Biocompatible and biodegradable fluorescent microfibers physiologically secreted by live cells upon spontaneous uptake of thiophene fluorophoreElectronic supplementary information (ESI) available. See DOI: 10.1039/c4tb01562b

Live cells can form multifunctional and environmentally responsive multiscale assemblies of living and non-living components. We recently reported the results of a unique approach to introduce supplementary properties, fluorescence in particular, into fibrillar proteins produced by live fibroblasts and extruded into the ECM. In this work, we demonstrate that the physiological secretion of fluorescent nanostructured microfibers upon the spontaneous uptake of the appropriate fluorophore extends to living cells derived by different tissue contexts. We also show that live cells seeded on fluorescent microfibers have a different fate in terms of the cellular morphology, cytoskeleton rearrangement and viability. These results suggest that the microfibers, which are biocompatible and biodegradable, can be used as multiscale biomaterials to direct the cell behaviour. Physiological secretion of fluorescent nanostructured microfibers upon spontaneous uptake of the appropriate organic fluorophore by live cells and the effects of cell seeding on the isolated microfibers.