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Two important goals in stem cell research are to control the cell proliferation without differentiation and to direct the differentiation into a specific cell lineage when desired. Here, we demonstrate such paths by controlling only the nanotopography of culture substrates. Altering the dimensions of nanotubular-shaped titanium oxide surface structures(More)
Engineered magnetic nanoparticles (MNPs) represent a cutting-edge tool in medicine because they can be simultaneously functionalized and guided by a magnetic field. Use of MNPs has advanced magnetic resonance imaging (MRI), guided drug and gene delivery, magnetic hyperthermia cancer therapy, tissue engineering, cell tracking and bioseparation. Integrative(More)
The titanium dioxide (TiO(2)) nanotube surface enables significantly accelerated osteoblast adhesion and exhibits strong bonding with bone. We prepared various sizes (30-100 nm diameter) of titanium dioxide (TiO(2)) nanotubes on titanium substrates by anodization and investigated the osteoblast cellular behavior in response to these different nanotube(More)
Delivery of therapeutic or diagnostic agents across an intact blood-brain barrier (BBB) remains a major challenge. Here we demonstrate in a mouse model that magnetic nanoparticles (MNPs) can cross the normal BBB when subjected to an external magnetic field. Following a systemic administration, an applied external magnetic field mediates the ability of MNPs(More)
Magnetic nanoparticles (MNPs) have shown great promise for use as tools in a wide variety of biomedical applications, some of which require the delivery of large numbers of MNPs onto or into the cells of interest. Here we develop a quantifiable model cell system and show that intracellular delivery of even moderate levels of iron oxide (Fe(2)O(3))(More)
Vertically aligned yet laterally spaced nanoscale TiO2 nanotubes have been grown on Ti by anodization, and the growth of MC3T3-E1 osteoblast cells on such nanotubes has been investigated. The adhesion/propagation of the osteoblast is substantially improved by the topography of the TiO2 nanotubes with the filopodia of growing cells actually going into the(More)
The in vitro endothelial response of primary bovine aortic endothelial cells (BAECs) was investigated on a flat Ti surface vs a nanostructured TiO2 nanotube surface. The nanotopography provided nanoscale cues that facilitated cellular probing, cell sensing, and especially cell migration, where more organized actin cytoskeletal filaments formed lamellipodia(More)
We found that leptin receptors were expressed in hypothalamic astrocytes and that their conditional deletion led to altered glial morphology and synaptic inputs onto hypothalamic neurons involved in feeding control. Leptin-regulated feeding was diminished, whereas feeding after fasting or ghrelin administration was elevated in mice with astrocyte-specific(More)
A vertically aligned nanotube array of titanium oxide was fabricated on the surface of titanium substrate by anodization. The nanotubes were then treated with NaOH solution to make them bioactive, and to induce growth of hydroxyapatite (bone-like calcium phosphate) in a simulated body fluid. It is shown that the presence of TiO2 nanotubes induces the growth(More)
Introduction Semiconductor fluorescent quantum dots are nanometer-sized functionalized particles that display unique physical properties that make them particularly well suited for visualizing and tracking molecular processes in cells using standard fluorescence microscopy (Jaiswal et al., 2003; Watson et al., 2003; Michalet et al., 2005). They are readily(More)