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분산염색에서 Cotelomer 타입 계면 활성제의 응용
이재호,최해욱,정영진,황대연,최영호,이언필,Lee, Jae-Ho,Choi, Hae-Wook,Jung, Young-Jin,Hwang, Dae-Youn,Choi, Young-Ho,Lee, Eon-Pil 한국섬유공학회 2010 한국섬유공학회지 Vol.47 No.1
Multi-chain surfactants usually form micelles more easily than single-chain surfactants due to their low surface tension and low solubility in water. In this study we prepared cotelomers of multi-alkylated nonionic surfactants with a molecular structure $xR_nMA$-yVA (x; hydrophobic group, y; hydrophilic group, MA; methacrylic ester, VA; vinyl alcohol, R; alkyl group) and investigated their properties as surfactants for the disperse dyeing of cellulose acetate, nylon 6, and PET fibers. Some cotelomers were synthesized via a radical polymerization of vinyl monomers MA and VA using azobisisobutyronitrile (AIBN) as an initiator. The ratio of x/y and degree of polymerization of $xR_nMA$-yVA with an alkyl chain length (n) of 4 or 6 were controlled by adjusting the ratio of thiol to monomers. We found that a cotelomer with a degree of polymerization 9.9 showed better dispersing performances than cotelomer with a degree of polymerization 4.4 or 12.5, and that the degree of dispersion increased to a certain level and then decreased as concentration of cotelomer increased. The highest value of dye uptake for the three fibers was obtained when using a cotelomer with a monomer unit ratio (x/y) of 0.2 and 0.5 g/l of concentration was 0.5 g/l.
γ-Secretase 활성억제단백질인 TMP21의 과발현이 신경세포주에서 NGF 수용체 신호전달과 정에 미치는 영향
Sun Il Choi(최선일),Seung Wan Jee(지승완),Youn Kyung Her(허윤경),Ji Eun Kim(김지은),So Hee Nam(남소희),In Sik Hwang(황인식),Hye Ryun Lee(이혜련),Jun Seo Goo(구준서),Young Ju Lee(이영주),Eon Pil Lee(이언필),Hae Wook Choi(최해욱),Hong 한국생명과학회 2011 생명과학회지 Vol.21 No.8
TMP21은 AD의 원인으로 작용하는 Aβ-42 펩타이드 생성에 중요한 γ-secretase 활성을 억제하는 p24 family에 속하는 type I 막 단백질이다. 본 연구에서는 TMP21이 세포의 성장과 분화에 중요한 NGF 수용체 신호전달과정에 미치는 영향을 분석하고자 인간의 TMP21 cDNA를 합성하고, CMV promoter 조절 하에 hTMP21를 클로닝하여, CMV/hTMP21 벡터를 제조하였다. 그리고 이들 벡터를 B35 neuroblastoma에서 과발현시킨 후 γ-secretase 구성단백질과 NGF 수용체 연관 단백질의 변화를 관찰하였다. 그 결과, 4종류의 γ-secretase 구성단백질의 발현은 vehicle transfectants보다 CMV/hTMP21 transfectants에서 유의적으로 감소하였다. 또한 NGF low affinity 수용체인 p75<SUP>NTR</SUP>과 downstream 단백질인 RhoA의 양은 NGF를 처리하지 않은 TMP21 transfectants에서 유의적으로 증가하였으나 NGF 처리에 의해 감소되었다. High affinity NGF 수용체인 TrkA의 인산화도 NGF 처리가 없는 경우 유의적으로 감소하였으나 NGF 처리에 의해 증가되었다. 또한 downstream 신호전달 과정 중에서 ERK의 인산화는 TrkA와 유사한 발현변화를 나타내었으나 Akt 인산화는 NGF의 처리에 의해 더욱 증가하였다. 이러한 결과는 TMP21이 neuroblastoma에서 NGF 수용체 신호전달과정를 조절하는 중요한 단백질로서 작용함을 제시하며, AD의 작용기전 연구에 중요한 기초자료를 제공할 것으로 사료된다. Transmembrane protein 21 (TMP21) is a member of the p24 cargo protein family and has been shown to modulate γ-secretase-mediated Aβ production which was specifically observed in the brains of subjects with Alzheimer’s disease (AD). In order to investigate whether TMP21 could affect nerve growth factor (NGF) receptor signaling pathway, the alteration of NGF receptors and their downstream proteins were detected in TMP21 over-expressed cells. CMV/hTMP21 vector used in this study was successfully expressed into TMP21 proteins in B35 cells after lipofectamin transfection. Expressed TMP21 proteins induced the down-regulation of γ-secretase complex components including Presenlin-1 (PS-1), PS-2, Nicastrin (NST), Pen-2 and APH-1. Also, the expression level of NGF receptor p75<SUP>NTR</SUP> and RhoA were significantly higher in CMV/hTMP21 transfectants than vehicle transfectants, while their levels returned to vehicle levels after NGF treatment. However, the phosphorylation of NGF receptor TrkA was dramtically decreased in NGF No-treated CMV/hTMP21 transfectants compared with vehicle transfectants, and increased in NGF treated CMV/hTMP21 transfectants. In TrkA downstream signaling pathway, the phosphorylation level of ERK was also decreased in CMV/hTMP21 transfectants, while the phosphorylation of Akt was increased in the same transfectants. Furthermore, NGF treatment induced the increase of phosphorylation level of Akt and ERK in CMV/hTMP21 transfectants. Therefore, these results suggested that over-expression of TMP21 may simultaneously induce the up-regulation of p75<SUP>NTR</SUP>/RhoA expression and the down-regulation of TrkA/ERK phosphorylation through the inhibition of γ-secretase activity.
