Vat photopolymerization 3D printing of acid-cleavable PEG-methacrylate networks for biomaterial applications

Abstract

Additive manufacturing (AM) is an emerging processing platform in clinical applications because of its ability to fabricate customized 3D structures for patient-specific needs. Vat photopolymerization additive manufacturing creates high-resolution, complex structures with excellent accuracy to fulfill these demands. However, materials selection for vat photopolymerization is limited. Many materials lack the biocompatibility and stimuli-responsive properties for biomaterial function in physiological environments. In this work, a vat photopolymerization AM process photocured acid-labile crosslinker within a methacrylate terminated poly(ethylene glycol) polymer network to yield biocompatible 3D structures with diverse architectures. At physiological temperature (37 °C), photocrosslinked networks exhibited thermal stability and tunable water sorption with respect to crosslinker amount. Crosslinker amount and geometry were varied to control dissolution in aqueous physiological environments. Acid-cleavable crosslinker amount increased dissolution in acidic (pH ˜1) environments. In neutral (pH ˜7) environments, acid-cleavable crosslinker amount did not increase dissolution to the same extent. Geometry, specifically cube and lattice structures exhibited differences in dissolution due to surface area driven diffusion. Structural by-products after dissolution demonstrated good in vitro cytocompatibility after 72-hours in culture. This class of 3D-printed biomaterials offer potential for drug delivery, tissue engineering scaffolds and wound dressing applications.