Biomedical subjects

Kyusik Yun

Publications and source records attributed to Kyusik Yun.

4 recordsLinked to original sources

PubMed2006

DNA biosensor based on the electrochemiluminescence of Ru(bpy)3(2+) with DNA-binding intercalators.

This paper reports a novel detection method for DNA hybridization based on the electrochemiluminescence (ECL) of Ru(bpy)(3)(2+) with a DNA-binding intercalator as a reductant of Ru(bpy)(3)(3+). Some ECL-inducible intercalators have been screened in this study using electrochemical methods combined with a chemiluminescent technique. The double-stranded DNA intercalated by doxorubicin, daunorubicin, or 4',6-diamidino-2-phenylindole (DAPI) shows a good ECL with Ru(bpy)(3)(2+) at +1.19 V (versus Ag/AgCl), while the non-intercalated single-stranded DNA does not. In order to stabilize the self-assembled DNA molecules during ECL reaction, we constructed the ECL DNA biosensor separating the ECL working electrode with an immobilized DNA probe. A gold electrode array on a plastic plate was assembled with a thru-hole array where oligonucleotide probes were immobilized in the side wall of thru-hole array. The fabricated ECL DNA biosensor was used to detect several pathogens using ECL technique. A good specificity of single point mutations for hepatitis disease was obtained by using the DAPI-intercalated Ru(bpy)(3)(2+) ECL.

Biosensing Techniques↗

PubMed2006

DNA chip replication for a personalized DNA chip.

We report the replication technology of DNA chip using by sequence specific localization of nucleic acids via hybridization and electric transfer of the nucleic acids onto a new substrate without losing their array information. The denatured DNA fragments are first spotted and UV-cross-linked on a nylon membrane. The membrane is then immersed and hybridized in a DNA mixture solution that contains all complementary sequences of the nucleic acids to be hybridized with the DNA fragments on the membrane. The hybridized DNA fragments are transferred to another membrane at the denatured condition. After separating two membranes, the transferred membrane contains a complementary array of DNA fragments. This method can be used for the replication of the same copy of DNA chip repeatedly and moreover could be applied for a personalized DNA chip fabrication, where specific information of each spot of DNA chip is originated from the genetic information of a personal sample.

Carbocyanines↗

PubMed2004

Immobilization of Arg-Gly-Asp (RGD) sequence in a thermosensitive hydrogel for cell delivery using pheochromocytoma cells (PC12).

A copolymer of N-isopropylacrylamide (98 mole% in the feed) and acrylic acid poly(N-isopropylacrylamide-co-acrylic acid) [p(NiPAAm-co-AAc)], and the adhesion molecule, an Arg-Gly-Asp (RGD)-incorporated hydrogel, were used to entrap pheochromocytoma cells (PC12). In a 28-d culture period, the PC12 cells in the RGD-conjugated gel maintained higher viability and produced dopamine at constant rates, while there was lower cell viability and less dopamine secretion by PC12 cells in p(NiPAAm-co-AAc). PC12 cells cultured in the RGD-conjugated gel would constitute a potentially useful three-dimensional cell system for application in nerve regeneration.

Journal Article↗

PubMed2003

Conjugation of heparin into carboxylated pullulan derivatives as an extracellular matrix for endothelial cell culture.

A carboxylated pullulan, for use as a structural material for a number of tissue engineering applications, was synthesized and conjugated with heparin. By immobilization of heparin to pullulan, endothelial cells (ECs) attached on the heparin-conjugated pullulan were more aggregated than when attached to other pullulan derivatives. Attachments were 50, 45, 49, and 90% for a polystyrene dish, pullulan acetate, carboxylated pullulan, and heparin-conjugated pullulan, respectively. Heparin-conjugated pullulan inhibited the proliferation of smooth muscle cells (SMCs) in vitro. Heparin-conjugated pullulan material can thus be used for the proliferation of vascular ECs and to inhibit the proliferation of SMCs.

Animals↗