Hybrid Polymer‐Grafted Multiwalled Carbon Nanotubes for In vitro Gene Delivery

Abstract

Carbon nanotubes (CNTs) consist of carbon atoms arranged in sheets of graphene rolled up into cylindrical shapes. This class of nanomaterials has attracted attention because of their extraordinary properties, such as high electrical and thermal conductivity. In addition, development in CNT functionalization chemistry has led to an enhanced dispersibility in aqueous physiological media which indeed broadens the spectrum for their potential biological applications including gene delivery. The aim of this study is to determine the capability of different cationic polymer-grafted multiwalled carbon nanotubes (MWNTs) (polymer-g-MWNTs) to efficiently complex and transfer plasmid DNA (pCMV-βGal) in vitro without promoting cytotoxicity. Carboxylated MWNT is chemically conjugated to the cationic polymers polyethylenimine (PEI), polyallylamine (PAA), or a mixture of the two polymers. In order to explore the potential of these polymer-g-MWNTs as gene delivery systems, we first study their capacity to complex plasmid DNA (pDNA) using agarose gel electrophoresis. Gel migration studies confirm pDNA binding to polymer-g-MWNT with different affinities, highest for PEI-g-MWNT and PEI/PAA-g-CNT constructs. β-galactosidase expression is assessed in human lung epithelial (A549) cells, and the cytotoxicity is determined by modified LDH assay after 24 h incubation period. Additionally, PEI-g-MWNT and/or PEI/PAA-g-MWNT reveal an improvement in gene expression when compared to the naked pDNA or to the equivalent amounts of PEI polymer alone. Mechanistically, pDNA was delivered by the polymer-g-MWNT constructs via a different pathway compared to those used by polyplexes. In conclusion, polymer-g-MWNTs may be considered in the future as a versatile tool for efficient gene transfer in cancer cells in vitro, provided their toxicological profile is established.

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

“…[1][2][3][4] Recent findings in nanomedicine have revealed that CNTs can be used as potential drug carriers, therapeutic agents and diagnostics tools as well. [5][6][7][8][9][10] In particular, due to their ability to cross cellular membranes, their nanosize dimension, high surface area and relatively good biocompatibility, CNTs have also been employed as a novel gene delivery vector system. [11][12][13] However, one of the major drawbacks is their low solubility and high propensity to aggregate in aqueous solutions.…”

Exposure to Carbon Nanotubes Leads to Changes in the Cellular Biomechanics

“…[12] Such broad applications of CNTs have led to an increased production level and thus increased concerns regarding human and environmental exposure. Further, given their applications in the biomedical field, [13,14] understanding how biological systems interact with this nanomaterial is urgently needed to create safer therapies, [14,15] and to regulate occupational exposures.…”

Nanotechnology-based approaches in anticancer research

“…The success of a gene therapy largely depends upon the activity induced by the target genes and the efficiency of gene delivery resulting from the combined effects of the delivery vector and the applied delivery route. 154 Various NPs have been investigated for gene delivery, including GNPs, 155 silver NPs, 156 CNTs, 157 liposomes, 158 polymersomes, 159 and polyplexes. Use of NPs enables targeting of tumor tissue through the EPR effect in gene therapy.…”