Characterization of Ionizable Amphiphilic Janus Dendrimer Nanoparticles for Nucleic Acid Delivery

Amphiphilic Janus dendrimers (JDs) are constructed from hydrophobic and hydrophilic dendrons, providing a synthetic alternative to lipids in genetic nanomedicines. Recently, ionizable amphiphilic Janus dendrimers (IAJDs) have emerged as a one-component delivery system for mRNA, offering an attractive alternative to four-component lipid nanoparticles (LNPs), which are the leading nonviral vectors for mRNA delivery used by both Pfizer and Moderna in their COVID-19 vaccines. IAJDs assemble into vesicles using a simple production method by injection and have great synthetic capacity. In particular, IAJDs 97 and 97-D have been demonstrated to co-assemble with mRNA to form dendrimersome nanoparticles (DNPs) and successfully deliver luciferase mRNA in in vivo models. Here, we investigated the influence of buffer conditions on DNP formation in the presence and absence of polyadenylated (PolyA) mRNA. This work suggests that IAJD structure and pH influences DNP diameter, polydispersity, and zeta potential, which may have downstream effects on in vivo nucleic acid delivery. Future applications of IAJDs are being investigated, specifically in the stability and efficiency of small interfering RNA (siRNA) delivery. We are currently establishing a model system for monitoring siRNA delivery using cells that express green fluorescent protein (GFP). Future work will demonstrate whether DNPs encapsulating siRNA can knockdown GFP expression.