title: RGD conjugation to polyethyleneimine does not improve DNA delivery to bone marrow stromal cells.
abstract: Bone marrow stromal cells (BMSC) modified with therapeutic genes are being actively pursued for gene therapy protocols. To develop safe and effective nonviral methods for BMSC modification, the cationic polymer polyethyleneimine (PEI) has been utilized to condense plasmid DNA for intracellular delivery. This study was conducted to explore the feasibility of increasing the PEI's effectiveness by coupling integrin-binding arginine-glycine-aspartic acid (RGD) peptides to the polymer. BMSC from rats were isolated and expanded in culture for gene transfer studies. In contrast to our expectations, RGD-conjugated PEI did not exhibit an enhanced binding to BMSC. This was the case where the peptides were conjugated to PEI by short, disulfide linkages or long poly(ethylene glycol) linkages. Using a reporter gene for the enhanced green fluorescent protein, the transfection efficiency of RGD-conjugated PEI was also lower than the delivery by the native PEI, which exhibited equivalent transfection efficiency to that of an adenovirus. We conclude that native PEI was sufficient for the transformation of BMSC and that coupling of the integrin-binding RGD-peptides did not improve the effectiveness of this polymer for BMSC transfection.
authors: Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, Alberta T6G 2G6, Canada.
authors: Basak Açan
authors: BA
authors: Clements
authors: Jiang
authors: J
authors: Bai
authors: Cezary
authors: C
authors: Kucharski
authors: Laura-Lee
authors: LL
authors: Farrell
authors: Afsaneh
authors: A
authors: Lavasanifar
authors: Bruce
authors: B
authors: Ritchie
authors: Aziz
authors: A
authors: Ghahary
authors: Hasan
authors: H
authors: Uludag