M. S. Cho

Dry Type Conducting Polymer Actuator Based on Polypyrrole–NBR/Ionic Liquid System

The fabrication of dry type conducting polymer actuator was presented. In the preparation of actuator system, nitrile rubber (NBR) was used as a base material of the solid polymer electrolyte. Thin films of NBR (150 ∼ 200 µm) were prepared by compression molding process. The conducting polymer, polypyrrole(PPy) was synthesized on the surface of NBR by chemical oxidation polymerization technique, and the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide (BMITFSI) was introduced into the composite film. The cyclic voltammetry responses and the redox switching dynamics of PPy in NBR/ionic liquid solid polymer electrolyte were studied. The displacement of actuator was measured by laser beam.

An electroactive conducting polymer actuator based on NBR/RTIL solid polymer electrolyte

This paper reports the fabrication of a dry-type conducting polymer actuator using nitrile rubber (NBR) as the base material in a solid polymer electrolyte. The conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), was synthesized on the surface of the NBR layer by using a chemical oxidation polymerization technique. Room-temperature ionic liquids (RTIL) based on imidazolium salts, e.g. 1-butyl-3-methyl imidazolium X (where X = BF4−, PF6−, (CF3SO2)2N−), were absorbed into the composite film. The compatibility between the ionic liquids and the NBR polymer was confirmed by DMA. The effect of the anion size of the ionic liquids on the displacement of the actuator was examined. The displacement increased with increasing anion size of the ionic liquids. The cyclic voltammetry responses and the redox switching dynamics of the actuators were examined in different ionic liquids.

Formation of Gold Nanoparticles During the Vapor Phase Oxidative Polymerization of EDOT Using HAuCl4 Oxidant

The thin layer of poly(3, 4-ethylenedioxythiophene) (PEDOT) on the PET film was obtained by a vapor-phase polymerization technique using HAuCl4 as an oxidant. The EDOT monomer was easily oxidized by the HAuCl4 oxidant while HAuCl4 was reduced to form metallic Au nanoparticles. The formation of PEDOT/Au composite film was monitored by UV-vis spectra and SEM, and the formation of metallic Au was confirmed by EDAX and XPS.

A Solid State Actuator Based on the PEDOT/NBR System: Effect of Anion Size of Imidazolium Ionic Liquid

The fabrication of a dry type conducting polymer actuator is presented using nitrile rubber (NBR) as the base material for the solid polymer electrolyte. A conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), was synthesized on the surface of the NBR by the chemical oxidation polymerization technique, and room temperature ionic liquids (RTIL) based on imidazolium salts, viz. 1-butyl-3-methyl imidazolium X [where X = BF4 −, PF6 −, (CF3SO2)2N−], were introduced onto the composite film. The effects of the anion size of the ionic liquids on the displacement of the actuator were investigated. The displacement increased with increasing anion-size of the ionic liquids. The cyclic voltammetric responses and the redox switching dynamics of the actuators were studied in different ionic liquids.

Characteristics of PEDOT/NBR/PEDOT Solid Actuator Depending on the NBR Polarity

A dry type conducting polymer actuator PEDOT/NBR/PEDOT is prepared. Nitrile rubber (NBR) containing room temperature ionic liquid, 1-butyl-3-methyl imidazoliumbis (trifluoromethylsulfonyl) imide (BMITFSI), have been utilized as a new type of solid polymer electrolytes. Various types of NBR having different amounts of acylonitrile (ACN), viz. 23, 35, and 40 mol.%, are synthesized in order to examine the effect of polarity of NBR on the actuation behavior. A conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), was synthesized on the surface of the SPEs by using a chemical oxidative polymerization technique. The electrical potential was applied on PEDOT layer which caused volume change to result in actuation behavior. The characteristics of the PEDOT/NBR/PEDOT actuator were carefully examined.

Hydrolysis of Hyaluronic Acid in Lymphedematous Tissue Alleviates Fibrogenesis via TH1 Cell-Mediated Cytokine Expression.

