Fibril motion improves peptide signaling: Artificial scaffolds that bear the peptide-signaling sequences of proteins for tissue regeneration often have limited effectiveness. Álvarez et al . synthesized supramolecular peptide fibril scaffolds bearing two peptide sequences that promote nerve regeneration, one that reduces glial scarring and another that promotes blood vessel formation (see the Perspective by Wojciechowski and Stevens). In a mouse model of paralyzing human spinal cord injury, mutations in a tetrapeptide domain outside of the signaling regions improved recovery by promoting intense supramolecular motion within the fibrils. The mutation with the most intense dynamics resulted in corticospinal axon regrowth and myelination, functional revascularization, and motor neuron survival. —PDS

The deposition of perylene diimide-based aggregates (PDI) onto wide band gap n-type Sb-doped SnO₂ (ATO) was investigated with the aim of finding efficient and versatile dye-sensitized platforms for photoelectrochemical solar fuel generation. These ATO-PDI photoanodes displayed hydrolytic stability in a wide range of pH (from 1 to 13) and revealed superior performances (up to 1 mA/cm² net photocurrent at 1 V vs SCE) compared to both WO₃-PDI and undoped SnO₂-PDI when used in a photoelectrochemical setup for HBr splitting. Although ATO, SnO₂, and WO₃ are endowed with similar conduction band edge energetics, in ATO the presence of a significant density of intrabandgap states, whose occupancy varies with the applied potential, plays a substantial role in tuning the efficiency of photoinduced charge separation and collection. Furthermore, the investigation of the charge injection kinetics confirmed that, even in the absence of applied bias, ATO and WO₃ are the best substrates for the oxidative quenching of poorly reducing PDI excited states, with at least a fraction of them injecting within <200 fs. The charge-separated states recombination occurs on longer time scales, allowing for their exploitation to drive demanding chemical reactions, as confirmed in photoelectrochemical water oxidation using IrO₂-modified ATO-PDI photoanodes.