Structurally Programmed Assembly of Translation Initiation Nanoplex for Superior mRNA Delivery

Abstract

Messenger RNA (mRNA) represents a promising class of nucleic acid-based therapeutics. While numerous nanocarriers have been developed for mRNA delivery, the inherent labile nature of mRNA results in a very low transfection efficiency and poor expression of desired protein. Here we preassemble the mRNA translation initiation structure through an inherent molecular recognition between 7-methyl guanosine (m7G) capped mRNA and eukaryotic initiation factor 4E (eIF4E) protein to form ribonucleoproteins (RNPs), thereby mimicking the first step of protein synthesis inside cells. Subsequent electrostatic stabilization of RNPs with structurally tunable cationic carriers leads to nano-sized complexes (nanoplexes), which elicit high levels of mRNA transfection in different cell types by enhancing intracellular mRNA stability and protein synthesis. By investigating a family of synthetic polypeptides bearing different side group arrangements of cationic charge, we find that the molecular structure modulates the nano-scale distance between the mRNA strand and the eIF4E protein inside the nanoplex, which directly impacts the enhancement of mRNA transfection. To demonstrate the biomedical potential of this approach, we use this approach to introduce mRNA/eIF4E nanoplexes to murine dendritic cells, resulting in increased activation of cytotoxic CD8 T cells ex vivo. More importantly, eIF4E enhances gene expression in lungs following a systemic delivery of luciferase mRNA/eIF4E in mice. Collectively, this bio-inspired molecular assembly method could lead to a new paradigm of gene delivery.

Structurally modulated codelivery of siRNA and Argonaute 2 for enhanced RNA interference

“…Therefore, keeping the same backbone while using distinct side-chain structures enables in-depth characterization of synthetic gene carrierassisted assembly and delivery of siRNA/Ago2 complexes. Moreover, these polypeptides have demonstrated superior transfection efficacy for mRNA and DNA delivery with minimal cytotoxicity in vitro and in vivo (20,(27)(28)(29).…”

Rethinking cancer nanotheranostics

“…Nanotechnology can also improve the delivery of mRNA vaccines. Antigen-encoding, in vitro transcribed modified mRNA vaccine generally has low risk of latent viral infection and potent T cell response 177–180 . Delivery of mRNA to APCs is prerequisite for optimal therapeutic efficacy but is challenged by nuclease susceptibility, inefficient intracellular delivery, and endosome mRNA trapping.…”

Aminal Protection of Epoxide Monomer Permits the Introduction of Multiple Secondary Amine Moieties at Poly(ethylene glycol)

“…Further investigations are part of an ongoing project that also targets the (co)polymerization of PyGA with EO and the optimization of the polymerization conditions to give access to higher degrees of polymerization in a well‐defined manner. Hammond et al recently demonstrated that 1,3‐diamines are superior to 1,2‐diamines for mRNA transfection, due to the complete protonation of both amino moieties at pH 7.4 . These options in combination with the established high biocompatibility of polyether structures render the monomer PyGA a highly promising building block both for functional materials and biomedical applications.…”