Targeting osteoarthritis with Nano-Ghost system entrapping RNA interference molecules

Osteoarthritis (OA) is a leading cause of joint disability worldwide, characterized by articular cartilage degradation, synovial inflammation and bone remodeling, with no disease-modifying treatments available. In recent years, RNA interference (RNAi) therapy has shown great potential, but the clinical translation is largely hindered by the lack of safe delivery systems. Recently, our lab has developed an innovative drug delivery platform, termed Nano-Ghosts (NGs), consisting of nano-vesicles reconstructed from the plasma membrane of mesenchymal stem cells (MSCs). The NGs retain MSCs’ surface features and targeting capabilities towards inflammation sites. This homing process is regulated by composition, orientation, and functions associated with MSCs’ membrane. NGs lack all the internal machinery of a cell, therefore they do not respond to external stimuli and they are not susceptible to host-induced changes. This study aimed to establish NGs as a new delivery platform for therapeutic antisense oligonucleotides for OA treatment. NGs were produced and characterized as previously published. The retention of the MSCs’ markers and the NGs capability of targeting different cells within the joint compartment (in vitro, ex vivo and in vivo) were demonstrated. Different approaches to load cargoes were studied and the characterization of the NGs after the loading was performed. Biological studies were performed to assess the delivery of oligonucleotides by NGs, and their ability to silence their targets to exert therapeutic functions. NGs showed high efficiency in delivering the loaded cargoes, and the oligonucleotides exhibited strong silencing actions. In conclusion, we developed a novel and effective NGs-based system for delivering different antisense oligonucleotides in the articular joint, demonstrating that the oligonucleotides exerted their functions of gene modulation once delivered. The results indicate that the NGs are a promising nano-carrier platform for antisense oligonucleotides therapy, not limited to OA, but for several diseases because of the high versatility of this class of therapeutics.