Two-photon fluorescence probes for imaging of mitochondria and lysosomes

Abstract

Novel biocompatible cyanines show not only a very large two-photon cross-section of up to 5130 GM at 910 nm in aqueous medium for high-contrast and -brightness two-photon fluorescence live cell imaging but also highly selective subcellular localization properties including localization of mitochondria and lysosomes.

Interplay between Cellular Uptake, Intracellular Localization and the Cell Death Mechanism in Triphenylamine-Mediated Photoinduced Cell Death

“…Indeed, near infrared (NIR) and infrared (IR) wavelengths used for two-photon excitation minimize autofluorescence and maximize tissue penetration due to smaller light scattering/absorption by the tissue and endogenous biomolecules 1 . Such probes were used for several types of applications including fluorescent markers such as nucleus and organelle markers or chemical probes [2][3][4][5] . Alternatively, two-photon excitation may allow to trigger photochemical/photobiological processes, for instance in the case of (i) optogenetics for the control of protein activity 6,7 , or (ii) photodynamic therapy (PDT) for light-dependence production of reactive oxygen species (ROS) [8][9][10][11][12] .…”

Wahrnehmung der chemischen Prozesse in einzelnen Organellen mit niedermolekularen Fluoreszenzsonden

“…Die Selektivität von Sonden für den Zellkern wird durch deren konkurrenzfähige Akkumulation im Zellkern verglichen mit anderen Organellen kontrolliert. Indes deuteten viele Berichte darauf hin, dass tatsächlich sogar geringe Änderungen der Struktur auf den Zellkern zielender Reagenzien deren Selektivität vollständig aufheben konnten und somit die Situation verkomplizieren . Sowohl Experimente als auch Modelle zur quantitativen Struktur‐Wirkungs‐Beziehung (QSAR) wiesen nach, dass die Selektivität von Reagenzien zur Abbildung des Zellkerns durch die Zahl positiver Ladungen, die Länge der hydrophoben Kette, die Größe des planaren aromatischen Systems sowie die Molekülgröße und ‐form kontrolliert wird .…”

Multiphoton Excited Fluorescent Materials for Frequency Upconversion Emission and Fluorescent Probes

“…To diversify the family of two‐photon probes for lysosomes, Wong et al. have recently developed a novel V‐shaped carbazole‐based bis‐cyanine fluorophore bearing 4‐(triethylammonio)butyl targeting groups, namely VPBN which exhibited highly selective subcellular localization to lysosomes of HK‐1 cells in sharp contrast to that of the parent bis‐cyanine without targeting groups (Figure ) . In addition to low cytotoxicity, VPBN showed a very large 2PA cross‐section of up to 5130 GM at 910 nm, which is among the highest σ max reported in aqueous medium highlighting the merit of using multi‐dimensional structure motifs to enhance σ 2 .…”

“…Recently, Wong et al. developed novel biocompatible mono‐cyanines bearing 4‐(triethylammonio)butyl and 6‐(triphenylphosphonio)hexyl substituent on pyridinium ring, namely SPBN and SPHP (Figure ), respectively, which showed a large maximum 2PA cross‐section of 243 GM and 109 GM at 890 nm, respectively, in aqueous medium for high‐contrast and ‐brightness two‐photon fluorescence live cell imaging of HK‐1 cells . The fluorescence images of SPBN and SPHP are almost identical with that of Mito Tracker, indicating that both SPBN and SPHP can exclusively localize at the mitochondria.…”