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While supramolecular hydrogels have received growing interest due to the unique dynamic features, their relatively weak mechanical properties have largely limited their biomedical applications. In this study, we proposed and demonstrated a strategy to reinforce the mechanical properties of supramolecular hydrogel by introducing polymeric multiple-unit linker (PMUL), which incorporates multiple supramolecular units into a polymeric backbone to crosslink supramolecular hydrogel. It has been demonstrated PMUL could effectively improve the kinetic stability of supramolecular crosslinkers through multiple-unit interaction in a DNA supramolecular hydrogel model system, thus leading to the higher mechanical strength. Meanwhile, the dynamic features of the supramolecular hydrogels have been well preserved, including shear-thinning, selfhealing properties and reversible thermal responsiveness. This strategy offers a simple but effective way for mechanical reinforcement of supramolecular hydrogels to construct novel biomaterials.

Ethylene propylene diene monomer (EPDM)/carbon black (CB)–zinc dimethacrylate (ZDMA) vulcanizate as a sealing material was prepared. Compared with EPDM, the addition of CB–ZDMA resulted in a remarkable increase in tensile/compressive properties, storage/loss modulus, and glass transition temperature, superior to that of vulcanizates with CB or ZDMA. Moreover, the increase in the compression set and decrease in the stress relaxation coefficient were inhibited during stress-thermal oxidation aging, resulting in enhancement of durable sealing resilience performance of vulcanizate. Combination of CB–ZDMA not only facilitated dispersion of CB in the matrix but also improved interface interaction and dispersion of ZDMA. A multiple covalent/ionic cross-linking network structure with increasing cross-linking density formed in composite during vulcanization, which maintained a stable free radical signal and cross-linking density, presented minimum degradation rate and carbonyl index growth rate, and surface damage was inhibited during aging, leading to retardation of cross-linking, degradation, and oxidation of EPDM molecules. Thus, synergistic reinforcing and the stabilization effect of CB–ZDMA on EPDM were achieved.

Pars plana vitrectomy plays an important role in treating serious ophthalmic diseases, which requires subsequent substitution of the natural vitreous. However, the current substitutes are known for the drawbacks in instability, toxicity, and injection‐induced fragmentation, so there is a very urgent need in novel artificial vitreous substitute for clinical practice. In this study, DNA supramolecular hydrogel is evaluated as a potential artificial vitreous substitute. It is observed that DNA supramolecular hydrogel exhibits relatively strong mechanical strength, shear‐thinning behavior, rapid recoverability, and other physical properties similar to the human vitreous body. The in vivo experiments further prove the injectability, excellent biocompatibility, and in vivo stability. With the support of the DNA supramolecular hydrogel, the morphology and basic functions of the operated eyes are well recovered without obvious inflammation, which demonstrate the DNA supramolecular hydrogel shows enormous potential as vitreous substitute.

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