Near-infrared and metal-free tetra(butylamino)phthalocyanine nanoparticles for dual modal cancer phototherapy

Synergistic phototherapy combining photodynamic therapy (PDT) and photothermal therapy (PTT) based on near-infrared (NIR) dyes using a single light source offers the opportunity to treat diseases at deep locations. In this study, we reported human serum albumin (HSA)-involving tetra(butylamino)phthalocyanine (Pc)-based nanomaterials of HSA-α-Pc and HSA-β-Pc as highly efficient dual-phototherapy agents, namely 1(4),8(11),15(18),22(25)-tetra(butylamino)phthalocyanine (α-Pc) and 2(3),9(10),16(17),23(24)-tetra(butylamino)phthalocyanine (β-Pc). Both HSA-α-Pc and HSA-β-Pc showed excellent photothermal effects under a single NIR (808 nm) laser irradiation due to the S(1) fluorescence emission quenching of Pcs. Compared to HSA-β-Pc, HSA-α-Pc exhibited better singlet oxygen generation ability and its highly efficient PDT/PTT dual-phototherapy was also well evidenced via in vitro and vivo experiments under a single 808 nm laser irradiation. Overall, this approach would be viable for the fabrication of more new Pc-based metal-free nano agents for PDT/PTT synergistic phototherapy upon a single NIR light source.