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Layer-by-Layer Coated Gold Nanoparticles: Size-Dependent Delivery of DNA into Cells
Link to Journal Abstract
Because nanoparticles are finding uses in myriad biomedical applications, including the delivery of nucleic acids, a detailed knowledge of their interaction with the biological system is of utmost importance. Here the size-dependent uptake of gold nanoparticles (AuNPs) (20, 30, 50 and 80 nm), coated with a layer-by-layer approach with nucleic acid and poly(ethylene imine) (PEI), into a variety of mammalian cell lines is studied. In contrast to other studies, the optimal particle diameter for cellular uptake is determined but also the number of therapeutic cargo molecules per cell. It is found that 20 nm AuNPs, with diameters of about 32 nm after the coating process and about 88 nm including the protein corona after incubation in cell culture medium, yield the highest number of nanoparticles and therapeutic DNA molecules per cell. Interestingly, PEI, which is known for its toxicity, can be applied at significantly higher concentrations than its IC50 value, most likely because it is tightly bound to the AuNP surface and/or covered by a protein corona. These results are important for the future design of nanomaterials for the delivery of nucleic acids in two ways. They demonstrate that changes in the nanoparticle size can lead to significant differences in the number of therapeutic molecules delivered per cell, and they reveal that the toxicity of polyelectrolytes can be modulated by an appropriate binding to the nanoparticle surface.
For this study, the size-dependent uptake of gold nanoparticles (AuNPs) (20, 30, 50 and 80 nm), coated with a layer-by-layer approach with nucleic acid and poly(ethylene imine) (PEI), into a variety of mammalian cell lines is investigated. In contrast to other studies, the optimal particle diameter for cellular uptake is determined but also the number of therapeutic cargo molecules per cell.
Peer Reviewed Journal Article
Exposure Or Hazard Target
Method Of Study
Risk Exposure Group
Small, 8(24): 3847-3856 (December 2012)
Elbakry A, Wurster EC, Zaky A, Liebl R, Schindler E, Bauer-Kreisel P, Blunk T, Rachel R, Goepferich A, Breunig M
Last updated on January 29, 2013
This work is supported in part by the Nanoscale Science and Engineering Initiative of the National Science Foundation
under NSF Award Number EEC-0118007.
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