Collaborative Research: Fluid Dynamics Foundations of Cell Printing

点击翻译按钮获取中文摘要

0936235/0936238Qiao/XuStructural cell printing (SCP), or printing three dimensional structures of cells held in a tissue matrix, has long been a fascinating idea. Drawing on the micrometer resolution of droplet based printing techniques, SCP holds the promise of achieving cell deposition resolution comparable to the size of a single cell. Achieving such a resolution in vitro will resolve one of the most fundamental challenges in tissue engineering and enable revolutionary breakthroughs in numerous areas. Despite significant concerns, in particular whether cells can survive the harsh printing process, the feasibility of SCP has been demonstrated recently. However, despite the explosive growth of research in SCP, such a technique is still in its infancy and many critical issues remain unresolved. Most importantly, the envisioned cell deposition resolution has yet to be achieved and the cell viability needs to be improved. Addressing these issues necessitates a thorough understanding of the SCP process. The objective of this project is to investigate a key step in the ink jet based SCP process, i.e., printing cell laden droplets onto a thin liquid film to form two dimensional cell patterns, using an integrated experimental and modeling approach. Two unit operations of this critical step will be studied, namely, the printing of a dot featuring a single cell (cell dot) and the printing of a line of cells (cell line). The study of cell dot printing will focus on elucidating the dynamics of a cell laden droplet impacting a liquid film with an emphasis on the spreading and penetration behavior of the droplet and the stress evolution of the cell, which govern the cell deposition resolution and cell viability. The study of cell line printing will focus on delineating the interactions between sequentially printed cell laden droplets and how these interactions affect the droplet liquid film impact, the stress of cells inside the droplets, and ultimately the cell deposition resolution and cell viability.Intellectual Merit: The proposed research is a pioneer study of the fluid dynamics involved in ink jet based SCP techniques. The insights gained here will provide a knowledge base for the rational design of SCP process to achieve optimal cell deposition resolution and cell viability, and thus will help remove critical barriers for this new technique to reach its fullest potential. By delineating the droplet and cell dynamics unique to the SCP process, e.g., the dynamics of cells in exceedingly strong shear flows at microsecond time scale, this research will also enrich the fluid dynamics theories of droplet and cell dynamics. The proposed research will benefit from the synergistic collaboration between two PIs with complementary expertise in cell printing and mutliphysics simulations, and is supported by state-of-the-art experimental and computing facilities.Broader Impacts: The project will be tied closely to the undergraduate graduate education at the PIs home institutions. Students participating in this interdisciplinary project will be exposed to diverse fields such as fluid dynamics, cell mechanics and bioengineering. Five undergraduate students will be involved in the research each year. Various resources, e.g., the minority recruitment programs at the PIs institutions, will be utilized to recruit students from underrepresented groups to participate in this project. Research results will be developed into movies for use in K-12 outreach activities and for submission to the gallery of fluid motion/image hosted by Efluid.com. To help disseminate research to lay audiences and to help them appreciate the significance of fluid dynamics research in developing useful technologies, we will develop a website named The Nerdy Side of Cell Printing. This website will explain the fluid dynamics involved in structural cell printing by using experiment/computer generated images and movies that are easily understandable to the general public. The website will be advertised to the target audience via formal and informal channels.