A Facile Method for Separating and Enriching Nano and Submicron Particles from Titanium Dioxide Found in Food and Pharmaceutical Products.

Recent studies indicate the presence of nano-scale titanium dioxide (TiO2) as an additive in human foodstuffs, but a practical protocol to isolate and separate nano-fractions from soluble foodstuffs as a source of material remains elusive. As such, we developed a method for separating the nano and submicron fractions found in commercial-grade TiO2 (E171) and E171 extracted from soluble foodstuffs and pharmaceutical products (e.g.

CRISPR/Cas9 and mitochondrial gene replacement therapy: promising techniques and ethical considerations.

Thousands of mothers are at risk of transmitting mitochondrial diseases to their offspring each year, with the most severe form of these diseases being fatal [1]. With no cure, transmission prevention is the only current hope for decreasing the disease incidence. Current methods of prevention rely on low mutant maternal mitochondrial DNA levels, while those with levels close to or above threshold (>60%) are still at a very high risk of transmission [2].

Survey of food-grade silica dioxide nanomaterial occurrence, characterization, human gut impacts and fate across its lifecycle.

There is increasing recognition of the importance of transformations in nanomaterials across their lifecycle, yet few quantitative examples exist. We examined food-grade silicon dioxide (SiO2) nanomaterials from its source (bulk material providers), occurrence in food products, impacts on human gastrointestinal tract during consumption, and fate at wastewater treatment plants. Based upon XRD, XPS and TEM analysis, pure SiO2 present in multiple food-grade stock SiO2 exhibited consistent morphologies as agglomerates, ranging in size from below 100nm to >500nm, with all primary particle size in the range of 9-26nm and were most likely amorphous SiO2 based upon high resolution TEM.

Food grade titanium dioxide disrupts intestinal brush border microvilli in vitro independent of sedimentation.

Bulk- and nano-scale titanium dioxide (TiO2) has found use in human food products for controlling color, texture, and moisture. Once ingested, and because of their small size, nano-scale TiO2 can interact with a number of epithelia that line the human gastrointestinal tract. One such epithelium responsible for nutrient absorption is the small intestine, whose constituent cells contain microvilli to increase the total surface area of the gut.

Engineered nanoparticles induced brush border disruption in a human model of the intestinal epithelium.

Nanoparticles hold great promise in cell biology and medicine due to the inherent physico-chemical properties when these materials are synthesized on the nanoscale. Moreover, their small size, and the ability to functionalize the outer nanoparticle surface makes them an ideal vector suited to traverse a number of physical barriers in the human body. While nanoparticles hold great promise for applications in cell biology and medicine, their downfall is the toxicity that accompanies exposure to biological systems.

Alpha-Fe(2)O(3) elicits diameter-dependent effects during exposure to an in vitro model of the human placenta.

Iron oxide nanoparticles offer unique possibilities due to the change in their physico-chemical parameters when synthesized on the nanoscale (10(-9) m) compared to their bulk forms. While novel uses exist for these materials when synthesized as nanoparticles, their unintended effects on the human body and specifically during pregnancy remain ill defined. In this study, an iron oxide nanoparticle, α-Fe2O3, was employed and the potential toxicity due to exposure was assessed in the widely used model human placental cell line BeWo b30.

Multifunctional scaffolds in eggs: sites for localization, signal transduction and meiotic spindle polarity.

Molecular scaffolds in the mammalian egg are capable of tethering specific proteins involved in regulation of early development. Scaffolds can take the form of cytoskeletal elements, or involve proteins such as MARCKs or RACKSs during important cellular transitions in the egg. Moreover, with each cellular transition (i.

Commenting on the effects of surface treated- and non-surface treated TiO(2) in the Caco-2 cell model.

In a recent work published in Particle and Fibre Toxicology by Fisichella and coworkers investigating surface-modified TiO2 nanoparticle exposure in a model human intestinal epithelium (Caco-2), albeit degraded to mimic conditions in the gut and exposure to natural sunlight, purportedly resulted in no toxic effects. The authors (Fisichella et al.) claim to have confirmed the results of a 2010 report by Koeneman et al.

Human intestinal epithelial cells exhibit a cellular response indicating a potential toxicity upon exposure to hematite nanoparticles.

This study examined the effects of different-sized nanoparticles on potential cytotoxicity in intestinal epithelia. Three sizes of hematite nanoparticles were used for the study at a 10 ppm concentration: 17, 53, and, 100 nm. Results indicate that, of the hematite nanoparticles tested, 17 nm was more toxic to the epithelial integrity than 53 or 100 nm.

Involvement of PKCζ and GSK3β in the stability of the metaphase spindle.

In the somatic cell, the mitotic spindle apparatus is centrosomal, and several isoforms of protein kinase C (PKC) have been associated with the mitotic spindle, but their role in stabilizing the mitotic spindle is still unclear. Other protein kinases such as, glycogen synthase kinase 3β (GSK3β) have also been shown to be associated with the mitotic spindle apparatus. In this study, we show the enrichment of active (phosphorylated) PKCζ at the centrosomal region of the spindle apparatus in metaphase stage of 3T3 cells.