Although surgery and radiation are beneficial for treating cancer, they can also lead to malfunctions of the lymphatic system such as secondary lymphedema. This abnormality of the lymphatic system is characterized by severe swelling, adipogenesis, inflammation, and fibrosis in the lymphedematous region. Moreover, the proliferation of fibrotic tissue in the lymphedematous region generates edema that is no longer spontaneously reversible. No treatment for fibrosis has been validated in patients with lymphedema. In our efforts to develop a therapeutic agent for lymphedema fibrosis, we used a newly established mouse hind limb model. Previous studies have demonstrated that hyaluronic acid accumulates in the lymphedematous region. Thus, we challenged mice with of hyaluronidase (HYAL), with the aim of reducing fibrogenesis. After subcutaneous injections in the lymphedematous mouse leg every two days, the volume of lymphedema had reduced significantly by 7 days post-operation. Histochemical analysis indicated that collagen accumulation and myofibroblast differentiation were decreased in epidermal tissues after HYAL injection. Moreover, it was associated with upregulation of interferon-gamma, increased numbers of Th1 cells, and downregulation of interleukin-4 and interleukin-6 in the lymphedematous region and spleen. These results indicate that hydrolysis of hyaluronic acid can boost an anti-fibrotic immune response in the mouse lymphedema model.

Preventive Activity against Influenza (H1N1) Virus by Intranasally Delivered RNA-Hydrolyzing Antibody in Respiratory Epithelial Cells of Mice.

The antiviral effect of a catalytic RNA-hydrolyzing antibody, 3D8 scFv, for intranasal administration against avian influenza virus (H1N1) was described. The recombinant 3D8 scFv protein prevented BALB/c mice against H1N1 influenza virus infection by degradation of the viral RNA genome through its intrinsic RNA-hydrolyzing activity. Intranasal administration of 3D8 scFv (50 μg/day) for five days prior to infection demonstrated an antiviral activity (70% survival) against H1N1 infection. The antiviral ability of 3D8 scFv to penetrate into epithelial cells from bronchial cavity via the respiratory mucosal layer was confirmed by immunohistochemistry, qRT-PCR, and histopathological examination. The antiviral activity of 3D8 scFv against H1N1 virus infection was not due to host immune cytokines or chemokines, but rather to direct antiviral RNA-hydrolyzing activity of 3D8 scFv against the viral RNA genome. Taken together, our results suggest that the RNase activity of 3D8 scFv, coupled with its ability to penetrate epithelial cells through the respiratory mucosal layer, directly prevents H1N1 virus infection in a mouse model system.

Development of a Dry Actuation Conducting Polymer Actuator For Micro-Optical Zoom Lenses

The objective of the present work is to demonstrate the efficiency and feasibility of NBR (Nitrile Butadiene Rubber) based conducting polymer actuator that is fabricated into a micro zoon lens driver. Unlike the traditional conducting polymer that normally operates in a liquid, the proposed actuator successfully provides fairly effective driving performance for the zoom lens system in a dry environment. And this paper is including the experiment results for an efficiency improvement. The result suggested by an experiment was efficient in micro optical zoom lens system. In addition, the developed design method of actuator was given consideration to design the system.

Evolution of Core-Shell Structure Using Functional Polystyrene and Gold

A core-shell of a carboxylic functional polystyrene (PS-COOH) with gold was prepared by the combination of surface gold-seeding and subsequent shell growth in a gold solution. The PS-COOH cores were prepared by a dispersion polymerization of styrene for seed formation followed by copolymerization of styrene and methacrylic acid. In the preparation of gold shell, PS-COOH cores were initially immersed into gold nanoparticles containing solution and continuous gold shell was formed by employing a mixed aqueous solution of Au(OH)3 and NH2OH. The gold nanoparticles impregnated into the PS-COOH cores were used as gold seeds to form continuous gold shells. The characteristics of the PS-COOH/Au core-shells were investigated by SEM, TEM, EDS and XPS.

Probiotic Lactobacillus Paracasei Expressing a Nucleic Acid-Hydrolyzing Minibody (3D8 Scfv) Enhances Probiotic Activities in Mice Intestine as Revealed by Metagenomic Analyses

Probiotics are well known for their beneficial effects for animals, including humans and livestock. Here, we tested the probiotic activity of Lactobacillus paracasei expressing 3D8 scFv, a nucleic acid-hydrolyzing mini-antibody, in mice intestine. A total of 18 fecal samples derived from three different conditions at two different time points were subjected to high-throughput 16S ribosomal RNA (rRNA) metagenomic analyses. Bioinformatic analyses identified an average of 290 operational taxonomic units. After administration of L. paracasei, populations of the probiotics L. paracasei, Lactobacillus reuteri, and Pediococcus acidilactici increased, whereas the population of harmful bacteria such as Helicobacter species decreased. Furthermore, continuous administration of L. paracasei resulted in L. paracasei emerging as the dominant probiotic after competition with other existing probiotics. Expression of 3D8 scFv protein specifically increased the population of P. acidilactici, which is another probiotic. In summary, our results showed that L. paracasei expressing 3D8 scFv protein enhanced probiotic activity in mice intestine with no observable side effects. Thus, the system developed in this study may be a good tool for the expression of recombinant protein using probiotics.