UC San Diego

Digital light processing (DLP)-based 3D printing is an emerging 3D printing technology that allows for the fabrication of tissue-engineered scaffolds with complex microarchitecture mimicking that of native tissue with high fidelity and resolution in a matter of a few seconds to minutes. This doctoral dissertation explores the application of light-based 3D printing, specifically the fabrication of poly(glycerol sebacate) acrylate (PGSA) scaffolds, for treating volumetric muscle loss (VML) and muscle-tendon junction (MTJ) ruptures. First, the scaffold’s mechanical properties were tuned to match those of native skeletal muscle by adjusting light intensity used during the 3D printing process. Cellular response to the tissue-engineered scaffold in terms of muscle progenitor cell infiltration, alignment, proliferation, and differentiation was evaluated both in vitro and in vivo. Next, a novel light-based 3D printing workflow to create a complex, multi-scale elastomeric scaffold with user-defined regional stiffness control through the adjustment of 3D printing parameters was explored. This developed 3D printing workflow was demonstrated to have great potential in fabricating elastomer-based scaffolds for interfacial tissue engineering applications, which demand high spatial control of 3D printed scaffold’s mechanical properties. The final section of this dissertation applied DLP-based 3D printing to fabricate PGSA-based muscle-tendon scaffolds featuring regional mechanical variations for MTJ repair. These scaffolds, exhibiting microstructure and mechanical properties akin to native muscle-tendon tissue, showed high cell viability post-seeding and expressed MTJ-related markers. This dissertation sets the stage for further investigations into the utilization of 3D printed elastomer-based scaffolds, potentially transforming treatment for patients with muscle-related injuries and degenerative conditions.