory responses after exposure to fine particles and nanoparticles in an epithelial airway model

Background  

Experimental studies provide evidence that inhaled nanoparticles may translocate over the airspace epithelium and cause increased cellular inflammation. Little is known, however, about the dependence of particle size or material on translocation characteristics, inflammatory response and intracellular localization.     

Loading of polymer nanocarriers: Factors,mechanisms and applications

The progress in synthetic polymer chemistry has allowed the precise design of hybrid and multifunctional colloidal particles, which differ in type, size and shape, thus enhancing their possible applications as target-oriented carriers of low and high molar mass active species. This survey discusses the basic principles and factors, associated with the process of loading of polymeric nanoparticles. For the purpose of this review, the polymeric nano-carriers are divided into five most studied types: micelles, nanogels, capsules (incl. vesicles), dendrimers, and hybrid nanoparticles with porous cores. Factors influencing the loading are described and their importance discussed. An important trend is the synthesis of multicompartment carriers for the encapsulation of different types of therapeutics. Special attention is focused on the loading of biomacromolecules.     

A dual functional staged hydrogen purifier for an integrated fuel processor–fuel cell power system

This paper describes the operation of a dual functional, membrane/catalytic CO_x methanator, hydrogen purifier that is well-suited for an integrated fuel processor/fuel cell power system. In combination with a pressure swing reformer (PSR) and a PEMFC, the system provides high overall efficiency and portability for distributed power or onboard vehicle use. Gas testing results illustrate the ability of the purifier to produce fuel cell purity hydrogen at peak power flux. The durability of this purifier is shown by its ability to meet target hydrogen purity even with a membrane that permeates >3000 ppm CO. Gas purge streams from both fuel cell electrodes are combined with the membrane retentate and combusted in the PSR combustion cycle to provide heat for the reforming reaction leading to high thermal efficiency. Most significantly, it is shown that staging of this purifier, enables recovery of some fraction of the purified hydrogen at pressures substantially approaching that of the feed hydrogen partial pressure. This creates an onboard source of high pressure hydrogen to be optionally fed to a storage device for use during vehicle startup, or to the fuel cell, either directly or via the storage device, under high power load conditions. The beneficial impact of this two-stage, dual functional purifier on membrane cost, dependability and fuel processor/fuel cell integration, will be discussed.     

N‐Lauroylation during the Expression of Recombinant N‐Myristoylated Proteins: Implications and Solutions

Incorporation of myristic acid onto the N terminus of a protein is a crucial modification that promotes membrane binding and correct localization of important components of signaling pathways. Recombinant expression of N‐myristoylated proteins in Escherichia coli can be achieved by co‐expressing yeast N‐myristoyltransferase and supplementing the growth medium with myristic acid. However, undesired incorporation of the 12‐carbon fatty acid lauric acid can also occur (leading to heterogeneous samples), especially when the available carbon sources are scarce, as it is the case in minimal medium for the expression of isotopically enriched samples. By applying this method to the brain acid soluble protein 1 and the 1–185 N‐terminal region of c‐Src, we show the significant, and protein‐specific, differences in the membrane binding properties of lauroylated and myristoylated forms. We also present a robust strategy for obtaining lauryl‐free samples of myristoylated proteins in both rich and minimal media.     

Fabrication,microstructure, and optical properties of Tm:Y3ScAl4O12 laser ceramics

Transparent 4 at.% Tm:Y₃ScAl₄O₁₂ (Tm:YSAG) laser ceramics were fabricated by solid-state reaction combined with vacuum sintering method. The 4 at.% Tm:YSAG ceramic sample sintered at 1800°C for 30 hours possesses homogenous microstructure and excellent optical properties, showing a transmittance of 79.3% at 2000 nm. The absorption and emission spectra of the Tm:YSAG ceramics are studied and compared with those of 4 at.% Tm:Y₃Al₅O₁₂ ceramics. The introduction of Sc³⁺ greatly affects the energy levels of the Tm³⁺, causing the disappearance and degeneration of some absorption and emission peaks in the middle infrared region. The laser performance of the 4 at.% Tm:YSAG ceramics is also tested in the Quasi-continuous-wave (QCW) mode by pumping with a 790 nm laser diode (LD). A maximum laser output power of 0.54 W with a slope efficiency of 4.8% is achieved, which is the first laser output for Tm:YSAG ceramics.     

