Gene Therapy Needs Robust Synthetic Nonviral Platform Technologies

Towards Safe Nanoparticle Technologies for Nucleic Acid Therapeutics

Nucleic acid therapeutics (or gene therapy) has to date failed to deliver on promise but rapid improvements in the understanding and use of delivery technologies should reverse this situation. In this review of work performed in and in collaboration with the Imperial College Genetic Therapies Centre, progress towards safe nanoparticles for efficient delivery of functional nucleic acids in vivo is described. The intention is to demonstrate the fruits of a journey from the results of initial studies in animal models of disease that suggested that so much should be possible so quickly, to the realization that new technologies are rarely successful so quickly, through to developments in the present day that appear to be approaching the preclinical/clinical threshold with realism but measured confidence. New chemistry is central to the design and formulation of safe nanotechnologies. Chemistry should have a central role to play in ensuring that nucleic acid therapeutics truly live up to their potential for therapy and cure, none more so than in the derivation of newer and better therapies for cancers.

Nanomedicine therapeutics and diagnostics are the goal

Understanding and exploiting molecular mechanisms in biology is central to chemical biology. In 20 years, chemical biology research has advanced from simple mechanistic studies using isolated biological macromolecules to molecular-level and nanomolecular-level mechanistic studies involving whole organisms. This review documents the best of my personal and collaborative academic research work that has made use of a solid organic chemistry and chemical biology approach toward nanomedicine, in which my focus has been on the design, creation and use of synthetic, self-assembly lipid-based nanoparticle technologies for the functional delivery of active pharmaceutical ingredients to target cells in vivo. This research is now leading to precision therapeutics approaches (PTAs) for the treatment of diseases that may define the future of nanomedicine.

Efficient DNA condensation by ruthenium(ii) polypyridyl complexes containing triptycenyl functionalized 1,10-phenanthroline

A series of luminescent ruthenium(ii) polypyridyl complexes containing an extended aromatic moiety derived from triptycene and 1,10-phenanthroline were synthesized and their photophysical, theoretical, and biological properties were investigated.

Lipid-based nanoparticles in cancer diagnosis and therapy

Today, researchers are constantly developing new nanomaterials, nanodevices, and nanoparticles to meet unmet needs in the delivery of therapeutic agents and imaging agents for cancer therapy and diagnosis, respectively. Of particular interest here are lipid-based nanoparticles (LNPs) that are genuine particles (approximately 100 nm in dimension) assembled from varieties of lipid and other chemical components that act collectively to overcome biological barriers (biobarriers), in order for LNPs to preferentially accumulate in or around disease-target cells for the functional delivery of therapeutic agents for treatment or of imaging agents for diagnosis. The capabilities of these LNPs will clearly vary depending on functional requirements, but the nanoscale allows for an impressive level of diversity in capabilities to enable corresponding LNPs to address an equally diverse range of functional requirements. Accordingly, LNPs should be considered appropriate vehicles to provide an integrated, personalized approach to cancer diagnosis and therapy in future cancer disease management.

Dinuclear metal(II) complexes of polybenzimidazole ligands as carriers for DNA delivery

A metal-based nonviral carrier for DNA-transfer in gene therapy was synthesized and characterized. The strong intermolecular pi-pi contacts are common in the observed dinuclear Cu(2+) and Co(2+) complexes of polybenzimidazole ligands. The affinity assays indicated that the strong binding of the complexes to DNA is driven by both electrostatic attractions between the complexes and DNA and the intercalation of the ligands between DNA base pairs. The typical in vitro studies showed that micromolar doses of each complex tested can efficiently and rapidly condense free DNA, either in linear or circular state, from solutions into well defined and globular nanoparticles with varied sizes. Therefore, the formation and dissociation of the DNA condensates were explored in detail under different conditions, indicating that the sizes of DNA condensates can be regulated by changing both doses and incubation time for the different dinuclear complexes. Since the intermolecular pi-pi interactions in the DNA-bound complexes may be a key force to drive DNA condensation, we propose a new DNA condensation model that is essentially distinct from that proposed for the most studied multivalent cationic reagents used in DNA condensation. The cellular uptake experiments successfully performed with the DNA condensates including plasmid pGL3 control vector that strongly expresses luciferase in many types of mammalian cells, as well as cytotoxicity evaluation, demonstrated the potentiality of the dinuclear metal(II) complexes as a new nonviral gene carrier. Finally, the dinuclear Co(2+) complexes of polybenzimidazole ligands are suggested to be the most potential nonviral gene carriers that are not impacted by serum proteins.

Integrated nanoparticle-biomolecule hybrid systems: synthesis, properties, and applications

Nanomaterials, such as metal or semiconductor nanoparticles and nanorods, exhibit similar dimensions to those of biomolecules, such as proteins (enzymes, antigens, antibodies) or DNA. The integration of nanoparticles, which exhibit unique electronic, photonic, and catalytic properties, with biomaterials, which display unique recognition, catalytic, and inhibition properties, yields novel hybrid nanobiomaterials of synergetic properties and functions. This review describes recent advances in the synthesis of biomolecule-nanoparticle/nanorod hybrid systems and the application of such assemblies in the generation of 2D and 3D ordered structures in solutions and on surfaces. Particular emphasis is directed to the use of biomolecule-nanoparticle (metallic or semiconductive) assemblies for bioanalytical applications and for the fabrication of bioelectronic devices.