A novel cationic microbubble coated with stearic acid-modified polyethylenimine to enhance DNA loading and gene delivery by ultrasound

• Published in: PloS one 2013-09, Vol.8 (9), p.e76544
• Main Authors: Jin, Qiaofeng, Wang, Zhiyong, Yan, Fei, Deng, Zhiting, Ni, Fei, Wu, Junru, Shandas, Robin, Liu, Xin, Zheng, Hairong
• Format: Article
• Language: English
• Subjects: Acids; Acoustics; Acylation; Bearing strength; Biology; Breast cancer; Carbonyls; Cations; Cavitation; Cell Survival - drug effects; Chemical synthesis; Contrast agents; Cytotoxicity; Deoxyribonucleic acid; DNA; DNA - chemistry; DNA - genetics; Drug Carriers - chemistry; Drug Carriers - toxicity; Efficiency; Gene therapy; Gene transfer; Genetic engineering; Lauterbur, Paul C; Lipids; Luciferases, Firefly - genetics; MCF-7 Cells; Medicine; Methods; Microbubbles; Plasmids - genetics; Polyethyleneimine; Polyethyleneimine - chemistry; Polyethyleneimine - toxicity; Polymers; Radiance; Size distribution; Stearic acid; Stearic Acids - chemistry; Stress concentration; Toxicity; Transfection; Transfection - methods; Ultrasonic imaging; Ultrasonics; Ultrasound; Vectors (Biology); Zeta potential
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0076544

A novel cationic microbubble (MB) for improvement of the DNA loading capacity and the ultrasound-mediated gene delivery efficiency has been developed; it has been prepared with commercial lipids and a stearic acid modified polyethylenimine 600 (Stearic-PEI600) polymer synthesized via acylation reaction of branched PEI600 and stearic acid mediated by N, N'-carbonyldiimidazole (CDI). The MBs' concentration, size distribution, stability and zeta potential (ζ-potential) were measured and the DNA loading capacity was examined as a function of the amount of Stearic-PEI600. The gene transfection efficiency and cytotoxicity were also examined using breast cancer MCF-7 cells via the reporter plasmid pCMV-Luc, encoding the firefly luciferase gene. The results showed that the Stearic-PEI600 polymer caused a significant increase in magnitude of ζ-potential of MBs. The addition of DNA into cationic MBs can shift ζ-potentials from positive to negative values. The DNA loading capacity of the MBs grew linearly from (5±0.2) ×10⁻³ pg/µm² to (20±1.8) ×10⁻³ pg/µm² when Stearic-PEI600 was increased from 5 mol% to 30 mol%. Transfection of MCF-7 cells using 5% PEI600 MBs plus ultrasound exposure yielded 5.76±2.58×10³ p/s/cm²/sr average radiance intensity, was 8.97- and 7.53-fold higher than those treated with plain MBs plus ultrasound (6.41±5.82) ×10² p/s/cm²/sr, (P