Understanding the cellular entry pathways of synthetic biomaterials is highly important to improve overall labeling and delivery efficiency. Herein, cellular entry mechanisms of conjugated polymer nanoparticles (CPNs) are presented. CPNs are intrinsic fluorescent materials used for various biological applications. While CPNs cause no toxicity, decreased CPN uptake is observed from cancer cells pretreated with genistein, which is an inhibitor of caveolae-mediated endocytosis (CvME). CvME is further confirmed by high co-localization with caveolin-1 proteins found in the caveolae and caveosomes. Excellent photophysical properties, non-toxicity, and non-destructive delivery pathways support that CPNs are promising multifunctional carriers minimizing degradation of contents during delivery.
