RESUMO
Digital light processing (DLP)-based three-dimensional (3D) printing offers large improvements in fabrication throughput and spatial resolution when compared to various other additive manufacturing techniques. Both properties are highly desirable when fabricating biomaterial scaffolds that require design precision. Poly(glycerol sebacate) acrylate (PGSA) is a degradable, biocompatible, and photocurable elastomer. In this work, PGSA ink was developed for DLP 3D printing of porous tubular structures. Ink formulations with varying prepolymer concentrations (10-60 wt %), diluent (dimethyl sulfoxide (DMSO), 2-butoxyethyl acetate (EGBEA), and 1:1 DMSO/EGBEA), and degree of PGSA acrylation (17-75%) were studied to optimize printing efficiency and bulk properties of the printed scaffolds. Prepolymer inks with viscosity (<5 Pa·s) and photopolymerization kinetics (exposure time <10 s) appropriate for DLP were developed. Photocrosslinked PGSA scaffolds were further exposed to postfabrication treatments including additional UV exposure or thermal curing (150 °C) to demonstrate tunability in scaffold degradation kinetics and mechanical properties. Complementary to this effort, a 3D model-generation tool was developed to enable user-friendly customization of tubular scaffold design by controlling the pore and strut size of the volumetric mesh. The resulting DLP-printed PGSA scaffolds present high mimicry to complex 3D models with a minimum feature thickness of 80 µm. The tunable properties of PGSA coupled with enhanced precision in microstructure geometry provide a fabrication platform for a variety of tissue regeneration applications.
