Porphyrin dyes for nonlinear optical imaging of live cells

Khadria, A., Fleischhauer, J., Boczarow, I., Wilkinson, J. D., Kohl, M. M. and Anderson, H. L. (2018) Porphyrin dyes for nonlinear optical imaging of live cells. iScience, 4, pp. 153-163. (doi: 10.1016/j.isci.2018.05.015) (PMID:30240737) (PMCID:PMC6147020)

Abstract

Second harmonic generation (SHG)-based probes are useful for nonlinear optical imaging of biological structures, such as the plasma membrane. Several amphiphilic porphyrin-based dyes with high SHG coefficients have been synthesized with different hydrophilic head groups, and their cellular targeting has been studied. The probes with cationic head groups localize better at the plasma membrane than the neutral probes with zwitterionic or non-charged ethylene glycol-based head groups. Porphyrin dyes with only dications as hydrophilic head groups localize inside HEK293T cells to give SHG, whereas tricationic dyes localize robustly at the plasma membrane of cells, including neurons, in vitro and ex vivo. The copper(II) complex of the tricationic dye with negligible fluorescence quantum yield works as an SHG-only dye. The free-base tricationic dye has been demonstrated for two-photon fluorescence and SHG-based multimodal imaging. This study demonstrates the importance of a balance between the hydrophobicity and hydrophilicity of amphiphilic dyes for effective plasma membrane localization.

• Item Type: Articles
• Additional Information: The authors thank the John Fell Fund and EP Abraham Cephalosporin Fund, University of Oxford, for partly funding the multiphoton microscope. This project was supported by the EPSRC (grants EP/H018565/1 and EP/G03706X/1 - Systems Biology Centre of Doctoral Training). A.K. acknowledges the Clarendon Scholarships, Hilla Ginwala Scholarships, Radhakrishnan Memorial Fund, and St Catherine's College Overseas Graduate Scholarships at the University of Oxford.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Kohl, Dr Michael
• Authors: Khadria, A., Fleischhauer, J., Boczarow, I., Wilkinson, J. D., Kohl, M. M., and Anderson, H. L.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Research Group: Kohl
• Journal Name: iScience
• Publisher: Elsevier (Cell Press)
• ISSN: 2589-0042
• ISSN (Online): 2589-0042
• Published Online: 26 May 2018
• Copyright Holders: Copyright © 2018 The Authors
• First Published: First published in iScience 4: 153-163
• Publisher Policy: Reproduced under a Creative Commons License