Abstract: The present invention generally relates to particles, including nanocapsules or other nanoentities, comprising a polymer such as polysialic acid. The particles are able to access the interior of the cells, and/or to procure the intracellular release of the associated drugs. In 5 one aspect, the present invention is directed to nanocapsules or other entities having an exterior or surface comprising a polymer such as polysialic acid. In some cases, targeting moieties such as Lyp-1 or tLyp-1 peptide are bonded to the polymer, e.g., using aminoalkyl (C1-C4) succinimide or other linkers. These may be created, for example, by reacting a carboxylate moiety on a polymer with an aminoalkyl maleimide (C1-C4) or an aminoalkyl 10 (C1-C4) methacrylamide, and reacting the resulting aminoalkyl (C1-C4) maleimide or the aminoalkyl (C1-C4) methacrylamide to a cysteine or other sulfur group.

Abstract: The present invention generally relates to particles, including nanocapsules or other nanoentities, comprising a polymer such as polysialic acid. The particles are able to access the interior of the cells, and/or to procure the intracellular release of the associated drugs. In 5 one aspect, the present invention is directed to nanocapsules or other entities having an exterior or surface comprising a polymer such as polysialic acid. In some cases, targeting moieties such as Lyp-1 or tLyp-1 peptide are bonded to the polymer, e.g., using aminoalkyl (C1-C4) succinimide or other linkers. These may be created, for example, by reacting a carboxylate moiety on a polymer with an aminoalkyl maleimide (C1-C4) or an aminoalkyl 10 (C1-C4) methacrylamide, and reacting the resulting aminoalkyl (C1-C4) maleimide or the aminoalkyl (C1-C4) methacrylamide to a cysteine or other sulfur group.