CONTEXT

Two-photon (2P) excitation is a method that has revolutionized many areas of biological science as it enables three-dimensionally defined excitation of chromophores in biological tissue. It has the advantage over one-photon excitation of retaining high precision deeper within live tissues such as the brain. Further, the photonics required has been mainly developed in two-photon fluorescence microscopes for deep imaging in live tissues. Although steady progress has been made in extending the range of tools available for one photon photolysis, the design and implementation of two-photon probes that have high photolysis cross-sections combined with good biological properties has proved elusive. Although several photosensitive protecting groups have been adapted, none of them satisfies adequately the criteria needed for both application in biological conditions and efficient two-photon photolysis.

TECHNICAL DESCRIPTION

This invention describes a new class of ‘caging’ compounds having increased two-photon absorption and fragmentation ability under IR-NIR (pulsed laser) irradiation. The design is based on the 2D and/or 3D arrangement of hydroxymethylquinoline units around a donor center (amine, or, triarylamine), or a photochemically neutral unit such as fluorine resulting a major TPA enhancement (up to 60 GM at 710 nm) as was compared to their dipolar precursors (3 GM). These photoprotecting groups were developed essentially to mask carboxylic acids, carbamates and phosphates.

BENEFITS

• The developed compounds have high two-photon absorption and uncaging cross-sections and have the potential releasing ligands under both one-photon and two-photon excitation conditions, allowing up to 4 dimensional resolution with close to 1fL (femto-litre) activation volume. The photo-activation can be realized by irradiation at the near IR region by readily available fs-pulsed lasers. This fact results lower cytotoxicity in biological applications compared to more conventional UV (CW) activation. The photofragmentation is very fast enabling to use these compounds in fast biochemical and physical processes (for example: to study synaptic transmission).

• INDUSTRIAL APPLICATIONS

• This innovation could be used in 3D microfabrication, molecular cell-biology, physiology and neurosciences.

DEVELOPMENT STAGE

We are currently working on increasing the solubility of the compounds in neutral aquous solution, and also optimizing the TP uncaging cross-section of the cages.

For further information, please contact us (Ref 03306-01)