Cyclen Grafted with poly[(Aspartic acid)-co-Lysine]: Preparation, Assembly with Plasmid DNA, and in Vitro Transfection Studies
Chunying Ma, Jin Zhang, Liwen Guo, Changguo Du, Ping Song, Baojing Zhao, Ling Li, Chao Li, Renzhong Qiao
Development of safe and effective gene carriers is the key to the success of gene therapy. Nowadays, it is still required to develop new methods to improve nonviral gene delivery efficiency. Herein, copolymers of poly[(aspartic acid)-co-lysine] grafted with cyclen (cyclen-pAL) were designed and evaluated for efficient gene delivery. Two copolymers with different Asp/Lys block ratios were prepared and characterized by NMR and gel permeation chromatography analysis. Agarose gel retardation, circular dichroism, and fluorescent quenching assays showed the strong DNA-binding and protection ability for the title compounds. Atomic force microscopy studies clearly delineated uniform DNA globules with a diameter around 100 nm, induced bycyclen-pAL. By grafting cyclen on Asp, relatively high gene delivery efficiency and low cytotoxicity of the modified copolymers were achieved compared with their parent compounds. The present work might help to develop strategies for design and modification of polypeptide copolymers, which may also be applied to favorable gene expression and delivery.
Circular dichroism, Pharmaceutical, Ligand binding, Biochemistry