In Vitro Evaluation of a Nanoparticle-Based mRNA Delivery System for Cells in the Joint

Biodegradable and bioresponsive polymer-based nanoparticles (NPs) can be used for oligonucleotide delivery, making them a promising candidate for mRNA-based therapeutics. In this study, we evaluated and optimized the efficiency of a cationic, hyperbranched poly(amidoamine)s-based nanoparticle system to deliver tdTomato mRNA to primary human bone marrow stromal cells (hBMSC), human synovial derived stem cells (hSDSC), bovine chondrocytes (bCH), and rat tendon derived stem/progenitor cells (rTDSPC). Transfection efficiencies varied among the cell types tested (bCH 28.4% +/- 22.87, rTDSPC 18.13% +/- 12.07, hBMSC 18.23% +/- 14.80, hSDSC 26.63% +/- 8.81) and while an increase of NPs with a constant amount of mRNA generally improved the transfection efficiency, an increase of the mRNA loading ratio (2:50, 4:50, or 6:50 w/w mRNA:NPs) had no impact. However, metabolic activity of bCHs and rTDSPCs was significantly reduced when using higher amounts of NPs, indicating a dose-dependent cytotoxic response. Finally, we demonstrate the feasibility of transfecting extracellular matrix-rich 3D cell culture constructs using the nanoparticle system, making it a promising transfection strategy for musculoskeletal tissues that exhibit a complex, dense extracellular matrix.

Automated summary

Biodegradable and bioresponsive polymer-based nanoparticles show promise for oligonucleotide delivery in mRNA-based therapeutics. The efficiency of a cationic, hyperbranched poly(amidoamine)s-based nanoparticle system in delivering tdTomato mRNA to different cell types was evaluated, with varying transfection efficiencies observed. Increasing the amount of nanoparticles generally improved transfection efficiency, but higher doses showed dose-dependent cytotoxicity in certain cell types. Transfection of extracellular matrix-rich 3D cell culture constructs using the nanoparticle system was demonstrated, suggesting a potential strategy for transfecting musculoskeletal tissues with complex extracellular matrices.