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.