Interrelation between HeLaS3 cell transfection an

Authors: Y Liu H Uno H Takatsuki M Hirano A Sakanishi

Publish Date: 2004/10/05

Volume: 34, Issue: 2, Pages: 163-169

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Abstract

We have studied the in vitro transfection of a plasmid DNA with the lacZ gene to HeLaS3 cells and hemolysis in a red blood cell RBC suspension under pulsed ultrasound with duty cycles γ of 10 20 and 30 using a digital sonifier at a frequency of 20 kHz and an intensity of 62 W/cm2 on the surface of a horn tip Cultured HeLaS3 cells in suspension were exposed to pulsed ultrasound for an apparent exposure time t′ from 0 to 60 s HeLaS3 viability decreased as a single exponential function of the total exposure time t=γt′ with a common time constant τ=38 s for three duty cycles Transfection was evaluated by counting the number of βgalactosidaseβGalpositive cells relative to the total number of cells Pulsed ultrasound provided an enhanced transfer of the βGal plasmid to HeLaS3 cells 34fold as compared with that in the case of the control The optimal transfection efficiencies were 075 080 and 074 near t=τ with γ=10 20 and 30 respectively The number ratio of βGalpositive cells to the surviving cells after exposure increased with t′ according to a modified logistic equation The degree of hemolysis also increased exponentially with t′ at a time constant τ′=τ0/γ for the RBC suspension in physiological saline at a hematocrit concentration of 05 with τ0=09 s Thus the total exposure time for the optimal transfection efficiency was τ that is nearly four times of τ0 Hemolysis in the RBC suspension may be a useful model for determining optimal transfection by pulsed ultrasound of various duty cycles

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