Synthesis and characterization of fourth generation polyester-based dendrimers with cationic amino acids-modified crown as promising water soluble biomedical devices

Dendrimers are nanostructured “architectural motifs” which fascinate researchers fortheir several potentiality due to well‐tailored structure, symmetric tree‐like shape,and abilities in entrapping or binding hydrophilic or hydrophobic entities such asgenetic materials, drugs, and target molecules. Nowadays dendrimers inhabit thetop places among the materials suitable for biomedical applications as drug delivery,gene transfection, and imaging. In this work, we report the design and realization oftwo versatile successful procedures to decorate a fourth generation polyester‐baseddendrimer matrix with a mixture of four different amino acids. The hydrochloridedendrimers achieved after removal of protecting groups were characterized by acore‐shell structure. They harmonized a not charged hydrolysable inner matrixpotentially able to accommodate hydrophobic molecules and a cationic highlyhydrophilic crown conferred by biocompatible amino acids that provided very satis-factory buffer capacity and will allow easy host/guest electrostatic interactions.Their structures and peripheral composition were confirmed by NMR analysis andexperimental molecular weight computed by volumetric titration, while their buffercapacity was obtained by potentiometric titrations. Because in the inner matrix, theachieved hetero dendrimers do not present the high density of positive chargestypical of PAMAM, they ensure a lower level of toxicity. But thanks to the cationicperiphery, as preliminary investigations still in progress have already put in evidence, they were able to entrap not water soluble molecules by electrostatic inter-actions, with the result to increase their water solubility in a very satisfactory oramazing way. They therefore represent two new very promising devices for bio-medical applications.