ALT In this work, we employ de novo protein design methodologies to generate a suite of self-assembling multimeric proteins, whose step-growth heteropolymerization into bulk hydrogels and condensates can be exogenously triggered through small-molecule addition. Our results highlight how changes in programmed multimer valency and their triggered assembly yield materials with varying structures and viscoelasticity. We anticipate that these approaches will prove useful in rapidly generating large libraries of stimuli-responsive biomaterials that are precisely tailored to specific applications in the biosciences and beyond.

ALT Phototriggered release of various cargos, including soluble protein factors and small molecules, has the potential to correct aberrant biological events by offering spatiotemporal control over local therapeutic levels. However, the poor penetration depth of light historically limits implementation to subdermal regions, necessitating alternative methods of light delivery to achieve the full potential of photodynamic therapeutic release. Here, we introduce a strategy exploiting bioluminescence resonance energy transfer (BRET)–an energy transfer process between light-emitting Nanoluciferase (NLuc) and a photosensitive acceptor molecule–to drive biomolecule release from hydrogel biomaterials.