Nanostructured Phthalocyanine Assemblies with Efficient Synergistic Effect of Type I Photoreaction and Photothermal Action to Overcome Tumor Hypoxia in Photodynamic Therapy

Most photodynamic therapy (PDT) paradigms work through the highly O-2-dependent type II photoreaction to generate singlet oxygen (O-1(2)). The hypoxic microenvironment of solid tumors severely hampers therapeutic outcomes. Here, we present a novel design that could transfer the photo-physical and photo-chemical properties of traditional phthalocyanine-based photo-sensitizers from type II photoreaction to efficient type I photoreaction and vibrational relaxation-induced photothermal conversion. These features enable the obtained nanostructured phthalocyanine assemblies (e.g., NanoPcAF) to display excellent phototherapies under both normoxic and hypoxic conditions. Moreover, NanoPcAF has a high level of accumulation in tumor tissues after intravenous injection, and 94% of tumor growth is inhibited in a preclinical model at a NanoPcAF dose of 0.8 nmol g(-1) and light dose of 300 J cm(-2).

Automated summary

A novel design is introduced to enhance the efficacy of photodynamic therapy for solid tumors, demonstrating excellent phototherapeutic effects under both normoxic and hypoxic conditions.