Characterization of commercially available and synthesized polyethylenimines for gene delivery
Characterization of commercially available and synthesized polyethylenimines for gene delivery
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DOI：
10.1016/s0168-3659(00)00317-5
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发表时间：
2000-11-03
影响因子：
10.8
通讯作者：
Kissel, T
中科院分区：
文献类型：
--
作者：
von Harpe, A;Petersen, H;Kissel, T
通过氮丙啶水溶液聚合法合成了五种新型的聚乙烯亚胺（PEI），并与几种市售的用于基因转移的PEI进行了比较。聚合物的特征在于通过C-13 NMR光谱，毛细管粘度计，电位滴定和Cu（II）络合物的形成，以深入了解结构和功能特性。C-13 NMR分析揭示了基于伯、仲和叔氨基的比率的支化程度的差异。合成的PEI的氨基比例为1度：2度：3度=1：2：1，而市售PEI通常显示出较高的支化度（1：1：1）。对于市售聚合物，具有足量盐的PEI水溶液的毛细管粘度测定给出α =0.26和K-V=1.00 cm（3）/g的Mark-Houwink参数。在合成聚合物的情况下，反应条件的变化产生在8000-24000 g/mol范围内的粘均摩尔质量（M-v）。通过电位滴定分析研究PEI溶液，表明它们的缓冲能力不受摩尔质量或聚合物结构的显著影响。pK（a）值（8.18-9.94）和缓冲容量β（0.08-0.014 mol/l）具有可比性。这项研究强调了更详细的表征方法的必要性PEI用于基因转移方案，因为物理化学性质并不反映转染效率的巨大差异。(C)2000 Elsevier Science B. V.保留所有权利。
Five new polyethylenimines (PEI) were synthesized by polymerization of aziridine in aqueous solution and compared to several commercially available PEI used for gene transfer. Polymers were characterized by C-13 NMR spectroscopy, capillary viscosimetry, potentiometric titration and Cu(II) complex formation to gain insight into structural and functional properties. C-13 NMR analysis revealed differences in the extent of branching based on the ratio of primary, secondary and tertiary amino groups. An amino group ratio 1 degrees :2 degrees :3 degrees =1:2:1 was obtained for the synthesized PEI, whereas commercially available PEI generally showed a higher degree of branching (1:1:1). Capillary viscosimetry of aqueous PEI solutions with a sufficient amount of salt gave Mark-Houwink parameters of alpha =0.26 and K-V=1.00 cm(3)/g for the commercially available polymers. In case of the synthesized polymers, variation of reaction conditions yielded viscosity average molar masses (M-v) in the range of 8000-24000 g/mol. PEI solutions were investigated by potentiometric titration analysis showing that their buffer capacity was not significantly influenced by molar mass or polymer structure. The pK(a) values (8.18-9.94) and the buffer capacity beta (0.08-0.014 mol/l) were of comparable magnitude. This study highlights the necessity of more detailed characterization methods for PEI used in gene transfer protocols since physico-chemical properties do not reflect the vast differences found in transfection efficiencies. (C) 2000 Elsevier Science B.V. All rights reserved.