Photodynamic therapy using silicon phthalocyanine conjugated with bovine serum albumin as a drug delivery system

Abstract

Abstract 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.