Small sized mesoporous silica nanoparticles functionalized with mannose for retinoblastoma cell imaging

Abstract

We report the study of the functionalization of small sized MSNs with mannose. Classical procedures which were efficient with 100 nm diameter MSNs led to aggregation of small sized MSNs. Therefore, we grafted long chain amino silane and PEG-silane on the surface of the MSNs and reacted squarate mannose with NH₂ groups. Although the MSN suspension was stable in EtOH, immediate aggregation was noticed in PBS which is attributed to remaining amino groups on the surface of the MSNs. We therefore grafted silylated mannose and PEG-silane on the MSN surface. Depending on the conditions, reversible aggregation was observed in PBS when heating to 37 °C and cooling to RT, or stable suspensions were obtained. The stable mannose-functionalized MSN suspensions were used for the imaging of retinoblastoma cells.