University of Illinois, Urbana, Illinois, USA.
Pharm Res. 2012 Feb;29(2):500-10. doi: 10.1007/s11095-011-0576-5. Epub 2011 Sep 3.
Crosslinked, degradable derivatives of low-molecular-weight polyethylenimine (PEI) are relatively efficient and non-cytotoxic gene delivery agents. To further investigate these promising materials, a new synthetic approach was developed using a poly(4-vinylpyridine)-supported Fe(III) catalyst (PVP(Fe(III))) that provides more facile synthesis and enhanced control of polymer molecular weight.
Biodegradable polymers (D.PEI) comprising 800-Da PEI crosslinked with 1,6-hexanediol diacrylate and exhibiting molecular weights of 1.2, 6.2, and 48 kDa were synthesized utilizing the PVP(Fe(III)) catalyst. D.PEI/DNA polyplexes were characterized using gel retardation, ethidium bromide exclusion, heparan sulfate displacement, and dynamic light scattering. In vitro transfection, cellular uptake, and cytotoxicity of the polyplexes were tested in human cervical cancer cells (HeLa) and human breast cancer cells (MDA-MB-231).
D.PEIs tightly complexed plasmid DNA and formed 320- to 440-nm diameter polyplexes, similar to those comprising non-degradable, 25-kDa, branched PEI. D.PEI polyplexes mediated 2- to 5-fold increased gene delivery efficacy compared to 25-kDa PEI and exhibited 20% lower cytotoxicity in HeLa and no toxicity in MDA-MB-231. In addition, 2- to 7-fold improved cellular uptake of DNA was achieved with D.PEI polyplexes.
PVP(Fe(III)) catalyst provided a more controlled synthesis of D.PEIs, and these materials demonstrated improved in vitro transfection efficacy and reduced cytotoxicity .
低分子量聚乙烯亚胺（PEI）的交联可降解衍生物是相对高效和非细胞毒性的基因传递剂。为了进一步研究这些有前途的材料，开发了一种新的合成方法，使用聚（4-乙烯基吡啶）负载的 Fe（III）催化剂（PVP（Fe（III））），该方法提供了更简便的合成和对聚合物分子量的更好控制。
使用 PVP（Fe（III））催化剂合成了包含 800-Da PEI 交联的 1,6-己二醇二丙烯酸酯的可生物降解聚合物（D.PEI），其分子量为 1.2、6.2 和 48 kDa。D.PEI/DNA 聚集体的特性通过凝胶阻滞、溴化乙锭排除、肝素硫酸盐置换和动态光散射进行了表征。在人宫颈癌（HeLa）和人乳腺癌（MDA-MB-231）细胞中测试了聚集体的体外转染、细胞摄取和细胞毒性。
D.PEIs 紧密地将质粒 DNA 复合物化，并形成 320 至 440nm 直径的聚集体，与不可降解的 25kDa 支化 PEI 形成的聚集体相似。D.PEI 聚集体介导的基因传递效率比 25kDa PEI 高 2 至 5 倍，在 HeLa 中表现出 20%的低细胞毒性，在 MDA-MB-231 中没有毒性。此外，D.PEI 聚集体实现了 2 至 7 倍的 DNA 细胞摄取的提高。
PVP（Fe（III））催化剂提供了 D.PEI 的更受控合成，并且这些材料表现出改善的体外转染效率和降低的细胞毒性。
