title: SiRNA delivery with functionalized carbon nanotubes.
abstract: Carbon nanotubes (CNTs) have been studied for drug, antigen and nucleic acid delivery both in vitro and in vivo. Due to their nano-needle structure, they are supposed to cross the plasma membrane and enter directly into the cytoplasm likely upon an endocytosis-independent mechanism without inducing cell death. In this study, two cationically functionalized CNTs (CNT-PEI and CNT-pyridinium) were investigated for siRNA delivery. Both functionalized CNTs complexed siRNA and showed 10-30% silencing activity and a cytotoxicity of 10-60%. However, in terms of reduced toxicity or increased silencing activity, CNT-PEI and CNT-pyridinium did not show an added value over PEI and other standard transfection systems. Probably, the type of functionalization of carbon nanotubes might be a key parameter to obtain an efficient and non-cytotoxic CNT-based delivery system. Nevertheless, in view of the present results and importantly also of the non-degradability of CNTs, preference should currently be given to designing biodegradable carriers which mimic the needle structure of CNTs.
authors.affiliation: Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht, The Netherlands.
authors.forename: Amir Khashayar
authors.initials: AK
authors.lastname: Varkouhi
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Foillard
authors.forename: Twan
authors.initials: T
authors.lastname: Lammers
authors.forename: Raymond M
authors.initials: RM
authors.lastname: Schiffelers
authors.forename: Eric
authors.initials: E
authors.lastname: Doris
authors.forename: Wim E
authors.initials: WE
authors.lastname: Hennink
authors.forename: Gert
authors.initials: G
authors.lastname: Storm
mesh_terms: D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D002594:Cetylpyridinium / Q000737:chemistry; D003593:Cytoplasm / Q000378:metabolism; D020868:Gene Silencing; D006801:Humans; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000633:toxicity; D011094:Polyethyleneimine / Q000737:chemistry; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000633:toxicity; D014162:Transfection
chemical_list: D037742:Nanotubes, Carbon; D034741:RNA, Small Interfering; D011094:Polyethyleneimine; D002594:Cetylpyridinium