Cell and Tissue-based Therapies for Insulin-Dependent Diabetes
Athanassios Sambanis, Ph.D.
National Science Foundation
Athanassios Sambanis will present a two-part talk. The first part focuses on the research of his laboratory on cell and tissue-based therapies for diabetes, while the second part describes the Biomedical Engineering Program at NSF.
Part A: A living biological substitute for treatment of insulin-dependent diabetes has significant potential in providing a less invasive, more physiologic regulation of blood glucose levels than insulin injections.
The critical technologies needed for such a substitute depend on the type of cells used. With cells from another individual (allogeneic) or another species (xenogeneic), encapsulation in semipermeable barriers improves immune acceptance, as it inhibits passage of antibodies and excludes cytotoxic cells of the host. However, immune protection is not complete, and immune suppression may still be needed to prolong survival of the graft. Non-pancreatic cells from the same patient (autologous), targeted by gene transfer vectors or retrieved surgically and genetically engineered ex vivo before being returned to the patient, may relax the immune acceptance problems but pose challenges regarding the amount and kinetics of insulin secretion in response to physiologic stimuli. Stem and progenitor cells constitute another promising cell source, however, their reproducible differentiation into pancreatic cells presents significant challenges.
In his laboratory, his team focuses on encapsulated allo- and xenogeneic pancreatic cells and on non-pancreatic cells genetically engineered to secrete insulin in response to physiologic stimuli. With encapsulated cells, the team is developing methods to improve immunoprotection by combining the semipermeable barrier with the local presentation and delivery of pro-survival and insulinotropic factors. Furthermore, they develop technologies for cryopreservation of encapsulated cells and for monitoring grafts in minimally invasive or non-invasive ways. With non-pancreatic cells, they genetically engineer hepatic and intestinal endocrine L cells for insulin secretion. The potential and challenges of each of these approaches will be discussed.
Part B: The second part of the talk will focus on an overview of the Biomedical Engineering (BME) Program at NSF. The overall objectives of the program will be presented, as will be funding opportunities and activities sponsored by the program. The program thrust areas of (i) cellular, molecular and tissue approaches for advanced biomanufacturing, and (ii) neural engineering and human brain mapping, will be discussed in the context of their significance within the biomedical field and of funding prospects offered to investigators.
Sambanis received his PhD in Chemical Engineering from the University of Minnesota. Following his postdoctoral appointment at the Massachusetts Institute of Technology Biotechnology Process Engineering Center, he joined the Georgia Institute of Technology in 1989, where he is currently professor in the School of Chemical & Biomolecular Engineering and in the Emory/Georgia Tech Department of Biomedical Engineering. As of September 2013, he is a rotator at the National Science Foundation, where he serves as Director of the Biomedical Engineering Program.
His research interests are in cellular and tissue engineering, and specifically in developing cell and tissue-based therapies for diabetes, including cell encapsulation, genetic engineering of cells for insulin secretion, monitoring of tissue constructs in vitro and post-transplantation in vivo, cell and tissue cryopreservation, cell and tissue functional evaluation, and mathematical modeling at the tissue, cell, and intracellular levels. He has authored or co-authored more than 85 book chapters and journal publications. He is a Fellow of the American Institute for Medical and Biological Engineering. His research is currently supported by NIH and the Juvenile Diabetes Research Foundation.