UV filter-loaded mesoporous silica nanoparticles-stabilized Pickering emulsions with improved UV protection and ROS inhibition

Pickering emulsions hold significant promise as platforms for encapsulating bioactive compounds. However, the platform is limited due to narrow UV protection spectra and the lack of reactive oxygen species (ROS) inhibition. Herein, a Pickering emulsion system stabilized by mesoporous silica particles loaded with organic UV filters is designed to protect photosensitive actives. In this tailored protective system, firstly, mesoporous silica particles loaded with different UV filters (UF@MPS) were synthesized by sol–gel method. Subsequently, these particles underwent silicification through a secondary sol–gel process, yielding silicified particles (UF@MPS@S), which not only reduces the free radicals generated by the photodegradation of the UV filters by 89.3%, but also adjusts the particle wettability to a favorable three phase contact angle of 89.6° for emulsion formation. For UVA protection, the AB@MPS@S-stabilized Pickering emulsion possesses high UVA-blocking efficiency, leading to a retention of UVA-sensitive astaxanthin that is 94% higher than that in the free group after 10-day UV exposure. For UVB protection, the OMC@MPS@S-stabilized emulsion shows UVB-blocking capacity, resulting in 91% higher retention of UVB-sensitive vitamin E compared to the free group after 10-day UV exposure. This work establishes a versatile photoprotection platform for diverse bioactive compounds with varying UV-sensitive spectra, with potential for extension into pharmaceutical, food, and cosmetic applications.