Caveolae-Mediated Endocytosis of Conjugated Polymer Nanoparticles

Abstract

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.

Exogenous expression of caveolin‐1 is sufficient for hepatic stellate cell activation

“…Endocytosis capacity of GRX and GRX EGFP‐Cav1 was determined according to Lee et al using red FluoSpheres® (Fluorescent microspheres; Molecular Probes). Briefly, cells were incubated in a ratio of 1:100 cell/microspheres for 4, 8, and 16 hours.…”

“…LysRed staining were performed as in accordance to the manufacturer's instructions. To visualize microspheres uptake cells were incubated by 8 hours with 1:100 cells/microspheres according . To contrast, actin cytoskeleton was stained with Phalloidin ‐ AlexaFluor 488 (Invitrogen) and cell nuclei with Hoechst 33342 (Invitrogen).…”

Phosphorylcholine‐Coated Semiconducting Polymer Nanoparticles as Rapid and Efficient Labeling Agents for In Vivo Cell Tracking

“…This suggested that SPN RD were internalized through an energy-dependent pathway, consistent with previous reports that SPNs entered cells through endocytosis. [19] As the pH of the cell culture medium was neutral, SPN RD should mainly bind to but not fuse into the cell membrane according to a previous study on the fusogenic capability of DPPC. [20] …”

Supramolecular nanoscale assemblies for cancer diagnosis and therapy

“…Polymeric systems demonstrate high efficacy of encapsulation and high endocytosis by EPR effect [250]. In addition, they are able to protect systemic bioavailability, avoiding normal cells to be exposed to the drug toxicity [251][252][253]. The natural polymers are suitable materials to interact with the normal cells conferring to the DDS high biocompatibility [72].…”