Polyelectrolyte-protein synergism; pH-responsive polyelectrolyte/insulin complexes as versatile carriers for targeted protein and drug delivery

Murmiliuk, A.*; Iwase, Hiroki*; Kang, J.-J.*; Mohanakumar, S.*; Appavou, M.-S.*; Wood, K.*; Almsy, L.*; Len, A.*; Schwrzer, K.*; Allgaier, J.*; Dulle, M.*; Gensch, T.*; Frster, B.*; Ito, Kanae*; Nakagawa, Hiroshi   ; Wiegand, S.*; Frster, S.*; Radulescu, A.*

The complexity of protein structure limits our ability to predict and tune the properties of the formed nanoparticles. The goal of our research is to elucidate the key triggers of the morphological transition in protein/PE complexes, evaluate their encapsulation efficacy, and assess particle stability by the systematic study of complexes formed by block copolymers with proteins and ionic drugs. We demonstrated that copolymers consisting of PE and neutral hydrophilic block co-assemble with insulin at pH values close to the protein isoelectric point. The insulin arrangement within the particle is controlled by electrostatic forces between protein molecules, and the morphology of the formed particles can be tuned by varying pH and ionic strength.