이재호,노창환,최해욱,정영진,황대연,이언필,Lee, Jae-Ho,Noh, Chang-Hwan,Choi, Hae-Wook,Jung, Young-Jin,Hwang, Dae-Youn,Lee, Eon-Pil 한국섬유공학회 2010 한국섬유공학회지 Vol.47 No.2
Chitosan/poly(vinyl alcohol)(PVA) blend films with non-toxicity, biodegradability, and biocompatibility were prepared by solvent blending method. The weight composition ratios of chitosan/PVA blend films were 100/0 (chitosan homopolymer), 75/25, 50/50, 25/75, and 0/100 (PVA homopolymer). Physicochemical properties of the prepared blend films according to various blend ratios were investigated by using universal testing machine, thermogravimeter (TGA), differential scanning calorimeter (DSC), wide angle X-ray diffractometer (WAXD), Fourier transform infrared (FTIR) spectrometer, and scanning electron microscope (SEM). The tensile stress and tensile strain of chitosan/PVA blend films increased as the amount of PVA increased. The thermal stability increased with increasing chitosan content in the chitosan/PVA blend films. The DSC curve of the PVA film shows an endotherm peak around $230^{\circ}C$, and the peak became smaller and broader with increasing chitosan content. The diffraction intensities of chitosan observed at 2 theta of $10^{\circ}$ decreased with increasing the content of PVA in the blend films, but the crystal intensities of the blend films increased as the amount of PVA increased. In the infrared spectra, the absorption band for -OH and -NH stretching vibrations in chitosan broadened and shifted obviously to lower wavenumber with the increase of PVA. Water-retention values of the chitosan/PVA blend films increased as the amount of PVA is increased owing to the hydrophilic nature of PVA. From the structural analyses, it is believed that chitosan and PVA are miscible due to the strong intermolecular hydrogen bonding.
강세미,노창환,황대연,정영진,최해욱,이언필,이재호,Kang, Se-Mi,Noh, Chang-Hwan,Hwang, Dae-Youn,Jung, Young-Jin,Choi, Hae-Wook,Lee, Eon-Pil,Lee, Jae-Ho 한국섬유공학회 2012 한국섬유공학회지 Vol.49 No.1
The uncrosslinked and crosslinked by ethylene glycol diglycidyl(EGDE) chitosan/sericin blend films were prepared by solvent blending method. Physicochemical properties of the prepared blend films according to various blend ratios were investigated. This was carried out by using universal testing machine, thermogravimeter(TGA), differential scanning calorimeter(DSC), wide angle X-ray diffractometer(WAXD), Fourier transform infrared spectrum(FTIR) and scanning electron microscopy(SEM). With an increase in the sericin mixing ratio, tensile stress increased whereas the tensile strain decreased for uncrosslinking blend films. For a cross linked chitosan/sericin blend film by EGDE, both the tensile stress and strain decreased. Chitosan/sericin blend films exhibit an excellent thermal stability when sericin mixing ratio is 25%. In the infrared spectra, chitosan/sericin blend films showed an absorption band of amide I peak at 1630 $cm^{-1}$ and it is concerned with C=O stretching vibration by strong hydrogen-bond between inter-molecular. These also showed an absorption band of amide II peak at 1521 $cm^{-1}$ concerned with N-H bending vibration. The absorption band of amide I peak decreased with an increase in the chitosan mixing ratio. We identified that there was good miscibility between chitosan and sericin. The water-retention values(WRV) of chitosan/sericin blend films increase as the amount of sericin is raised and this owes to the hydrophilic nature of sericin. Weight loss of the citosan/sericin blend films by cleaning with an aqueous sodium hydroxide increased with an increase in the sericin mixing ratio. This loss is the loss of acetic acid and sericin in the chitosan/sericin blend films and this is because of the molecular weight of the sericin is 1/5 of the chitosan and sericin is dissolved into NaOH solution. Weight loss increased when sericin content was more than 50% for the cross linked chitosan/sericin blend films. From the structure analysis, we identified that there was good miscibility and strong intermolecular interaction between the chitosan molecules that resulted from intermolecular hydrogen bonds.