biostudies-literaturePujol MUniversité de BordeauxCarnot Institute 3BCARINRAEUniversity of Bordeauxe13937https://www.ebi.ac.uk/biostudies/studies/S-EPMC12759241biostudies-literatureUnknown65(1)Polystyrene (PS) is one of the most widely used synthetic polymers, with annual global production of around 20 million tons. However, its robust C─C backbone renders it highly recalcitrant to (bio)chemical depolymerization, and no sustainable re-/up-cycling method has yet been developed. Here, we establish a proof-of-concept for the efficient depolymerization of PS under mild aqueous conditions, using a laccase-mediator system (LMS) composed of Trametes versicolor laccase, 1-hydroxybenzotriazole (HBT), and ambient oxygen. To overcome substrate accessibility issues, PS is formulated into colloidally stable nanoparticles, promoting interfacial remote biocatalysis. Under such conditions, up to 99.9% decrease in molar mass is achieved from an initial PS of over 2 million g mol^-1, synthesized by ab initio free-radical emulsion polymerization. This colloidal dispersion strategy is also effective for commercial PS and expanded PS waste processed by post-dispersion in surfactant-containing aqueous media. Mechanistic studies suggest that LMS-mediated depolymerization proceeds via HBT radical diffusion into PS nanoparticles, triggering hydrogen atom transfer (HAT)-based oxidation and β-scissions of PS chains. This approach provides an efficient method for PS depolymerization using aqueous conditions, ambient O₂ and a native enzyme without harsh solvents or experimental conditions.Angewandte Chemie (International ed. in English)Harnessing Colloidal Dispersion for Laccase-Driven Enzymatic Depolymerization of Polystyrene.PMC12759241PAF_02Berrin JGTaton DSeksek FGonsales SAPujol MBissaro BfalseHarnessing Colloidal Dispersion for Laccase-Driven Enzymatic Depolymerization of Polystyrene.Polystyrene (PS) is one of the most widely used synthetic polymers, with annual global production of around 20 million tons. However, its robust C─C backbone renders it highly recalcitrant to (bio)chemical depolymerization, and no sustainable re-/up-cycling method has yet been developed. Here, we establish a proof-of-concept for the efficient depolymerization of PS under mild aqueous conditions, using a laccase-mediator system (LMS) composed of Trametes versicolor laccase, 1-hydroxybenzotriazole (HBT), and ambient oxygen. To overcome substrate accessibility issues, PS is formulated into colloidally stable nanoparticles, promoting interfacial remote biocatalysis. Under such conditions, up to 99.9% decrease in molar mass is achieved from an initial PS of over 2 million g mol^-1, synthesized by ab initio free-radical emulsion polymerization. This colloidal dispersion strategy is also effective for commercial PS and expanded PS waste processed by post-dispersion in surfactant-containing aqueous media. Mechanistic studies suggest that LMS-mediated depolymerization proceeds via HBT radical diffusion into PS nanoparticles, triggering hydrogen atom transfer (HAT)-based oxidation and β-scissions of PS chains. This approach provides an efficient method for PS depolymerization using aqueous conditions, ambient O₂ and a native enzyme without harsh solvents or experimental conditions.2026-01-01T00:00:00Z2026 Jan2026-06-06T09:17:02.326Z2026-05-28T03:11:48.994ZS-EPMC127592414116904110.1002/anie.202513937