Multifunctional nanocomposite based on halloysite nanotubes for efficient luminescent bioimaging and magnetic resonance imaging.

A novel multifunctional halloysite nanotube (HNT)-based FeO@HNT-polyethyleneimine-Tip-Eu(dibenzoylmethane) nanocomposite (Fe-HNT-Eu NC) with both photoluminescent and magnetic properties was fabricated by a simple one-step hydrothermal process combined with the coupling grafting method, which exhibited high suspension stability and excellent photophysical behavior. The as-prepared multifunctional Fe-HNT-Eu NC was characterized using various techniques. The results of cell viability assay, cell morphological observation, and in vivo toxicity assay indicated that the NC exhibited excellent biocompatibility over the studied concentration range, suggesting that the obtained Fe-HNT-Eu NC was a suitable material for bioimaging and biological applications in human hepatic adenocarcinoma cells. Furthermore, the biocompatible Fe-HNT-Eu NC displayed superparamagnetic behavior with high saturation magnetization and also functioned as a magnetic resonance imaging (MRI) contrast agent in vitro and in vivo. The results of the MRI tests indicated that the Fe-HNT-Eu NC can significantly decrease the signal intensity values of the normal liver tissue and thus make the boundary between the normal liver and transplanted cancer more distinct, thus effectively improving the diagnosis effect of cancers.