Abstract:
Thesis Abstract:
Title: Development of biomimetic photo-responsive artificial carriers for the transmembrane
chloride transport
The transport of ions across the cell membrane through naturally occurring ion carriers and ion
channels is crucial for multiple physiological functions. In particular, the transport of chloride
ions is known to induce chloride-mediated apoptosis inside the cancer cells. Traditional
transporters lack ion selectivity and hence can damage the normal healthy tissues. Stimuli such
as voltage, pH, enzymes, ligands, light, etc., have been employed for activating ion transporters
inside the cancer cells. Light-responsive ion transport systems, in particular, are important
systems because of their spatiotemporal control, remote addressability, and less cytotoxicity.
Herein, we developed several light-responsive synthetic ion carriers, which were
manifestly controlled utilizing the external electromagnetic radiations. Initially, the most
widely used azobenzene photoswitch was used to generate the light-responsive ion transport
systems, and efficient “OFF-ON” photoreguatory ion transport activity was achieved.
Acylhydrazone-based photoswitches were employed to enhance the exciting state thermal
stability. The reversibly-gated ion transport activity was achieved utilizing light and catalytic
acid, respectively, as the external stimuli. Phenylhydrazone-based photoswitches were utilized
to enhance the excitation wavelength. These photoswitches function comparatively at higher
wavelengths compared to that of acylhydrazone switches. Eventually, we demonstrated an onitrobenzyl-based photocaged ion transport system could be selectively activated inside the
cancer cells to induce chloride-mediated apoptosis utilizing the external electromagnetic
radiations.
