Volumetric Printing of Thiol-Ene Photo-Cross-Linkable Poly(ε-caprolactone): a Tunable Material Platform serving Biomedical Applications.

Current thoroughly described biodegradable and cross-linkable polymers mainly rely on acrylate cross-linking. However, despite the swift cross-linking kinetics of acrylates, the concomitant brittleness of the resulting materials limits their applicability. Here, we introduce photo-cross-linkable PCL networks through orthogonal thiol-ene chemistry. The step-growth polymerized networks are tunable, predictable by means of the rubber elasticity theory and it is shown that their mechanical properties are significantly improved over their acrylate cross-linked counterparts. Tunability is introduced to the materials, by altering M c (or the molar mass between cross-links), and its effect on the thermal properties, mechanical strength and degradability of the materials is evaluated. Moreover, excellent volumetric printability is illustrated and we report the smallest features obtained via volumetric 3D-printing to date, for thiol-ene systems. Finally, by means of in-vitro and in-vivo characterization of 3D-printed constructs, we illustrate that the volumetrically 3D-printed materials are biocompatible. This combination of mechanical stability, tunability, biocompatibility and rapid fabrication by volumetric 3D-printing charts a new path towards bedside manufacturing of biodegradable patient-specific implants. This article is protected by copyright. All rights reserved.