RESUMEN

Recent advances in synthetic methods and monomer design have given access to precision carbohydrate polymers that extend beyond native polysaccharides. In this article, we present the synthesis of a class of chemically recyclable ester-linked pseudo-polysaccharides via the living anionic ring-opening polymerization of glucurono-1,6-lactones. Notably, the pseudo-polysaccharides exhibited defined chain-end groups, well-controlled molecular weights, and narrow molecular weight distributions, all hallmarks of living polymerization. Furthermore, we demonstrate that our approach is modular, as evidenced by tunable glass transition temperatures (Tg) and the ability to produce both amorphous and semicrystalline polymers by adjusting the monomer side chain structure. Lastly, we showcased the complete catalytic chemical recycling of these pseudo-polysaccharides back to the monomers. The flexibility of the polymerization and the recyclability of these pseudo-polysaccharides promote a sustainable circular economy while offering the potential to access polysaccharide-like materials with tunable thermal and mechanical properties.

RESUMEN

Bioorthogonal catalysis using transition-metal catalysts (TMCs) provides a toolkit for the in situ generation of imaging and therapeutic agents in biological environments. Integrating TMCs with nanomaterials mimics key properties of natural enzymes, providing bioorthogonal "nanozymes". ZnS nanoparticles provide a platform for bioorthogonal nanozymes using ruthenium catalysts embedded in self-assembled monolayers on the particle surface. These nanozymes uncage allylated profluorophores and prodrugs. The ZnS core combines the non-toxicity and degradability with the enhancement of Ru catalysis through the release of thiolate surface ligands that accelerate the rate-determining step in the Ru-mediated deallylation catalytic cycle. The maximum rate of reaction (Vmax) increases ∼2.5-fold as compared to the non-degradable gold nanoparticle analogue. The therapeutic potential of these bioorthogonal nanozymes is demonstrated by activating a chemotherapy drug from an inactive prodrug with efficient killing of cancer cells.

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RESUMEN

Bioorthogonal catalysis provides a promising strategy for imaging and therapeutic applications, providing controlled in situ activation of pro-dyes and prodrugs. In this work, the use of a polymeric scaffold to encapsulate transition metal catalysts (TMCs), generating bioorthogonal "polyzymes," is presented. These polyzymes enhance the stability of TMCs, protecting the catalytic centers from deactivation in biological media. The therapeutic potential of these polyzymes is demonstrated by the transformation of a nontoxic prodrug to an anticancer drug (mitoxantrone), leading to the cancer cell death in vitro.

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