Acetylxylan‐pheophorbide‐a nanoparticles designed for tumor‐targeted photodynamic therapy

The poor solubility of most photosensitizers (PS) hampers their practical use as clinical agents. Conjugation of PS with water-soluble nanoparticles has been often used to bypass this hurdle. We describe in this study the extraction of glucuronoacetylxylan from chestnut sawdust, the hemisynthesis of pheophorbide-a (Pha) and its covalent attachment to xylan. The resulting conjugates (xyl-Pha) spontaneously form water-soluble spherical nanoparticles (xyl-Pha NPs) ranging between 100 and 250 nm in diameter. Assayed against the HT-29 colorectal cancer cell line, xyl-Pha NPs exhibited a dose-dependent phototoxicity only when irradiated with red light.