Reduced immune response to polymeric micelles coating sialic acids.

Effects of sialic acid coatings on polymeric micelle consisting of poly(sarcosine)-block-poly(l-lactic acid) (Lactosome) in the aim of prevention of the accelerated blood clearance (ABC) phenomenon are studied. Two kinds of the sialic acid-presenting Lactosomes targeting the immunosuppressive receptors of Siglec-G and CD22 have been successfully prepared. Lactosome presenting 5-N-acetylneuraminic acid or 5-N-acetylneuraminyl-α(2→6)-galactosyl-ß(1→4)-N-acetylglucosamine at the nanocarrier surface diminished the ABC phenomenon due to the reduction of the anti-poly(sarcosine) IgM production. Further, the sialic acid moieties could interact possibly with Siglec-E on immune cell to suppress phagocytosis of the opsonized nanocarriers.