Reducing the Visibility of the Vector/DNA Nanocomplexes to the Immune System by Elastin-Like Peptides

One of the major hurdles facing nanomedicines is the antibody production against nanoparticles that subsequently results in their opsonization and clearance by macrophages. The objective of this research was to examine and identify the sequence of a low-immunogenic peptide based on recombinant elastin-like polypeptides (ELPs) that does not evoke IgG response and can potentially be used for masking the surfaces of the nanoparticles.

Biopolymers composed of a DNA condensing domain in fusion with anionic, neutral and cationic elastin-like peptides were genetically engineered. The biopolymers were used to complex with plasmid DNA and form ELP-coated nanoparticles. Then, the potential immunogenicity of nanoparticles in terms of IgM/IgG response after repeated injections was evaluated in Balb/c immunocompetent mice.

The results revealed the sequence of a non-immunogenic ELP construct that in comparison to control group did not elicit any significant IgG response, whereas the vector/DNA complexes that were coated with polyethylene glycol (PEG) did elicit significant IgG response under the same conditions.

The identification of the sequence of an ELP-based peptide that does not induce IgG response opens the door to more focused in-depth immunotoxicological studies which could ultimately lead to the production of safer and more effective drug/gene delivery systems such as liposomes, micelles, polymeric nanoparticles, viruses and antibodies.