A three-dimensional model of the human blood-brain barrier to analyse the transport of nanoparticles and astrocyte/endothelial interactions [version 1; referees: 2 approved with reservations]

The aim of this study was to develop a three-dimensional (3D) model of the human blood-brain barrier in vitro, which mimics the cellular architecture of the CNS and could be used to analyse the delivery of nanoparticles to cells of the CNS. The model includes human astrocytes set in a collagen gel, which is overlaid by a monolayer of human brain endothelium (hCMEC/D3 cell line). The model was characterised by transmission electron microscopy (TEM), immunofluorescence microscopy and flow cytometry. A collagenase digestion method could recover the two cell types separately at 92-96% purity. Astrocytes grown in the gel matrix do not divide and they have reduced expression of aquaporin-4 and the endothelin receptor, type B compared to two-dimensional cultures, but maintain their expression of glial fibrillary acidic protein. The effects of conditioned media from these astrocytes on the barrier phenotype of the endothelium was compared with media from astrocytes grown conventionally on a two-dimensional (2D) substratum. Both induce the expression of tight junction proteins zonula occludens-1 and claudin-5 in hCMEC/D3 cells, but there was no difference between the induced expression levels by the two media. The model has been used to assess the transport of glucose-coated 4nm gold nanoparticles and for leukocyte migration. TEM was used to trace and quantitate the movement of the nanoparticles across the endothelium and into the astrocytes. This blood-brain barrier model is very suitable for assessing delivery of nanoparticles and larger biomolecules to cells of the CNS, following transport across the endothelium

Glucose-coated gold nanoparticles transfer across human brain endothelium and enter astrocytes in vitro

The blood-brain barrier prevents the entry of many therapeutic agents into the brain. Various nanocarriers have been developed to help agents to cross this barrier, but they all have limitations, with regard to tissue-selectivity and their ability to cross the endothelium. This study investigated the potential for 4 nm coated gold nanoparticles to act as selective carriers across human brain endothelium and subsequently to enter astrocytes. The transfer rate of glucose-coated gold nanoparticles across primary human brain endothelium was at least three times faster than across non-brain endothelia. Movement of these nanoparticles occurred across the apical and basal plasma membranes via the cytosol with relatively little vesicular or paracellular migration; antibiotics that interfere with vesicular transport did not block migration. The transfer rate was also dependent on the surface coating of the nanoparticle and incubation temperature. Using a novel 3-dimensional co-culture system, which includes primary human astrocytes and a brain endothelial cell line hCMEC/D3, we demonstrated that the glucose-coated nanoparticles traverse the endothelium, move through the extracellular matrix and localize in astrocytes. The movement of the nanoparticles through the matrix was >10 µm/hour and they appeared in the nuclei of the astrocytes in considerable numbers. These nanoparticles have the correct properties for efficient and selective carriers of therapeutic agents across the blood-brain barrier

Effectiveness of pyramided genes in conferring resistance to anthracnose disease in common bean populations

Anthracnose disease (Colletotrichum lindemuthianum (Sacc. et. Magn) Lams. Scrib.) is one of the most devastating diseases that constrain common bean production in Uganda. A cascading pedigree pyramiding scheme was used to develop common bean populations to evaluate the effectiveness of pyramided and single resistance genes (Co-42, Co-43, Co-5, and Co-9) on disease development. Detached leaf trifoliates of F4:6 genotypes were screened with four C. lindemuthianum races (352, 713,767 and 2047). Disease severity data were subjected to ANOVA. Races, genotypes and Race x Genotype interaction were significant. Genes Co-42 and Co-5 conferred resistance to the four races and the gene pyramids Co-42+Co-5+Co-9 and Co-42+Co-5 had the lowest severity scores. Gene Co-43 conferred resistance to race 352 and weak resistance to race 713; whereas gene Co-9 conferred resistance to race 352. Co-43+Co-9 gene pyramid showed resistance only to race 352. The Co-42 and Co-5 genes conferred resistance to all the four races 352, 713, 767 and 2047. The single gene Co-42 was not significantly different from the pyramids Co-42+Co-5+Co-9 and Co-42+Co-5 (P<0.01). Similarly, the Co-5gene was not significantly different from Co-42+Co-5, Co-42+Co-9 and Co-5+Co-9 pyramids. The Co-9gene showed antagonism in all pyramids. These results indicate that pyramiding of resistance genes would be effective for disease management in Uganda, but pyramids with Co-9 gene would be less effective

Blue and Green Phosphorescent Liquid-Crystalline Iridium Complexes with High Hole Mobility

Blue- and green-emitting cyclometalated liquid-crystalline iridium complexes are realized by using a modular strategy based on strongly mesogenic groups attached to an acetylacetonate ancillary ligand. The cyclometalated ligand dictates the photophysical properties of the materials, which are identical to those of the parent complexes. High hole mobilities, up to 0.004 cm2 V-1 s-1, were achieved after thermal annealing, while amorphous materials show hole mobilities of only approximately 10-7-10-6 cm2 V-1 s-1, similar to simple iridium complexes. The design strategy allows the facile preparation of phosphorescent liquid-crystalline complexes with fine-tuned photophysical properties

Influence of Early Low-Temperature and Later High-Temperature Diagenesis on Magnetic Mineral Assemblages in Marine Sediments From the Nankai Trough

Funding Information: This research used samples and data provided by the International Ocean Discovery Program (IODP). The authors thank the Marine Works Japan staff at the Kochi Core Center for support during sampling. This work was supported by the Japan Society for the Promotion of Science Grant-in-Aid for Science Research (grant 17K05681 to Myriam Kars), the German Research Foundation (DFG grants 388260220 to Male Koster and Susann Henkel, and 408178672 to Florence Schubotz), and the Australian Research Council (grant DP200100765 to Andrew P. Roberts). The authors also thank two anonymous reviewers for their constructive comments and Editor Joshua Feinberg for handling the manuscript.Peer reviewedPublisher PD

Control of human cytomegalovirus replication by liver resident natural killer cells

Natural killer cells are considered to be important for control of human cytomegalovirus– a major pathogen in immune suppressed transplant patients. Viral infection promotes the development of an adaptive phenotype in circulating natural killer cells that changes their anti-viral function. In contrast, less is understood how natural killer cells that reside in tissue respond to viral infection. Here we show natural killer cells resident in the liver have an altered phenotype in cytomegalovirus infected individuals and display increased anti-viral activity against multiple viruses in vitro and identify and characterise a subset of natural killer cells responsible for control. Crucially, livers containing natural killer cells with better capacity to control cytomegalovirus replication in vitro are less likely to experience viraemia post-transplant. Taken together, these data suggest that virally induced expansion of tissue resident natural killer cells in the donor organ can reduce the chance of viraemia post-transplant

TangiBall: development of a prototype tangible user interface for detection of speed and accuracy variation in pre-school autistic children

The creation of digital tools to assist in diagnostic pathways for children at-risk of autism is a priority due to increased prevalence. This project reports on the development of a tangible user interface as an ecologically valid option for children at-play in clinic. The toy aims to assist in useful data capture for preschool populations