Differential internalization of brick shaped iron oxide nanoparticles by endothelial cells.

Nanoparticles targeting endothelial cells to treat diseases such as cancer, oxidative stress, and inflammation have traditionally relied on ligand-receptor based delivery. The present studies examined the influence of nanoparticle shape in regulating preferential uptake of nanoparticles in endothelial cells. Spherical and brick shaped iron oxide nanoparticles (IONPs) were synthesized with identical negatively charged surface coating.

Biodistribution of negatively charged iron oxide nanoparticles (IONPs) in mice and enhanced brain delivery using lysophosphatidic acid (LPA).

Effective treatment of brain disorders requires a focus on improving drug permeability across the blood-brain barrier (BBB). Herein, we examined the pharmacokinetic properties of negatively charged iron oxide nanoparticles (IONPs) and the capability of using lysophosphatidic acid (LPA) to transiently disrupt the tight junctions and allow IONPs to enter the brain. Under normal conditions, IONPs had a plasma half-life of six minutes, with the liver and spleen being the major organs of deposition.

Magnetic field enhanced convective diffusion of iron oxide nanoparticles in an osmotically disrupted cell culture model of the blood-brain barrier.

Purpose: The present study examines the use of an external magnetic field in combination with the disruption of tight junctions to enhance the permeability of iron oxide nanoparticles (IONPs) across an in vitro model of the blood-brain barrier (BBB). The feasibility of such an approach, termed magnetic field enhanced convective diffusion (MFECD), along with the effect of IONP surface charge on permeability, was examined.

Methods: The effect of magnetic field on the permeability of positively (aminosilane-coated [AmS]-IONPs) and negatively (N-(trimethoxysilylpropyl)ethylenediaminetriacetate [EDT]-IONPs) charged IONPs was evaluated in confluent monolayers of mouse brain endothelial cells under normal and osmotically disrupted conditions.

One-pot synthesis of iron oxide nanoparticles with functional silane shells: a versatile general precursor for conjugations and biomedical applications.

Iron oxide nanoparticles (IONPs) and their surface modifications with therapeutic or diagnostic (theranostic, TN) agents are of great interest. Here we present a novel one-pot synthesis of a versatile general TN precursor (aminosilane-coated IONPs [IONP-Sil(NH2)]) with surface amine groups. Surface functional group conversion to carboxylic acid was accomplished by conjugating poly(ethylene glycol) diacid to IONP-Sil(NH2).

Characterization of cellular uptake and toxicity of aminosilane-coated iron oxide nanoparticles with different charges in central nervous system-relevant cell culture models.

Background: Aminosilane-coated iron oxide nanoparticles (AmS-IONPs) have been widely used in constructing complex and multifunctional drug delivery systems. However, the biocompatibility and uptake characteristics of AmS-IONPs in central nervous system (CNS)-relevant cells are unknown. The purpose of this study was to determine the effect of surface charge and magnetic field on toxicity and uptake of AmS-IONPs in CNS-relevant cell types.

Leptin inhibits neutrophil apoptosis in children via ERK/NF-κB-dependent pathways.

Introduction And Rationale: Previous studies have shown that delayed neutrophil apoptosis is associated with chronic airway diseases. Leptin is an adipocyte-derived hormone that acts as a regulator of energy homeostasis and food intake. Emerging evidence suggests that leptin can regulate immune responses including the release of proinflammatory cytokines and protection of inflammatory cells from apoptosis.

Secretion, purification, and characterization of a recombinant Aspergillus oryzae tannase in Pichia pastoris.

Tannase (tannin acyl hydrolase) is an industrially important enzyme produced by a large number of fungi, which hydrolyzes the ester and depside bonds of gallotannins and gallic acid esters. In the present work, a tannase from Aspergillus oryzae has been cloned and expressed in Pichia pastoris. The catalytic activity of the recombinant enzyme was assayed.