Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran; Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
J Pharm Pharm Sci. 2011;14(2):181-95. doi: 10.18433/j3tp4t.
Interleukin-12 (Il-12) as a cytokine has been proved to possess antitumor effects via stimulating the immune system. Non-viral gene delivery systems exhibit low toxicity and are easier to prepare compared to their viral counterparts. In this study, we aimed to prepare plasmid DNA loaded chitosan nanoparticles for expression of Il-12 and to evaluate their physicochemical characteristics, cytotoxicity and transfection efficiency in Murine CT-26 colon carcinoma cells.
Nanoparticles were prepared using a complex coacervation process at different N/P ratios and characterized in terms of size, zeta potential, polydispersity index, morphology, encapsulation efficiency and polyplex formation. The cytotoxicities and transfection efficiencies of the prepared polyplexes were evaluated by MTT assay and ELISA (for hIL-12, p70), respectively.
Size and zeta potential varied from 76.73 to 867.03 nm and between 5.68 and 16.77 mV, respectively. Strong attachment of the DNA to chitosan was observed after polyplex preparation. Encapsulation efficiencies were high (72.97-94.87%). The transfection efficiencies of the prepared complexes were obviously higher than those of naked pDNA when N/P ratios were between 16 and 60. Maximum level of phIL-12 expression was obtained at (N/P = 16) with mean particle size of 381.83±82.77 nm (polydispersity index=0.44) indicating the improved transfection of pUMVC3-hIL12 about 2.80 times compared to that of the naked pUMVC3-hIL12. Prepared polyplexes were nontoxic to CT-26 cells.
Chitosan-DNA nanoparticles at N/P = 16 with minimal cytotoxicity, can be used as suitable candidate for Il-12 delivery. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.
白细胞介素 12（IL-12）作为一种细胞因子，已被证明通过刺激免疫系统具有抗肿瘤作用。与病毒载体相比，非病毒基因传递系统的毒性更低，更容易制备。在这项研究中，我们旨在制备负载质粒 DNA 的壳聚糖纳米粒，用于表达 IL-12，并评估其在鼠 CT-26 结肠癌细胞中的理化特性、细胞毒性和转染效率。
采用复凝聚法在不同的 N/P 比下制备纳米粒，并从粒径、Zeta 电位、多分散指数、形态、包封效率和多聚物形成等方面对其进行了表征。通过 MTT 法和 ELISA（用于 hIL-12、p70）分别评估了制备的多聚物的细胞毒性和转染效率。
粒径和 Zeta 电位分别在 76.73-867.03nm 和 5.68-16.77mV 之间变化。多聚物制备后，DNA 与壳聚糖紧密结合。包封效率较高（72.97%-94.87%）。当 N/P 比在 16-60 之间时，制备的复合物的转染效率明显高于裸 pDNA。当（N/P=16）时，phIL-12 的表达水平最高，平均粒径为 381.83±82.77nm（多分散指数=0.44），表明与裸 pUMVC3-hIL12 相比，pUMVC3-hIL12 的转染效率提高了约 2.80 倍。制备的多聚物对 CT-26 细胞无毒性。
N/P=16 时具有最小细胞毒性的壳聚糖-DNA 纳米粒可作为 IL-12 传递的合适候选物。本文接受发表后评审。注册读者（见“读者须知”）可以在问题的内容页面上点击摘要进行评论。
