Synthesis, self-assembly and drug solubilization of hyperbranched block polyethers

Three hyperbranched block polyethers H3, H5 and H7 with the same PPO block numbers but different PEO contents were synthesized by anionic polymerization. The self-assembly behaviors of H3, H5 and H7 in aqueous solution were investigated by surface tension, fluorescence spectroscopy and transmission electron microscopy (TEM). Meanwhile, the commercially available linear block polyether Pluronic F127 and X shaped block polyether Tetronic1107 (T1107) were also selected for comparison. The goal of this study was to gain an insight into the self-assembly behaviors and drug solubilization capability of these different block polyethers. The results indicated that the solubilization abilities of H3, H5 and H7 are much larger than those of F127 and T1107. H3, H5 and H7 spontaneously form spherical vesicles in aqueous solution as observed by TEM, which demonstrated that the vesicle space available for solubilization of drug is much larger than the micelle formed by F127 and T1107. Furthermore, proved by fluorescence spectroscopy measurement, H3, H5 and H7 can provide aggregates with more hydrophobic environment which is directly correlated with the ability of the polyethers to host the drug in aggregates. The hyperbranched architecture has a great effect on the self-assembly behavior and the drug solubilization ability of block polyethers.