ND-O1 (SM-86 Analog-2) is a novel ionizable lipid designed to improve the delivery of siRNA via lipid nanoparticles (LNPs) for treating liver fibrosis. It is derived from SM-86 (structurally similar to SM-102, used in COVID-19 mRNA vaccines) but incorporates an ether bond within its hydrophobic tail, a first-of-its-kind modification aimed at enhancing delivery efficiency. In Vitro Efficiency: ND-O1 LNPs (LNP-O1) showed significantly higher siRNA transfection efficiency in activated fibroblasts compared to Lipid 5 LNPs (LNP-M). In Vivo Efficacy: In a CCl4-induced liver fibrosis mouse model, LNP-O1/siHSP47 (loaded with HSP47-targeting siRNA) reduced HSP47 expression by ~84%, threefold more effective than LNP-M. This led to a dramatic reduction in collagen deposition and marked improvement in liver fibrosis. Safety: The ether bond modification did not introduce additional toxicity, maintaining biocompatibility. ND-O1 represents a breakthrough in ionizable lipid design, demonstrating that strategic placement of ether bonds in hydrophobic tails can enhance LNP performance without compromising safety. Its success highlights its potential for clinical translation in RNA-based therapies for liver fibrosis and other hepatic diseases.
