• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.54-55
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• 2006

Polymeric micelles, supramolecular assemblies of block copolymers, are useful nanocarriers for the systemic delivery of drugs and genes. Recently, novel polymeric micelles with various functions such as the targetability and stimuli-sensitivity have been emerged as promising carriers that enhance the efficacy of drugs and genes with minimal side effects. This presentation focuses our recent approach to the preparation of functional block copolymers that are useful for constructing smart micellar delivery systems in advanced therapeutics, including chemo-gene therapy. Particular emphasis is placed on the characteristic behaviors of intracellular environment-sensitive micelles that selectively exert drug activity and gene expression in live cells.

• Polymer Science and Technology
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• v.22 no.5
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• pp.447-453
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• 2011

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4739-4743
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• 2014

Nanotechnology is an emerging field with many promising applications in drug delivery systems. Because of outstanding developments in this field, rapidly increasing research is directed to the development of nanocarriers that may enhance the availability of drugs to the target sites. Substantial fraction of information has been added into the existing scientific literature focusing on the fact that nanoparticles usually generate reactive oxygen species to a greater extent than micro-sized particles. It is worth mentioning that oxidative stress regulates an array of cell signaling cascades that resulted in cancer cell damage. Accumulating experimental evidence over the years has shown that wide-ranging biological mechanisms are triggered by these NPs in cultured cells due to the unique properties of engineered nanoparticles. In this review, we have attempted to provide an overview of the signaling cascades that are activated by oxidative stress in cancer cells in response to different kinds of nanomaterials, including quantum dots, metallic and polymeric nanoparticles.

• Food Science and Industry
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• v.53 no.1
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• pp.56-68
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• 2020

Recently, chitosan has increased attention in commercial applications in the food industry in terms of its biocompatibility and nontoxicity. In particular, chitosan has been used as a good hosting material for producing nanoparticles due to its unique property of ionic gelation. Chitosan has disadvantages such as low solubility at physiological pH, causing the metabolism of core material in the intestine and gastric juice. To overcome these limitations, various chitosan derivatives such as carboxylated, thiolated, and acylated chitosan have been studied. This review focuses on the changes in the physicochemical properties of chitosan nanoparticles with the introduction of hydrophobic groups, the application of functional nanocapsules as coatings, and their applicability in the food sector. The physicochemical modification of chitosan is expected to be an attractive research field for the development of chitosan applications for food as well as for improving bioavailability in functional food.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.639-647
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• 2014

Laccases have a broad range of industrial applications. In this study, we immobilized laccase on $SiO_2$ nanoparticles to overcome problems associated with stability and reusability of the free enzyme. Among different reagents used to functionally activate the nanoparticles, glutaraldehyde was found to be the most effective for immobilization. Optimization of the immobilization pH, temperature, enzyme loading, and incubation period led to a maximum immobilization yield of 75.8% and an immobilization efficiency of 92.9%. The optimum pH and temperature for immobilized laccase were 3.5 and $45^{\circ}C$, respectively, which differed from the values of pH 3.0 and $40^{\circ}C$ obtained for the free enzyme. Immobilized laccase retained high residual activities over a broad range of pH and temperature. The kinetic parameter $V_{max}$ was slightly reduced from 1,890 to 1,630 ${\mu}mol/min/mg$ protein, and $K_m$ was increased from 29.3 to 45.6. The thermal stability of immobilized laccase was significantly higher than that of the free enzyme, with a half-life 11- and 18-fold higher at temperatures of $50^{\circ}C$ and $60^{\circ}C$, respectively. In addition, residual activity was 82.6% after 10 cycles of use. Thus, laccase immobilized on $SiO_2$ nanoparticles functionally activated with glutaraldehyde has broad pH and temperature ranges, thermostability, and high reusability compared with the free enzyme. It constitutes a notably efficient system for biotechnological applications.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4915-4918
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• 2014

Background and Aims: Advances in the treatment of cervical cancer over the last decade have predominantly involved the development of genes directed at molecular targets. Gene therapy is recognized to be a novel method for the treatment of cervical cancer. Genes can be administered into target cells via nanocarriers. This study aimed to develop systemically administrable nano-vectors. Floate (Fa) containing gene loaded nanoparticles (NPs) could target HeLa human cervical cancer cells through combination with receptors on the cells to increase the nuclear uptake of genetic materials. Methods: Fa was linked onto Poly (ethylene glycol)-b-poly (D, L-lactide) (PEG-PLA) to form Fa-PEG-PLA, and the resulting material was used to load plasmids of enhanced green fluorescence protein (pEGFP) to obtain gene loaded nanoparticles (Fa-NPs/DNA). Physical-chemical characteristics, in vitro release and cytotoxicity of Fa-NPs/DNA were evaluated. The in vitro transfection efficiency of Fa-NPs/DNA was evaluated in HeLa cells and human umbilical vein endothelial cells (HUVEC). PEG-PLA without Fa was used to load pEGFP from NPs/DNA as a control. Results: Fa-NPs/DNA has a particle size of 183 nm and a gene loading quantity of 92%. After 72h of transfection, Fa-NPs/DNA displayed over 20% higher transfection efficiency than NPs/DNA and 40% higher than naked DNA in HeLa cells. However, in HUVECs, no significant difference appeared between Fa-NPs/DNA and NPs/DNA. Conclusions: Fa-PEG-PLA NPs could function as excellent materials for gene loading. This nano-approach could be used as tumor cell targeted medicine for the treatment of cervical cancer.

• Journal of Ginseng Research
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• v.45 no.2
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• pp.228-235
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• 2021

Backgroud: Ginsenoside compound K (GK) is a major metabolite of protopanaxadiol-type ginsenosides and has remarkable anticancer activities in vitro and in vivo. This work used an ionic cross-linking method to entrap GK within O-carboxymethyl chitosan (OCMC) nanoparticles (Nps) to form GK-loaded OCMC Nps (GK-OCMC Nps), which enhance the aqueous solubility and stability of GK. Methods: The GK-OCMC Nps were characterized using several physicochemical techniques, including x-ray diffraction, transmission electron microscopy, zeta potential analysis, and particle size analysis via dynamic light scattering. GK was released from GK-OCMC Nps and was conducted using the dialysis bag diffusion method. The effects of GK and GK-OCMC Nps on PC3 cell viability were measured by using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Fluorescent technology based on Cy5.5-labeled probes was used to explore the cellular uptake of GK-OCMC Nps. Results: The GK-OCMC NPs had a suitable particle size and zeta potential; they were spherical with good dispersion. In vitro drug release from GK-OCMC NPs was pH dependent. Moreover, the in vitro cytotoxicity study and cellular uptake assays indicated that the GK-OCMC Nps significantly enhanced the cytotoxicity and cellular uptake of GK toward the PC3 cells. GK-OCMC Nps also significantly promoted the activities of both caspase-3 and caspase-9. Conclusion: GK-OCMC Nps are potential nanocarriers for delivering hydrophobic drugs, thereby enhancing water solubility and permeability and improving the antiproliferative effects of GK.