This Faculty Early Career Development (CAREER) Program award supports fundamental research to provide needed knowledge for the development of a novel additive manufacturing process using soft, tissue-like hydrogels. Additive manufacturing for biological applications, also called 3D bioprinting, has the potential to revolutionize the fabrication of medical devices and engineered tissues by making custom shapes that can integrate with a person's unique anatomy. However, additive manufacturing processes that work well for metal or plastic parts are unable to print with hydrogels and living cells at high fidelity. This new process will enable deposition of hydrogels and cells in complex 3D structures and will be used to bioprint heart muscle. Scaffolds and parts made from biological hydrogels are preferred for interfacing with living cells and tissues and are needed in the healthcare and biomedical industries. Therefore, results from this research will benefit the U.S. economy and society and spur growth in biofabrication. This research involves several disciplines including manufacturing, biology, mechanical engineering, and materials science. This multi-disciplinary approach will help to broaden participation of underrepresented groups in research. The research team will positively impact engineering education by integrating 3D bioprinting into undergraduate curriculum and creating low-cost bioprinting kits for K-12 education.
This new hydrogel additive manufacturing process has advantages over existing additive manufacturing techniques because it can support deposition of hydrogels and cells in complex 3D structures that would collapse under their own weight if 3D printed in air. However, there are scientific barriers that need to be overcome to realize the full potential of this process and improve resolution, fidelity, and cell viability. This research is focused on understanding fundamental mechanism(s) of hydrogel formation within a thermo-reversible support bath composed of microparticles that acts as a viscoplastic during the print process and then is non-destructively removed using a thermal trigger. The objective of the research is to determine (1) effects of hydration and size of the microparticles on rheological properties of the support bath; (2) effects of support bath's rheological properties on resolution, fidelity, and pore size of the 3D printed hydrogel structure; and (3) effects of process parameters on cellular integration and the ability to print functional heart muscle.
