Fabrication of Mechanically Reinforced Photo‐Cross‐linked Hydrogels with Steep Post‐Gelation Threshold Curing via Vinylated Self‐Assembling Peptides

Abstract

ABSTRACT Tomographic volumetric 3D printing (TVP) enables the ultrafast, layer‐free fabrication of hydrogel devices. However, its widespread application is hindered by insufficient curing within the narrow light‐dose processing window, which ultimately compromises the fidelity and stability of the printed hydrogels. To address this challenge, we introduce a peptide self‐assembly‐mediated polymerization strategy to engineer mechanically reinforced hydrogels that exhibit steep curing immediately following the gelation threshold. In our approach, vinylated self‐assembling peptides (vSAPs) are conjugated to tetra‐arm polyethylene glycol macromers (vSAP‐macromers). The self‐assembly of vSAP‐macromers induces nanoscale spatial confinement of vinyl groups, which substantially shortens the diffusion distance for radical propagation. Consequently, vSAP‐macromers exhibit steep conversion and rapid network formation once the light dose exceeds the polymerization threshold. Moreover, the incorporation of vSAPs induces a potential nanoreinforced network, leading to substantial mechanical reinforcement. Owing to these features, vSAP‐macromers ensure the in‐process stability of hydrogel constructs under restricted light doses. Consequently, this leads to improvements in both the printing fidelity and mechanical performance of the final TVP‐fabricated hydrogels. Collectively, this work offers a generalizable design framework for tailoring high‐performance hydrogels for TVP and a solution to resolve the polymerization kinetic mismatch in hydrogel volumetric printing.