Polymeric nanoparticles with tunable architecture formed by biocompatible star shaped block copolymer

An amphiphilic star shaped block copolymer, based on well known biocompatible components, was synthesized using branched poly(epsilon-caprolactone) as hydrophobic core and branched poly(ethyleneglycol) as hydrophilic corona. The composition of this macromolecule, based on two well differentiated blocks, conferred amphiphilic behavior to the whole system that acted as driving force for its self-assembling in aqueous media. Depending on the polymer concentration it was possible to obtain different architectures. The TEM micrographs permitted to follow the evolution of the system from single vesicles toward necklace entanglements. In this work, we discuss the mechanism that would be involved in the evolution of the system's morphology as a function of the block copolymer concentration. In addition, the proposed star shaped block copolymer presented good solubilizing properties that were used to disperse in water, poorly soluble molecules such as chlorine-carbazoles, which were used to investigate the suitability of the self-assembled nanostructures as drug nano-carriers. (C) 2012 Elsevier Ltd. All rights reserved.