title: Guanidinium-rich, glycerol-derived oligocarbonates: a new class of cell-penetrating molecular transporters that complex, deliver, and release siRNA.
abstract: A highly versatile and step-economical route to a new class of guanidinium-rich molecular transporters and evaluation of their ability to complex, deliver, and release siRNA are described. These new drug/probe delivery systems are prepared in only two steps, irrespective of length or composition, using an organocatalytic ring-opening co-oligomerization of glycerol-derived cyclic carbonate monomers incorporating either protected guanidine or lipid side chains. The resultant amphipathic co-oligomers are highly effective vehicles for siRNA delivery, providing an excellent level of target protein suppression (>85%). These new oligocarbonates are nontoxic at levels required for cell penetration and can be tuned for particle size. Relative to the previously reported methyl(trimethylene)carbonate (MTC) scaffold, the ether linkage at C2 in the new transporters markedly enhances the stability of the siRNA/co-oligomer complexes. Both hybrid co-oligomers, containing a mixture of glycerol- and MTC-derived monomers, and co-oligomers containing only glycerol monomers are found to provide tunable control over siRNA complex stability. On the basis of a glycerol and CO2 backbone, these new co-oligomers represent a rapidly tunable and biocompatible siRNA delivery system that is highly effective in suppressing target protein synthesis.
authors.affiliation: Departments of Chemistry and Chemical and Systems Biology, Stanford University , Stanford, California 94305, United States.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Wender
authors.forename: Melanie A
authors.initials: MA
authors.lastname: Huttner
authors.forename: Daryl
authors.initials: D
authors.lastname: Staveness
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Vargas
authors.forename: Adele F
authors.initials: AF
authors.lastname: Xu
mesh_terms: D001702:Biopharmaceutics; D002254:Carbonates / Q000737:chemistry; D002460:Cell Line; D002463:Cell Membrane Permeability; D016503:Drug Delivery Systems; D005990:Glycerol / Q000031:analogs & derivatives / Q000737:chemistry; D019791:Guanidine / Q000031:analogs & derivatives / Q000737:chemistry; D006801:Humans; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage*; D000067492:RNAi Therapeutics / Q000379:methods
chemical_list: D002254:Carbonates; D034741:RNA, Small Interfering; D019791:Guanidine; D005990:Glycerol
keywords: 1,3-glycerol carbonate; guanidinium-rich molecular transporters; oligocarbonates; organocatalytic ring-opening oligomerization; siRNA delivery