Fu Hui-Li, Cheng Si-Xue, Zhang Xian-Zheng, Zhuo Ren-Xi
Key Laboratory of Biomedical Polymers of Ministry of Education, Department of Chemistry, Wuhan University, Wuhan, PR China.
J Gene Med. 2008 Dec;10(12):1334-42. doi: 10.1002/jgm.1258.
To overcome the extracellular barriers in gene delivery and direct gene delivery to target tissues, substrate-mediated transfection, which sustains the release of naked DNA or vector/DNA complexes, and also supports cell growth, has been developed.
In the present study, polyamidoamine (PAMAM) dendrimer/DNA complexes encapsulated functional biodegradable polymer films for substrate-mediated gene delivery were prepared. To maintain the activity of DNA during dehydration, the dendrimer/DNA complexes were encapsulated in a water soluble polymer, poly alpha,beta-[N-(2-hydroxyethyl)-(L)-aspartamide], and then deposited on or sandwiched in functional polymer films with a fast degradation rate to mediate gene transfection. The in vitro gene transfections of pGL3-Luc and pEGFP-C1 plasmids in HEK293 cells mediated by different films were studied. For comparison, the transfection mediated by the film fabricated by conventional linear poly((DL)-lactide) was also investigated.
The expression of pGL3-Luc and pEGFP-C1 plasmids could effectively be mediated by the PAMAM/DNA complexes deposited or sandwiched polymer films, with transfection efficiencies comparable to that of solution-based transfections. The cells on the functionalized star poly((DL)-lactide) film exhibited much higher gene expression compared to the cells on the conventional linear poly((DL)-lactide) film because the fast degradation rate of star poly((DL)-lactide) facilitated the access of PAMAM/DNA complexes for the cells seeded on the film. In addition, the films did not exhibit any additional cytotoxicity to the cells during the degradation and transfection.
The fast degrading functional polymer has great potential for localized transfection.
为了克服基因递送中的细胞外屏障并将基因直接递送至靶组织，已开发出底物介导的转染技术，该技术可维持裸DNA或载体/DNA复合物的释放，并支持细胞生长。
在本研究中，制备了用于底物介导基因递送的聚酰胺-胺（PAMAM）树枝状大分子/DNA复合物包封的功能性可生物降解聚合物薄膜。为了在脱水过程中保持DNA的活性，将树枝状大分子/DNA复合物包封在水溶性聚合物聚α，β-[N-（2-羟乙基）-（L）-天冬酰胺]中，然后沉积在具有快速降解速率的功能性聚合物薄膜上或夹在其中以介导基因转染。研究了不同薄膜介导的pGL3-Luc和pEGFP-C1质粒在HEK293细胞中的体外基因转染。作为比较，还研究了由传统线性聚（DL-丙交酯）制备的薄膜介导的转染。
沉积或夹在聚合物薄膜中的PAMAM/DNA复合物可有效介导pGL3-Luc和pEGFP-C1质粒的表达，转染效率与基于溶液的转染相当。与传统线性聚（DL-丙交酯）薄膜上的细胞相比，功能化星形聚（DL-丙交酯）薄膜上的细胞表现出更高的基因表达，因为星形聚（DL-丙交酯）的快速降解速率促进了接种在薄膜上的细胞对PAMAM/DNA复合物的摄取。此外，在降解和转染过程中，薄膜对细胞没有表现出任何额外的细胞毒性。
快速降解的功能性聚合物在局部转染方面具有巨大潜力。
