Preparation and Self-assembly of Biocompatible Polyrotaxane and Hemolysis Evaluation of Amphotericin B After Being Loaded by the Self-assembly

A kind of novel amphiphilic triblock copolymers containing polyrotaxane (PR) as a central block was synthesized via the ATRP of poly (ethylene glycol) methyl ether methacrylate (PEGMA) initiated with polypseudorotaxanes made from a distal 2-bromopropionyl end-capped Pluronic F127 with a varying amount of β-CDs in the presence of CuCl/N,N,N',N'',N''-pentamethyldiethylenetriamine (PMDETA) at 25℃ in an aqueous medium. The structure of the resulting copolymers was characterized in detail by 1H-NMR, GPC and DSC analyses. As a typical sample, F-30β-CD-60 was found to be self-assembled into nano-sized aggregates in water. Its critical aggregation concentration was estimated by the fluorescence probe technique. The transmission electron microscopy images further revealed that the sizes of the polymeric micelles of this selected copolymer were in nano-scale and smaller than those of the blank brush-like block copolymer. These nano-sized particles showed a great potential to be used as carrier for the controlled release of Amphotericin B (AmB) with 8.7% drug-loading content and 87 % drug-loading efficiency. And it is also true that the hemolysis of AmB has been significantly decreased after being loaded by the self-assembly.