Anionic amphiphilic dendrimers as antibacterial agents.

An anionic amphiphilic dendrimer is reported that possesses increased cytotoxicological potency against prokaryotic cells compared to eukaryotic cells. The half-maximal effective concentration (EC50) for the dendrimer against Bacillus subtilis, a Gram-positive bacterial strain, was measured to be 4.1 x 10(-5) M, while that against human umbilical vein endothelial cells (HUVEC) was more than 36x greater at a value of 1.5 x 10(-3) M. EC50 ratios for two commercial amphiphiles, sodium dodecyl sulfate (SDS) and Triton X-100, in addition to a similar synthesized dendritic structure were at most only 3.8x greater. Furthermore, the observed EC50 values appear to be correlated to the critical aggregation constant (CAC) in solution suggesting a mechanism of action for these anionic amphiphilic dendrimers related to their supramolecular structures.

Synthesis and aqueous aggregation properties of amphiphilic surface-block dendrimers.

[reaction: see text] A family of dendritic amphiphiles were synthesized from the natural metabolites of glycerol, succinic acid, and myristic acid. The surfaces of these dendrimers display different numbers of alkyl chains and carboxylic acids, varying the hydrophobic-to-hydrophilic ratio over a relatively broad range. In solution these dendritic amphiphiles form supramolecular structures, and these aggregates have been characterized by light microscopy, transmission electron microscopy, and tensiometry. These aggregates can entrap the hydrophobic species pyrene.

The convergent synthesis of poly(glycerol-succinic acid) dendritic macromolecules.

The high-yield convergent synthesis of dendrons, dendrimers, and dendritic-linear hybrid macromolecules composed of succinic acid, glycerol, and poly(ethylene glycol) (PEG) is described. This convergent synthesis relies on two orthogonal protecting groups; namely, the benzylidene acetal (bzld) for the protection of the 1,3-hydroxyls of glycerol and the tert-butyldiphenylsilyl (TBDPS) ester for protection of the carboxylic acid of succinic acid. These novel polyester dendritic macromolecules are composed entirely of building blocks known to be biocompatible or degradable in vivo to give natural metabolites. Derivatization of the dendritic periphery with a methacrylate affords a polymer that can be subsequently photo-cross-linked. The three-dimensional cross-linked gels formed by ultraviolet irradiation are optically transparent, with mechanical properties dependent on the initial cross-linkable dendritic macromolecule.