Filamented Light (FLight) Biofabrication of Aligned Fibrillar Structures to Direct 3D Cell Organization Within Microgels.

Controlling cellular organization in hydrogels is of great interest in tissue engineering and regenerative medicine. In the body, cell organization is regulated by aligned extracellular matrices, such as collagen fibers. However, generating patterned extracellular matrix fibers in hydrogels, such as microfabricated gels, is not easily accomplished. Here, filamented-light (FLight)-based 3D microfabrication is used to fabricate microgels with precise internal architecture to direct cellular organization. It is demonstrated that fibrillated rod-shaped microgels encapsulating C2C12 muscle cells promote highly aligned myotube formation, offering potential as mini-injectable muscle tissues for minimally invasive muscle loss therapies. Furthermore, photoreceptor cells encapsulated in rod-shaped microgels generated structures that mimicked the outer retina. Moreover, these microgels can be used as injectable scaffolds, both in vitro and in vivo, where they facilitate angiogenesis when conjugated with QK peptide. Overall, this technique can be used to generate microgels with precise internal architecture thus providing a potentially significant tool for engineering tissue-like structures.