DNA Condensation Processes Mediated by Metal-Based Drug Entities and Morphological Studies

The term ‘condensation’ is used to depict aggregates of a finite size with orderly morphology that are provoked by chemical agents, multivalent cations. Agents that cause ‘condensation’ of DNA in vitro include many compounds such as spermine 4+ inorganic cations and polycations spermidine3+, lipids, polymer, and nanoparticles. However, Baldwin and Wisdom reported first inorganic cation [Co(NH3)6] complex that was used in the condensation of DNA was reported by which was found to be advantageous over other DNA condensing agents. This prompted researchers in twenty-first century to study metal complexes to ‘compact DNA’ in a more detailed manner and for non-viral gene delivery applications. DNA condensation adducts adopt different toroidal and non-toroidal rod-like morphologies. The morphologies and sizes of DNA condensates were found to depend on the polycation-induced DNA condensates and type of metal complexes. Among the various mechanistic pathways of DNA condensation, the most dominant and prerequisite mechanism of DNA condensation is the electrostatic interaction between positively charged metal complexes and negatively charged DNA molecules, as DNA condensation cannot proceed unless DNA phosphate charge is neutralized; therefore, it provides a sound rational to utilize metal complexes as efficient condensing agents. We present a detailed comprehensive chapter on metal-based drug candidates that can undergo morphological changes in the presence of DNA, due to the compaction process initiated by DNA condensation.