Dendrimer facilitated synthesis of multifunctional lanthanide based hybrid nanomaterials for biological applications

Abstract

A poly(amido amine) (PAMAM) dendrimer has been successfully used for the first time as a linking agent for the synthesis of a luminescent lanthanide based multifunctional nanohybrid (YPO₄:Tb³⁺@Fe₃O₄). Characterization of the materials was done by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and thermogravimetric analysis (TGA). The HRTEM images showed spindle shaped YPO₄:Tb³⁺@Fe₃O₄ in the presence of a PAMAM dendrimer which is due to the incorporation of the Fe₃O₄ nanoparticles in the branches of the PAMAM dendrimer when they are attached on the surfaces of the YPO₄:Tb³⁺ nanorods. Photoluminescence studies showed the Tb–O charge transfer transition which is produced by electron delocalization from the filled 2p shell of the O²⁻ to the partially filled 4f shell of Tb³⁺. The nanohybrid materials yielded a specific absorption rate (SAR) value of 39.22 W g⁻¹ of magnetite under the influence of an AC magnetic field of 110 Oe and 425 kHz frequency. Biocompatibility of the developed hybrid nanomaterials was evaluated in vitro by assessing their cytotoxicity on human cervical cancer cells (HeLa cells) using a sulforhodamine B (SRB) assay. These YPO₄:Tb³⁺@Fe₃O₄ nanohybrids have potential biomedical applications in the area of imaging and magnetic hyperthermia.