Accomplishment of α-Chymotrypsin on Photodynamic Effect of Octa-Substituted Zn(II)- and Ga(III)-Phthalocyanines against Melanoma Cells

Octa-methylpyridiloxy-substituted Zn(II)- and Ga(III)-phthalocyanines (ZnPc1 and GaPc1) were studied on human pigmented melanoma (SH4) and keratinocyte (HaCaT) cell lines. The efficacy of ZnPc1 and GaPc1 against melanoma cells was compared to the results in the presence of a protease alpha-chymotrypsin (ChT). The synthesis and characterization of compounds were carried out using well-known approaches. The formation of physical conjugates due to the addition of ChT was studied via absorption and fluorescence. The proteolytic activity of ChT was verified with casein as a substrate. The photosafety of compounds was proven on embryonal cells (BALB 3T3) under solar exposure (LED 360-1100 nm). The photodynamic activity of GaPc1 and ZnPc1 was studied for a concentration range of irradiation (LED 660 nm). The reduction of the proteolytic activity of ChT was observed only for the irradiation of ZnPc1 or GaPc1. GaPc1 and ChT and their conjugates, except ZnPc1 (PIF similar to 6), were evaluated as photo-safe to solar light (PIF < 2). The efficiency of GaPc1 was shown to be much higher than that of ZnPc1 in their individual applications. The phototherapeutic index of GaPc1 (PI = 1.71) on SH4 cells was higher for the conjugate. alpha-Chymotrypsin and phthalocyanine have the advantages of reducing high toxicity and increasing the phototherapeutic index.