Cyclodextrin- and calixarene-based polycationic amphiphiles as gene delivery systems: a structure-activity...

Area of Science:

• Supramolecular Chemistry
• Nanotechnology
• Gene Therapy

Background:

• Monodisperse gene delivery systems utilizing cyclodextrin (CD) and calixarene (CA) scaffolds offer precise molecular control for structure-activity relationship studies.
• Designing diverse compounds is essential for evaluating DNA condensation and nanoparticle formation for gene delivery.

Purpose of the Study:

• To prepare an oriented library of β-cyclodextrin (βCD) and calix[4]arene (CA4) vectors with facial amphiphilic character.
• To ascertain the effect of cationic head groups (aminothiourea, arginine, guanidine) and macrocyclic platforms on plasmid DNA (pDNA) complexation and transfection efficiency.

Main Methods:

• Synthesis of βCD and CA4 based amphiphilic vectors with varying cationic head groups.
• Characterization of self-assembly with pDNA using Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), and Atomic Force Microscopy (AFM).
• In vitro transfection evaluation in epithelial COS-7 and human rhabdomyosarcoma RD-4 cells.

Main Results:

• All compounds self-assembled with pDNA to form spherical, monomolecular transfection nanoparticles.
• Primary amino groups in the vector were critical for high transfection efficiency, likely due to their buffering capacity.
• Optimal cationic head groups varied: aminothiourea for βCD and arginine for CA4.
• Transfection efficiency was cell-type independent within a series but the optimal platform (βCD or CA4) was cell-type dependent.

Conclusions:

• Monodisperse vector prototypes and diversity-oriented strategies are effective for identifying optimal gene delivery candidates.
• The choice of cationic head group and macrocyclic platform significantly impacts gene delivery efficiency.
• These findings advance the development of tailored vectors for gene therapy applications.