A multi-material bioprinting platform towards stratified articular cartilage tissue fabrication

Additive manufacturing processes, which build parts by adding material layer by layer based on the specified computer model, is used frequently in tissue engineering for its capability to construct tissue scaffolds with highly reproducible architecture and compositional variation. This paper highlights the development of a bioprinter towards zonal-stratified articular cartilage tissue fabrication. This bioprinter is designed to concurrently print filament structures with varying porosity levels to mimic natural cartilage constructs. This is achieved by developing a bioprinter that consists of two Cartesian robots mounted in parallel on the same mechanical frame. A structure is fabricated and deposited with spheroids to validate this system. Preliminary results showed that the bioprinter was able to produce filaments and spheroids with well-defined geometry and the cell viability of cartilage progenitor cells (CPCs) spheroids is close to 99% in 24h post-printing.