A Bio-Based and Biocompatible Lipoate-Oil Platform for 3D Digital Light Processing

In the search for alternatives to petrochemically derived monomers for digital light processing (DLP), vegetable oils are an attractive renewable feedstock. However, most reported oil-based inks still rely on acrylate-based cross-linking strategies, limiting the bio-based content and biocompatibility of the resulting printed materials. Here, we present a fully bio-based oil-derived DLP ink that exploits lipoates as photocross-linking units, thereby avoiding the use of acrylates and eliminating the need for photoinitiators. A lipoated triglyceride is synthesized and formulated into a 100% bio-based ink using ethyl lipoate as a reactive diluent and p-cymene as a solvent. The ink exhibits good curing performance and enables the fabrication of complex three-dimensional architectures, which can be depolymerized on demand. Cytocompatibility is demonstrated in a live/dead assay, with cell viability exceeding 97%. These results establish this fully bio-based system as a promising platform for the next generation of sustainable materials for biomedical applications.