Lipid-Like Delivery Materials for Efficient siRNA Delivery - Nanotechnology for the Delivery of Therapeutic Nucleic Acids - page 163

possessed an interesting structural element not yet analyzed. Similar
to the Michael addition, the epoxide ring-opening reaction does not
require purification or protection steps and can be performed in
open air. As a result, a structurally diverse library was synthesized
quickly for high-throughput analysis.

Figure 7.3 Synthesis of epoxide-derived lipidoid library. (Top) Epoxide-

terminated alkyl chains and amine-containing monomers were
used in synthesis of combinatorial library. (Bottom) Addition
of epoxides to amines by efficient ring-opening enables parallel
synthesis of library members. Reproduced with permission
from Ref. [20].

More than 100 second-generation lipidoids were evaluated
in vitro

using the dual HeLa assay. Several compounds conferred
90% silencing at an siRNA dose of 33 nM. Negligible off-target
effects initially measured by constant Renilla expression were
later confirmed using an MTS cell-viability assay. Subsequent dose-
response studies in HeLa cells demonstrated that three compounds
(C14-113, C12-113, and C14-120) silenced the target gene by 70%
at 3.3 nM. Based on these studies, 12 promising candidates were
tested for their ability to silence F7 at a dose of 3 mg/kg. Three

compounds (C12-200, C16-96, and C14-110) silenced F7 completely.

in vivo