The Surprisingly Positive Effect of Zinc-Phthalocyanines With High Photodynamic Therapy Efficacy of Melanoma Cancer

Author(s)

Castro, Kelly A. D. F. ; Prandini, Juliana A. ; Biazzotto, Juliana Cristina ; Tome, Joao P. C. ; da Silva, Roberto S. S. ; Lourenco, Leandro M. O.

• Document type: Journal article
• Source: RONTIERS IN CHEMISTR; v. 10, p. 9-pg., 2022-03-14.

Abstract

Phthalocyanine (Pc) dyes are photoactive molecules that can absorb and emit light in the visible spectrum, especially in the red region of the spectrum, with great potential for biological scopes. For this target, it is important to guarantee a high Pc solubility, and the use of suitable pyridinium units on their structure can be a good strategy to use effective photosensitizers (PSs) for photodynamic therapy (PDT) against cancer cells. Zn(II) phthalocyanines (ZnPcs) conjugated with thiopyridinium units (1-3) were evaluated as PS drugs against B16F10 melanoma cells, and their photophysical, photochemical, and in vitro photobiological properties were determined. The photodynamic efficiency of the tetra- and octa-cationic ZnPcs 1-3 was studied and compared at 1, 2, 5, 10, and 20 mu M. The different number of charge units, and the presence/absence of a-F atoms on the Pc structure, contributes for their PDT efficacy. The 3-(4 ',5 '-dimethylthiazol-2 '-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays on B16F10 melanoma cells show a moderate to high capacity to be photoinactivated by ZnPcs 1-3 (ZnPc 1 > ZnPc 2 > ZnPc 3). The best PDT conditions were found at a Pc concentration of 20 mu M, under red light (lambda = 660 +/- 20 nm) at an irradiance of 4.5 mW/cm(2) for 667 s (light dose of 3 J/cm(2)). In these conditions, it is noteworthy that the cationic ZnPc 1 shows a promising photoinactivation ratio, reaching the detection limit of the MTT method. Moreover, these results are comparable to the better ones in the literature. (AU)

• FAPESP's process: 16/12707-0 - Cytotoxicity and photo-cytotoxicity of new ruthenium-phthalocyanines compounds as nitric oxide and oxygen singlet producers in cancer cell lines. an innovative purpose for metal based drug
• Grantee: Roberto Santana da Silva
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/07937-8 - Redoxome - Redox Processes in Biomedicine
• Grantee: Ohara Augusto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 19/19448-8 - Effect of photobiomodulation as synergistic addendum on photocytotoxicity of ruthenium-phthalocyanine compounds as nitric oxide and singlet oxygen producers: in vitro biochemical evaluation in two- and three-dimensional (3D) tumor cell lines
• Grantee: Roberto Santana da Silva
• Support Opportunities: Regular Research Grants