Development of collagen-based bioinks for cartilage tissue engineering applications.

Articular cartilage has poor regenerative ability and current techniques fail to deliver successful long-term repair of the articular surface. Recently bioprinting has shown promise as a method for the fabrication of scaffolds for cartilage tissue engineering applications. Collagen-based bioinks offer numerous advantages including biocompatibility and biodegradability, however, the printability of these bioinks presents challenges. The objective of this research was to develop a biomimetic natural biomaterial-based bioink with the required printability for the fabrication of scaffolds for cartilage tissue engineering applications using extrusion-based bioprinting. Specifically, the study focuses on exploring bioink extrudability and the shape fidelity of bioprinted constructs. Four bioinks compositions were compared: sodium alginate (SA), sodium alginate and hyaluronic acid (SAHA), sodium alginate and collagen (SACOL) and sodium alginate hyaluronic acid and collagen (SAHACOL). Three printing nozzle sizes were also compared, 20G, 22G and 23G. To further enhance the bioactivity of the bioinks, chondroitin sulfate (CS) was added to the optimal bioink in varying concentrations. The optimal bioink was identified to be the SACOL with 0.8 wt./vol.% CS added. The optimal printing nozzle was identified to be the 22G nozzle. Current research is focused on the application of Machine Learning (ML) algorithms during the bioprinting process and post-printing for the analysis of bioprinted constructs. Overall, this research aims to optimise the bioprinting of collagen-based bioinks for cartilage tissue engineering. [ABSTRACT FROM AUTHOR]