Department of Biotechnology, Norwegian Biopolymer Laboratory (NOBIPOL), Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway.
Biomacromolecules. 2011 Mar 14;12(3):721-9. doi: 10.1021/bm1013525. Epub 2011 Feb 4.
Chitosan possesses many characteristics of an ideal gene delivery system. However, the transfection efficiency of conventional chitosans is generally found to be low. In this study, we investigated the self-branching of chitosans as a strategy to improve its gene transfer properties without compromising its safety profile. Self-branched (SB) and self-branched trisaccharide-substituted (SBTCO) chitosans with molecular weights of 11-71 kDa were synthesized, characterized, and compared with their linear counterparts with respect to transfection efficiency, cellular uptake, formulation stability, and cytotoxicity. Our studies show that in contrast with unmodified linear chitosans that were unable to transfect HeLa cells, self-branched chitosans mediated high transfection efficiencies. The most efficient chitosan, SBTCO30, yielded gene expression levels two and five times higher than those of Lipofectamine and Exgen, respectively, and was nontoxic to cells. Nanoparticles formed with SBTCO chitosans exhibited a higher colloidal stability of formulation, efficient internalization without excessive cell surface binding, and low cytotoxicity.
壳聚糖具有许多理想的基因传递系统的特性。然而，传统壳聚糖的转染效率通常较低。在这项研究中，我们研究了壳聚糖的自分支作为一种提高其基因传递特性的策略，同时不影响其安全性。合成了分子量为 11-71 kDa 的自分支（SB）和自分支三糖取代（SBTCO）壳聚糖，并将其与线性对应物进行了比较，以评估其转染效率、细胞摄取、制剂稳定性和细胞毒性。我们的研究表明，与不能转染 HeLa 细胞的未修饰线性壳聚糖相反，自分支壳聚糖介导了高转染效率。最有效的壳聚糖 SBTCO30 的基因表达水平分别比 Lipofectamine 和 Exgen 高 2 倍和 5 倍，且对细胞无毒。用 SBTCO 壳聚糖形成的纳米颗粒具有更高的制剂胶体稳定性、高效的内化而不发生过度的细胞表面结合，以及低细胞毒性。
