LDH-DNA Nanohybrids: a complete biophysical characterization
- PDF / 363,438 Bytes
- 6 Pages / 595 x 842 pts (A4) Page_size
- 8 Downloads / 212 Views
EE9.18.1
LDH-DNA Nanohybrids : a complete biophysical characterization Fabrice Leroux†, Malha Ben Belkacem†, Ghislain Guyot††, Christine Taviot-Guého†, Philippe Léone*, Laurent Cario*, Léa Desigaux‡, Bruno Pitard‡ †
Laboratoire des Matériaux Inorganiques UMR 6002, ††Laboratoire de Photochimie Moléculaire et Macromoléculaire UMR 6505 - Université Blaise Pascal (Clermont-Ferrand II), 24 avenue des Landais, 63177 Aubière cedex, France E-mail: [email protected] * Institut des Matériaux Jean Rouxel, 2 rue de la Houssinière, B.P. 32229 44322 Nantes cedex, France ‡ Inserm, U533, 1 rue Gaston Veil, BP 53508, 44035 Nantes cedex1, France
ABSTRACT Recently, LDH have been considered as a new kind of gene delivery system [1, 2]. In this work, we report the formation of magnesium-gallium LDH-DNA nanohybrids using the coprecipitation method. This “self assembly” approach enabled the incorporation of long DNA fragments up to 6000-8000 bp. X-ray diffraction analyses indicate a parallel orientation of DNA double helix in the interlamellar space with respect to the hydroxide sheets. The Mg/Ga molar ratio within the hydroxide layers appears to be determined by DNA macromolecules which may interact with charged complexes that form during cation hydrolysis. The presence of DNA macromolecules also inhibits the crystal growth : hydrodynamic diameter measurements revealed homogeneous populations of particles with a mean diameter ranging from 90 to 150 nm, compatible with cell penetration through endocytosis. Concerning the charge surface of this new DNA delivery system, ζ-potential measurements indicate negative values ranging from –20 to - 40 mV which suggest incomplete DNA intercalation. Yet, this small negative surface might be suitable for protecting DNA from extra-cellular degradations without preventing cell penetration. INTRODUCTION Over the past decade, non viral vectors have mainly involved the use of organic cationic molecules to interact with negatively charged DNA. These complexes have proven their efficacy for in vitro gene but display low in vivo transfection efficiency. Therefore, there is still a need to develop other concepts to deliver DNA into cells. Recently, layered double hydroxides represented by the general formula [MII1-xMIIIx(OH)2][Am-x/m.nH2O] where MII, MIII are di- and trivalent metal cations and Am- interlayer anions, have been considered as a new kind of inorganic delivery vectors for genes and drug molecules [1-4]. Jin-Ho Choy and co-workers have found that oligonucleotides can be stabilized and internalized into cells when intercalated in LDH. These authors have thus reported the formation of LDH hybrids intercalated with short DNA fragments (500-1000 base pairs) prepared through ion exchange route upon substituting NO3- anions in pre synthesized magnesium-aluminum hydroxides [1a]. In the lysosome, where the pH is slightly acidic, DNA molecules are released from the hybrid by dissolution of the basic hydroxide layers. Choy also demonstrated that antisense oligonucleotides can enter into HL60
Data Loading...
