Nanoobjects formed by ionic PAMAM dendrimers: hydrophilic/lipophilic modulation and encapsulation propertiesElectronic supplementary information (ESI) available: Synthesis and chemical characterization data; TGA and DSC thermograms; aggregation and encapsulation procedures; TEM images; and the cytotoxicity evaluation protocol. See DOI: 10.1039/c5sm01153a

In this paper, we present the preparation and properties of some ionic PAMAM derivatives, which combine hydrophilic and lipophilic carboxylic acid chains as counter-ions for all protonable inner and outer amino groups. The amphiphilic nature of the final ionic codendrimers and, hence, their self-assembling features can be modulated by using different ratios between hydrophilic and lipophilic chains. In the bulk, these new materials self-organize into smectic A liquid crystal phases. In water, they self-assemble into different types of nano-objects depending on the molecular composition. The study of the morphology of these nano-structures, their cytotoxicity and their capability to encapsulate a lipophilic anticancer drug are reported herein. Some of these nanoobjects are non-cytotoxic and present good drug trapping ability, which make them interesting nanocarriers for applications in nanotechnology and biomedicine. The HLB of ionic-PAMAM codendrimers determines the mesomorphism, the aggregation in water, the cytotoxicity and the encapsulation of a lipophilic drug.