Figure 1.

Synthesis of MA-Chol and formation of a small lipid nanoparticle (SLNP). (A) Synthetic scheme for the synthesis of MA-Chol. Cholesterol was conjugated to an arginine by esterification using DMAP and DCC. After purification on a silica gel column and subsequent deprotection using TFA, pure MA-Chol was obtained. (B) Schematic illustration of a siRNA@SLNP prepared using MA-Chol:DOPE (1:1) and 2.5 mol% PEG₁₀₀₀-DSPE. (C) Representative TEM image of siRNA@SLNPs and a magnified image of a nanoparticle (inset). (D) DLS measurement of the hydrodynamic size of siRNA@SLNPs, showing a narrow size distribution.