Ultrasound-enhanced transgene expression in vascular cells is not dependent upon cavitation-induced free radicals.

Although acoustic cavitation is clearly important in ultrasound (US)-enhanced gene delivery (UEGD), the relative importance of mechanical and sonochemical (free radical) bioeffects remains unclear, as does the mechanism of gene delivery at the cellular level. Porcine vascular smooth muscle cells (VSMC) were transfected with luciferase or green fluorescent protein (GFP) plasmid +/- pulsed 956 kHz US (2.0 mechanical index (MI), 128 W cm(-2) spatial peak pulse average intensity, ISPPA) for 60 s, in the presence or absence of 20 mM cysteamine or N-acetyl-L-cysteine.