3. MSN for gene transfection

Gene transfection involves introducing an exogenous DNA fragment into the host cell. The MSNs are used to transport the DNA fragment into the cell, where it is bound to the MSNs by weak (electrostatic) bonds. Lin's group [28] encapsulated a marker, red-texas, in the nanoparticle mesopores and then plugged the pores by covalently binding a dendrimer: a generation 2 polyamidoamine. This dendrimer, bound to the nanoparticles, is positively charged and has the ability to bind negatively charged DNA plasmids. The plasmid pEGFP-C1, which expresses GFP, was thus bound to MSNs and the binding monitored by electrophoresis. MSNs are effective in protecting the plasmid from endonucleases. Transfection of HeLa cells with MSNs was performed and compared with commercial agents. Transfection is much more efficient with MSNs: the level...