title: Sonoporation efficacy on SiHa cells in vitro at raised bath temperatures-experimental validation of a prototype sonoporation device.
abstract: BACKGROUND
  A device was devised which aimed to reduce the time and expertise required to perform sonoporation on adherent cell cultures. This prototype device was used to examine the superficial effect of bath temperature on sonoporation efficacy.
  
  
  METHODS
  The prototype device consisted of six ultrasound transducers affixed beneath an Opticell stage. Six transducers with nominal diameters of 20 mm were constructed and the acoustic field of each was characterized using hydrophone scanning. A near field treatment plane was chosen for each transducer to minimize field heterogeneity in the near field. Cervical cancer-derived SiHa cells were exposed to nine different treatments in the presence of plasmid DNA-expressing green fluorescent protein (GFP). Ultrasound treatment with Definity ultrasound contrast agent (US+UCA) present, ultrasound treatment without contrast agent present (US), and a sham ultrasound treatment in the presence of ultrasound contrast agent (CA) were each performed at bath temperatures of 37, 39.5, and 42 °C. Each treatment was performed in biological triplicate. GFP expression and PARP expression following treatment were measured using fluorescent microscopy and digital image processing. Cell detachment was measured using phase contrast microscopy before and after treatment.
  
  
  RESULTS
  Mean (± s.d.) transfection rates for the US+UCA treatment were 5.4(±0.92), 5.8(±1.3), and 5.3(±1.1) % at 37, 39.5, and 42 °C, respectively. GFP expression and cell detachment were both significantly affected by the presence of ultrasound contrast agent (p < 0.001, p < 0.001). Neither GFP expression, PARP expression, or detachment differed significantly between bath temperatures.
  
  
  CONCLUSIONS
  Bath temperature did not impact the efficacy of sonoporation treatment on SiHa cells in vitro. The prototype device was found to be suitable for performing sonoporation on adherent cell cultures and will reduce the time and expertise required for conducting sonoporation experiments on adherent cell cultures in the future.
authors.affiliation: Department of Electrical Engineering, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, P7B 5E1 Canada.|Image-Guided Interventions, Thunder Bay Regional Research Institute, 980 Oliver Road, Thunder Bay, Ontario, P7B 6V4 Canada.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Kivinen
authors.affiliation: Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, P7B 5E1 Canada.|Probe Development and Biomarker Exploration, Thunder Bay Regional Research Institute, 980 Oliver Road, Thunder Bay, Ontario, P7B 6V4 Canada.
authors.forename: Melissa
authors.initials: M
authors.lastname: Togtema
authors.affiliation: Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, P7B 5E1 Canada.|Probe Development and Biomarker Exploration, Thunder Bay Regional Research Institute, 980 Oliver Road, Thunder Bay, Ontario, P7B 6V4 Canada.
authors.forename: Gregor
authors.initials: G
authors.lastname: Mulzer
authors.affiliation: Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, P7B 5E1 Canada.
authors.forename: Joshua
authors.initials: J
authors.lastname: Choi
authors.affiliation: Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, P7B 5E1 Canada.|Probe Development and Biomarker Exploration, Thunder Bay Regional Research Institute, 980 Oliver Road, Thunder Bay, Ontario, P7B 6V4 Canada.
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Zehbe
authors.affiliation: Department of Electrical Engineering, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, P7B 5E1 Canada.|Image-Guided Interventions, Thunder Bay Regional Research Institute, 980 Oliver Road, Thunder Bay, Ontario, P7B 6V4 Canada.
authors.forename: Laura
authors.initials: L
authors.lastname: Curiel
authors.affiliation: Department of Electrical Engineering, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, P7B 5E1 Canada.|Image-Guided Interventions, Thunder Bay Regional Research Institute, 980 Oliver Road, Thunder Bay, Ontario, P7B 6V4 Canada.
authors.forename: Samuel
authors.initials: S
authors.lastname: Pichardo
keywords: Drug delivery; HPV; In vitro; SiHa; Sonoporation; Temperature; Transducer array; Ultrasound