Dextran graft poly((N-amidino)hexyl methacrylamide) (Dex-g-PAHMA) copolymers were synthesized by free radical polymerization in aqueous solution and characterized. Dex-g-PAHMA copolymers can self-assemble into micelles with the PAHMA rich core and dextran rich shell in aqueous media. The CO₂ sensitivity of the micelles was investigated by dynamic light scattering (DLS), conductivity and zeta potential. The results confirmed that the Dex-g-PAHMA copolymer micelles have reversible CO₂ sensitivity. The micelles can be used as doxorubicin (DOX) carriers and DOX molecules are mainly located in the core of the micelles. The MTT assay indicated that the Dex-g-PAHMA graft copolymers are non-toxic to cells in the copolymer concentration range of 5–1000 μg mL⁻¹, whereas the relative cell viability is greatly reduced with the increase of copolymer concentration for DOX-loaded micelles. The DOX-loaded micelles can be endocytosed by MCF-7 cells and the DOX can release from micelles and diffuse into the cell nucleus. The Dex-g-PAHMA copolymers have promising applications as drug carriers for cancer therapy. 

Polymer Chemistry, 2014