-temporal analysis of collective migrationby particle image velocimetry.

Collective cell migration drives the formation of complex organ systems as well as certain tumour invasions and wound healing processes. A characteristic feature of many migrating collectives is tissue-scale polarity, whereby 'leader' cells at the tissue edge guide 'followers' cells that become assembled into polarized epithelial tissues. In this study, we employed particle image velocimetry (PIV) as a tool to quantitate local dynamics underlying the migration of the posterior lateral line primordium (pLLP) in zebrafish at a short time scale.

Anionic Quantum Dots reveal actin-microridges in zebrafish epidermis.

Enhancement of hydrophilicity and functionalization of CdTe QDs (Quantum Dots) via surface modifications have made them suitable to be used as specific probes for cell imaging. Applications for targeting cell surfaces have been widely demonstrated in vitro but their use in animal models is not trivial. Here, we reported the interaction of mercaptosuccinic-coated (MSA) CdTe QDs with the epidermis of living and Carnoy-fixed zebrafish embryos.

E-cadherin expression pattern during zebrafish embryonic epidermis development.

: E-cadherin is the major adhesion receptor in epithelial adherens junctions (AJs). On established epidermis, E-cadherin performs fine-tuned cell-cell contact remodeling to maintain tissue integrity, which is characterized by modulation of cell shape, size and packing density. In zebrafish, the organization and distribution of E-cadherin in AJs during embryonic epidermis development remain scarcely described.

Assembly, characterization, and delivery of quantum dot labeled biotinylated lipid particles.

Lipid nanoparticles composed of mixtures of PEGylated-lipids; cationic and neutral lipids prepared by detergent dialysis can encapsulate biological active molecules and show considerable potential as systemic therapeutic agents. Addition of biotinylated lipids to this formulation allows surface modification of these particles with a suitable ligand or probe conjugated to streptavidin for specific cell targeting. Monitoring long circulating particles and cellular uptake requires stable and bright fluorescent probes.

A modular perfused chamber for low- and normal-temperature microscopy of living cells.

An inexpensive modular perfused chamber (MPC) designed for low- and normal-temperature live-cell imaging is presented. The device consists of four lathed pieces of stainless steel assembled as a cylindrical open chamber that can hold either round or square glass coverslips. The chamber is connected to a thermal-bath operating with recirculation.

Targeted cellular delivery of quantum dots loaded on and in biotinylated liposomes.

We describe the preparation, biophysical characterization, and receptor-mediated cellular internalization of biotinylated lipid particles (BLPs) loaded on the surface and internally with two distinct (colors) of quantum dot (QD) probes. BLPs were formulated with 1.4 and 2.

Self-assembling supramolecular complexes by single-stranded extension from plasmid DNA.

Self-assembling supramolecular complexes are of great interest for bottom-up research like nanotechnology. DNA is an inexpensive building block with sequence-specific self-assembling capabilities through Watson-Crick and/or Hoogsteen base pairing and could be used for applications in surface chemistry, material science, nanomechanics, nanoelectronics, nanorobotics, and of course in biology. The starting point is usually single-stranded DNA, which is rather easily accessible for base pairing and duplex formation.

A simple and effective method to improve intrasplenic rat hepatocyte transplantation.

Transplanted hepatocytes integrate, survive, and express their specific functions in the liver parenchyma. The aim of this study was to determine whether a large number of hepatocytes could move from the spleen to the liver when the cells are injected together with sodium nitroprusside, and if the improved hepatocyte migration may be related with portal vein dilatation. Wistar rats were transplanted in the spleen with fluorescent-labeled hepatocytes alone or together with sodium nitroprusside.