Geng Jing, Song Hao, Gao Fang, Kong Yueqi, Fu Jianye, Luo Jiangqi, Yang Yannan, Yu Chengzhong
Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia.
J Mater Chem B. 2020 Jun 7;8(21):4593-4600. doi: 10.1039/d0tb00720j. Epub 2020 May 11.
Polyethylenimine (PEI) functionalization onto nanoparticles is a widely used strategy for constructing particulate vectors for gene delivery. However, how to control the conformation of PEI chains and the resultant impact on gene transfection efficiency remains largely unexplored. Herein, we report that drying methods dramatically affect the conformation of PEI chains modified on the surface of silica nanoparticles and consequently the plasmid DNA transfection performance. Specifically, lyophilization renders less entangled PEI compared to commonly used vacuum drying as evidenced by an elevated glass transition temperature. The lyophilization induced disentangled conformation is likely associated with the solid-to-gas phase transition drying mechanism, which removes the bound crystal water content and thus reduces hydrogen bonding between amines. Moreover, we find that the stretched PEI chains on the surface of rambutan-like silica nanoparticles promote their binding capacity towards plasmid DNA molecules and thereby enhanced gene delivery and transfection efficiency. Our findings have provided new understanding about amine based polymers modified on nanoparticles, and have significant implications on the design of efficient particulate vectors for gene delivery.
将聚乙烯亚胺（PEI）功能化到纳米颗粒上是构建用于基因递送的颗粒载体的一种广泛使用的策略。然而，如何控制PEI链的构象以及由此对基因转染效率产生的影响在很大程度上仍未得到探索。在此，我们报道干燥方法会显著影响二氧化硅纳米颗粒表面修饰的PEI链的构象，进而影响质粒DNA转染性能。具体而言，与常用的真空干燥相比，冻干使PEI的缠结程度更低，这由升高的玻璃化转变温度所证明。冻干诱导的解缠结构象可能与固-气相转变干燥机制有关，该机制去除了结合的结晶水含量，从而减少了胺之间的氢键。此外，我们发现毛荔枝状二氧化硅纳米颗粒表面伸展的PEI链促进了它们与质粒DNA分子的结合能力，从而提高了基因递送和转染效率。我们的研究结果为纳米颗粒上修饰的胺基聚合物提供了新的认识，并对设计高效的基因递送颗粒载体具有重要意义。
