Hydrazone-Functionalized trans-A2B-Corroles: Effective Synergy in Photodynamic Therapy of Lung Cancer.

A synthetic route to trans-A2B-corroles combining the macrocyclic core with a hydrazone moiety, based on the reactivity of azoalkenes toward dipyrromethanes, has been established with the aim of developing a new class of photosensitizers for photodynamic therapy of lung cancer. The study of the photophysical properties of the novel macrocycles allowed the identification of photosensitizers with absorption within the phototherapeutic window and high singlet oxygen quantum yield. Relevant structure-photodynamic activity correlations were established by studying the new corroles-based photodynamic therapy (PDT) in human lung cancer cell lines (A549 and H1299). The methyl-hydrazone corroles were more active than phenyl-hydrazone corroles, with the N-Boc and N-Ts groups being key structural features to ensure high activity. The lead photosensitizers, with IC50 values below 100 nM and no cytotoxicity per se, were significantly more active than 5,10,15-triphenylcorrole, showing that the presence of the hydrazone functional group has a strong influence on PDT activity.

Novel fluorinated ring-fused chlorins as promising PDT agents against melanoma and esophagus cancer.

Investigation of novel 4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine-fused chlorins, derived from 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin, as PDT agents against melanoma and esophagus cancer is disclosed. Diol and diester fluorinated ring-fused chlorins, including derivatives with 2-(2-hydroxyethoxy)ethanamino groups at the phenyl rings, were obtained via a two-step methodology, combining SNAr and [8π + 2π] cycloaddition reactions. The short-chain PEG groups at the para-position of the phenyl rings together with the diol moiety at the fused pyrazole ring promote a red-shift of the Soret band, a decrease of the fluorescence quantum yield and an increase of the singlet oxygen formation quantum yield, improving the photophysical characteristics required to act as a photosensitizer. Introduction of these hydrophilic groups also improves the incorporation of the sensitizers by the cells reaching cellular uptake values of nearly 50% of the initial dose. The rational design led to a photosensitizer with impressive IC50 values, 13 and 27 nM against human melanoma and esophageal carcinoma cell lines, respectively.

Conjugated Photosensitizers for Imaging and PDT in Cancer Research.

Early cancer detection and perfect understanding of the disease are imperative toward efficient treatments. It is straightforward that, for choosing a specific cancer treatment methodology, diagnostic agents undertake a critical role. Imaging is an extremely intriguing tool since it assumes a follow up to treatments to survey the accomplishment of the treatment and to recognize any conceivable repeating injuries. It also permits analysis of the disease, as well as to pursue treatment and monitor the possible changes that happen on the tumor. Likewise, it allows screening the adequacy of treatment and visualizing the state of the tumor. Additionally, when the treatment is finished, observing the patient is imperative to evaluate the treatment methodology and adjust the treatment if necessary. The goal of this review is to present an overview of conjugated photosensitizers for imaging and therapy.