Synergistic effects between natural histone mixtures and polyethylenimine in non-viral gene delivery in vitro

Antibody-targeted chromatin enables effective intracellular delivery and functionality of CRISPR/Cas9 expression plasmids

We report a novel system for efficient and specific targeted delivery of large nucleic acids to and into cells. Plasmid DNA and core histones were assembled to chromatin by salt gradient dialysis and subsequently connected to bispecific antibody derivatives (bsAbs) via a nucleic acid binding peptide bridge. The resulting reconstituted vehicles termed ‘plasmid-chromatin’ deliver packaged nucleic acids to and into cells expressing antigens that are recognized by the bsAb, enabling intracellular functionality without detectable cytotoxicity. High efficiency of intracellular nucleic acid delivery is revealed by intracellular expression of plasmid encoded genes in most (∼90%) target cells to which the vehicles were applied under normal growth/medium conditions in nanomolar concentrations. Specific targeting, uptake and transgene expression depends on antibody-mediated cell surface binding: plasmid chromatin of identical composition but with non-targeting bsAbs or without bsAbs is ineffective. Examples that demonstrate applicability, specificity and efficacy of antibody-targeted plasmid chromatin include reporter gene constructs as well as plasmids that enable CRISPR/Cas9 mediated genome editing of target cells.

A comprehensive review on histone-mediated transfection for gene therapy

Histone has been considered to be an effective carrier in non-viral gene delivery due to its unique properties such as efficient DNA binding ability, direct translocation to cytoplasm and favorable nuclear localization ability. Meanwhile, the rapid development of genetic engineering techniques could facilitate the construction of multifunctional fusion proteins based on histone molecules to further improve the transfection efficiency. Remarkably, histone has been demonstrated to achieve gene transfection in a synergistic manner with cationic polymers, affording to a significant improvement of transfection efficiency. In the review, we highlighted the recent developments and future trends in gene delivery mediated by histones or histone-based fusion proteins/peptides. This review also discussed the mechanism of histone-mediated gene transfection and provided an outlook for future therapeutic opportunities in the viewpoint of transfection efficacy and biosafety.

Genipin-Cross-Linked Thermophilic Histone-Polyethylenimine as a Hybrid Gene Carrier

A hybrid gene carrier, HGP, has been successfully constructed through the genipin-mediated cross-linking of thermophilic histone and PEI25K. The thermophilic histone gene GK2215 was cloned from Geobacillus kastophilus HTA426 and overexpressed in Escherichia coli BL21. The thermophilic histone was systematically characterized and then cross-linked with PEI25K by genipin to obtain HGP. Notably, HGP exhibited superior transfection efficiency due to the synergistic effects between these two components: PEI25K mainly contributed to the condensation and transfer of pDNA, while thermophilic histone could enhance the endosomal escape and further nuclear location to achieve high gene expression. Meanwhile, HGP showed much lower cytotoxicity and hemolytic activity than PEI25K due to the introduction of nontoxic thermophilic histone. In addition, a strong intrinsic red fluorescence could be obviously observed in HGP. In conclusion, the protein-polymer hybrid carrier could potentially be used as a theranostic delivery system for achieving both efficient gene therapy and in vivo imaging.

A protein–polymer hybrid gene carrier based on thermophilic histone and polyethylenimine

Protein–polymer hybrid gene carrier with high transfection efficiency and low cytotoxicity.

The dendrimer impact on vesicles can be tuned based on the bilayer charge and the presence of albumin

PAMAM (polyamidoamine) dendrimers are promising in biomedical applications that can interact with both the bilayer and . Here we employed giant unilamellar vesicles (GUVs) of two different charge densities to study the effect of albumin, one of the major in blood plasma, on the interactions between PAMAM dendrimers and membranes. The results show that albumin exacerbates the effect of dendrimers on the destabilization of the vesicles in terms of leakage, aggregation and collapse in particular for negatively charged vesicles while neutrally charged membranes are not affected. We conclude that the higher affinity of both albumin and PAMAM G6 towards negatively charged membranes explains their synergistic behavior in this case. In the case of neutral vesicles, the affinity between PAMAM G6 and albumin is stronger than that between PAMAM G6 (or albumin) and neutral vesicles, and thus no synergism is observed for the mixture during the interaction with neutral membranes.