Thiol-ene-Based 3D Printing of Bioresorbable Fumarate-Based ABA Triblock Copolyester Elastomers

Additive manufacturing continues to evolve as a powerful tool for the fabrication of tissue-engineered scaffolds and medical devices. With this evolution, a library of materials with a broad range of mechanical properties and degradation behaviors is needed. Photochemically crosslinked polymeric systems typically possess a network of covalent bonds which limit their degradability and serve to hinder the clinical translation of medical devices made from these materials. In this work, the use of ABA triblock poly(propylene fumarate-b-gamma-methyl-epsilon-caprolactone-b-propylene fumarate) copolymers coupled with a degradable, thiol-based crosslinking system on a continuous liquid interface production (CLIP) digital light processing (DLP) 3D printer is reported. The printed elastomeric structures experience a range of mechanical behaviors (strain at failure spanning from 55% to 290%) and degradation behavior that is dependent on the stoichiometry of the individual blocks within the ABA copolymer and the alkene-to-thiol crosslinking ratios.