Athanassios Sambanis
Professor
Education
BS Chemical Engineering, National Technical University, Athens, Greece, 1979
PhD Chemical Engineering, University of Minnesota, Minneapolis, Minnesota, 1985
Post-Doctoral training at the Biotechnology Process Engineering Center, Massachusetts Institute of Technology (1987-1989)
Overview of Research Activities
The main focus of Dr. Sambanis’ research group is on developing core technologies for engineering metabolic and
secretory tissue substitutes, and specifically a pancreatic substitute for treatment of insulin-dependent
diabetes. The therapeutic approaches considered are shown schematically in the Figure below.
Allogeneic and xenogeneic cells can be pancreatic islets isolated from human or animal organs, continuous beta
pancreatic cell lines, or beta-like cells derived from stem cells. These cells are encapsulated for partial
immune protection from the host. For off-the-shelf availability, inventory management and sterility testing,
capsules need to be cryopreserved.
Autologous cells are potentially beta-like cells derived from adult stem or progenitor cells, or cells produced by
genetic engineering non-beta cells for insulin expression in response to physiologic stimuli. These cells could
be implanted either as such or in combination with biomaterials. Hopefully, the cells would be capable of ex
vivo amplification, so that some of them can be cryopreserved for later use by the same patient.
It is important to pursue these directions in parallel, as it is currently unclear which approach will eventually
yield a viable therapeutic procedure. However, it should be noted that the core technologies that need to be
developed in the two cases are quite different. For instance, with allo/xenogeneic cells, encapsulation and
immune acceptance issues are critical. With autologous cells, engineering these cells to acquire beta cell
characteristics, in particular insulin secretion and physiologic responsiveness, is one of the major challenges.
In our research group, we are developing enabling technologies intrinsic to both the autologous and
allo/xenogeneic cell approaches. Heather Bara is working on genetically engineering intestinal
endocrine L cells for insulin secretion in response to metabolic cues, and on developing implantable substitutes
based on these cells. Hajira Ahmad and Alison Stucky are developing and characterizing
ice-free cryopreservation (vitrification) methods for encapsulated insulin-secreting cell
systems. Fernie Goh is studying the effect of perfluorocarbons (PFC) on encapsulated cell viability and
function and also developing methods to non-invasively monitor encapsulated cell systems in vitro and in vivo.
Saif Al-Mamari is developing and using bioreactor systems for neonatal porcine islet maturation in vitro
and for assessing their metabolic and secretory competency.