Filamentous micelles with aspect ratio of 20 were formulated with PP2 polymer and shown to have lower cellular uptake by macrophages than spherical micelle. (A) TEM image of fVPM (inset: sVPM for comparison, scale bar = 100 nm), (B) aspect ratio (AR) distribution of fVPM post-lyophilization reconstituted in water, (C) DLS mean size and PDI of fVPM following reconstitution with 1x PBS (n=3, mean ± SD), and (D) sVPM and fVPM uptake efficiency in RAW 264.7 cells and geometric mean of uptake normalized to untreated cells measured by flow cytometry after treatment for 1 hr at equivalent VP concentrations (n=4, mean ± SD, One-way ANOVA with Tukey post-hoc test).