Dopamine-mimetic-coated polyamidoamine-functionalized Fe3O4 nanoparticles for safe and efficient gene delivery

Fe 3 O 4 nanoparticles (NPs) are widely used in the construction of drug and gene delivery vectors because of their particular physicochemical properties. Surface modification can not only reduce the cytotoxicity of Fe 3 O 4 , but also further improve the biocompatibility and delivery efficiency. In this work, firstly, polydopamine (PDA)-coated Fe 3 O 4 NPs (named Fe 3 O 4 @PDA) were prepared by using the self-polymerization characteristics of dopamine in alkaline environment. Then, polyamidoamine (PAMAM) was modified by the Michael addition reaction to prepare water-soluble core—shell magnetic NPs of Fe 3 O 4 @PDA@PAMAM, and its potential as gene vector was further evaluated. The results revealed that Fe 3 O 4 @PDA@PAMAM had the ability to condense and protect DNA, and showed lower cytotoxicity, higher cell uptake and transfection efficiency than those of PAMAM. It has the potential to become a magnetic targeted gene vector for further study.