Conjugation of nanomaterials containing rare-earth ion Tb3+ with CD133 monoclonal antibody and its potentials for labeling colon cancer cells (HT-29)

Abstract

Nanotechnology is the key technology that brings many important applications in biomedical research.
Nanolantanites present high stability, easy fabrication and functionalization. Tb3+ ion-containing nanomaterial, 

a specific type of nanolantanites, possess great prospects. In addition, cancer stem cells (CSCs) are directly
related to drug resistance, metastasis, recurrent cancer, etc. Therefore, CSCs are considered as the target for
cancer researching and for discovery of more effective therapies. CD133, a trans-membrane glycoprotein, is
one of the typical markers that are found to appear very commonly on the surface of many types of CSCs. In
this study, CD133 monoclonal antibody (MAb) was cojugated with nanomaterials containing Tb3+. The
coupling between fluorescented nanomaterials containing Tb3+ ions and CD133 MAb was then incubated with
human colon cancer cells (HT-29) to evaluate its ability to label CSCs in vitro. The results showed that
nanorods containing rare-earth based Tb3+ ions which were fabricated by hydrothermal method, present the
length of about 300 - 800 nm and the diameter in range of 40 - 50 nm. The Tb3+ nanoparticals also have
hexagonal structure of terbium phosphate monohydrate and green illuminant. Tb3+ nanorods were also further
surface silica coated and amino-silane functionalized. This nanostructure was successfully combined with
monoclonal antibodies against CD133 which labelled the surface marker of HT-29 human colon cancer cells.
As a result, the combination of CD133+TbPO4@Silica-NH2 (functionalized surface) showed stronger
luminescence than the CD133+TbPO4 unfunctionalized combination.