2. Academic Validation
  3. β-catenin mRNA encapsulated in SM-102 lipid nanoparticles enhances bone formation in a murine tibia fracture repair model

β-catenin mRNA encapsulated in SM-102 lipid nanoparticles enhances bone formation in a murine tibia fracture repair model

  • Bioact Mater. 2024 May 23:39:273-286. doi: 10.1016/j.bioactmat.2024.05.020.
Anna Laura Nelson 1 2,  Chiara Mancino 3,  Xueqin Gao 1,  Joshua A Choe 4,  Laura Chubb 5,  Katherine Williams 6,  Molly Czachor 1,  Ralph Marcucio 7,  Francesca Taraballi 3,  John P Cooke 8,  Johnny Huard 1 5,  Chelsea Bahney 1 5 7,  Nicole Ehrhart 2 5 6
Affiliations

Affiliations

  • 1 Steadman Philippon Research Institute (SPRI), Center for Regenerative and Personalized Medicine, Vail, CO, USA.
  • 2 Colorado State University, School of Biomedical Engineering, Fort Collins CO, USA.
  • 3 Houston Methodist Research Institute, Center for Musculoskeletal Regeneration, Houston TX, USA.
  • 4 University of Wisconsin-Madison, Department of Orthopedics and Rehabilitation, Department of Biomedical Engineering, Medical Scientist Training Program, Madison, WI, USA.
  • 5 Colorado State University, Department of Clinical Sciences, Fort Collins CO, USA.
  • 6 Colorado State University, Department of Microbiology, Immunology, and Pathology, Fort Collins, CO, USA.
  • 7 University of California, San Francisco (UCSF), Orthopaedic Trauma Institute, San Francisco, CA, USA.
  • 8 Houston Methodist Research Institute, Center for RNA Therapeutics, Department of Cardiovascular Sciences, Houston, TX, USA.
PMID: 38832305 DOI: 10.1016/j.bioactmat.2024.05.020
Abstract

Fractures continue to be a global economic burden as there are currently no osteoanabolic drugs approved to accelerate fracture healing. In this study, we aimed to develop an osteoanabolic therapy which activates the Wnt/β-catenin pathway, a molecular driver of endochondral ossification. We hypothesize that using an mRNA-based therapeutic encoding β-catenin could promote cartilage to bone transformation formation by activating the canonical Wnt signaling pathway in chondrocytes. To optimize a delivery platform built on recent advancements in liposomal technologies, two FDA-approved ionizable Phospholipids, DLin-MC3-DMA (MC3) and SM-102, were used to fabricate unique ionizable lipid nanoparticle (LNP) formulations and then tested for transfection efficacy both in vitro and in a murine tibia fracture model. Using firefly luciferase mRNA as a reporter gene to track and quantify transfection, SM-102 LNPs showed enhanced transfection efficacy in vitro and prolonged transfection, minimal fracture interference and no localized inflammatory response in vivo over MC3 LNPs. The generated β-cateninGOF mRNA encapsulated in SM-102 LNPs (SM-102-β-cateninGOF mRNA) showed bioactivity in vitro through upregulation of downstream canonical Wnt genes, axin2 and RUNX2. When testing SM-102-β-cateninGOF mRNA therapeutic in a murine tibia fracture model, histomorphometric analysis showed increased bone and decreased cartilage composition with the 45 μg concentration at 2 weeks post-fracture. μCT testing confirmed that SM-102-β-cateninGOF mRNA promoted bone formation in vivo, revealing significantly more bone volume over total volume in the 45 μg group. Thus, we generated a novel mRNA-based therapeutic encoding a β-catenin mRNA and optimized an SM-102-based LNP to maximize transfection efficacy with a localized delivery.

Keywords

Canonical Wnt; Fracture healing; Gene therapy; Lipid nanoparticles; mRNA.

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