Zinc-metal–organic frameworks with tunable UV diffuse-reflectance as sunscreens

Abstract

Background UV exposure continues to induce many health issues, though commercial sunscreens are available. Novel UV filters with high safety and efficacy are urgently needed. Metal–organic frameworks (MOFs) could be a suitable platform for UV filter development, due to their tunable optical, electrical, and photoelectric properties by precise controlled synthesis. Results Herein, four zinc-based MOFs with various bandgap energies were chose to investigate their optical behaviors and evaluate their possibility as sunscreens. Zeolitic imidazolate framework-8 (ZIF-8) was found to possess the highest and widest UV reflectance, thereby protecting against sunburn and DNA damage on mouse skin and even achieving a comparable or higher anti-UV efficacy relative to the commercially available UV filters, TiO2 or ZnO, on pig skin, a model that correlates well with human skin. Also, ZIF-8 exerted appealing characteristics for topical skin use with low radical production, low skin penetration, low toxicity, high transparency, and high stability. Conclusion These results confirmed ZIF-8 could potentially be a safe and effective sunscreen surrogate for human, and MOFs could be a novel source to develop more effective and safe UV filters. Graphical Abstract

Design of Bombyx mori (B. mori) Silk Fibroin Microspheres for Developing Biosafe Sunscreen

“…The application stability of SFMP was investigated under a simulated sweat environment . 0.5 mg of SFMP was added into 5 mL of artificial sweat solution consisting of 0.5% NaCl, 0.1% lactic acid, and 0.1% urea (pH = 6.5, 32 °C); then, the mixture suspension was incubated at an oscillation of 100 rpm.…”

Conjugated Network Supporting Highly Surface-Exposed Ru Site-Based Artificial Antioxidase for Efficiently Modulating Microenvironment and Alleviating Solar Dermatitis

“…17,18 However, inorganic sunscreen agents including ZnO and TiO 2 nanoparticles possess enormous photocatalytic activity, which further leads to the production of ROS. 19 Therefore, the key to the overall inhibition of UVB-caused skin damage is to scavenge ROS and modulate the microenvironment in keratinocytes.…”

“…Solar dermatitis, a form of acute radiation burn that affects the skin, results from an overexposure to ultraviolet B (UVB, 280–320 nm) in strong sunlight. , Excessive UVB radiation from sunshine also causes many other skin problems such as inflammation, sunburn, and photoaging. − The main pathogenic mechanisms of solar dermatitis are oxidative stress and inflammation, related to UVB-induced reactive oxygen species (ROS) generation of mitochondria in keratinocytes. − On the one hand, excess ROS results in a variety of harmful cellular responses such as double-strand breaks (DSBs) in DNA and pro-apoptotic processes of keratinocytes. − On the other hand, excess ROS can regulate oxidative stress-activated mitogen-activated protein kinases (MAPKs) and nuclear factor kappa-B (NF-κB)-mediated signaling pathways, which can increase the protein levels including c-Jun N-terminal kinase (JNK) and p38, and inflammatory cytokine levels including interleukin-6 (IL-6), IL-8, tumor necrosis factor-α (TNF-α), and cyclooxygenase-2 (Cox-2), which further aggravate skin inflammation. − Sunscreen with inorganic filters has been widely used to mitigate damage from UVB by physical barrier action. , However, inorganic sunscreen agents including ZnO and TiO 2 nanoparticles possess enormous photocatalytic activity, which further leads to the production of ROS . Therefore, the key to the overall inhibition of UVB-caused skin damage is to scavenge ROS and modulate the microenvironment in keratinocytes.…”

ZIF-8 integrated with polydopamine coating as a novel nano-platform for skin-specific drug delivery

“…16 Currently, ZIF-8 based nanoparticles have been mainly used to target the delivery of drugs to the diseased tissues or cells via vein injection, in terms of their high loading capacity, pHresponsiveness, and surface functionalization. [17][18][19] Most recently, the therapeutic activity of ZIF-8 has begun to attract attention for dermal use, such as treating acne, 20 promoting wound healing, 21 avoiding ultraviolet damage, 22 inhibiting bacterial growth, 21 and so on. There have also been some attempts to use the microneedle-based ZIF-8 composite engineering system based on microneedles, loaded with photosensitizers, drugs, or proteins.…”