Monoclonal antibody-functionalized mesoporous silica nanoparticles (MSN) for selective targeting breast cancer cells

In this work, we conjugate anti-HER2/neu mAb (monoclonal antibody) to green fluorescent dye loaded mesoporous silica nanoparticles (Her-Dye@MSN) through a polyethylene glycol (MW = 5000) spacer. We examine their targeting properties toward HER2/neu over-expressing breast cancer cells and their internalization into the cells. Her-Dye@MSN nanoparticles exhibit a high targeting efficiency and the specific targeting capability is strongly affected by the mAb density on the Her-Dye@MSN. The time-course of competitive experiments with free antibody indicates that Her-Dye@MSN serves as a multivalent ligand. Moreover, Her-Dye@MSNs are internalized into cells through a receptor-mediated endocytosis and may escape from endosome to cytosol. The results reported here further support the potential of MSNs as a multifunctional smart nanocarriers for cell imaging and drug delivery.