Dipartimento di Chimica Organica e Industriale, Universitá degli Studi di Milano, via Venezian 21, 20133 Milan, Italy.
J Control Release. 2012 Dec 28;164(3):372-9. doi: 10.1016/j.jconrel.2012.07.029. Epub 2012 Jul 27.
In this study, the gene delivery properties of new hyperbranched poly(amido amine)s (PAAs) with disulfide linkages in the main chain were investigated in comparison with their linear analogs. Eight different bioreducible PAAs were prepared by Michael addition of N,N'-bisacryloylpiperazine (BP) with cystamine (CYST) or N,N'-dimethylcystamine (DMC) and of N,N'-cystaminebisacrylamide (CBA) with N,N'-ethylenediamine (EDA) or N,N'-dimethylethylenediamine (DMEDA). In order to study the effect of terminal groups on the transfection efficiency, each polymer was terminated with 4-aminobutanol (ABOL) or with 2-aminoethanol (ETA). The hyperbranched and the linear PAAs generally formed polyplexes with plasmid DNA with sizes around 200nm and positive zeta potentials ranging from +10 to +22mV at polymer/DNA weight ratios equal or higher than 3/1. Remarkably low or no cytotoxicity was observed for both hyperbranched and linear PAAs. Hyperbranched CBA-containing PAAs showed higher gene expression in DNA transfection tests with COS-7 cells than their linear analogs and up to two times higher than linear PEI that was used as the reference polymer. Transfection efficiencies of the branched PAAs were generally enhanced by the presence of serum, which is a promising property for future in vivo studies with these hyperbranched PAAs. In this study the ease of synthetic modification of both linear and hyperbranched poly(amido amide)s and the versatility of hyperbranched PAAs in regulating DNA transfection and cytotoxicity are demonstrated. The results show the large possibilities for this class of polymers to provide polymeric vectors with controllable properties for gene therapy applications.
在这项研究中，研究了具有主链中二硫键的新型超支化聚（酰胺-胺）（PAA）的基因传递特性，并将其与线性类似物进行了比较。通过 N，N'-双丙烯酰基哌嗪（BP）与胱胺（CYST）或 N，N'-二甲胱胺（DMC）的迈克尔加成以及 N，N'-胱胺双丙烯酰胺（CBA）与 N，N'-乙二胺（EDA）或 N，N'-二甲基乙二胺（DMEDA）的迈克尔加成制备了 8 种不同的生物还原 PAA。为了研究端基对转染效率的影响，每个聚合物均用 4-氨基丁醇（ABOL）或 2-氨基乙醇（ETA）终止。超支化和线性 PAA 通常与质粒 DNA 形成大小约为 200nm 的聚集体，并在聚合物/DNA 重量比等于或高于 3/1 时具有正的 ζ 电位，范围从+10 到+22mV。观察到超支化和线性 PAA 均具有低细胞毒性或无细胞毒性。与线性类似物相比，含超支化 CBA 的 PAA 在 COS-7 细胞的 DNA 转染试验中显示出更高的基因表达，并且比用作参考聚合物的线性 PEI 高 2 倍。分支 PAA 的转染效率通常通过血清的存在而增强，这是将来用这些超支化 PAA 进行体内研究的有希望的特性。在这项研究中，证明了线性和超支化聚（酰胺-胺）易于进行合成修饰，并且超支化 PAA 在调节 DNA 转染和细胞毒性方面具有多功能性。结果表明，该类聚合物具有很大的可能性为基因治疗应用提供具有可控性质的聚合物载体。
