Nucleic acids complexation with cationic elastin-like polypeptides: Stoichiometry and stability of nano-assemblies

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Gene Delivery

Background:

• Elastin-like polypeptides (ELPs) are versatile biopolymers with tunable properties.
• Developing efficient and safe methods for genetic material compaction is crucial for gene therapy and biotechnology.
• Post-modification of ELPs allows for the introduction of specific functionalities for enhanced complexation.

Purpose of the Study:

• To synthesize and characterize positively charged ELP derivatives for genetic material compaction.
• To investigate the electrostatic complexation between ELP derivatives and plasmid DNA.
• To determine the stability and properties of the resulting ELP-DNA nanoparticles.

Main Methods:

• Recombinant ELP synthesis and post-modification to introduce amine groups.
• Characterization using SDS-PAGE, size exclusion chromatography, 1H NMR, potentiometric titrations, and dynamic light scattering.
• Electrostatic complexation studies with plasmid DNA, including stability assessments under physiological salt and surfactant conditions.

Main Results:

• Successfully synthesized and functionalized positively charged ELPs with primary and secondary amine groups.
• Identified optimal conditions for ELP-DNA complex formation, yielding stable nanoparticles.
• Demonstrated that ELP-DNA complexes are stable up to charge ratios of 2.5 under physiological salt concentrations, protecting DNA from dissociation.

Conclusions:

• Positively charged ELPs are effective polycations for condensing plasmid DNA.
• The resulting ELP-DNA nanoparticles exhibit stability under physiological conditions, indicating potential for gene delivery applications.
• The study provides a foundation for designing advanced ELP-based nanocarriers for genetic material delivery.