Achieving biocompatibility and tailoring mechanical properties of SLA 3D printed devices for microfluidic and cell culture applications

• Published in: Lab on a chip Vol. 24; no. 19; pp. 4632 - 4638
• Main Authors: Nelson, Matt D, Tresco, Patrick A, Yost, Christian C, Gale, Bruce K
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 24.09.2024
• Subjects: Animals; Baking; Biocompatibility; Biocompatible Materials - chemistry; Biocompatible Materials - pharmacology; Cell culture; Cell Culture Techniques - instrumentation; Cell Survival - drug effects; Cytotoxicity; Elastic Modulus; Ethanol; Humans; Lab-On-A-Chip Devices; Lithography; Materials Testing; Mechanical properties; Microfluidic Analytical Techniques - instrumentation; Microfluidic devices; Modulus of elasticity; Modulus of rupture in bending; Photopolymerization; Platforms; Printing, Three-Dimensional; Spectrophotometry; Stereolithography; Toxicity; Ultraviolet radiation; Ultraviolet Rays
• ISSN: 1473-0197; 1473-0189; 1473-0189
• DOI: 10.1039/d4lc00354c

Stereolithography (SLA) and other photopolymerization-based additive manufacturing approaches are becoming popular for the fabrication of microfluidic devices and cell-infused platforms, but many of the resins employed in these techniques are cytotoxic to cells or do not have the appropriate mechanical properties for microfluidic components. Here, using a commercially available resin, we demonstrate that biocompatibility and a range of mechanical properties can be achieved through post-print optimization involving baking, soaking, network swelling, and UV exposure. We show that UV-vis spectrophotometry can be used to detect methacrylate monomer/oligomer, and utilizing this method, we found that baking at 120 °C for 24 hours was the optimal method for removing cytotoxic chemical species and creating nontoxic cell culture platforms, though UV exposure and soaking in 100% ethanol also can substantially reduce cytotoxicity. Furthermore, we show that the mechanical properties can be modified, including up to 50% for the Young's modulus and an order of magnitude for the flexural modulus, through the post-processing approach employed. Based on the study results, users can choose post-processing approaches to achieve needed cytotoxicity and mechanical profiles, simultaneously.