*3.3. Cellular Uptake, Toxicity, and DC Stimulatory Ability of Monomeric Molecules*

EG*<sup>n</sup>* peptides exist as monomeric molecules in aqueous media at concentrations below ca. 15–30 μM. The cellular uptake of monomeric peptides was not dependent on EG length (Figure 5a) and this may be attributed to size. Monomeric peptides are too small for efficient uptake by DC regardless to EG length. In addition, the monomeric peptides exhibited some cytotoxicity but no DC activation ability, which is in sharp contrast to the results with NFs (Figure 7a, Figure 8, and Figure 9). These results suggest that monomeric peptides interact with cell membranes, possibly through an N-terminal hydrophobic region, but are not well recognized by receptors involved in DC activation. Recognition by receptors would be dependent on the size of the hydrophobic portion.
