DNA transfer and cell killing in epidermoid cells by diagnostic ultrasound activation of contrast agent gas bodies in vitro.
DNA transfer by sonoporation and cell killing in monolayer cells were examined by contrast-aided low-power diagnostic ultrasound (US). Culture chambers with epidermoid cell monolayers were scanned at about 1 mm/s with a 1.5-MHz scan head aimed upward at the chamber in a 37 degrees C water bath. For DNA transfer tests, plasmids coding for green fluorescent protein (GFP) were added to the medium, and GFP expression was assessed by flow cytometry after 2 days. In separate tests, cell killing was determined immediately after treatment. GFP-positive cell counts were 0.4% (0.7% SD) for shams and 3.7% (1.2% SD) of cells for exposure at 2.3 MPa with 2% Optison contrast agent. The fraction of dead cells was 3.4% (1.7% SD) in shams and 28.6% (6.3% SD) in exposed chambers. Both effects increased for increasing Optison concentration and increasing peak rarefactional pressure amplitude. Contrast-aided diagnostic US has a potential therapeutic application for gene transfer, but a trade-off appears to exist with cell killing.
Department of Radiology, University of Michigan Medical Center, Ann Arbor, MI 48109, USA. douglm@umich.edu
Douglas L
DL
Miller
Chunyan
C
Dou
Jianming
J
Song
D000418:Albumins; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002417:Cattle; D002478:Cells, Cultured; D003287:Contrast Media; D004247:DNA / Q000032:analysis*; D005466:Fluorocarbons; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins / Q000032:analysis; D014464:Ultrasonic Therapy / Q000379:methods*
D000418:Albumins; D015415:Biomarkers; D003287:Contrast Media; C099458:FS 069; D005466:Fluorocarbons; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D004247:DNA