PORPH_IMP_SHG · Porphyrin-Based Dyes for Imaging Membrane Potential via Second Harmonic Generation
FP7 — People (Marie Curie Actions)
- Duration
- 2010-05-01 → 2012-04-30
- EU contribution
- €172,741
- Participants
- 1
- Scheme
- MC-IEF
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Results in brief
Porphyrin-Based Dyes for Imaging Membrane Potential via Second Harmonic Generation
Understanding brain function is a modern frontier in science. Following communication in neuronal pairs and networks will lead to clearer interpretations of physiological experiments, better modelling of brain activity and advances towards cures for neurodegenerative disorder. Second harmonic generation (SHG) imaging is a promising technique for the imaging of the transmembrane potentials which drive neuron function. Push-pull chromophores orientated in the neuronal plasma membrane generate a high contrast signal that is sensitive to the local electric field. Furthermore, SHG is a scattering effect and it does not require the population of excited-states, so it should be possible to design SHG dyes which are free from photobleaching and photo-induced degradation. The high polarizability and intense optical transitions of porphyrins make them excellent candidates for engineering efficient SHG voltage-sensitive probes. A first generation of amphiphilic donor-acceptor meso-ethynyl porphyrins, with polar pyridinium acceptor head- groups and hydrophobic dialkyl-aniline donors has been synthesised and tested with the aim of exploring how different structural parameters such as charge on the head-group or meso-substituent affect both photophysical and biophysical properties. These compounds were first synthesised2 before the start of my fellowship, but I significantly improved their synthesis and carried out detailed experiments to explore their properties.
Data: CORDIS, © European Union
Project objective
Based on recently published work from Anderson’s group in Oxford, this proposal aims to develop a new technique for optical imaging of membrane potential in living cells using second-harmonic generation (SHG) microscopy with porphyrin-based dyes. This technology should enable the function of neurons, and other excitable cells, to be monitored in real time, with high spatial resolution, in their native networks. The objectives of this project include (1) the synthesis of new porphyrins that bind efficiently to the plasma membranes of cells, exhibit strong voltage-dependent SHG and which avoid photo-damage and phototoxicity, and (2) the demonstration that these dyes can be used to monitor membrane potential in living cells. Prof. Anderson's group in Oxford has pioneered research into porphyrin-based nonlinear optical dyes for many years, and has great expertise in this area. The Department of Chemistry in Oxford has world-class facilities for this research. Ismael López Duarte will soon complete his PhD in the field of phthalocyanine chemistry, but he has no experience in the synthesis of porphyrins, nor of the design and testing of dyes for biological applications. This Fellowship will give him the opportunity to apply his expertise in synthesis to the creation of useful new biological probes. It will provide him with experience in a new and rapidly growing area of research and enable him to broaden his horizons.
Original text from CORDIS.
Participants
- THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF OXFORD · OxfordCoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union