Figure 12.

Schematic illustration of the use of protein/bPE micelles as a strategy for delivery of the protein. Charge-conversion of the protein is employed to gain precise pH-responsive control on micelle association and dissociation and delivery inside cells. Conjugation of IgG with citraconic anhydride, cis-aconitic anhydride, or succinic anhydride leads to conversion of free amines into an amide bond, which in stable and negatively charged at physiological pH. These charge-converted IgG globules can micellize with PEG-b-pAsp(DET) and be delivered to cells with minimal proteolytic degradation. In the two former cases, the amide bond can be cleaved upon exposure to endosomal pH, thus dissociating the micelle and releasing the IgG inside the cells. Reprinted with permission from Ref. [156].