DSciLab Co., Ltd.

Wilson disease (WD), a copper metabolism disorder caused by ATP7B mutations, requires alternative gene therapies due to the limitations of current treatments such as drug resistance and side effects. Here, we developed a hepatocyte-targeted ATP7B mRNA therapeutic system using a low immunoreactivity lipid nanoparticle (LNP), in which hydroxy-terminated polyethylene glycol lipid (OH-PEG) was utilized to evade human pre-existing anti-PEG antibody recognition and reduce immunogenicity compared with methoxy-terminated polyethylene glycol lipid (MeO-PEG). By optimizing the OH-PEG molar ratio at 3 %, LNP-mediated mRNA expression in hepatocytes increased twofold, while non-target cell expression (Kupffer cells, B cells) decreased by 2 to 6 folds. In vitro studies confirmed ATP7B protein localization to the trans-Golgi network and copper transport functionality. In WD model mice, long-term intervention (6 months) induced reductions in hepatic copper accumulation (up to 72.1 %) in a dose-dependent manner, restored multi-organ copper homeostasis, and normalized ceruloplasmin activity. Safety assessments revealed improved serum biochemical parameters and histopathology, with 95 % of ionizable lipid metabolically cleared within one week after treatment, without allergic reactions or organ toxicity. This study establishes a translatable WD gene therapy platform using a hepatocyte-targeted, low immunoreactivity LNP for full-length ATP7B mRNA delivery, which also serves as an mRNA delivery system for other liver diseases.

Venous thromboembolism significantly contributes to the global disease burden. Anticoagulant and antiplatelet therapies are currently the treatment strategies. However, challenges remain due to hemorrhagic complications and the inability to resolve established thrombi. There is an urgent need for a new generation of antithrombotic agents. Given the fibrin specificity and rapid thrombus dissolution capacity of recombinant tissue plasminogen activator (TPA) protein, along with the significant advantages of mRNA therapeutics in protein replacement, we aim to develop an antithrombotic strategy through the targeted delivery of TPA mRNA to vascular endothelial cells using synthetic lipid nanoparticles (LNPs). A series of amino ionizable lipids were synthesized to create an LNP library, from which the LNP selectively targeting vascular endothelial cells (vtLNP) was selected by a DNA barcode labeling high-throughput screening method. The antithrombotic efficacy and safety of vtLNP loaded with TPA mRNA (vtLNP@TPA) were evaluated in a deep vein thrombosis (DVT) mouse model and normal ICR mice, respectively. The results revealed that vtLNP@TPA significantly prevented the occurrence and development of venous thrombosis. This study provides relevant experimental evidence for a novel antithrombotic therapy strategy for venous thrombosis using mRNA therapeutics.