Cell tracer with low toxicity and high cell uptake rate as well as preparation method and application of cell tracer

[0070] This embodiment provides a cell tracer with low toxicity and high cell uptake rate. The cell tracer is ultra-small superparamagnetic iron oxide nanoparticles coated with PAA and PEG. The cell tracer is obtained by thermal decomposition. After synthesizing ultra-small superparamagnetic iron oxide nanoparticles, it is obtained by coating PAA and PEG in sequence.

[0072] This embodiment provides a method for preparing the cell tracer with low toxicity and high cell uptake rate described in Embodiment 1, which includes the following steps:

[0073] 1) Preparation of ultra-small superparamagnetic iron oxide nanoparticles USPIO by thermal decomposition method:

[0074] 1-1) Mix 0.3532g of iron acetylacetonate and 25mL of triethylene glycol and add it into a three-necked round-bottomed flask. Fix the three-necked round-bottomed flask in an oil bath, and add silicone oil to the oil bath (resistance to high temperature of 500 degrees) Submerge the liquid level in the three-necked round-bottomed flask, place the oil bath on the magnetic stirring heater, and sequentially fill the three-necked round-bottomed flask with a magnetic stirrer, a spherical condenser tube, and a thermometer to form a heating and condensing reflux device;

[0075] 1-2) Under magnetic stirring at a stirring speed of 300 rpm, argon gas was introduced into the three-necked ro

[0096] This example provides an application of PAA and PEG-coated ultra-small superparamagnetic iron oxide nanoparticles USPIO-PAA / PEG prepared by the preparation method in Example 2 as a cell tracer in nuclear magnetic resonance imaging.