Laser-induced fluorescence studies of the biodistribution of carotenoporphyrins in mice

Abstract

Summary The biodistribution of two recently developed tumour markers, trimethylated (CP(Me)3) and trimethoxylated (CP(OMe)3) carotenoporphyrin, was investigated by means of laser-induced fluorescence (LIF) after i.v. injection into 38 tumour-bearing (MS-2 fibrosarcoma) female Balb/c mice. At 3, 24, 48 or 96 h after administration, the carotenoporphyrin fluorescence was measured in tumoral and peritumoral tissue, as well as in the abdominal, thoracic and cranial cavities. The fluorescence was induced by a nitrogen laser-pumped dye laser, emitting light at 425 nm, and analysed by a polychromator equipped with an image-intensified CCD camera. The fluorescence was evaluated at 490, 655 and 720 nm: the second and third wavelengths represent the carotenoporphyrin (CP)-related peaks, whereas the first one is close to the peak of the tissue autofluorescence. The tumour and the liver were the two tissue types showing the strongest carotenoporphyrin-related fluorescence, whereas the cerebral cortex and muscle consistently exhibited weak substance-related fluorescence. In most tissue types, the fluorescence intensities decreased over time. A few exceptions were observed, notably the liver, in which the intensity remained remarkably constant over the time period investigated.

Chronic hypoxia as a factor of enhanced autofluorescence of endogenous porphyrins in soft biological tissues

“…After that, it was estimated that not only a number of cancerous tissues have an enhanced and specific "red" AF, but also different tissues with different inflammatory and purulent processes have frequently an enhanced "red" AF as well [5]. During 1996-2006 a lot of research groups all over the World using the modern laser noninvasive spectroscopic equipment have demonstrated a potential of in vivo noninvasive AFD to detect different diseases, precancerous and cancerous changes in tissues [1][2][3][4][5][6][7][8]. However, up to now in many clinical cases the biological and/or biophysical reasons to differ between normal and abnormal (diseased) tissues by means of analysis of their AF spectra, especially of porphyrin's AF spectra, are not well understood yet [1].…”

Strong Inhibition of Singlet Oxygen Sensitization in Pyridylferrocene−Fluorinated Zinc Porphyrin Supramolecular Complexes

“…It is also important to find a way to inhibit generation of singlet oxygen whenever it is desired after PDT, since the exposure to light needs to be prohibited for a long time. Carotenoid pigments are known to quench the chlorophyll singlet excited state both in vivo and in vitro, preventing the chlorophyll- and porphyrin-sensitized formation of singlet oxygen by intercepting the triplet states via photoinduced electron transfer. − In this context, carotenoid−porphyrin linked systems have been extensively studied to limit damage in tumor imaging applications related to PDT. , However, there has so far been no report on a supramolecular porphyrin system which inhibits the generation of singlet oxygen in sensitization of porphyrins.…”

Advances in fluorescence diagnosis to track footprints of cancer progression in vivo

“…Early studies using laser‐induced fluorescence spectroscopy (LIFS) were conducted by Svanberg and coworkers to characterize the localization and retention of different photosensitizers (hematoporphyrin derivative (HPD) , hematoporphyrin (Hp) , polyhematoporphyrin ester (PHE) , tetrasulphonated Pc (TSPc) , BPD‐monoacid (BPD‐MA) , carotenoporphyrins (CPs) , and meso‐tetra(hydroxyphenyl)chlorin (mTHPC) ) in rat tissue during the intravenous uptake and clearing of the photosensitizers. In LIFS, a low‐power laser is directed towards biological agents, inducing fluorescence emission at wavelengths characteristic of the chemical composition of the agent , which in turn can be used for tissue characterization and cancer detection.…”