Here we introduce silyl ether linkage as a novel dynamic covalent motif for dynamic material design. Through introduction of a neighboring amino moiety, we show that the silyl ether exchange rate can be accelerated by almost three orders of magnitude. By incorporating such silyl ether linkages into covalently cross-linked polymer networks, we demonstrate dynamic covalent network polymers displaying both malleability and reprocessability. The malleability of the networks is studied by monitoring stress relaxation at varying temperature, and their topology freezing temperatures are determined. The tunable dynamic properties coupled with the high thermal stability and reprocessability of silyl ether-based networks open doors to many potential applications for this family of materials.

RNA-based therapeutics have garnered tremendous attention due to their potential to revolutionize protein replacement therapies, immunotherapy, and treatment of genetic disorders. The lack of safe and efficient RNA delivery methods has significantly hindered the clinical translation and widespread application of RNA-based therapeutics. With differing sizes and structures of therapeutic RNA molecules, a critical challenge of the field is to develop RNA delivery systems that accommodate these variations while retaining high biocompatibility and efficacy. In this study, we developed a series of multivalent peptide-functionalized bioreducible polymers (MPBP) as a safe and efficient delivery vehicle derived from a core polymer backbone for various RNA species. The facile synthesis of MPBPs from a single polymer backbone provides access to numerous polymers with diverse architectures that enable cellular delivery of different RNA cargos. Postfunctionalization with multifunctional peptides enables strong RNA complexation, enhanced cellular uptake, and facilitates endosomal escape of cargo. The high delivery efficiency and low cytotoxicity for various RNA-MPBP nanoparticles in multiple cell lines demonstrates that the MPBP approach is a novel promising vector strategy for future RNA delivery systems.

Herein, we report the design, synthesis and characterization of self-healing magnetic nanocomposites prepared from readily available commodity monomers.

In nature, living systems operate far from equilibrium by consuming and dissipating energy to perform vital processes. Biological systems use chemically derived energy to power outof-equilibrium processes to generate complex macroscopic motion by dissipating energy at the molecular scale. In contrast, it remains a major challenge to create synthetic out-ofequilibrium systems that operate on the macroscopic scale. Herein we report a chemically fueled out-of-equilibrium system that can perform macroscopic actuation and do work by lifting objects. We achieve this by driving a lower critical solution temperature (LCST) transition of poly(N-isopropylacrylamide) (pNIPAAm) hydrogels with heat generated by a coppercatalyzed azide-alkyne cycloaddition (CuAAc) reaction. Upon completion of the reaction, heat dissipates to the environment, and the system returns to equilibrium, completing one cycle of out-of-equilibrium behavior, which can be repeated for multiple cycles by adding new chemical fuels.

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