Thermosensitive Liposomal Nanoplatform Based on Metal-Free Phthalocyanine with Copper(II)-Regulated Photoactivities

This work reports the development of a multifunctional thermosensitive liposomal nanoplatform (PcS₄@Lip-FA) based on a metal-free phthalocyanine modified with tetra-sulfonates (PcPS₄), which exhibited photodynamic and photothermal activities simultaneously. Upon irradiation with a near infrared laser, thermosensitive PcS₄@Lip-FA could release PcS₄ as a result of the local hyperthermia of PcS₄. Interestingly, PcS₄ could easily chelate with Cu²⁺, leading to the enhancement of photothermal activity and decrease of photodynamic activity. In addition, in vivo fluorescence imaging revealed that PcS₄@Lip-FA could selectively accumulate in tumor tissue of H22 tumor-bearing mice after tail vein injection, and exhibited a significant anticancer phototherapeutic effect, with a tumor inhibition rate of 83.5 %. Therefore, PcPS₄@Lip-FA has realized fluorescence imaging-guided combined cancer treatment, providing a promising multifunctional nanoplatform for cancer diagnostics and therapy.