Polycationic beta-cyclodextrin "click clusters": monodisperse and versatile scaffolds for nucleic acid delivery

Area of Science:

• Polymer Chemistry
• Biomaterials Science
• Gene Delivery Systems

Background:

• Developing efficient and safe non-viral vectors for therapeutic plasmid DNA (pDNA) delivery is crucial for gene therapy.
• Beta-cyclodextrin-based scaffolds offer biocompatibility and multivalency, making them attractive for drug delivery applications.

Purpose of the Study:

• To synthesize and characterize novel multivalent polycationic beta-cyclodextrin

Main Methods:

• Synthesis of beta-cyclodextrin click clusters via copper-catalyzed 1,3-dipolar cycloaddition.
• Characterization using gel electrophoresis, dynamic light scattering, and transmission electron microscopy.
• In vitro evaluation of pDNA complexation, nuclease protection, cellular uptake, gene expression, and cytotoxicity.

Main Results:

• Synthesized click clusters effectively complexed and compacted pDNA into nanoparticles (80-130 nm).
• Polycations protected pDNA from nuclease degradation, with significant protection observed for up to 48 hours in serum.
• Compounds 9d and 9e demonstrated high cellular uptake and gene delivery efficiency in HeLa and H9c2 cells, comparable to commercial transfection agents.
• Gene expression levels correlated positively with the number of oligoethyleneamine units in the cluster arms.
• All synthesized click clusters exhibited low cytotoxicity, in contrast to the high toxicity of commercial controls (Jet-PEI and Superfect).

Conclusions:

• Novel beta-cyclodextrin-based click clusters are effective and non-toxic pDNA carriers.
• Compounds 9d and 9e represent promising candidates for further development in gene therapy.
• The design strategy allows for tunable properties, paving the way for optimized systemic delivery vehicles.