• Title/Summary/Keyword: Dendrimers

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Synthesis of Fréchet-type Dendrimers with Tripodal Core via Staudinger/Aza-Wittig Reactions (Staudinger/Aza-Wittig 반응에 의한 삼발이 핵을 갖는 Fréchet-type 덴드리머의 합성)

  • Han, Seung Choul;Lee, Jae Wook;Jin, Sung-Ho
    • Polymer(Korea)
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    • v.38 no.3
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    • pp.386-390
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    • 2014
  • Efficient stitching methods for the synthesis of tripodal Fr$\acute{e}$chet-type dendrimers containing secondary amine as a connector were elaborated. The synthetic strategy involved Staudinger/aza-Wittig reactions (new click reaction) between tripodal tris(azides) and aldehyde-dendrons in toluene in the presence of triphenylphosphine and followed by the reduction of imine intermediates. The tripodal core (1,3,5-tris-(3-azido-propoxy)-benzene) was chosen to serve as the azide functionalities for dendrimer growth. 1,3,5-Tris-(3-azido-propoxy)-benzene was stitched with the aldehyde-functionalized Fr$\acute{e}$chet-type dendrons via Staudinger/aza-Wittig reactions leading to the formation of the corresponding Fr$\acute{e}$chet-type dendrimers in high yields.

Facile Synthesis of Dendritic-Linear-Dendritic Materials by Click Chemistry

  • Lee, Jae-Wook;Han, Seung-Choul;Kim, Byoung-Ki;Lee, Un-Yup;Sung, Sae-Reum;Kang, Hwa-Shin;Kim, Ji-Hyeon;Jin, Sung-Ho
    • Macromolecular Research
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    • v.17 no.7
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    • pp.499-505
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    • 2009
  • General, fast, and efficient stitching methods are presented for the synthesis of Fr$\acute{e}$chet-type dendrimers with linear units at a core, as a preliminary investigation for the synthesis of dendritic-linear-dendritic materials. The synthetic strategy involved an inexpensive, 1,3-dipolar, cycloaddition reaction between an alkyne and an azide in the presence of the Cu(I) species, which is known as the best example of click chemistry. The linear core building blocks, 1,7-octadiyne and 1,6-diazidohexane, were chosen to serve as the alkyne and azide functionalities for dendrimer growth via click reactions with the azide and alkyne-dendrons, respectively. These two building blocks were employed together with the azide- and alkyne-functionalized Fr$\acute{e}$chet-type dendrons in a convergent strategy to synthesize two kinds of Fr$\acute{e}$chet-type dendrimers with different linear core units. This comparative efficiency of the click methodology supports the fast and efficient synthesis of dendritic-linear-dendritic materials with the tailor made core unit.

Gadobutrol-dendrimer effects on metastatic and apoptotic gene expression

  • Kebriaezadeh, Abbas;Ashrafi, Sepehr;Rasouli, Rahimeh;Ebrahimi, Seyed Esmaeil Sadat;Hamedani, Morteza Pirali;Assadi, Artin;Saffari, Mostafa;Ardestani, Mehdi Shafiee
    • Advances in nano research
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    • v.4 no.2
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    • pp.145-156
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    • 2016
  • Dendrimers are one of the most appropriate nanocaries for imaging moieties in imaging applications.The purpose of this study was the evalution of cytotoxicity and inducing apoptosis of dendrimers. This study was conducted in order to investigate the metastasis suppression effect of dendrimer in human breast MCF-7 cell line and finding the nanoparticle protein corona in biological enviromental. Dendrimer cytotoxicity effect was assessed by MTT assay. The mRNA experession level of KAI1 as a metastasis suppressor gene, Bax as Pro- apoptotic gene, Bcl-2 as an anti-apoptotic gene and GAPDH as a housekepping gene were determined by real-time PCR assays.concentration-dependent nanoparticle cytotoxicity effect was proofed at range of 1-2 mg/mL in 24 hours, significant upregulation of mRNA expression of Bax, was observed whereas expression of anti-apoptotic Bcl-2 was down-regulated, also expression of metastasis suppressor gene KAI1 was up-regulated. So far a few studies confirmed apoptosis enhancement effect of dendrimers in MCF-7 cell line via bax/bcl-2 pathways. dendrimer nanoparticles was able to act as metastase inhibitor via upregulation of KAI1 gene.