Cellular internalization mechanisms of polyamine-coated carbon nanotubes

Introduction Carbon nanotubes (CNTs) are emerging as promising systems for transfection of drugs, small molecules and, recently, have been widely studied for the delivery of nucleic acids. In our previous paper, we reported... [ view full abstract ]

Introduction
Carbon nanotubes (CNTs) are emerging as promising systems for transfection of drugs, small molecules and, recently, have been widely studied for the delivery of nucleic acids. In our previous paper, we reported the preparation of efficient delivery systems consisting of polymer-functionalized carbon nanotubes (CNTs). These systems efficiently delivered microRNAs (miRNAs) in endothelial cells (ECs).
Methods
These compounds were obtained through coating of CNTs with two polyamine polymers (i.e., polyethyleneimine, PEI and polyamidoamine dendrimer, PAMAM), followed by complexation with miRNA mimics. In particular, both PEI-coated and PAMAM-coated CNTs were able to stabilize miR-503 oligonucleotides and allowed an efficient delivery of polyplexes to ECs.
We further investigated the cellular internalization mechanism of polymer-coated CNTs compared to polymers alone. Using inhibitors of clathrin-mediated endocytosis (i.e, chlorpromazine) and caveolae-mediated uptake (i.e., filipin/genistein) we studied the internalization mechanisms of polymer-coated CNTs by different cell lines.
Results
FACS analysis suggested that these compounds may enter cells following different internalization pathways. In this contribution we will show the obtained preliminary results.
Discussion
Inhibition assays may contribute to understand the internalization processes by polyamines/dendrimers and polyamine-coated CNTs.