Ultrasound and microbubble parameter optimization for maximizing sonoporation

Sonoporation is being employed as a technique to facilitate transport of drugs, genes, and other large molecules into cells. We investigated the effects of pulse repetition frequency, acoustic pressure, cell-bubble exposure time, along with microbubble size and concentration on cell internalization of calcein. Calcein cellular uptake was measured by fluorescence microscopy. A linear increase in uptake was seen with increased pressure and repetitions. A 10-fold increase was seen when pressure was increased from 300 kPa to 1.2 MPa, while a 4-fold increase was observed by repeating exposure three times. No significant differences were found by increasing pulse repetition frequency or incubation time. A dependence of calcein uptake on microbubble concentration was found, whereas no significant differences were seen with microbubble size.