Polymeric nanoparticles promote endocytosis of a survivin molecular beacon: localization and fate of nanoparticles and beacon in human A549 cells
Authors: Adinolfi B., Pellegrino M., Tombelli S., Trono C., Giannetti A., Domenici C., Varchi G., Sotgiu G., Ballestri M., Baldini F.
Autors Affiliation: Istituto di Fisica Applicata “Nello Carrara”, CNR, Sesto Fiorentino (FI), Italy
Istituto Nazionale di Ottica, CNR, Pisa (PI), Italy
Istituto di Fisiologia Clinica, CNR. Pisa (PI), Italy
Istituto per la Sintesi Organica e la Fotoreattività, CNR, Bologna (BO), Italy
Abstract: Polymethylmethacrylate core-shell fluorescent nanoparticles promote, in human lung A549 cancer cells, the internalization of a molecular beacon (MB) specific for survivin mRNA, an anti-apoptotic protein overexpressed in cancer cells.
To design an effective drug delivery system, the knowledge of the uptake mechanism and of the NP nanoparticles (NPs) and MB fate is required.
Materials and Methods and Key findings
Experiments with dextran as marker for endocytosis showed that in the presence of nanoparticles the number of endocytic vesicles per cell doubled and their mean size significantly (p<0.001) increased, indicating a promotion of endocytosis. By using LysoTracker™ Deep Red, as marker of lysosomes, we found that nanoparticles co-localize with lysosomes. Moreover, a cellular release of nanoparticles detected in the culture medium, suggested a role of lysosomal exocytosis in nanoparticle elimination. The MB fluorescence in proximity of the labelled Endoplasmic Reticulum was indicative that the opening of the MB occurs in proximity of its target mRNA. Significance The results show the involvement of endocytotic pathway in the uptake of NPs, which are an appropriate delivery system capable of being eliminated by cells. Furthermore the data confirm that the MB can be considered an effective tool for the intracellular sensing. Journal/Review: LIFE SCIENCES
Volume: 215 Pages from: 106 to: 112