Nia Azadeh Hashem, Amini Abbas, Taghavi Sahar, Eshghi Hossein, Abnous Khalil, Ramezani Mohammad
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.
School of Computing, Engineering and Mathematics, Western Sydney University, Locked Bag 1797, NSW 2751, Australia.
Int J Pharm. 2016 Apr 11;502(1-2):125-37. doi: 10.1016/j.ijpharm.2016.02.034. Epub 2016 Feb 22.
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.
碳纳米管的低化学反应活性是通过化学反应对其进行功能化的主要障碍之一。作为一种非破坏性方法，在已探索的反应中提出了傅克酰基化反应，在苛刻的反应条件下（例如高温），只有少数几种方法被报道，且所有这些方法都导致产率较低。在本研究中，我们提出了一种在低温（即42°C）下对多壁碳纳米管（MWCNT）进行酰化的新方法，使用SiO₂ - Al₂O₃作为催化剂，6 - 溴己酸作为酰化剂，以高产率制备功能化的MWCNT。酰化后，MWCNT与三种分子量（1.8、10和25 kDa）的聚乙烯亚胺（PEI）共轭。合成了三种不同的MWCNT - PEI共轭物，并对其凝聚能力、活力、尺寸和zeta电位性质进行了评估。使用荧光素酶测定法和流式细胞术在神经母细胞瘤细胞系中评估功能化MWCNT的转染效率。与其他共轭物相比，MWCNT - PEI（10 kDa）共轭物显示出最高的转染效率。对于这种载体，在相似的载体与质粒重量比（C/P）下，转染效率超过了25 kDa的PEI，并且在C/P = 0.8时，作为阳性对照，其转染效率约为25 kDa的PEI的3倍，且细胞毒性较低。
