Gelatin

Fascicle

Engineering

Biology

Fabrication

Biomedical engineering

Materials science

Tissue engineering

Biochemistry

Skeletal muscle

Computer science

Protein filament

Alternative medicine

Actin

Nanotechnology

Anatomy

Myosin

Composite material

Medicine

Chemistry

Biophysics

Extrusion

Pathology

Bioprinting

In this study, chaotic flows are used to biofabricate muscle tissue-like constructs that mimics the hierarchical architecture of native skeletal muscle. Multi-layered and multi-material filaments (~1.2 ​mm in diameter) are easily obtained in a one-step extrusion protocol by using a Kenics static mixer (KSM). These filaments contain intercalated layers (~130 ​μm in thickness) of myoblast-laden gelatin-methacryloyl (GelMA)-alginate and physical barriers composed of alginate. Cells exhibit a high post-printing viability (>85%) and remain highly viable even at 28 days after bioprinting. Alginate barriers prevent cells from migrating to neighboring layers. The spatially controlled microarchitecture achieved here, resembles a muscle fascicle at each intercalated layer. This straightforward approach promotes an effective alignment of cells (~60%) with respect to the filament axis. The expression of myosin and sarcomeric actin was verified at day 28. In summary, we demonstrate the fabrication of a hierarchically structured engineered muscle-like constructs in a continuous and simple fashion using an extrusion-based technique that modulates printing resolution simply by switching the number of KSM elements in the printhead.

Continuous chaotic bioprinting of skeletal muscle-like constructs