Novel biocompatible nanohydrogels for gene delivery

Here in, we have developed novel biocompatible nanohydrogels (NHG’s) for nucleic acid packaging and delivery towards gene expression and regulation. The NHG’s are obtained from mixtures of N-isopropylacrylamide, acrylonitrile, di-block, and tri-block jeffamine macro-monomers in the presence of a cross-linker and radical initiator. The mechanism of NHG formation includes the formation of a self-assembly obtained by heating the thermo-responsive monomer’s mixture. The final size of the final NHG is dictated by the size of the intermediary self-assembly. Sizes are tuned by combining different ratios of the starting monomeric mixtures which upon heating form self-assemblies of varied sizes. Initiator is then added at high temperature and the polymerization gives place to the formation of NHG’s. The obtained NHG’s are then chemically reduced generating NHG’s with positive zeta potential. The obtained reduced NHG’s of 50, 200 and 400 nm were extensively characterized including DLS, zeta potential and AFM. The NHG’s are highly biocompatible and can complex pDNA to form polyplexes devoid of cell toxicity as assessed by XTT assays. The in-vitro results reveal that the NHG’s can deliver DNA to cells and mediate long-term gene expression. Additionally, results obtained after in-vivo administration of m-Cherry/NHGs polyplexes indicate a delayed but prolonged expression of the marker gene.