Superparamagnetic iron oxide labeling and its effects on biological characteristics of neural stem cells

Zhaoyan WANG; Yinxiang YANG; Zuo LUAN

ABSTRACT

BACKGROUND:

Cell labeling and nuclear magnetic resonance can non-invasively in vivo label the region, existing mode and some bionomics of transplanted neural stem cells (NSCs).

OBJECTIVE:

To observe the outcome of superparamagnetic iron oxide in vitro labeled human NSCs. DESIGN, TIME AND

SETTING:

The cytology, in vitro, observation study was performed at the Laboratory of Department of Pediatrics, Navy General Hospital of Chinese PLA from December 2006 to June 2007. MATERIALS Aborted human embryo was provided by Navy General Hospital of Chinese PLA. Superparamagnetic iron oxide (Lot number 97060601) was produced by Advanced magnetics,inc., USA.

METHODS:

Monoplast suspension was isolated from human embryo hippocampus using the mechanical method, and in vitro incubated in NSC medium, supplemented with epidermal growth factor and basic fibroblast growth factor. 11.2 g/L superparamagnetic iron oxide was diluted into 28 mg/L using NSC medium, mixed with 1.0 mg/L polylysine (8 ?L), and then made into superparamagnetic iron oxide-polylysine composite labeled medium. NSC spheres with active proliferation were obtained, made into single cell suspension (1?109/L), and then treated with serum-free medium containing superparamagnetic iron oxide. One week later, various cytokines were removed, and 5% fetal bovine serum was used for 24 hours to induce the NSC differentiation. MAIN OUTCOME

MEASURES:

Prussian blue staining was utilized to determine marking positive rate. Immunofluorescence staining was applied to detect glial fibrillary acidic protein and neurofilament expression.

RESULTS:

Superparamagnetic iron oxide labeled NSCs were yellow, and the speed of clone formation was not stepped down compared with the non-labeled cells. 20 hours following superparamagnetic iron oxide labeling, blue iron particles in NSCs cytoplasm were found, with the positive rate of 90%. Following induction, superparamagnetic iron oxide labeled NSCs were positive for glial fibrillary acidic protein and neurofilament.

CONCLUSION:

Superparamagnetic iron oxide can highly effectively label NSCs in vitro, and not affect biological features following labeling. NSCs can normally amplify and orientedly differentiate into neurons and astrocytes.