Rhodamine B hydrazide loaded polysulfone fabrics for Cu(II) detection: Morphological and optical properties

Polysulfone-based materials were fabricated as casted films, porous membranes, and nanofibers by solution casting, phase inversion process, and electrospinning technique, respectively. Photoactive rhodamine B hydrazide molecules were loaded into the fabrics either in preloading or postloading processes. The morphological structure of the fabrics was investigated by scanning electron microscopy and the wettability was determined by contact angle measurements. Detailed spectroscopic characterizations of the closed and open forms of rhodamine B was performed both in solution and in the solid-state composite materials. Theoretical investigations supported the depiction of the absorption and emission features of the two forms. The response of the prepared composite materials to Cu(II) ions has been tested by absorption and emission spectroscopy and confocal fluorescence imaging. The most effective materials for Cu(II) detection were found to be polysulfone films prepared by phase inversion and postloaded with 10% rhodamine B hydrazide. These results open the way to the development of composite sensory membranes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48408.     

Novel Neuroprotective Agents to Treat Neonatal Hypoxic-Ischemic Encephalopathy: Inter-Alpha Inhibitor Proteins

Perinatal hypoxia-ischemia (HI) is a major cause of brain injury and mortality in neonates. Hypoxic-ischemic encephalopathy (HIE) predisposes infants to long-term cognitive deficits that influence their quality of life and place a large burden on society. The only approved treatment to protect the brain after HI is therapeutic hypothermia, which has limited effectiveness, a narrow therapeutic time window, and is not considered safe for treatment of premature infants. Alternative or adjunctive therapies are needed to improve outcomes of full-term and premature infants after exposure to HI. Inter-alpha inhibitor proteins (IAIPs) are immunomodulatory molecules that are proposed to limit the progression of neonatal inflammatory conditions, such as sepsis. Inflammation exacerbates neonatal HIE and suggests that IAIPs could attenuate HI-related brain injury and improve cognitive outcomes associated with HIE. Recent studies have shown that intraperitoneal treatment with IAIPs can decrease neuronal and non-neuronal cell death, attenuate glial responses and leukocyte invasion, and provide long-term behavioral benefits in neonatal rat models of HI-related brain injury. The present review summarizes these findings and outlines the remaining experimental analyses necessary to determine the clinical applicability of this promising neuroprotective treatment for neonatal HI-related brain injury.     

Changes in the Physicochemical Properties of Blood and Skin Cell Membranes as a Result of Psoriasis Vulgaris and Psoriatic Arthritis Development

Psoriasis is accompanied by disturbed redox homeostasis, with systemic and local oxidative stress promoting the modification of basic components of cellular membranes. Therefore, the aim of the study was to investigate the effect of development of psoriasis vulgaris and psoriatic arthritis on the composition and physicochemical properties of skin cell membranes (keratinocytes and fibroblasts) and blood cells (lymphocytes, granulocytes and erythrocytes). Both forms of psoriasis are characterized by decreased levels and changes in the localization of membrane phospholipids, and an increased level of sialic acid as well as the lipid peroxidation product (malondialdehyde), which resulted in an increase in the zeta potential of skin cells and blood cells, with granulocytes and lymphocytes affected more than erythrocytes. Using theoretical equations and the dependence of the cell membrane surface charge density as a function of pH, it was shown that patients with psoriatic arthritis have a greater increase in the concentration of negatively charged groups on the membrane surface and reduced the value of the association constant with H⁺ compared to patients with psoriasis vulgaris. Therefore, it can be suggested that the physicochemical parameters of membranes, skin and blood cells, especially lymphocytes, can be used to assess the severity of the disease.