Antisense Oligonucleotide Embedded Context Responsive Nanoparticles Derived from Synthetic Ionizable Lipids for lncRNA Targeted Therapy of Breast Cancer

The long noncoding RNAs (lncRNA) are primarily associated with several essential gene regulations but are also connected to cancer metabolism and progression. HOTAIR and MALAT1 are two such lncRNAs that are detected in malignancies of various origins and are responsible for the poor prognosis of cancer patients. Due to these factors, the lncRNAs have emerged as prime targets for the development of anticancer therapeutics. However, nonviral delivery of lncRNA-targeted antisense oligonucleotides (ASOs) still remains a critical challenge while maintaining their structural and functional integrity. Herein, we have designed and synthesized a new series of ionizable lipids with variations in their head groups to prepare lipid nanoparticle (LNP) formulation along with cholesterol-based twin cationic lipid and amphiphilic zwitterionic lipid. The context responsiveness of these formulations in delivering the ASOs has been thoroughly investigated by various bioanalytical techniques, and an optimum formulation has been identified. The LNPs are utilized to deliver the ASOs targeting HOTAIR lncRNA in human cancer cell lines and MALAT1 lncRNA in mouse models. This study thus standardizes an advanced nanomaterial system for nonviral gene delivery that has been validated by a considerable reduction in the target lncRNA level under <i>in vitro</i> and a significant reduction in tumor volume under <i>in vivo</i> settings.