Fluorinated polymer-photosensitizer conjugates enable improved generation of ROS for anticancer photodynamic therapy

Photodynamic therapy (PDT) is an adjuvant, non-invasive cancer treatment that is often limited by the photosensitizer solubility and the availability of oxygen in the tumor environment during treatment. This study describes the use of a water-dispersible fluorous polymer to deliver a small molecule photosensitizer with the goal of overcoming these limitations. Covalent conjugation of the photosensitizer to a fluorous polymer demonstrated enhanced singlet oxygen production, showing the potential to improve the PDT efficacy in hypoxic tumor environments. Cellular uptake and efficiency were evaluated using models for squamous cell carcinoma and melanoma. The high fluorine content of the photosensitizer-conjugated polymer drove self-assembly into micellar nanoparticles that showed uptake into both cancer cell lines, inducing cell death when exposed to broad based white light, but was non-toxic otherwise. Taken together these results demonstrate that the fluorous polymer platform serves as an effective delivery system for small molecule photosensitizers while increasing the generation of toxic reactive oxygen species.