Synergistic Protein-reinforced DNA Hydrogels with Tunable Biomechanics for Mechanoresponsive Drug Release

Abstract

DNA hydrogels are widely explored in biomedical research for their programmability and soft tissue-mimicking mechanics. However, their application in load-bearing implants is restricted by insufficient mechanical robustness, especially for mimicking the biomechanics of nucleus pulposus, which are natural functional tissues essential for spinal flexibility and shock absorption in the invertebrate disk. Existing strategies to reinforce biomaterial hydrogels largely depend on chemical crosslinkers or the incorporation of synthetic polymers, which can compromise native biomolecular function and restrict cell migration. Here, we report a novel single-pot, two-step fabrication strategy in which long DNA strands produced by rolling circle amplification form an initial viscoelastic network that is subsequently reinforced through controlled thermal self-assembly of protein, physically stapling the DNA chains into a mechanically tunable hybrid matrix. This synergistic protein-reinforcement enables precise control over the morphological and mechanical properties of the DNA hydrogels while improving stability under enzymatic and pH stress. The reinforced hydrogels maintain structural integrity under complex deformation and sustained compression in ex vivo nucleus pulposus models and exhibit pressure-dependent drug release. Overall, this study establishes protein-reinforcement within viscoelastic gel networks as a distinct materials design strategy for creating programmable biomaterials that integrate molecular precision with mechanical resilience for use in mechanically demanding biological environments.New concepts statementWe report a one-pot strategy to engineer BRIDGe hydrogels by integrating rolling circle amplification with protein-mediated reinforcement, yielding a hybrid DNA-protein network. In this system, self-assembled proteins function as molecular staples that stabilize DNA architectures while enabling decoupled tuning of microporosity and mechanical stiffness. The resulting hydrogels exhibit compression-gated transport, wherein applied mechanical load dynamically modulates molecular diffusion and drug release. This mechanoresponsive behavior positions BRIDGe as a versatile platform for load-adaptive therapeutics in mechanically active environments, such as the intervertebral disc.