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Assessment of the Antineoplastic Effect of Photosensitizing Bis-Cyanines in Different Tumor Cell Culture Models


Photodynamic therapy has been under analysis as a promising alternative to conventional therapeutic interventions in combating neoplasms. Utilizing a minimally invasive approach, the methodology employs light and photosensitizing molecules to induce damage in neoplastic cells. The present study undertakes a comparison of the efficacy of applying photosensitizing molecules derived from cyanines in relation to the compound Photogem when employed in cell culture models with varying levels of complexity, both 2D and 3D.


To assess the cytotoxicity of photosensitizing molecules derived from cyanine dyes (BCDs), used as photosensitizing agents in vitro photodynamic therapy, across different levels of cellular organization. In this context, the aim is to compare the effectiveness of the photoactive BCD compounds with that of Photogem®, currently approved by ANVISA for photodynamic therapy application.


Tumor cell lines of melanoma A375, head and neck VU147T and VU120T, squamous cell carcinoma HCB54, and healthy HACAT were used. Viability in the two-dimensional (2D) culture model was determined by MTS after 72 hours of exposure to photosensitizing agents and subsequent low-power LED irradiation. The protein profile of cell damage and oxidative stress proteins was evaluated through western blotting. Subsequently, A375 and HCB541 cell lines were cultured in three-dimensional (3D) models using microwell devices, exposed to the agents, and irradiated with low-power LEDs. The morphology of 3D spheroids was evaluated at 24-hour intervals, and at the end of 72 hours, the spheroids were incubated with calcein, and their cellular viability was assessed using the commercial Cell Titer Glo 3D kit.


As a result of viability analysis, we obtained IC50 values for BCDs of 0.19 µM and 0.25 µM for A375 and HCB541 cell lines, respectively, whereas the values for Photogem were 6.61 µM and 2.32 µM. In the protein expression analysis, it was found that cells treated with cyanine bicromophores exhibited higher levels of damage, as they expressed greater amounts of the PARP protein involved in DNA damage repair. Additionally, cells treated with BCDs showed higher amounts of superoxide dismutase in response to oxidative stress damage. Morphological analysis of spheroids revealed reduced cellular viability; quantitatively, BCD treatment showed lower ATP viability rates, suggesting greater cytotoxicity of the BCD compound compared to Photogem.


The results of this study demonstrate the cytotoxic potential of the cyanine bicromophore compound (BCD) in photodynamic therapy, with reduced IC50 concentrations, low toxicity to healthy cells, and activation of oxidative stress and DNA damage in tumor cells. The results introduce a promising therapeutic approach that will be evaluated in further experimental stages, involving equivalent skin models


Photodynamic therapy, photosensitizers, cyanines.

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Pesquisa básica / translacional


PEDRO VICTOR SILVA RESENDE, Izabela Natália Faria Gomes, Vladimir Alexandrovich Kuzmin, Iouri Borissevitch, Rui Manoel Reis, Vinícius Lima Vazquez, Lucimara Perpetua Ferreira, Renato José Silva Oliveira