NSF/FDA SIR: Assurance of Cellular Function in High-Shear Three-Dimensional Bioprinting

University Of Kentucky Research Foundation, Lexington KY

Investigators

Abstract

Despite rigorous testing of drugs and medical devices in animals, many products fail in early stage human testing. These failed products have the potential to result in adverse health outcomes for trial participants and billions in lost capital each year. The manufacturing of artificial human tissue samples is a potential way of predicting human response to new, regulated products. These manufacturing processes are being designed to use special bioprinters to print human cells in three dimensional (3D) constructs. The goal is to use these synthetic tissues as another screening step to reveal potential hazards of new medical products before they enter human testing. The eventual goal would be that only the safest, most effective products reach human testing. The 3D printing process, however, exerts mechanical forces on the cells and leads to cellular dysfunction or death. This project is a collaboration between researchers in biomaterials at the University of Kentucky and cellular biomechanics and bioprinting experts at the United States Food & Drug Administration to determine how 3D printing procedures may change the way cells behave. Changes in cellular physiology and behavior can, in turn, affect the usefulness of the artificial tissues for medical product screening. As a result of this work, researchers will be able to better predict if printed cells will return to their natural function and how long after being printed this function will be restored. With this new information, researchers will be able to develop and evaluate new methods to preserve normal cellular function during tissue manufacturing. During this project, the research team will also develop publicly available, educational tools that describe the science and engineering concepts underlying three dimensional bioprinting. This project seeks to determine how 3D bioprinting affects cellular physiology, in particular cellular membrane transport. It is known that the high shear environment of the bioprinting nozzle impacts cellular response; however, the precise changes in the cells and whether normal function can be recovered within a range of bioprinting parameters has not been assessed. This gap in knowledge makes it difficult to determine if a 3D printed tissue actually will replicate normal (or defined pathological) physiology -- a key feature if such bioprinted tissue structures are going to be used for pre-clinical assessment of drugs or medical devices. The scientific objectives of this proposal are to: 1) quantify the magnitude and timescale of unnatural transport across the cell membrane, including multiple forms of active and passive transport, following simulated extrusion bioprinting; and 2) quantify how cellular coatings, which are hypothesized to protect cells from mechanical damage, affect the extrusion-based alterations in cellular membrane transport. In addition to measurements of membrane transport, appropriate assays for basic cell function and viability will also be conducted for each cell type. Experiments will be conducted using five cell lines (HepG2 - hepatic; Caco2 - intestinal; H9C2 - myocardial; A549 - human lung carcinoma; and mesenchymal stem cells), each of which is of current interest in the biomanufacturing arena. This collaboration will result in mutual education, with the post-doctoral fellow becoming trained in the area of regulatory affairs and the PI educating CDRH (Center for Devices and Radiologic Health) team members at the FDA on emerging technology for encapsulated cell systems and devices. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.