Current Organic Chemistry

ISSN: 1385-2728

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Chitosan Amphiphilic Derivatives. Chemistry and Applications 2010; 14(3): Pp. 308-330
Inmaculada Aranaz, Ruth Harris and Angeles Heras
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Rational Design of Functional DNA with a Non-Ribose Acyclic Scaffold 2009; 13(11): Pp. 1065-1084
Hiromu Kashida, Xingguo Liang and Hiroyuki Asanuma
[Abstract] [Full Text Article]


Advanced Microfluorescence Methods in Monitoring Intracellular Uptake of “Antisense” Oligonucleotides 2007; 11(6): Pp. 515-527
Petr Praus, Eva Kocisova, Olivier Seksek, Franck Sureau, Josef Stepanek and Pierre-Yves Turpin
[Abstract] [Full Text Article]

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Chitosan Amphiphilic Derivatives. Chemistry and Applications
Inmaculada Aranaz, Ruth Harris and Angeles Heras

Chitosan is a natural polymer composed of randomly distributed β-(1-4)-linked D-glucosamine (deacetylated unit) and Nacetyl- D-glucosamine (acetylated unit).

It has been described as a non-toxic, biodegradable and biocompatible polymer with very interesting biological properties, such as permeation-enhancing and mucoadhesive properties, anticoagulant and antimicrobial activity and so on.

Chitosan has been used in several areas such as biomedical, pharmaceutical and biotechnological fields as well as in the food industry.

Recently, there has been a growing interest in the modification of chitosan to improve its solubility in physiological conditions, to introduce new applications or to improve chitosan biological properties.

Research and development on a variety of amphiphilic copolymers containing hydrophobic and hydrophilic segments, have been very active due to their spontaneous self-assembly behaviour in aqueous media These smart transitions often lead to diverse functional compartment structures like micelles, vesicles and gels, which represent promising applications in the field of biotechnology and pharmaceutics.

The aim of the present paper is to review the latest advances in the synthesis of chitosan amphiphilic derivatives with a special emphasis in their applications.

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Rational Design of Functional DNA with a Non-Ribose Acyclic Scaffold
Hiromu Kashida, Xingguo Liang and Hiroyuki Asanuma

The growing field of DNA technology requires new modified DNAs that can perform advanced functions. No matter how we optimize the length and sequence of DNA using only the four naturally occurring nucleotides, potential performance is limited. In this review, we describe a facile and effective method of rationally designing new functional DNA by focusing on acyclic scaffolds, especially threoninols, which are utilized to incorporate functional molecules into DNA. Wedge-type insertion of a functional molecule with a planar structure of proper size in D-threoninol to DNA does not destabilize the duplex, although the backbone structure is changed. Rather, intercalation offsets such distortions and significantly raises the melting temperature of the DNA duplex. Based on the wedge-type insertion, photoresponsive DNA (tethering azobenzenes) and fluorescent probes that can detect single nucleotide polymorphisms (SNPs) and insertion/ deletion (indel) polymorphisms have been designed. Furthermore, a variety of molecular clusters of dyes have also been prepared from acyclic scaffolds tethering dyes.

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Advanced Microfluorescence Methods in Monitoring Intracellular Uptake of “Antisense” Oligonucleotides
Petr Praus, Eva Kocisova, Olivier Seksek, Franck Sureau, Josef Stepanek and Pierre-Yves Turpin

Antisense strategy represents a promising molecular tool for efficient and selective chemotherapeutic action. It belongs among oligonucleotide strategies that employ specific single-stranded sequences of deoxyribo- and ribonucleotides or their synthetic analogs to block or suppress expression of a pathogen in its early stage. This approach is also promising for studies of the biological function of the gene. However, the routine use of modified oligonucleotides in practice is complicated by non-ideal properties of currently available oligonucleotide analogs. A successful medical treatment requires not only proper binding of the modified oligonucleotide to its cellular target but also its efficient cellular uptake, stability and appropriate distribution in the intracellular environment. The latter processes can be effectively studied by various microfluorescence techniques. The paper reviews the current situation in the application of advanced microfluorescence methods in this field and gives a brief description of the oligonucleotide strategy and possibilities to support the cellular uptake, theoretical and technical basics of current fluorescence microimaging and fluorescence microspectroscopy including time-resolved measurements. Second part of the paper describes experiment preparation, surveys the most interesting studies published so far and outlines the perspectives.