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Characterizations of Modified Silica Nanoparticles(I)
Min, Seong-Kee,Park, Chan-Young,Lee, Won-Ki,Seul, Soo-Duk Materials Research Society of Korea 2012 한국재료학회지 Vol.22 No.6
(3-mercaptopropyl)trimethoxysilane (MPTMS) was used as a silylation agent, and modified silica nanoparticles were prepared by solution polymerization. 2.0 g of silica nanoparticles, 150 ml of toluene, and 20 ml of MPTMS were put into a 300 ml flask, and these mixtures were dispersed with ultrasonic vibration for 60 min. 0.2 g of hydroquinone as an inhibitor and 1 to 2 drops of 2,6-dimethylpyridine as a catalyst were added into the mixture. The mixture was then stirred with a magnetic stirrer for 8 hrs. at room temperature. After the reaction, the mixture was centrifuged for 1 hr. at 6000rpm. After precipitation, 150 ml of ethanol was added, and ultrasonic vibration was applied for 30 min. After the ultrasonic vibration, centrifugation was carried out again for 1 hr. at 6000rpm. Organo-modification of silica nanoparticles with a ${\gamma}$-methacryloxypropyl functional group was successfully achieved by solution polymerization in the ethanol solution. The characteristics of the ${\gamma}$-mercaptopropyl modified silica nanoparticles (MPSN) were examined using X-ray photoelectron spectroscopy (XPS, THERMO VG SCIENTIFIC, MultiLab 2000), a laser scattering system (LSS, TOPCON Co., GLS-1000), Fourier transform infrared spectroscopy (FTIR, JASCO INTERNATIONL CO., FT/IR-4200), scanning electron microscopy (SEM, HITACHI, S-2400), an elemental analysis (EA, Elementar, Vario macro/micro) and a thermogravimetric analysis (TGA, Perkin Elmer, TGA 7, Pyris 1). From the analysis results, the content of the methacryloxypropyl group was 0.98 mmol/g and the conversion rate of acrylamide monomer was 93%. SEM analysis results showed that the organo-modification of ultra-fine particles effectively prevented their agglomeration and improved their dispensability.
Triamcinolone Acetonide가 배양 켈로이드 섬유아세포의 G1 세포주기 관련 유전자 발현에 미치는 영향
설정현,우상현,백원기,서성일,서민호 大韓成形外科學會 1998 Archives of Plastic Surgery Vol.25 No.2
The effect of triamcinolone acetonide(TA) on the expression of Gl related genes was investigated the cultured keloid fibroblast. The addition of TA to the culture medium resulted in growth inhibition of keloid fibroblast. TA reduced the expression of cyclin A, B, E and cyclin dependent kinase(CDK) 2 mRNA, but unexpectedly, the expression of cyclin C, Dl and CDK4 mRAN was not affected significantly as compared with those of normal fibroblast. Expressions of p16, p21 and p27, the wellestabilished CDK-inhibitors, were also investigated. The level of p16 was not detected in both normal and keloid fibroblasts and the expression of p27 was significantly decreased in keloid fibroblast. The expression of p21 was dramatically increased in keloid fibroblast but not significantly changed in normal fibroblast. Also the expressions of p53 and pRb, the well known tumor suppressor genes, were increased by the addition of TA. These data suggested that the observed growth inhibitory effect of TA may be related to transcriptional inactivation of cyclin A, B, E and CDK2 and to the transcriptional activation of p21, but the mechanisms of unchanged expression of cyclin C, Dl and CDK4 mRNA remain to be elucidated.
Min, Seul Ki,Kim, Cho Rong,Kim, Sung Hoon,Shin, Hwa Sung Hindawi Limited 2014 Journal of nanomaterials Vol.2014 No.-
<P>Tissue engineering using a biomaterial including bioactive compounds has been researched as a way to restore injured neural systems. Extracellular polymeric substances (EPS) extracted from marine seaweeds have been known to produce positive effects on physiological activities in human tissues. In this study, an electrospun nanofiber containing brown seaweed EPS was proven to be a candidate biomaterial for neural tissue engineering. Glial fibrillary acidic protein (GFAP) as a specific marker protein increased in the astrocytes cultured on the polycaprolactone (PCL) nanofiber containing EPS (EPS-PCL nanofiber), compared with PCL nanofiber. The upregulation of GFAP indicates that the EPS-PCL nanofiber induced astrocyte activation, which supports physiological agents favorable to restore injured neural tissue. Astrocytes could infiltrate into the EPS-PCL nanofiber mat without toxicity, comparable to PCL nanofiber. These results imply that EPS-PCL nanofiber could be a useful biomaterial to regulate astrocyte activity at a molecular level and could be considered as a novel therapeutic material for neural tissue engineering.</P>