Design, synthesis, and evaluation of 5,15-diaryltetranaphtho [2,3]porphyrins as photosensitizers in real-time photodynamic therapy and photodiagnosis

Synthesis of Novel Meso-Tetraphenyltetrabenzoporphyrins and Evaluation of Their Photodynamic Anticancer Activities

To discover a potential anticancer photosensitizer drug, a series of meso-tetraphenyltetrabenzoporphyrins (m-Ph4TBPs) with four carboxyl groups were afforded through a multistep reaction starting from cyclohexene. These new m-Ph4TBPs demonstrated favorable antiaggregation properties and exhibited obvious absorption in the phototherapeutic window (600-800 nm). Additionally, m-Ph4TBPs 1-5 displayed notable reactive oxygen species generation ability and obvious photodamage effectiveness against Eca-109 cells. Furthermore, m-Ph4TBP 4 was able to inhibit tumor growth in mice bearing Eca-109 cells and demonstrated superior biosafety toward the kidney and liver both in vitro and in vivo. These results indicated that compound 4 could be considered a promising candidate for further studies in photodynamic therapy.

Quaternary ammonium cations conjugated 5,15-diaryltetranaphtho[2,3]porphyrins as photosensitizers for photodynamic therapy

In quest for new photosensitizers (PSs) with remarkable antitumor photodynamic efficacy, a series of fifteen quaternary ammonium (QA) cations conjugated 5,15-diaryltetranaphtho[2,3]porphyrins (Ar2TNPs) was synthesized and evaluated in vitro and in vivo to understand how variations in the length of the alkoxy group and the kind of QA cations on meso-phenyl influence the photodynamic antitumor activity. All final compounds (I1-5, II1-5, and III1-5) exhibited robust absorption at 729 nm with significant bathochromic shift and high molar extinction coefficients (1.16 × 105-1.41 × 105 M-1 cm-1), as well as other absorptions at 445, 475, 651, and 714 nm for tumors and other diseases of diverse sizes and depths. Upon exposure to 474 nm light, they displayed intense fluorescence emission with fluorescence quantum yields ranging from 0.32 to 0.43. The ability to generate reactive oxygen species (ROS) was also quantified, attaining a maximum rate of up to 0.0961 s-1. The IC50 values of all the compounds regarding phototoxicity and dark toxicity were determined using KYSE-150 cells, and the phototoxicity indices were calculated. Among these compounds, III1 demonstrated the highest phototoxic index with minimal dark toxicity, and suppressed successfully the growth of esophageal carcinoma xenograft with favorable tolerance in vivo. Furthermore, the histological results showed III1-mediated PDT had a significant cytotoxic effect on the tumor. These outcomes underscore the potential of III1 as a highly effective antitumor photosensitizer drug in photodynamic therapy (PDT).