Drug delivery: Logic‐Embedded Vectors for Intracellular Partitioning,Endosomal Escape,and Exocytosis of Nanoparticles (Small 23/2010)

A new generation of nanocarriers, logic‐embedded vectors (LEVs), is endowed with the ability to localize components at multiple intracellular sites, thus creating an opportunity for synergistic control of redundant or dual‐hit pathways. LEV encoding elements include size, shape, charge, and surface chemistry. In this study, LEVs consist of porous silicon nanocarriers, programmed for cellular uptake and trafficking along the endosomal pathway, and surface‐tailored iron oxide nanoparticles, programmed for endosomal sorting and partitioning of particles into unique cellular locations. In the presence of persistent endosomal localization of silicon nanocarriers, amine‐functionalized nanoparticles are sorted into multiple vesicular bodies that form novel membrane‐bound compartments compatible with cellular secretion, while chitosan‐coated nanoparticles escape from endosomes and enter the cytosol. Encapsulation within the porous silicon matrix protects these nanoparticle surface‐tailored properties, and enhances endosomal escape of chitosan‐coated nanoparticles. Thus, LEVs provide a mechanism for shielded transport of nanoparticles to the lesion, cellular manipulation at multiple levels, and a means for targeting both within and between cells.