Phospholipids-based microbubbles sonoporation pore size and reseal of cell membrane cultured in vitro

Abstract

Objective: To investigate phospholipids-based microbubbles induced sonoporation and cell membrane reseal in vitro under various conditions.

Methods: A breast cancer cell line SK-BR-3 was used to investigate ultrasonic sonoporation under various conditions. Atomic force microscopy (AFM) scanning techniques were employed to observe the change of membrane pores.

Results: Normal SK-BR-3 cells membrane pores were evenly distributed and less than 1 μm. After ultrasound exposure, membrane pores were enlarged at different degree depending on ultrasound exposure durations, filling gas species and microbubble suspension concentration. With microbubble suspension concentration being increased to 5% or ultrasound exposure reached 30 s, membrane pores in fluorocarbon (C₃F₈ or SF₆)-filled microbubble groups exceeded 1 μm, which were significantly larger than that of air-filled microbubble group. Membrane pores were about 2–3 μm under ultrasound 60 s with 5% fluorocarbon-filled microbubble suspension. After 24 h of incubation, most of the enlarged membrane pores could reseal to normal size, which corresponded to cell viability.

Conclusions: Membrane pores can be obviously enlarged by ultrasonic sonoporation of fluorocarbon-filled microbubbles, whose reseal time depended on ultrasound exposure duration and microbubble suspension concentration.

Keywords: :

• Ultrasound
• sonoporation
• microbubbles
• membrane pore
• liposomes

Abbreviations
AFM	=	atomic force microscopy
UCA	=	ultrasound contrast agent
HPC	=	hydrogenated phosphatidylcholine

Abbreviations
AFM	=	atomic force microscopy
UCA	=	ultrasound contrast agent
HPC	=	hydrogenated phosphatidylcholine