Synthesis and self-assembly of perylene-cored poly(amidoamine) dendrimers with poly[2-(dimethylamino)ethyl methacrylate]-modified arms as fluorescent bio-imaging probes and doxorubicin carriers

A poly(amidoamine) (PAMAM) dendrimer is prepared using a divergent method, with perylene-3,4,9,10-tetracarboxylic diimide (PTCDI) as luminescent core. The peripheral amines are modified using α-bromoisobutyryl bromide, allowing the dendrimers to act as macroinitiators for the synthesis of poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) through atom transfer radical polymerization (ATRP) with three different degrees of polymerization. The successful synthesis is verified by conducting a range of analyses, including Fourier-transform infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (¹H NMR) spectroscopy, and X-ray diffraction (XRD). Additionally, the impact of changes in solution pH on the self-assembly of dendrimers is explored. Field emission scanning electron microscopy (FE-SEM) and dynamic light scattering (DLS) showed unique morphologies, including spherical micelles and cubic-hexagonal structures, at varying pH levels. The self-assembled dendrimers are utilized to load doxorubicin (DOX) and the drug release kinetics are studied under various conditions. The biocompatibility of the dendrimers is assessed using the MTT assay against SH-SY5Y cells. Additionally, higher dendrimer generations improved the solubility, compatibility, and fluorescent properties of the core. The dendrimers' capacity for cellular uptake and fluorescence imaging is also evaluated using SH-SY5Y cells, demonstrating their effectiveness in live-cell fluorescence imaging.