Polymer-Zn(II) sunscreens for protection against harmful blue ray.

Harmful blue rays (HBRs, 400-450 nm) originating from the sun and numerous electronic devices are similar to ultraviolet rays (UVRs) and can induce skin photoaging. Ordinary sunscreens exhibit poor HBR-blocking capability, and traditional anti-HBR materials are unsuitable for skin protection. Herein, we develop a polymer-metal complex that can be applied to the skin to effectively block HBRs. Hydroxyquinoline is introduced into the polymer backbone via the Biginelli reaction. This polymer (P) exhibits strong coordination with Zn(II). The resulting P-Zn(II) complex undergoes a spectral redshift through metal-ligand orbital transitions, enabling effective shielding of both UVRs and HBRs. The P-Zn(II) complex protects fibroblasts from HBR-induced cell death, oxidative stress, and cellular aging by preventing HBR-triggered dysregulation of multiple photoaging-related signaling pathways and genes. In mouse experiments, the P-Zn(II) complex exhibits minimal skin irritation and low hepatic and renal toxicity. It can be applied to the skin in a manner similar to sunscreens and effectively prevents HBR-induced skin damage, which fills the gap in HBR protection left by current commercial products. This study highlights the potential of polymer-metal ion complexes as advanced photoprotective materials and provides valuable insights into the development of anti-HBR biomaterials.