To develop an efficient magnetic labeling method to cabel the H-22 cells of mice by ultrasound,and to observe the effect of various physical parameters such as ultrasound exposure duration,acoustic density and the ferum oxide concentrations on both labeling efficiency and cell viability. The dimension size of (200～300 nm)×(400～600 nm)×(50～70 nm) dextran-coated meso-supermagnetic iron oxide nanoparticles is synthesised by the co-precipitation method and is used for H-22 cells labeling in vitro. The sonoporation study is performed when the output electrical power of amplifier is 2 W and the transducer is working in a continuous mode with resonant frequeacy 1.43 MHz. Labeling efficiency and viability of labeled cells is evaluated by prussian blue staining and trypan blue exclusion test. H-22 cells is efficiently labeled at 30 s exposure time and particle concentration is 410 μg/mL and the labeling efficiency is about 90%.Prussian blue staining confirmed iron uptake and showed numerous blue-stained iron particles in the cytoplasm and more than 92% labeled cells remained viable. Ultrasound might be feasible for in vitro labeling of the H-22 cells.

superparamagnetic iron oxide; nanoparticle; magnetic labeling; sonoporationWeiss1eder于1999年提出了分子影像学概念，并实现了在细胞和分子水平内活体评价生物过程．体内示踪细胞迁徙即成为分子影像学任务之一．但实现该过程首先要解决的问题是如何用磁性物质标记目标细胞使细胞具有能被(Magnetic Resonance, MR)检测到的磁性，同时保持原有活性和功能．