Polyion complex micelles prepared by self-assembly of block-graft polycation and hyperbranched polyanion

Polyion complex (PIC) micelles were prepared by self-assembly of block-graft polycation monomethoxy poly(ethylene glycol)-block-(poly(ε-caprolactone)-graft-polyethylenimine) (PEG-b-(PCL-g-PEI)) and hyperbranched polyanion sodium carboxyl-modified hyperbranched polyesters (Hx-COONa, x = 20, 30, 40). The results from commonly used MTT assay indicated that PIC micelles had good biocompatibility. PIC micelles with N/COO− of 8/3 had appropriate size (sub-110 nm) and moderate zeta potential (~3 mV). PIC micelles were nano-sized spheres, and the average size was about 50 nm. PIC micelles had high drug loading capacity for hydrophilic drugs such as doxorubicin (DOX) hydrochloride and released the drugs under the influence of pH and ionic strength.