Fluorescence Anisotropy Imaging Reveals Localization of meso-Tetrahydroxyphenyl Chlorin in the Nuclear Envelope

  title={Fluorescence Anisotropy Imaging Reveals Localization of meso-Tetrahydroxyphenyl Chlorin in the Nuclear Envelope},
  author={Thomas H.C. Foster and Benjamin D Pearson and Soumya Mitra and Chad E. Bigelow},
  booktitle={Photochemistry and photobiology},
Abstract We have measured the intrinsic fluorescence anisotropies of six photosensitizers in homogeneous solution, and we have imaged the anisotropies of these sensitizers in tumor cell monolayers using polarization-sensitive laser-scanning confocal microscopy. The intrinsic anisotropies are unremarkable and are within the approximate range of 0.2–0.27. In cells, however, very interesting behavior is exhibited by meso-tetrahydroxyphenyl chlorin (mTHPC). Polarization-sensitive images of mTHPC's… 

Influence of Incubation Time and Sensitizer Localization on Meta-tetra(hydroxyphenyl)chlorin (mTHPC)-Induced Photoinactivation of Cells

The present study addresses the impact of different aggregation states of meta-tetra(hydroxyphenyl)chlorin (mTHPC) on the photoinactivation of cells by measuring the photophysical properties of mTHPC in MCF-7 cells and the efficiency of photodynamic therapy and Sensitizer Localization.

Photodynamic Therapy: Porphyrins and Phthalocyanines as Photosensitizers

The present work is focussed on the principles of photodynamic therapy (PDT), emphasizing the photochemical mechanisms of reactive oxygen species formation and the consequent biochemical processes

Imaging Molecular Order in Cell Membranes by Polarization-Resolved Fluorescence Microscopy

This work shows that polarization-resolved fluorescence microscopy allows retrieving a wealth of information on the constraints that hinder rotational mobility of lipid probes and proteins in membranes, bringing thus new insights on inter-proteins and lipid-protein interactions, on membrane morphology at the sub-diffraction length scale and on local membrane physical properties such as viscosity.

Measurement of drug-target engagement in live cells by two-photon fluorescence anisotropy imaging

This work describes an optimized protocol for simultaneous dual-channel two-photon fluorescence anisotropy microscopy acquisition to perform drug-target measurements and provides the necessary software to implement stream processing to visualize images and to calculate quantitative parameters.

Confocal fluorescence polarization microscopy in turbid media: effects of scattering-induced depolarization.

  • C. BigelowT. Foster
  • Physics
    Journal of the Optical Society of America. A, Optics, image science, and vision
  • 2006
From this detailed analysis and comparison of experiment with simulation, it is determined that fluorescence polarization is maintained to depths at which meaningful intensity images can be acquired.

Polarization-resolved nonlinear microscopy: application to structural molecular and biological imaging

In this tutorial I analyze the polarization-dependent properties of different optical contrasts widely used today in imaging, applied to biology and biomedical diagnostics. I derive the essential

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Fluorescence lifetime imaging is a key fluorescence microscopy technique to map the environment and interaction of fluorescent probes, and FLIM can also be used to image viscosity, temperature, pH, refractive index and ion and oxygen concentrations.

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There is a need for treatment monitoring and feedback in order to ascertain delivery of a prescribed light dose to the entire target tissue, and it was concluded that the realtime dosimetry module makes it possible to deliver a certain light dose despite spatial and temporal variations of the optical properties of the target tissue.



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The results suggest that Pc 4 binds preferentially and strongly to mitochondria and Golgi complexes.


NHIK 3025 cells were incubated with Photofrin II and/or tetra (3‐hydroxyphenyl)porphyrin and exposed to light at either 400 or 420 nm and the kinetics of the photodegradation of the dyes were studied.

Fluorescence polarization microscopy.

Endoplasmic reticulum and Golgi apparatus are the preferential sites of Foscan® localisation in cultured tumour cells

This is the first study to demonstrate unambiguously that the endoplasmic reticulum and Golgi apparatus are preferential sites of Foscan® accumulation in the MCF-7 cell line.

Direct Near-infrared Luminescence Detection of Singlet Oxygen Generated by Photodynamic Therapy in Cells In Vitro and Tissues In Vivo¶

It is believed that these are the first direct observations of PDT-generated intracellular and in vivo 1O2, using a new NIR-sensitive photomultiplier tube and the detector technology provides a new tool for PDT research and possibly clinical use.

Fluorescence resonance energy transfer reveals a binding site of a photosensitizer for photodynamic therapy.

Evidence for fluorescence resonance energy transfer from NAO to Pc 4 is shown, defining a binding site for the photosensitizer, establishing an innovative tool for exploring the localization of other photosensiters and additional fluorescent, mitochondrion-localizing drugs having appropriate spectral properties.

Imaging enzyme activity with polarization‐sensitive confocal fluorescence microscopy

Wide applicability of the technique for imaging enzyme activity through steady‐state fluorescence anisotropy measurements on a per‐pixel basis with a confocal microscope is suggested when used in conjunction with appropriately designed constructs.

Correlation between subcellular localization and photodynamic efficacy

This review classifies a group of photosensitizers according to their initial affinity for specific sub-cellular organelles in vitro, and describes the consequences of each major localization site with regard to direct tumor cell kill.

Secondary Reactive Oxygen Species Extend the Range of Photosensitization Effects in Cells: DNA Damage Produced Via Initial Membrane Photosensitization¶,†

Results show that primary photosensitization reactions involving O2(Δg), even when tightly confined in extranuclear locations, leads to the production of secondary reactive oxygen species, probably as a result of lipid peroxidation, that can act at greater distances from the photosensitizer itself.