Event
Bioengineering Seminar Series: John Fisher
Friday, February 1, 2013
11:00 a.m.-11:45 a.m.
Room 1200, Jeong H. Kim Engineering Building
Professor Ian White
ianwhite@umd.edu
Bridging Stem Cell Technology with Tissue Vascularization in Tissue Engineering
John P. Fisher
Professor and Associate Chair
Director of Graduate Studies
Fischell Department of Bioengineering
University of Maryland
Blood vessels are an integral part of the circulatory system as they provide a mechanism for the transport of oxygen, carbon dioxide, nutrients, and waste. A major challenge in regenerative medicine, however, is that engineered tissues cultured in the laboratory and subsequently implanted into a tissue defect site often lack a similar mechanism for cellular respiration. A lack of proper nutrition can result in hypoxia, non-uniform cell distribution, altered stem cell differentiation, and ultimately decreased tissue function. Ultimately, In vitro and in vivo nutrient transfer limits must be overcome in order to increase the feasibility of stem cell based therapeutic strategies. In this presentation, we will explore the interplay between stem cell based engineered tissues and tissue vascularization strategies. To enhance in vitro nutrient transport, we have recently develop a novel tubular perfusion system (TPS) that consists of a bioreactor for culture of human mesenchymal stem cells in three dimensional scaffolds. This system utilizes an elegant design to create an effective cell culture environment without the drawbacks often associated with more complicated perfusion systems. The TPS design consists of hMSCs encapsulated in alginate beads which are tightly packed in a tubular growth chamber. Perfusing media through this growth chamber enhances nutrient transfer while exposing the cells to shear stress. To consider in vivo vascularization, we will explore concepts related to the templating a prevascular network with an engineered tissue. Finally, recent efforts in our laboratory have focused on the development of small diameter vascular grafts. We will present novel approaches for the development and characterization of these grafts, as well as discuss their ultimate integration into engineered tissues. Overall, we aim to establish new strategies in regenerative medicine based upon the integration of vascularization into stem cell based engineered tissues.
