Zhou X.,Wuhan University |
Zhou X.,Key Laboratory of Biomedical Polymers of Ministry of Education |
Zhang M.,Wuhan University |
Li H.,Wuhan University |
And 5 more authors.
Chemistry and Biodiversity | Year: 2012
In the presence of hemin and under appropriate conditions, some modalities of G-quadruplexes can form a peroxidase-like DNAzyme that has been widely used in biology. Structure-function studies on the DNAzyme revealed that its catalytic ability may be dependent on the unimolecular parallel G-quadruplex. In this report, we present the preliminary investigation on the relationship between the structure and function of DNAzymes through a terminal oligo modification in G-quadruplex sequences by adding different lengths of oligo-dT to the 3′- or 5′-end of the aptamers. The results suggested that adding dT n to the 5′-end of the DNA sequence of the enzyme improved the ability of hemin to bind with DNA, but the addition of dT n to the 3′-end decreased the binding ability of hemin for DNA. The increased stability of the assembled DNAzyme would lead to more favorable binding between the enzyme and substrate (H 2O 2), facilitating higher peroxidase activity; on the contrary, with lower stability of the DNAzyme complex, we observed reduced peroxidase activity. Copyright © 2012 Verlag Helvetica Chimica Acta AG, Zürich. Source
Yu H.,Key Laboratory of Biomedical Polymers of Ministry of Education |
Sun J.,Key Laboratory of Biomedical Polymers of Ministry of Education |
Zhang Y.,Key Laboratory of Biomedical Polymers of Ministry of Education |
Zhang G.,Hubei University of Education |
And 3 more authors.
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2015
A novel kind of graft polymer poly(aspartic acid)-ethanediamine-g-adamantane/methyloxy polyethylene glycol (Pasp-EDA-g-Ad/mPEG) was designed and synthesized for drug delivery in this study. The chemical structure of the prepared polymer was confirmed by proton NMR. The obtained polymer can self-assemble into micelles which were stable under a physiological environment and displayed pH- and β-cyclodextrin (β-CD)-responsive behaviors because of the acid-labile benzoic imine linkage and hydrophobic adamantine groups in the side chains of the polymer. The doxorubicin (Dox)-loaded micelles showed a slow release under physiological conditions and a rapid release after exposure to weakly acidic or β-CD environment. The in vitro cytotoxicity results suggested that the polymer was good at biocompatibility and could remain Dox biologically active. Hence, the Pasp-EDA-g-Ad/mPEG micelles may be applied as promising controlled drug delivery system for hydrophobic antitumor drugs. © 2015 Wiley Periodicals, Inc. Source