Post‐Print Processing to Minimize Cytotoxicity of <scp>3D</scp>‐Printed Photopolymer Resins for Biomedical Applications

ABSTRACT Light‐based 3D printing techniques, including stereolithography (SLA) and digital light processing (DLP), are of great utility owing to their ability to create complex geometries with high speed, high spatial resolution, and often, optical transparency. These are useful for fabricating custom components and structures for various biomedical applications—scaffolds, implants, microfluidic devices, in vitro cellular experiments, etc. However, a drawback of light‐based methods is that uncured resin monomers and other additives have the potential for cytotoxic effects, adversely impacting cells and tissues. In this study, we investigate a facile method to process light‐based 3D printing to mitigate cytotoxicity. Three optically clear, photocurable resins—a commercially available acrylate‐based resin, BioMed Clear, and an ecoresin derived from soybean oil—are subjected to various post‐treatment protocols. These involve combinations of isopropanol (IPA) washing, UV curing, and water or IPA agitation. The in vitro cytotoxicity and effect on cell proliferation are characterized using two cell lines (myoblasts and fibroblasts). Compared to untreated controls, IPA or water wash, and cleaning with a commercial developer, the results indicate that a short postprint cure with double IPA wash effectively reduces cytotoxicity across all resins, particularly BioMed Clear and ecoresin, maintaining nearly 100% cell viability after 7 days and avoiding material cloudiness or brittleness. The study therefore highlights a low‐cost postprint treatment method applicable to existing commercial resins and 3D printers. The minimization in leachate and cytotoxicity of optically clear 3D‐printed parts can pave the way for broader adoption in resource‐limited settings and safer use in cell studies, microfluidics, and other biomedical applications.