Selective Modification of Chitosan to Enable the Formation of Chitosan-DNA Condensates by Electron Donator Stabilization

Karl E Kador,Anuradha Subramanian

doi:10.1155/2011/146419

Abstract

Chitosan, a polyaminosaccharide, has been investigated for its use in the field of drug-delivery and biomaterial applications because of its natural biocompatibility and polycationic properties. Chemical modifications of chitosan have been attempted in an effort to increase the transfection efficiency with respect to gene delivery applications; however, it is unknown how these modifications affect the formation of the condensates. This study attempts to determine the effects of modification of the cationic center of chitosan on the ability to condense DNA. Specifically, electron-donating or -withdrawing groups were used as modifiers of the cationic charge on the chitosan backbone to stabilize the protonated form of chitosan, which is necessary to form condensates and increase the efficiency of the polymer to condense DNA by yielding condensates at a lower nitrogen to phosphorous (N : P) ratio. While an N : P ratio of 7 is needed to condense DNA with unmodified chitosan, phthalate-modified chitosan yielded condensates were obtained at an N : P ratio of 1.0.

Highlights

A natural polymer that has received increased research attention because of its inherent biocompatibility is chitin and its deacetylated derivative, chitosan [β (1–4)-2 amino-2-deoxyD-glucose] [1, 2]
Chitosan and modified chitosans find a variety of applications in biomedical applications, including biomaterials for use in tissue engineering and drug delivery systems, and in bioseparation applications, including nano- and macro scale separations, and classical affinity- and nonaffinitybased chromatographic systems [2, 6, 7, 9,10,11,12,13,14,15,16]
The number average molecular weight of the unmodified and modified chitosan samples used in this study was determined by gel permeation chromatography with internal standards ranging from 59 to 788 kDa

Summary

Introduction

A natural polymer that has received increased research attention because of its inherent biocompatibility is chitin and its deacetylated derivative, chitosan [β (1–4)-2 amino-2-deoxyD-glucose] [1, 2]. Due to its good biological activity, relative ease of solubility, biocompatibility, and biodegradability, chitosan and its derivatives have attracted attention as potential applicants in the field of biomedical polymers [3, 6, 7]. In the area of targeted delivery, chitosan-based particles have been extensively investigated for the delivery of DNA macromolecules, proteins, peptides, and drugs [4, 17,18,19]. The particles must be able to effectively diffuse through or be actively transported across the cell membrane. For research purposes, it is best to study each of these three areas

Objectives

Methods

Discussion

Conclusion