Phthalocyanines, which are classified as second-generation photosensitizers, have advantageous photophysical properties, and extensive studies have demonstrated their potential applications in photodynamic therapy. The present work describes the preparation of a new zinc phthalocyanine conjugated to bovine serum albumin (compound 4a) and its photodynamic efficiency in human larynx-carcinoma cells (HEp-2 cells). The unconjugated precursor (compound 4) was also studied. Compounds 4 and 4a penetrated efficiently into the cell, exhibiting cytoplasmic localization, and showed no cytotoxicity in the dark. However, high photodynamic activities were observed in HEp-2 cells after treatments with 5 µM photosensitizers and 4.5 J cm−2 light. These conditions were sufficient to decrease the cell viability to 57.93% and 32.75% for compounds 4 and 4a, respectively. The present results demonstrated high photodynamic efficiency of zinc phthalocyanine conjugated with bovine serum albumin in destroying the larynx-carcinoma cells.

In the present study, we describe a new silicon phthalocyanine conjugated to bovine serum albumin (PcSiN3M-BSA) and its photodynamic activity in murine macrophages cells (J774.A1). The nonconjugated precursor, bis(trimethylaminoethanoxy)–phthalocyaninato silicon (IV) (PcSiN3M), was also studied. Compounds PcSiN3M and PcSiN3M-BSA showed no cytotoxicity in the dark, but exhibited high photodynamic activities following exposure to 5 µM photosensitizers and 45 J cm−2 irradiation. These conditions were sufficient to decrease the cell viability to 40% and 5% in cells treated with PcSiN3M and PcSiN3M-BSA, respectively. These results demonstrated an increase of 87% in the photodynamic activity of PcSiN3M when conjugated with BSA. The results shown in this work suggest that PcSiN3M-BSA had higher uptake by J774.A1 cells, which contributed to its higher photoactivity compared with the unconjugated form, PcSiN3N.