Kyung-hwa Yoo

We report direct measurements of electrical transport through poly(dA)-poly(dT) and poly(dG)-poly(dC) DNA molecules containing identical base pairs. The observed experimental results suggest that electrical transport through DNA molecules occurs by polaron hopping. We have also investigated the effect of gate voltage on the current-voltage curve. It demonstrates the possibility of a DNA field-effect transistor operating at room temperature. Moreover, the gate-voltage dependent transport measurem

To facilitate combined doxorubicin and photothermal treatments, we developed doxorubicin-loaded poly(lactic-co-glycolic acid)-gold half-shell nanoparticles (DOX-loaded PLGA-Au H-S NPs) by depositing Au films on DOX-loaded PLGA NPs. As the PLGA NPs biodegraded, DOX was released, and heat was locally generated upon near-infrared (NIR) irradiation due to NIR resonance of DOX-loaded PLGA H-S NPs. Compared with chemotherapy or photothermal treatment alone, the combined treatment demonstrated a synerg

We have developed RGD-attached gold (Au) half-shell nanoparticles containing methotrexate (MTX) for the treatment of rheumatoid arthritis (RA), where MTX is the most widely used disease-modifying anti-rheumatic drug (DMARD) for the treatment of RA, and RGD peptide is a targeting moiety for inflammation. Upon near-infrared (NIR) irradiation, heat is locally generated due to Au half-shells, and the drug release rate is enhanced, delivering heat and drug to the inflamed joints simultaneously. RA is

Doxorubicin-loaded PEG-PLGA-Au half-shell nanoparticles provide multifunctions, such as photothermal treatment, photothermally controlled drug delilvery, and in vivo optical imaging. In addition, the combined doxorubicin and photothermal treatments using these multifunctional nanoparticles show synergistic therapeutic effects. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are ma

Drug and heat delivery to tumors by active targeting with Herceptin-conjugated doxorubicin-loaded poly(ethylene glycol)–poly(lactic-co-glycolic acid)–Au half-shell nanoparticles (HER-DOX-PLGA-Au H-S NPs) is more effective than passive targeting with their HER-free counterparts (DOX-PLGA-Au H-S NPs). Thus, on NIR irradiation, higher intratumoral temperatures were reached in tumor-bearing mice that were treated with the HER-conjugated particles (see picture). Detailed facts of importance to specia

Optoelectronic memory devices, whose states can be controlled using electrical optical signals, are receiving much attention for their potential applications in image sensing and parallel data transmission and processes. Here, we report MoS₂-based devices with top floating gates of Au, graphene, and MoS₂. Unlike conventional floating gate memory devices, our devices have the photoresponsive floating gate at the top, acting as a charge trapping layer. Stable and reliable swi

We fabricated MoS₂-based flash memory devices by stacking MoS₂ and hexagonal boron nitride (hBN) layers on an hBN/Au substrate and demonstrated that these devices can emulate various biological synaptic functions, including potentiation and depression processes, spike-rate-dependent plasticity, and spike-timing dependent plasticity. In particular, compared to a flash memory device prepared on an hBN substrate, the device fabricated on the hBN/Au exhibited considerably more

We have developed carbon nanotube-based dual-mode biosensors with a metal semiconductor field effect transistor structure on a quartz substrate. DNA hybridization occurring on the Au top gate can be detected by simultaneously measuring the change in the electrical conductance and the surface plasmon resonance (SPR). Since electrical and SPR measurements offer high sensitivity and reliability, respectively, this dual-mode biosensor is expected to provide both of these features.

Bi2Te3 nanowires exhibit the phase-change memory switching behavior. The as-grown nanowire has a linear current–voltage curve and a crystalline structure. After switching to the high-resistance state with a voltage pulse, the crystalline phases are partially changed to amorphous phases. This indicates that a crystalline–amorphous phase change in Bi2Te3 nanowires can be induced by a voltage pulse.

BACKGROUNDS: Despite the advances of rheumatoid arthritis (RA) therapeutics, several patients do not receive adequate treatment due to the toxicity and/or insufficient response of drugs. The aim of this study is to design photothermally controlled drug release from multifunctional nanoparticles (MNPs) at a near-infrared (NIR) irradiated site to improve therapeutic efficacy for RA and reduce side effects. METHODS: Au film was deposited onto methotrexate (MTX)-loaded poly(ethylene glycol)-poly(lac