The novelty and importance of this new approach is the combination of the automated musculoskeletal tissue production using 3D bioprinting with a new microwell plate addressing the specific tissue attachment requirements. Thus, this screening platform represents a promising new tool for musculoskeletal drug discovery and development.
Muscle and tendon tissue models are fabricated by printing alternating layers of photo-polymerised gelatin-methacryloyl-based bioink and cell suspensions in a dumbbell shape onto a newly designed cell culture insert in 24-well plates containing two vertical posts. The cells show high viability after printing in culture and good tissue differentiation based on marker gene and protein expressions.
In addition, functionality of the muscle tissue models is demonstrated by calcium signaling of Fluo4-loaded cells and myofiber contractility induced by electrical pulse stimulation. Finally, the authors successfully fabricate tendon-muscle-tendon co-cultures by printing tenocytes around the posts of the cell culture inserts and myoblasts between the posts.