Zhou et al. show that reduced mitochondrial motility and energy deficits in injured axons are intrinsic mechanisms contributing to regeneration failure in mature neurons.

Crystal engineering can be regarded as the highly ordered and complicated supramolecular synthesis of functional crystalline solids by control of intermolecular interactions. As one of the most important organic solids for crystal engineering, organic optoelectronic materials have received tremendous interest in the past several decades. In this review, we discuss systematically how to design organic optoelectronic materials from the perspective of crystal engineering including molecular structures, intermolecular interactions, packing arrangements, crystal growth, and patterning methods as well as two-component and multi-component molecular materials. We underline the correlations among molecular structures, packing modes, crystal morphologies, and optoelectronic properties. Finally, we address several key points for further exploration in this field.