Psoriatic skin-sensitive degradable mesoporous zinc phosphate microsphere as a photosensitizer in photodynamic therapy for anti-psoriasis

Blue light will be a promising alternative for photodynamic therapy in psoriasis, but the photosensitizer in vivo remains unexplored. Mesoporous zinc phosphate microparticle (MZP) was synthesized successfully in this study, as evidenced by XPS, XRD, and nitrogen adsorption experiments. Its psoriatic skin-sensitive property was corroborated by SEM and the higher cumulative release rate of that impregnated with curcumin (Cur) and glycyrrhizic acid (GA), namely Cur-GA-MZP, at pH 5.4, which mimic the acidic environment of the inflammatory psoriatic skin. Moreover, by detecting the decrease of absorbance of 1,3-Diphenylisobenzofuran (DPBF) which had been mixed with MZP irradiated by blue light, MZP is confirmed to reinforce ROS along with irradiation time at pH 5.4, rather than that at pH 7.2. This phenomenon led to a strengthened anti-inflammatory effect of MZP on xylene-induced auricle inflammation, as well as on imiquimod-induced psoriatic-like plaques exists only under blue light irradiation, with the alleviated macroscopic and microscopic appearance, decreased IL-17A levels of skin lesion area as well as spleen index. The mechanism is likely attributed to the NFƙB pathway as well as the MAPK pathway detected by western blot. In sum, MZP, which could dissociate at psoriatic skin condition, will be a promising photosensitizer with the prerequisite of blue light as an effective photodynamic therapy for the management of psoriasis.