Formulation of Lipid-Free Polymeric Mesoscale Nanoparticles Encapsulating mRNA.

Introduction: Nanoparticle-mediated gene therapy has found substantial clinical impact, primarily focused on lipid-based nanoparticles. In comparison with lipid nanoparticles, polymeric particles may have certain advantages such as increased biocompatibility and controlled release. Our prior studies have found that polymeric mesoscale nanoparticles exhibited specific targeting to the renal proximal tubules. Thus, in this study, we sought to identify formulation parameters that allow for development of polymeric mesoscale nanoparticles encapsulating functional mRNA for delivery into tubular epithelial cells.

Methods: We evaluated particle uptake in vitro prior to exploring formulation parameters related to introduction of a primary mixture of polymer in acetonitrile and hydrophilic mRNA in water. Finally, we evaluated their functionality in a renal tubular epithelial cell line.

Results: We found that MNPs are endocytosed within 15 min and that the mesoscale nanoparticle formulation procedure was generally robust to introduction of a primary mixture and encapsulation of mRNA. These particles exhibited substantial uptake in renal cells in vitro and rapid (< 1 h) expression of a model mCherry fluorescent protein.

Conclusion: We anticipate these findings having potential in the delivery of specific gene therapies for renal disorders and cancer.