Enhancing Biocompatibility: 3D-Printed Cyclic Olefin Copolymer Structures for Advanced Laboratory Applications

Additive manufacturing, particularly 3D-printing, has emerged as a crucial method for creating prototypes and specialized components in various scientific fields. This study investigates the biocompatibility and performance of 3D-printed materials, with focus on cyclic olefin copolymer (COC) in comparison with traditional materials such as polylactic acid (PLA) and COC combined with glass (Glass + COC) inlays. Biocompatibility is especially critical for cell-based research and millifluidic applications, impacting cell culture experiments and the interaction of 3D-printed structures with reactive substances. To investigate material influence, experiments were conducted using rat cardiomyocyte (H9c2) and human embryonal kidney (HEK293) cell lines, with comprehensive assays including lactate, lactate dehydrogenase (LDH), and thiazolyl blue tetrazolium bromide assays assessing metabolic activity, cell stress, and cell viability. Results demonstrated that Glass + COC exhibited increased metabolic activity and cell viability compared with standard polystyrene (PS) culture dishes, with COC and PLA materials showing comparable viability with standard PS dishes, although with slight differences favoring COC. Lactate assays revealed subtle increases in lactate secretion, notably in Glass + COC cultures, suggesting a correlation with cell viability. LDH assays provided insights into potential material-associated toxicity. Microscopy experiments visually confirmed cell growth and distribution within culture vials, using various transparent materials, including PLA foil, COC foil, standard microscope glass slides, and Glass + COC. Furthermore, atomic force microscopy (AFM) examined surface roughness and differences between the upper and lower surfaces of 3D-printed PLA and COC parts, contributing to the understanding of material surface characteristics. In conclusion, this study highlights the biocompatibility of 3D-printed materials for cell-based research, emphasizing the potential of COC and Glass + COC manufactured via 3D-printing for such applications. The interplay among cell viability, metabolic activity, and lactate levels underscores the importance of material selection. Microscopy and AFM analyses enhance the comprehension of cell growth behavior and surface properties, advancing the selection of 3D-printed materials for biocompatible applications.