Biocompatible conjugated fluorenylporphyrins for two-photon photodynamic therapy and fluorescence imaging

Abstract

Three new biocompatible porphyrin-based oxygen photosensitisers were tested in vitro on breast cancer cells via 2P-PDT: one of them, 66 times more active than H2TPP, gave quite promising results for theranostic applications.

Phthalocyanine-Cored Fluorophores with Fluorene-Containing Peripheral Two-Photon Antennae as Photosensitizers for Singlet Oxygen Generation

“…For all these compounds, the n-butyl chains at the nine positions of fluorenyl groups are clearly identified by four multiplets between 0 and 2 ppm corresponding to Ha, Hb, Hc, and Hd, and the OH proton appears as a large singlet peak at about 5 ppm (Figure 4, bottom). The various fluorene precursors (3)(4)(5)(6)(7)(8)(9), as well as the phthalonitriles Pn1-4, were conveniently characterized by 1 H-NMR (Figures S1-S13, Supplementary Materials). This spectroscopy can even be used to monitor the various reactions using diagnostic signals.…”

“…The chemistry of porphyrins and phthalocyanines involving new structural motifs and subunits, either within the central macrocycle or in its periphery, is in full development, in particular for photonic applications related to cancer therapy [1][2][3][4], such as photodynamic therapy (PDT) [2,5,6]. In this context, given the well-known oxygen photosensitizing properties of these macrocycles [7][8][9], Thus, in spite of its remarkably high fluorescence quantum yield (ΦF = 88%) [30], H2OFPc ( Figure 2) suffers from a poorly efficient energy transfer (ET) from the fluorenyl-based antennae toward the central macrocycle, possibly due to the unfavorable conformations adopted by the peripheral antennae relative to the central phthalocyanine core, these conformations being likely induced by steric strain.…”

“…Furthermore, when compared to known porphyrin analogues, the interest in replacing the porphyrin by a phthalocyanine as the central core to obtain more fluorescent two-photon oxygen photosensitizers is clearly established. As such, this contribution paves the way for the future development of innovative biphotonic photosensitizers usable in theranostics.Molecules 2020, 25, 239 2 of 30 studying new porphyrin-or phthalocyanine-based molecular assemblies that might efficiently undergo two-photon excitation [10-13] while presenting a significant luminescence, constitutes an appealing goal for researchers interested in developing new photosensitizers for theranostic applications [4,5,[14][15][16]. Along these lines, some of us [17,18] and others [19], independently reported that fluorenyl units, when appended at the meso positions of porphyrins, were particularly suited to enhance the fluorescence quantum yields of this macrocyclic core, most likely by limiting the rate of non-radiative decay via internal conversion [20].…”

Multiphoton microscopy for monitoring the occurrence, metastasis and therapy of breast cancer

“…Short‐term two‐photon laser irradiation in the near infrared had a lethal effect on cancer cells. Therefore, these compounds were promising in two‐photon photodynamic therapy and imaging 150 . Croissant et al designed a new type nanoparticles of porphyrin photosensitizer.…”

“…Therefore, these compounds were promising in two-photon photodynamic therapy and imaging. 150 Croissant et al designed a new type nanoparticles of porphyrin photosensitizer. The endocytosis and nanospheres could be clearly seen in the MCF-7 breast cancer cells in vitro based on two-photon confocal microscope.…”