Ultrathin Ceramic Membranes as Scaffolds for Functional Cell Coculture Models on a Biomimetic Scale.

Epithelial tissue serves as an interface between biological compartments. Many in vitro epithelial cell models have been developed as an alternative to animal experiments to answer a range of research questions. These in vitro models are grown on permeable two-chamber systems; however, commercially available, polymer-based cell culture inserts are around 10 μm thick.

Comparison of human olfactory and skeletal MSCs using osteogenic nanotopography to demonstrate bone-specific bioactivity of the surfaces.

Recently we identified a novel population of mesenchymal stem cells (MSCs) from human olfactory mucosa (OM-MSCs), a tissue which promotes neurogenesis throughout life, and demonstrated that they promoted CNS myelination to a greater extent than bone marrow-derived (BM)-MSCs. Previous data demonstrated that nanotopographies with a degree of disorder induce BM-MSC osteogenic differentiation. Thus, using biomaterials as non-chemical tools, we investigated if MSCs from a completely different cellular niche could be induced to differentiate similarly to nanoscale cues alone.

Delineating fibronectin bioadhesive micropatterns by photochemical immobilization of polystyrene and poly(vinylpyrrolidone).

Bioadhesive micropatterns, capable of laterally confining cells to a 2D lattice, have proven effective in simulating the in vivo tissue environment. They reveal fundamental aspects of the role of adhesion in cell mechanics, proliferation, and differentiation. Here we present an approach based on photochemistry for the fabrication of synthetic polymer micropatterns.

Increased plasticity of the stiffness of melanoma cells correlates with their acquisition of metastatic properties.

Unlabelled: The stiffness of tumor cells varies during cancer progression. In particular, metastatic carcinoma cells analyzed by Atomic Force Microscopy (AFM) appear softer than non-invasive and normal cells. Here we examined by AFM how the stiffness of melanoma cells varies during progression from non-invasive Radial Growth Phase (RGP) to invasive Vertical Growth Phase (VGP) and to metastatic tumors.

Transfer of ultrasmall iron oxide nanoparticles from human brain-derived endothelial cells to human glioblastoma cells.

Nanoparticles (NPs) are being used or explored for the development of biomedical applications in diagnosis and therapy, including imaging and drug delivery. Therefore, reliable tools are needed to study the behavior of NPs in biological environment, in particular the transport of NPs across biological barriers, including the blood-brain tumor barrier (BBTB), a challenging question. Previous studies have addressed the translocation of NPs of various compositions across cell layers, mostly using only one type of cells.

Optimizing the osteogenicity of nanotopography using block co-polymer phase separation fabrication techniques.

Both temporary and permanent orthopedic implants have, by default or design, surface chemistry, and topography. There is increasing evidence that controlling nanodisorder can result in increased osteogenesis. Block co-polymer phase separation can be used to fabricate a nanotopography exhibiting a controlled level of disorder, both reproducibly and cost-effectively.

Parallel AFM imaging and force spectroscopy using two-dimensional probe arrays for applications in cell biology.

Atomic force microscopy (AFM) investigations of living cells provide new information in both biology and medicine. However, slow cell dynamics and the need for statistically significant sample sizes mean that data collection can be an extremely lengthy process. We address this problem by parallelizing AFM experiments using a two-dimensional cantilever array, instead of a single cantilever.

Measuring cell adhesion forces during the cell cycle by force spectroscopy.

Force spectroscopy has been used to measure the adhesion of Saos-2 cells to a glass surface at different phases of the cell cycle. The cells were synchronized in three phases of the cell cycle: G(1), S, and G(2)M. Cells in these phases were compared with unsynchronized and native mitotic cells.

Use of force spectroscopy to investigate the adhesion of living adherent cells.

The use of force spectroscopy to study the adhesion of living fibroblasts to their culture substrate was investigated. Both primary fibroblasts (PEMF) and a continuous cell line (3T3) were studied on quartz surfaces. Using a fibronectin-coated AFM cantilever, it was possible to detach a large proportion of the 3T3 cells from the quartz surfaces.

FluidFM: combining atomic force microscopy and nanofluidics in a universal liquid delivery system for single cell applications and beyond.

We describe the fluidFM, an atomic force microscope (AFM) based on hollow cantilevers for local liquid dispensing and stimulation of single living cells under physiological conditions. A nanofluidic channel in the cantilever allows soluble molecules to be dispensed through a submicrometer aperture in the AFM tip. The sensitive AFM force feedback allows controlled approach of the tip to a sample for extremely local modification of surfaces in liquid environments.

Scattering of light by a single layer of randomly packed dielectric microspheres giving color effects in transmission.

Strong scattering properties are obtained for a monolayer of randomly packed polystyrene microspheres. This gives rise to structural colors in transmission. For a sphere diameter between 0.

Fabrication of multiscale surface-chemical gradients by means of photocatalytic lithography.

We describe a new method for the fabrication of surface-chemical gradients. A film of titanium dioxide is brought into close proximity to a uniformly monolayer-covered surface and exposed to UV light to produce oxygen radicals. The use of a gradated grayscale mask between the UV source and the TiO2 allows the production of surface-chemical gradients via oxidation of the monolayer.

Organization of nanoparticles on hard substrates using block copolymer films as templates.

We present a technique for the organization of pre-synthesized nanoparticles on hard substrates, using block copolymer films as sacrificial templates. A thin block copolymer film is dip-coated on the substrate of interest and the sample is exposed to a solution containing nanoparticles. Spontaneous preferential adsorption of the nanoparticles on one phase of the block copolymer film results in their lateral organization.

Micrometer-long gold nanowires fabricated using block copolymer templates.

Micrometer-long gold nanowires were fabricated via self-assembly. Diblock copolymer films served as templates for the selective adsorption of 10 nm gold nanoparticles from solution to form well-defined nanostructures. An oxygen plasma treatment induced aggregation of the nanoparticles and the formation of continuous gold nanostructures.