Semi-automated Collagen Bioink Preparation and Influence on its pH and Resulting 3D Bioprinting Quality

This work deals with the preparation of a collagen bioink for 3D bioprinting. The bioink was prepared using different collagens, a neutralizing medium, with the pH level optimized through the addition of varying concentrations of NaOH, and a cell suspension. The optimal pH value for cell viability and bioink printability, as well as bioink’s mechanical properties, was achieved with a collagen concentration of 20 mg/ml with 0.05% acetic acid, and 50 μl/ml of 1M NaOH. This bioink containing porcine stromal cells was then used to print a filled monolayer square, which was stained with live-dead staining solution and showed promising results after 24-h cultivation.