An experimental workflow for bioprinting optimization: Application to a custom-made biomaterial ink

Bioprinting is an emerging technology with significant potential in biomedical fields, enabling the creation of highly customized, cell-laden constructs. Despite the promise, achieving high-quality, reproducible prints remains challenging due to the lack of standardized protocols, which has hindered widespread adoption of the technique. In this study, we present a systematic bioprinting protocol designed to optimize the performance of an in-house photo-curable biomaterial ink composed of gelatin methacryloyl (GelMA) and egg white protein. Printing quality was evaluated through three key assessments: extrusion, deposition, and printability. To facilitate accurate image analysis, we developed a custom 3D-printed lens support specifically designed for a USB-microscope. Additionally, we implemented a Python script to quantitatively assess bioprinting quality. Our results indicate that a pressure range of 70-80 KPa, combined with speeds between 300 and 900 mm/min, yields reliable extrusion flow, with 75 KPa and 600 mm/min emerging as optimal parameters for bioprinting 3D constructs. These findings underscore the importance of carefully tuning parameters – including pressure and speed – to achieve stable, high-resolution extrusions. Such optimization mitigates common printing issues, including tip clogging, filament dragging, and unintended merging of adjacent filaments, thereby enhancing structural accuracy. This work provides a comprehensive framework for evaluating and optimizing bioprinting parameters, offering a reproducible methodology to enhance print quality. Contributing to the ongoing efforts to standardize bioprinting processes and advance their applications in tissue engineering and regenerative medicine.