Browsing by Author "Hsieh, Chia-Jung"

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Graphene Oxide Based Nanocarrier Combined with a pH-Sensitive Tracer: A Vehicle for Concurrent pH Sensing and pH-Responsive Oligonucleotide Delivery
(2015-06-03)
Hsieh, Chia-Jung
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Chen, Yu-Cheng
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Hsieh, Pei-Ying
;
Liu, Shi-Rong
;
Wu, Shu-Pao
We chemically tuned the oxidation status of graphene oxide (GO) and constructed a GO-based nanoplatform combined with a pH-sensitive fluorescence tracer that is designed for both pH sensing and pH-responsive drug delivery. A series of GOs oxidized to distinct degrees were examined to optimize the adsorption of the model drug, poly dT(30). We determined that highly oxidized GO was a superior drug-carrier candidate in vitro when compared to GOs oxidized to lesser degrees. In the cell experiment, the synthesized pH-sensitive rhodamine dye was first applied to monitor cellular pH; under acidic conditions, protonated rhodamine fluoresces at 588 mm (lambda(ex) = 561 nm). When the nanocarrier was introduced into cells, a rhodamine-triggered competition reaction occurred, and this led to the release of the oligonucleotides and the quenching of rhodamine fluorescence by GO. Our results indicate high drug loading (FAM-dT(30)/GO = 25/50 mu g/mL) and rapid cellular uptake (<0.5 h) of the nanocarrier which can potentially be used for targeted RNAi delivery to the acidic milieu of tumors.
Performance of vanadium oxide on multi-walled carbon nanotubes/titanium electrode for supercapacitor application
(2011)
Liu, Ming-Yang
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Hsieh, Tung-Feng
;
Hsieh, Chia-Jung
;
Chuang, Chia-Chih
;
Shu, Chi-Min
Composite electrodes based on vertically aligned multi-walled carbon nanotubes (MWCNTs) coated with vanadium oxide (V2O5) have used in supercapacitors. The vanadium (V) oxide (V2O5) cathodically deposited on titanium collector in vanadium oxide solution. The novel supercapacitor performed by V2O5/MWCNTs/Ti electrode in 1.0 M HCl aqueous solution can reach a specific capacitance of 713.3 F/g at 10 mV/s, which is larger than that of MWCNTs/Ti. To characterize the V2O5/MWCNTs/Ti composite electrode, cyclic voltammetry and galvanostatic charge-discharge method were executed, and the morphology of the composite electrode was examined by scanning electron microscope. This nanocomposite electrode greatly enhanced the utilization efficiency of supercapacitor electrode material, low material cost and provided both high capacitance and power density.