(158g) Biofabrication of Muscle Fibers Using Surface Chaotic Flows: Chaotic 2D-Printing

Multiple human tissues exhibit a fibrous nature. Therefore, the fabrication of hydrogel fibers for biomedical engineering applications is a topic of current interest. Here we present a simple strategy, based on the use of chaotic flows, to fabricate continuous, long and thin filaments of gelatin methacryloyl (GelMA) for muscle tissue engineering. The fabrication of these hydrogel fibers was achieved by chaotic elongation in a finely controlled and miniaturized version of the journal bearing (JB) system. A drop of a pre-gelled solution of GelMA is injected onto a higher-density viscous fluid and a chaotic flow is applied in an iterative process. The chaotic flow exponentially deforms and elongates the drop to generate a fiber that is then photocrosslinked under UV light exposure. The progression of the elongation process can be rigorously modeled. We showed that computational fluid dynamics (CFD) simulations closely predict the motion of the inks, as well as the lengths of the filaments obtained by this chaotic advection-based fabrication process.

This technological platform is a low-cost and simple alternative to 3D-printing and other biofabrication strategies. The hydrogel filaments produced were proven to be effective scaffolds for C2C12 myoblast cells. Cells were initially seeded on the surface of these GelMA filaments and progressively developed into coherent and highly aligned muscle-like fibers within three weeks of culture. A detailed characterization of such fibers was performed through optical and scanning electron microscopy techniques, which highlighted their potential to be used as cost-effective models for muscle tissue engineering and regenerative medicine.

In this work, we introduced a simple technique, based on the use of surface chaotic 2D-flows, which enables the facile fabrication of hydrogel filaments. We demonstrated its use to fabricate muscle-like fibers, and envision the extension of the technique to other exciting tissue engineering applications.