Novel KIAA0753 mutations extend the phenotype of skeletal ciliopathies.

The skeletal ciliopathies are a heterogeneous group of disorders with a significant clinical and genetic variability and the main clinical features are thoracic hypoplasia and short tubular bones. To date, 25 genes have been identified in association with skeletal ciliopathies. Mutations in the KIAA0753 gene have recently been associated with Joubert syndrome (JBTS) and orofaciodigital (OFD) syndrome. We report biallelic pathogenic variants in KIAA0753 in four patients with short-rib type skeletal dysplasia. The manifestations in our patients are variable and ranging from fetal lethal to viable and moderate skeletal dysplasia with narrow thorax and abnormal metaphyses. We demonstrate that KIAA0753 is expressed in normal fetal human growth plate and show that the affected fetus, with a compound heterozygous frameshift and a nonsense mutation in KIAA0753, has an abnormal proliferative zone and a broad hypertrophic zone. The importance of KIAA0753 for normal skeletal development is further confirmed by our findings that zebrafish embryos homozygous for a nonsense mutation in kiaa0753 display altered cartilage patterning.

Engineered three-dimensional microfluidic device for interrogating cell-cell interactions in the tumor microenvironment.

Stromal cells in the tumor microenvironment play a key role in the metastatic properties of a tumor. It is recognized that cancer-associated fibroblasts (CAFs) and endothelial cells secrete factors capable of influencing tumor cell migration into the blood or lymphatic vessels. We developed a microfluidic device that can be used to image the interactions between stromal cells and tumor cell spheroids in a three dimensional (3D) microenvironment while enabling external control of interstitial flow at an interface, which supports endothelial cells. The apparatus couples a 200-µm channel with a semicircular well to mimic the interface of a blood vessel with the stroma, and the design allows for visualization of the interactions of interstitial flow, endothelial cells, leukocytes, and fibroblasts with the tumor cells. We observed that normal tissue-associated fibroblasts (NAFs) contribute to the "single file" pattern of migration of tumor cells from the spheroid in the 3D microenvironment. In contrast, CAFs induce a rapid dispersion of tumor cells out of the spheroid with migration into the 3D matrix. Moreover, treatment of tumor spheroid cultures with the chemokine CXCL12 mimics the effect of the CAFs, resulting in similar patterns of dispersal of the tumor cells from the spheroid. Conversely, addition of CXCL12 to co-cultures of NAFs with tumor spheroids did not mimic the effects observed with CAF co-cultures, suggesting that NAFs produce factors that stabilize the tumor spheroids to reduce their migration in response to CXCL12.

Structural characterization of iron oxide/hydroxide nanoparticles in nine different parenteral drugs for the treatment of iron deficiency anaemia by electron diffraction (ED) and X-ray powder diffraction (XRPD).

Drug products containing iron oxide and hydroxide nanoparticles (INPs) are important for the treatment of iron deficiency anaemia. Pharmaceuticals prepared by the complexation of different kinds of INPs and carbohydrates have different physicochemical and biopharmaceutic characteristics. The increasing number of parenteral non-biological complex drugs (NBCD) containing iron requires physicochemical methods for characterization and enabling of cross comparisons. In this context the structure and the level of crystallinity of the iron phases may be connected to the in vitro and in vivo dissolution rates, which etiologically determine the therapeutic and toxic effects. X-ray powder diffraction (XRPD) and electron diffraction (ED) methods were used in order to investigate the nine different parenteral iron formulations Ferumoxytol (Feraheme(®)), sodium ferric gluconate sucrose (Ferrlecit(®)), iron sucrose (Venofer(®)), low molecular weight iron dextran (CosmoFer(®)), low molecular weight iron dextran (Infed(®)), high molecular weight iron dextran (Ironate(®)), high molecular weight iron dextran (Dexferrum(®)), iron carboxymaltose (Ferinject(®)) and iron isomaltoside 1000 (Monofer(®)). The iron phase in CosmoFer(®), Ferinject(®), Monofer(®), Infed(®), Ironate(®) and Dexferrum(®) was identified as Akaganéite/Akaganéite-like (ß-FeOOH), with low amounts of chloride. By combining results of both methods the iron oxide in Feraheme(®) was identified as Magnetite (Fe3O4) with spinel-like structure. Ferrlecit(®) and Venofer(®) were difficult to analyze due to the low degree of crystallinity, but the iron phase seems to fit Lepidocrocite/Lepidocrocite-like (γ-FeOOH) or an amorphous kind of structure. The structural information on the type of iron oxide or hydroxide together with the particle size allows predicting the stability of the different complexes including their labile iron content. The combination of ED and XRPD methods is a very helpful approach especially for structural analysis of nanoscopic or low crystalline materials.

Solution-cast high-aspect-ratio polymer structures from direct-write templates.

This letter presents a novel strategy for template synthesis of polymer structures with laser machined substrates. User-designed patterns of submicrometer holes with aspect ratios >10:1 and depths >10 µm were produced by focusing 160 fs, 5.2 µJ laser pulses on the surface of fused silica with a high numerical aperture microscope objective. Some holes were enlarged by chemical etching. Polymer solutions were cast into the templates to create high-aspect-ratio polymer structures using replication. Engineered polymer structures prepared by this unique method are useful for a number of applications such as high surface area electrodes and biological substrates.

Femtosecond laser machined microfluidic devices for imaging of cells during chemotaxis.

Microfluidic devices designed for chemotaxis assays were fabricated on fused silica substrates using femtosecond laser micromachining. These devices have built-in chemical concentration gradient forming structures and are ideally suited for establishing passive diffusion gradients over extended periods of time. Multiple gradient forming structures, with identical or distinct gradient forming characteristics, can be integrated into a single device, and migrating cells can be directly observed using an inverted microscope. In this paper, the design, fabrication, and operation of these devices are discussed. Devices with minimal structure sizes ranging from 3 to 7 lm are presented. The use of these devices to investigate the migration of Dictyostelium discoideum cells toward the chemoattractant folic acid is presented as an example of the devices' utility.

Analysis of the cleaved topaz (001) surface.

We report on the first study of the cleaved (001) topaz surface and the characterization of the chemical composition and atomic arrangement of the surface. We conclude that there is strong evidence for a hydroxyl group termination appropriate for further chemical reactions. The surface itself is easily accessible, atomically flat and suitable for potential technological applications.