DNA cross-over motifs-based, programmable supramolecular hydrogels for the mechanoregulatory effects of cellular...

The development of mechanically tunable hydrogels that replicate the dynamic mechanoelastic properties of native extracellular matrices (ECMs) is essential for advancing 3D tissue engineering. DNA, with its precise, programmable architecture and exceptional control at the nanometre scale, offers a valuable platform for designing ECM-mimicking scaffolds. This study presents stiffness-tuneable DNA supramolecular hydrogels with different branching architectures for programming cellular and organellar states. Utilizing precise DNA motifs-including DX (Double Crossovers), PX (Paranemic Crossovers), and Tensegrity architectures-we engineer hydrogels with widely adjustable mechanical properties (50-185 kPa) without chemical additives or enzymatic crosslinking. These hydrogels exhibit excellent strain-bearing and load-bearing capacity, making them suitable for biomedical applications. Additionally, these DNA hydrogels influence cellular behaviour in retinal pigment epithelial (RPE1) cells by enhancing cellular adhesion, encouraging elongation (a 3-8-fold increase in area compared to control), and improving viability (dependent on concentration, 1-8-fold increase vs. control), while also maintaining organellar homeostasis, including mitochondrial fragmentation and ER stress reduction. This work presents a framework for automating the production of stiffness-tunable DNA hydrogel scaffolds, aligning with the mechanical needs of various cells and tissues, thereby advancing personalized, high-throughput tissue engineering platforms.