Synthesis and Self-Assembly of Stimuli-Responsive Amphiphilic Dendrimers

The synthesis of stimuli-responsive amphiphilic dendrimers consisting of two or three hydrophobic octadecyl groups linked to either a second or third generation hydrophilic polylysine dendron through disulfide linkage is reported. The polylysine dendrimers functionalized with four or eight tert-butyloxycarbonyl (Boc)-protected amino groups are characterized by H-1 NMR spectroscopy and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. With the positively charged versions generated by removing the Boc groups, their ability to form spherical micelles that can be readily disassembled in the presence of glutathione (GSH) is demonstrated. The self-assembly behavior is monitored by scanning electron microscopy (SEM) and dynamic light scattering (DLS). The amphiphilic dendritic systems containing cleavable disulfide linkage serve as key building blocks for generating stimuli-responsive supramolecular architectures.