Extrusion Based Bioprinting: An In Vitro Model for Dental Pulp Tissue Engineering

Although more than 16 million endodontic procedures are performed in the United States annually, reinfections and tooth fractures have prompted recent advances in tissue engineering approaches for pulp regeneration. Barriers to viable scaffold designs include combining an optimal cell source with desired material properties that facilitate cellular nutrient transport requirements. Use of mesenchymal stem cells from human dental pulp stem cells (hDPSCs) have shown promise in pulp/dentin regeneration efforts. However, populating these cells into tissue analogues that closely mimic in vivo architecture in both structure and function will require additional research. Three-dimensional (3D) bioprinting is an innovative approach that may overcome the limitations of conventional scaffold design methods by enabling controlled manufacturing of both cellular and extracellular components of a target tissue. This project seeks to expand current knowledge of hDPSC behavior by utilizing extrusion-based bioprinting (EBB) as an in vitro model for dental pulp tissue engineering. We hypothesized that photopolymerized gelatin-methacrylate bioink could be tuned to mimic the viscoelastic properties of human dental pulp tissue. This dissertation considers the following three aims: (1) Rheological characterization of gelatin methacrylate bioink (2) Bioink optimization for human dental pulp stem cell viability and (3) Viscoelastic tuning of gelatin-methacrylate for human dental pulp tissue mimicry. This research offers a foundational platform to investigate hDPSC behavior in 3D using EBB.