Photophysical properties and intracellular imaging of water-soluble porphyrin dimers for two-photon excited photodynamic therapy

Abstract

14.09.12 KB. Accepted version, ok to add to spiral, embargo period elapsed

A Molecular Rotor that Measures Dynamic Changes of Lipid Bilayer Viscosity Caused by Oxidative Stress

“…The first set of GUVs studied contained PD, a known singlet oxygen photosensitizer45, 46 that is bound to the lipid bilayer surface39 and BODIPY‐C 10 , which probes viscosity of the inner part of the lipid bilayer 40. Previously, we have utilized PD as both the photosensitizer and as a molecular rotor and recorded a large increase in the DOPC monolayer viscosity upon PDT 39.…”

Dual mode quantitative imaging of microscopic viscosity using a conjugated porphyrin dimer

“…27 Here we tested the molecular rotor properties of 1, a dimer analogous to 2, with excellent biocompatibility properties. 28 The absorption and fluorescence spectra of 1 along with the proposed energy levels diagram are shown in Figure 1b,c. The excitation into higher energy absorption bands (depicted by green dots in either Q or Soret bands) results in the excitation of a twisted conformer, 29 which can either emit light (640 nm, green dot on the insert) or interconvert into a planar form, which emits at 700 nm (red dot on the insert).…”

“…Given that porphyrin dimers such as 1 have an extremely large two photon absorption cross section, up to 2 x 10 5 GM, 28 we performed the ratiometric and lifetime calibration of 1 following two photon excitation, varied between 850 and 950 nm (SI, Figure S3). However, due to poor absorption of two photon light by the twisted conformer 31 because of a loss of conjugation and symmetry, the dynamic range observed in both imaging modalities was significantly reduced compared to the one photon excitation and cannot be considered useful for imaging.…”

Imaging intracellular viscosity of a single cell during photoinduced cell death

“…Recently, the remarkable non-linear optical properties of 1, together with its high intracellular uptake, photostability and favorable photophysical properties, have been exploited to create an efficient photosensitizer for one-photon and two-photon excited photodynamic therapy (PDT) of cancer. [17][18][19][20] In PDT, cell death and tissue eradication is achieved upon irradiation of the photosensitizer and the subsequent production of cytotoxic species, in particular 4 singlet molecular oxygen, O 2 (a 1 Δ g ), Fig. 1b.…”