Parylene-C coating protects resin 3D printed devices from materials erosion and prevents cytotoxicity towards primary cells

Resin 3D printing is attractive for rapid fabrication of microscale cell culture devices, but common resin materials are unstable and cytotoxic under culture conditions. Strategies such as leaching or over-curing are insufficient to protect sensitive primary cells such as white blood cells. Here, we evaluated the effectiveness of using parylene-C coating of commercially available clear resins to prevent cytotoxic leaching, degradation of microfluidic devices, and absorption of small molecules. We found that parylene-C significantly improved both the cytocompatibility with primary murine white blood cells and the material integrity of prints, while maintaining the favorable optical qualities held by clear resins.