Biodegradable Poly(ester) Urethane Acrylate Resins for Digital Light Processing: From Polymer Synthesis to 3D Printed Tissue Engineering Constructs

Digital light processing (DLP) is one of the most accurate and fastest additive manufacturing technologies to produce a variety of products, from patient-customized biomedical implants to consumer goods; however, DLP’s use in tissue engineering is limited largely due to a lack of biodegradable resins. Herein, a library of biodegradable urethane acrylate-capped poly(esters) (with variations in molecular weight) is investigated as the basis for a DLP printable ink for tissue engineering. The synthesized oligomers show good printability in a DLP resin, capable of creating complex structures with mechanical properties matching those of medium-soft tissues (1–3 MPa). While fabricated films from different molecular weight resins showed few differences in surface topology, wettability, and protein adsorption, the adhesion and metabolic activity of L929 and human dermal fibroblasts (HDFs) were significantly different: resins from higher molecular weight oligomers provided greater cell adhesion and metabolic activity. These printable and biodegradable resins show the importance of oligomer molecular weight on scaffold properties, and facilitate the printing of elastomeric customizable scaffolds for a variety of tissue engineering applications.