Caveolae‐Mediated Endocytosis of Conjugated Polymer Nanoparticles

Understanding cellular interactions and entry pathways of synthetic biomaterials are highly important to improve overall labeling and delivery efficiency. Conjugated polymer nanoparticles (CPNs) are emerging, fluorescent materials that have been used for cancer cell labeling and small interfering RNA (siRNA) delivery. In this contribution, detailed biophysical properties of CPNs including entry mechanisms and subcellular localization were studied using fluorescent-based techniques. While CPNs cause no toxicity, decreased CPN uptake was observed from cancer cells pretreated with genistein, which is an inhibitor of caveolae-mediated endocytosis (CvME). CvME was further confirmed by high co-localization with caveolin-1 proteins, which are 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.