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

Adv Mater. 2023 May;35(19):e2210136. doi: 10.1002/adma.202210136. Epub 2023 Mar 24.

Abstract

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, photo-cross-linkable poly(ε-caprolactone) networks through orthogonal thiol-ene chemistry are introduced. 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 Mc (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 the smallest features obtained via volumetric 3D-printing to date are reported, for thiol-ene systems. Finally, by means of in vitro and in vivo characterization of 3D-printed constructs, it is illustrated 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 toward bedside manufacturing of biodegradable patient-specific implants.

Keywords: computed axial lithography; poly(ε-caprolactone); thiol-ene; tissue engineering; volumetric 3D-printing.

MeSH terms

  • Biocompatible Materials* / chemistry
  • Humans
  • Printing, Three-Dimensional
  • Tissue Engineering* / methods

Substances

  • Biocompatible Materials
  • polycaprolactone
  • acrylic acid