Hydrogel microfibers with perfusable folded channels for tissue constructs with folded morphology

Fiber-based materials with microchannels have drawn considerable attention in recent years owing to their ability to mimic intrinsic morphologies of living tissues. Folded morphologies, which are common in vivo, such as in skeletal muscle capillaries and intestine luminal endoderm, play important roles in the achievement of tissue functions. Here, microfibers with folded hollow channels are fabricated. Channel morphologies, such as straight-folded, double-folded and double-helical channels, can be regulated by adjusting flow conditions in the microfluidic devices. To further demonstrate the potential to be used in tissue engineering, intestine and skeletal muscle constructs are fabricated using these microfibers as building blocks. Furthermore, the properties of perfusability, permeability, cytocompatibility and weavability of the microfibers are evaluated. The asymmetric molecular distributions in the microfibers provide promising platforms for the study of nutrient exchange and energy supplement between normal and tortuous tissues. The new features of biofibers and proof-of-concept of tissue constructs with folded morphologies may contribute to the development of regenerative medicine and drug screening in the future.