title: A facile Friedel-Crafts acylation for the synthesis of polyethylenimine-grafted multi-walled carbon nanotubes as efficient gene delivery vectors.
abstract: Low chemical reactivity of carbon nanotubes is one of the major obstacles in their functionalization via chemical reactions. As a non-destructive method, Friedel-Crafts acylation was suggested among the explored reactions for which only a few methods have been reported under harsh reaction conditions, e.g., high temperature all leading to low yields. In this study, we propose a novel method for the acylation of multi-walled carbon nanotubes (MWCNTs) at a low temperature (i.e., 42°C), using SiO2-Al2O3 as a catalyst and 6-bromohexanoic acid as the acylating agent to produce high yield functionalized MWCNTs. After acylation, MWCNTs are conjugated with polyethylenimines (PEIs) with three molecular weights (1.8, 10 and 25kDa). Three different MWCNT-PEI conjugates are synthesized and evaluated for their condensation ability, viability, size and zeta potential properties. The transfection efficiency of the functionalized MWCNTs is evaluated using luciferase assay and flow cytometry in a Neuroblastoma cell line. MWCNT-PEI (10 kDa) conjugate shows the highest transfection efficacy compared to others. For this carrier transfection efficacy exceeds the amount of PEI 25 kDa at similar carrier to plasmid weight ratio (C/P) and is around 3 times higher compared to PEI 25 kDa at C/P=0.8 as positive control regarding its high transfection efficiency and low cytotoxicity.
authors.affiliation: Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran; School of Sciences, Department of Chemistry, Ferdowsi University of Mashhad, Mashhad, Iran.
authors.forename: Azadeh Hashem
authors.initials: AH
authors.lastname: Nia
authors.affiliation: School of Computing, Engineering and Mathematics, Western Sydney University, Locked Bag 1797, NSW 2751, Australia.
authors.forename: Abbas
authors.initials: A
authors.lastname: Amini
authors.affiliation: Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Sahar
authors.initials: S
authors.lastname: Taghavi
authors.affiliation: School of Sciences, Department of Chemistry, Ferdowsi University of Mashhad, Mashhad, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Eshghi
authors.affiliation: Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Khalil
authors.initials: K
authors.lastname: Abnous
authors.affiliation: Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address: ramezanim@mums.ac.ir.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ramezani
mesh_terms: D000215:Acylation; D000077410:Aluminum Chloride; D017607:Aluminum Compounds / Q000737:chemistry; D000818:Animals; D002208:Caproates / Q000737:chemistry; D045744:Cell Line, Tumor; D002712:Chlorides / Q000737:chemistry; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins / Q000235:genetics; D051379:Mice; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011094:Polyethyleneimine / Q000008:administration & dosage / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: C523145:6-bromohexanoate; D017607:Aluminum Compounds; D002208:Caproates; D002712:Chlorides; D037742:Nanotubes, Carbon; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D000077410:Aluminum Chloride; D012822:Silicon Dioxide; D011094:Polyethyleneimine
keywords: Friedel-Crafts acylation; Functionalization; Gene delivery; Multi-walled carbon nanotube; Polyethylenimine