Ruthenium(II) Tris(bipyridine)-Centered Poly(ethylenimine) for Gene Delivery

• Published in: Biomacromolecules Vol. 8; no. 9; pp. 2829 - 2835
• Main Authors: Fiore, Gina L, Edwards, James M, Payne, Sarah J, Klinkenberg, Jessica L, Gioeli, Daniel G, Demas, J N, Fraser, Cassra L
• Format: Journal Article
• Language: English
• Published: 01-01-2007
• ISSN: 1525-7797; 1526-4602
• DOI: 10.1021/bm700481hPII:S1525-7797(70)00481-6

Ruthenium(II) tris(bipyridine)-centered poly(ethylenimine) (Ru PEI) was synthesized via acid hydrolysis of Ru tris(bipyridine)-centered poly(2-ethyl- 2-oxazoline) (Ru PEOX), and the luminescence, DNA entrapment, and transfection efficiencies were evaluated. Emission maxima for Ru PEI samples are red-shifted compared to Ru PEOX precursors, and the luminescence lifetimes are shorter in both methanol and aqueous solutions. Slower oxygen quenching of Ru PEOX and Ru PEI luminescence versus [Ru(bpy) sub(3)]Cl sub(2) (bpy = bipyridine) is attributed to polymer shielding effects. Ru PEI luminescence is similar in the presence and absence of DNA. Ru PEI (7900 Da) and linear PEI (L-PEI; 22 000 Da) fully entrapped DNA (5.4 kb; pcDNA) at an N/P ratio of 2. LNCaP prostate cancer cells were transfected with a plasmid encoding for green fluorescent protein using Ru PEI and L-PEI vectors for comparison. For N/P = 48, the transfection efficiency for Ru PEI was similar to 50% relative to that of L-PEI.