The Effect of a Peptide Targeting Ligand on Transfection Efficiency of Polymeric Nanoparticles to Dendritic Cells

Autoimmune diseases affect approximately 5-8% of the global population, leading to chronic symptoms, long-term treatment, and reduced quality of life. Current therapies primarily rely on lifelong administration of immunosuppressants, which are associated with severe side effects and heightened susceptibility to infections. This has spurred interest in cellular therapies that manipulate dendritic cells (DCs) effectively and can selectively treat these diseases. This work aims to improve the efficacy of dendritic cell-based therapies using cationic polymers that can electrostatically complex with nucleic acids, forming nanoparticles referred to as polyplexes, that can deliver therapeutic nucleic acid cargo. These particles are a favorable alternative to traditional nucleic acid delivery vectors as they are cheaper, have greater tunability, and can be modified using simple techniques to incorporate cell targeting moieties. A chain-transfer agent (CTA) was functionalized with a peptide sequence that has established specificity for targeting DCs and was utilized for the photoiniferter polymerization of N-(2-(dimethylamino)ethyl) acrylamide (DMAEAm) to generate homopolymers that are cationic at physiological pH. The synthesized polymers were characterized via 1H nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). Polymers were then complexed with mRNA at varying amine to phosphate (N/P) ratios before characterizing their hydrodynamic diameter via dynamic light scattering (DLS). Formulated complexes were then evaluated for their cytotoxicity and transfection efficiency in relevant in vitro models.