Photoactive Fluoropolymer Surfaces That Release Sensitizer Drug Molecules

Abstract

We describe a physical–organic study of two fluoropolymers bearing a photoreleasable PEGylated photosensitizer that generates ¹O₂(¹Δ_g) [chlorin e₆ methoxy tri­(ethylene glycol) triester]. The surfaces are Teflon/poly­(vinyl alcohol) (PVA) nanocomposite and fluorinated silica. The relative efficiency of these surfaces to photorelease the PEGylated sensitizer [shown previously to be phototoxic to ovarian cancer cells (Kimani, S. et al. <i>J. Org. Chem</i> <b>2012</b>, <i>77</i>, 10638)] was slightly higher for the nanocomposite. In the presence of red light and O₂, ¹O₂ is formed, which cleaves an ethene linkage to liberate the sensitizer in 68–92% yield. The fluoropolymers were designed to deal with multiple problems. Namely, their success relied not only on high O₂ solubility and drug repellency but also on the C–F bonds, which physically quench little ¹O₂, for singlet oxygen’s productive use away from the surface. The results obtained here indicate that Teflon-like surfaces have potential uses in delivering sensitizer and singlet oxygen for applications in tissue repair and photodynamic therapy (PDT)