Microencapsulated sunblock nanoparticles based on zeolitic imidazole frameworks for safe and effective UV protection

Sunscreen is believed to protect human skin from photo damage due to UV exposure. However, substantial concerns remain associated with skin contact with UV filters and the subsequent reactive oxygen species from photoactivation of UV filters. Herein, we show that the microencapsulation of octyl p-methoxycinnamate (OMC), a typical UV filter, into the nanoporous structure of zeolitic imidazole frameworks (ZIF-8) prevents the skin exposure to UV filters while improving UV protection performance. Meanwhile, the UV filter photostability has been obviously improved due to the nanoconfinement effect. Microencapsulated OMC in ZIF-8 adhered to the stratum corneum could not only reduce OMC transdermal penetration, but also prevent skin exposure to the deleterious reactive oxygen species (ROS) from photoactivation of OMC. Therefore, this microencapsulated UV filter system based on a metal organic frameworks microporous polymer would find important applications in skin care products through providing safe and effective UV protection.