Piperazine‐Derived Bisphosphonate‐Based Ionizable Lipid Nanoparticles Enhance mRNA Delivery to the Bone Microenvironment
Il‐Chul Yoon, Lulu Xue, Qinyuan Chen, Jingyi Liu, Junchao Xu, Zain Siddiqui, Dongyoon Kim, Bingling Chen, Qiangqiang Shi, Emily L. Han, Mia Ruiz, Kyle H. Vining, Michael J. Mitchell
Abstract
Abstract Nucleic acid delivery with mRNA lipid nanoparticles are being developed for targeting a wide array of tissues and cell types. However, targeted delivery to the bone microenvironment remains a significant challenge in the field, due in part to low local blood flow and poor interactions between drug carriers and bone material. Here we report bone‐targeting ionizable lipids incorporating a piperazine backbone and bisphosphate moieties, which bind tightly with hydroxyapatite ([Ca 5 (PO 4 ) 3 OH]), a key component of mineralized tissues. These lipids demonstrate biocompatibility and low toxicity in both vitro and in vivo studies. LNP formulated with these lipids facilitated efficient cellular transfection and improved binding to hydroxyapatite in vitro, and targeted delivery to the bone microenvironment in vivo following systemic administration. Overall, our findings demonstrate the critical role of the piperazine backbone in a novel ionizable lipid, which incorporates a bisphosphonate group to enable efficient bone‐targeted delivery, highlighting the potential of rational design of ionizable lipids for next‐generation bone‐targeting delivery systems.