Synthesis and characterization of versatile amphiphilic dendrimers peripherally decorated with positively charged amino acids

Abstract

AbstractDendrimers are nanostructured ‘architectural motifs’ with a well‐tailored polymeric structure, symmetric tree‐like shape and the presence of several functional groups and inner cavities, and are of eminent interest in many biomedical applications such as drug delivery, gene transfection and imaging. In the work reported, reliable protocols for the synthesis of polyester‐based, hydrolysable, amphiphilic polycationic dendrimers were developed. A C‐18 hydrocarbon chain provided by a biocompatible fatty acid, stearic acid, and second‐ and third‐generation dendrons based on 2,2‐bis(hydroxymethyl)propionic acid were built on 2,2‐bis(hydroxymethyl)propanol and pentaerythritol as core molecules. αN‐BOC‐ω'N‐(NO2)‐l‐arginine alone, mixed with αN,ϵN‐di‐BOC‐l‐lysine or also with N,N′‐dimethylglycine and αN‐BOC‐methylglycine were successfully bound to the prepared polyester neutral scaffolds and, after the removal of protecting groups, five cationic dendrimers were obtained. Their structure was confirmed using NMR analysis and experimental molecular weight. Their buffer capacity, comparable to that of polyethyleneimines, was optimal, high viability percentage values were obtained from cytotoxicity assays and zeta potential and mean particle size were in the desired ranges. The synthesized nanostructured compounds that harmonize a multifunctional polycationic shell, a biodegradable uncharged polyester matrix and a C‐18 hydrophobic portion helpful for an improved hydrophilic–lipophilic balance in their structure embody all the fundamental features to be suitable for biomedical applications. © 2018 Society of Chemical Industry