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An Integrated System to Remotely Trigger Intracellular Signal Transduction by Upconversion Nanoparticle-mediated Kinase Photoactivation

Upconversion nanoparticle (UCNP)-mediated photoactivation is a new approach to remotely control bioeffectors with much less phototoxicity and with deeper ...

National Taipei University of Technology

C(6)F(6) vapor is employed to react with CaC(2) and Mg(3)N(2) to grow CaF(2)/a-C and Mg(2)F(2)/a-C core/shell nanowires (tens of micrometers in length, tens to hundreds of nanometers in wire diameter, and tens of nanometers in core diameter), respectively, in high yields. The growth mechanism is proposed to proceed via a reaction at the interface of the vapor and solid reactants.

Reaction growth of MF2/a-C (M = Ca, Mg) core/shell nanowires at the interface of vapor and solid reactants.

Porous carbon materials with pore sizes from 3 to 200 nm were synthesized by reacting hexafluorobenzene with Na liquid at 623 K. NaF crystals, a byproduct formed in the reaction, acted as nanotemplate to assist the pore formation. By employing hexafluorobenzene to react with Na incorporated within the channels (diameter 200 nm) of anodized aluminum oxide (AAO) membranes at 323-623 K, the carbon material can be fabricated into aligned porous nanotube arrays (ca. 250 nm in diameter, ca. 20 nm in wall thickness, ca. 0.06 mm in length, and ca. 3-90 nm in pore diameter). These materials were characterized by X-ray diffraction, scanning and transmission electron microscopy, X-ray energy dispersive spectroscopy, electron diffraction, thermal gravimetric analysis, and nitrogen physical adsorption experiments.

Formation of porous carbon materials with in situ generated NaF nanotemplate.

Direct nanopatterning of a number of high-melting-temperature molecules has been systematically investigated by dip-pen nanolithography (DPN). By tuning DPN experimental conditions, all of the high-melting-temperature molecules transported smoothly from the atomic force microscope (AFM) tip to the surface at room temperature without tip preheating. Water meniscus formation between the tip and substrate is found to play a critical role in patterning high-melting-temperature molecules. These results show that heating an AFM probe to a temperature above the ink's melting temperature is not a prerequisite for ink delivery, which extends the current "ink-substrate" combinations available to DPN users.

Dip-pen nanolithography of high-melting-temperature molecules.

Photoactivatable (caged) bioeffectors provide a way to remotely trigger or disable biochemical pathways in living organisms at a desired time and location with a pulse of light (uncaging), but the phototoxicity of ultraviolet (UV) often limits its application. In this study, we have demonstrated the near-infrared (NIR) photoactivatable enzyme platform using protein kinase A (PKA), an important enzyme in cell biology. We successfully photoactivated PKA using NIR to phosphorylate its substrate, and this induced a downstream cellular response in living cells with high spatiotemporal resolution. In addition, this system allows NIR to selectively activate the caged enzyme immobilized on the nanoparticle surface without activating other caged proteins in the cytosol. This NIR-responsive enzyme-nanoparticle system provides an innovative approach to remote-control proteins and enzymes, which can be used by researchers who need to avoid direct UV irradiation or use UV as a secondary channel to turn on a bioeffector.

Yu-Hsu Chang

Department of Materials and Mineral Resources Engineering

National Taipei University of Technology

An Integrated System to Remotely Trigger Intracellular Signal Transduction by Upconversion Nanoparticle-mediated Kinase Photoactivation

Yu-Hsu Chang

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Materials and Mineral Resources Engineering

National Taipei University of Technology

An Integrated System to Remotely Trigger Intracellular Signal Transduction by Upconversion Nanoparticle-mediated Kinase Photoactivation

Department of Materials and Mineral Resources Engineering