Regulation of angiogenesis through the efficient delivery of microRNAs into endothelial cells using polyamine-coated carbon nanotubes

Abstract

MicroRNAs (miRNAs) directly regulate gene expression at a post-transcriptional level and represent an attractive therapeutic target for a wide range of diseases. Here, we report a novel strategy for delivering miRNAs to endothelial cells (ECs) to regulate angiogenesis, using polymer functionalized carbon nanotubes (CNTs). CNTs were coated with two different polymers, polyethyleneimine (PEI) or polyamidoamine dendrimer (PAMAM), followed by conjugation of miR-503 oligonucleotides as recognized regulators of angiogenesis. We demonstrated a reduced toxicity for both polymer-coated CNTs, compared with pristine CNTs or polymers alone. Moreover, polymer-coated CNT stabilized miR-503 oligonucleotides and allowed their efficient delivery to ECs. The functionality of PAMAM-CNT-miR-503 complexes was further demonstrated in ECs through regulation of target genes, cell proliferation and angiogenic sprouting and in a mouse model of angiogenesis. This comprehensive series of experiments demonstrates that the use of polyamine-functionalized CNTs to deliver miRNAs is a novel and effective means to regulate angiogenesis.

Biophysical and biological contributions of polyamine-coated carbon nanotubes and bidimensional buckypapers in the delivery of miRNAs to human cells

“…Both PEI and PAMAM polymers formed large aggregates with the miRNA that were unable to migrate into the gel, in agreement with data already reported. 21,43 Similarly, the complete formation of PEI-CNTs and PAMAM-CNTs complexes occurred at a higher weight ratio of 10:1 (lane 8) and 20:1 (lane 16), respectively. The higher amount of PAMCNTs needed to bind completely the oligo suggests that this compound could bind the nucleic acid less tightly.…”

“…These compounds have low cytotoxicity, ability to conjugate microRNAs (such as miR-503) and, at the same time, transfect efficiently endothelial cells. 21 However, the parameters contributing to the good efficiency of transfection that we observed were not investigated in detail. In fact, the diameter and length of CNTs are important parameters to be taken into account when evaluating the effects on drug delivery efficiency.…”

“…To establish the optimal preparation condition, we modified the synthesis method reported in our previous paper 21 ( Figure 1). Starting from a commercial batch of short (0.5-2 μm) multiwalled CNTs, we suspended them into three different polymer solutions of PEI or PAMAM (at a concentration of 10%, 20% and 40%, w/w, respectively).…”

Getting miRNA Therapeutics into the Target Cells for Neurodegenerative Diseases: A Mini-Review

“…CNTs were coated with two different polymers, PEI or PAMAM, to improve the electrostatic interaction of CNTs with the negatively charged siRNAs or plasmid DNA, followed by conjugation of miR-503. The results showed an increasing nucleic acids loading and improving cell uptake (Masotti et al, 2016). …”

Derivatized Carbon Nanotubes for Gene Therapy in Mammalian and Plant Cells

“…Gene silencing using nanotubes as a carrier has achieved significant success in suppressing the growth of cancer cells. Figure highlights some of the cancer gene therapies using different biological payloads . Of which, RNA interference is one of the most versatile techniques employed to selectively block gene expression in the cell .…”