Adsorption of hematite nanoparticles onto Caco-2 cells and the cellular impairments: effect of particle size.

The increasing applications of engineered nanomaterials nowadays have elevated the potential of human exposure through various routes including inhalation, skin penetration and digestion. To date there is scarce information on a quantitative description of the interactions between nanoparticles (NPs) and cell surfaces and the detrimental effects from the exposure. The purpose of this work was to study in vitro exposure of Caco-2 cells to hematite (alpha-Fe(2)O(3)) NPs and to determine the particle size effects on the adsorption behaviors.

Involvement of the PKC family in regulation of early development.

Protein kinase C (PKC) isotypes have been implicated in a number of key steps during gametogenesis, fertilization, and early development. The 11-member family of PKC isotypes, many with different cofactor requirements for activation, can provide for differential activation of the specific kinases. In addition the enrichment of particular PKC isotypes to unique locations within gametes, zygotes, and early embryos likely promotes specific substrate interactions.

Toxicity and cellular responses of intestinal cells exposed to titanium dioxide.

The increasing use of nanomaterials in healthcare and industrial products heightens the possibility of their ingestion by humans, other mammals, and fish. While toxicity of many nanomaterials has recently been studied, reports of non-lethal effects of nanomaterials remain ill-defined. This study investigates possible pathways by which nanoparticles, titanium dioxide (TiO(2)), could cross the epithelium layer by employing both toxicity and mechanistic studies.

Experimental approach for an in vitro toxicity assay with non-aggregated quantum dots.

Engineered nanoparticles are increasingly used in consumer products. While the potential of these products hold great promise, it is not known what potential toxic effects these nanomaterials may have on human health. There is a need to develop affordable, systematic, short-term in vitro assays aimed at allowing rapid assessment of potential toxicity.

GSK3 beta mediates acentromeric spindle stabilization by activated PKC zeta.

Upon fertilization, the mammalian egg undergoes a precise series of signaling events that orchestrate its conversion into a zygote. Mouse eggs contain acentrosomal spindle poles when arrested at meiotic metaphase II. The meiotic spindle is thought to provide a scaffold that mediates spatial and temporal regulation of the signaling pathways orchestrating post-fertilization events.

Thin structure segmentation and visualization in three-dimensional biomedical images: a shape-based approach.

This paper presents a shape-based approach in extracting thin structures, such as lines and sheets, from three-dimensional (3D) biomedical images. Of particular interest is the capability to recover cellular structures, such as microtubule spindle fibers and plasma membranes, from laser scanning confocal microscopic (LSCM) data. Hessian-based shape methods are reviewed.

PKC isotypes in post-activated and fertilized mouse eggs: association with the meiotic spindle.

Several isotypes of protein kinase C (PKC) have been reported to be expressed in mammalian eggs, but it is unknown whether these isotypes have a common function in the egg during or within the first few hours of fertilization. Here we show that the isotypes of PKC exhibit distinct patterns of enrichment immediately after mouse egg activation. PKCalpha and gamma accumulate in the egg cortex 25 min post-activation, while only PKCalpha accumulates at the contractile ring of the forming second polar body about 1.

An ex vivo method for evaluating the biocompatibility of neural electrodes in rat brain slice cultures.

Failure of neural recording electrodes implanted in the brain is often attributed to the formation of glial scars around the implant. A leading cause of scar formation is the electrode material. Described below is an approach to evaluate the biocompatibility of novel electrode materials in a representative three-dimensional model.

Cellular scaffolds in mammalian eggs.

Cellular scaffolds serve as structural components to which various elements of signal transduction pathways can be associated. The association of components on a scaffold can have several important functions, for example they can: 1) associate upstream regulatory components in a cascade that can increase the speed of response to a stimulus; 2) restrict access of substrates to enzymes associated with the scaffold; 3) permit cross talk between distinct signaling pathways, and; 4) aid in the establishment of cellular polarity. The conversion of the mammalian egg into the zygote requires many rapid alterations during a distinct time frame to mediate the biochemical and structural changes that occur.

A Freeze-Sectioning Method for Preparation of the Detergent-Resistant Cytoskeleton Identifies Stage-Specific Cytoskeleal Proteins and Associated mRNA in Xenopus Oocytes and Embryos: (Cytoskeleton/amphibian/mRNA).

Proteins of the detergent-resistant cytoskeleton fraction and the detergent-soluble fraction from Xenopus oocytes and embryos are examined using a procedure which allows rapid and uniform extraction of tissues and large, single cells. SDS-polyacrylamide gels reveal only a few prominent cytoskeletal proteins in the early embryo, however qualitatively different proteins begin to appear after gastrulation. Incorporation of [ S]-methionine into newly synthesized proteins indicates that there is synthesis and assembly of proteins into the cytoskeleton, but the amount remains low until after gastrulation.

Role of calcium in the localization of maternal poly(A)RNA and tubulin mRNA in Xenopus oocytes.

Poly(A)RNA and tubulin mRNA are localized in the periphery of Xenopus oocytes and become delocalized during meiotic maturation. Delocalization of this RNA can be triggered by incubation in agents which reduce entry of calcium ions into the cell (e.g.