Metal‐Phenolic Networks Enable Biomimetic Antioxidant Interfaces Through Nanocellulose Engineering

Abstract Metal‐phenolic networks (MPNs) integrated with functionalized cellulose nanofibers present a promising platform for stabilizing oxidation‐sensitive compounds. Here, a novel antioxidant pickering emulsion system utilizing MPN‐decorated carboxyl‐functionalized pulp cellulose nanofibers (MPN‐PCNF) is demonstrated. The system exhibits exceptional interfacial stability through synergistic effects of MPN coating and alkyl functionalization, validated by DLVO theoretical modeling and rheological characterization. MPN‐PCNF demonstrates remarkable antioxidant efficacy, achieving 94% α‐tocopherol retention over 50 days and 80% reduction in cellular reactive oxygen species. In reconstructed human skin models, the system significantly attenuates UV‐induced oxidative stress, evidenced by preserved stratum corneum integrity and suppressed matrix metalloproteinase‐1 expression. This biocompatible platform represents a versatile solution for protecting oxidation‐sensitive compounds across pharmaceutical, cosmetic, and food applications, offering a sustainable alternative to conventional synthetic antioxidant systems.