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Simpson Lab

Nick Simpson, PhD


Dr. Simpson received his Ph.D. in Cancer Biology from Wayne State University, Detroit MI, in 1997. As a graduate student under the mentorship of Dr. Jeffrey Evelhoch, he was a recipient of an institutional NRSA Training grant and a grant from the American Cancer Society. He trained as a post-doctoral fellow under the direction of Dr. Ioannis Constantinidis at Emory University, Atlanta GA, and was the recipient of an individual NRSA Fellowship. Dr. Simpson joined the University of Florida Faculty of the Department of Medicine in the Division of Endocrinology in January 2002.

Research Focus

Presently, Dr. Simpson directs research in the Endocrinology Division’s Laboratory for Tissue Engineering, and he is the principal investigator on a number of currently funded grants. A major research focus of the Laboratory for Tissue Engineering is concerned with developing, engineering and characterizing a tissue construct comprised of insulin-secreting cells entrapped in a matrix (an aptly named ‘bioartificial pancreas’). These substitutes may someday be used as a replacement for the insulin-secreting cells that have failed in patients with diabetes (particularly type 1). We now have taken the bioartificial pancreas into the animal model  and are obtaining in vivo images and spectroscopic data with nuclear magnetic resonance (NMR) techniques.  This work also entails the development of implantable NMR coils and circuits.  Furthermore, through bioanalytical, histological, and NMR spectroscopic and imaging techniques, the relationship between cellular function and the composition of the construct is being elucidated. Though much is known about the mechanism of insulin secretion, the significance of bioenergetic status with regard to secretion remains poorly understood. By identifying critical metabolic pathways, new targets for engineering metabolically superior surrogate cell lines can be distinguished. These approaches have major implications for the research of any cell system where energetics plays a role in the function of the cell. Additionally, we are studying mitochondrial processes in diabetes, cancer, and rare inborn errors of metabolism using NMR spectroscopic techniques and computer modeling analysis.

Selected Collaborations

Stephen Blackband, PhD. University of Florida, Department of Neuroscience. Development of a noninvasive method to monitor the in vivo function of an implanted insulin-secreting construct with NMR spectroscopy and imaging, and on NMR methods to monitor metabolism of glutathione and other antioxidants.

Thomas Mareci, PhD.  University of Florida, Department of Biochemistry & Molecular Biology.  We collaborate on the development of a noninvasive method to monitor the in vivo function of an implanted insulin-secreting construct through NMR spectroscopy and imaging; and the development of novel NMR coil technology to noninvasively switch to desired radiofrequencies with little loss in sensitivity.

Athanassios Sambanis, PhD. Georgia Institute of Technology, School of Chemical & Biomolecular Engineering.  Currently, we collaborate on three projects related to the bioartificial pancreas: developing NMR imaging and spectroscopic methods to determine the impact of cryogenic storage of bioartificial insulin-secreting constructs; developing a pancreatic substitute based on insulin-secreting recombinant hepatocytes and intestinal endocrine cells; and the development of NMR techniques to monitor the bioartificial pancreas in vivo.

Peter Stacpoole, PhD, MD. University of Florida, Clinical & Translational Science Institute. We collaborate on studies looking at the response of rare inborn errors of metabolism to potential therapies through NMR spectroscopy, and monitoring mitochondrial metabolism with fluorescent and flow cytometry techniques.

Staff

Mark Beveridge, MS

Mark Beveridge is a Senior Biological Scientist and has been a member of the Simpson lab since 2007.  He received his Bachelor’s of Science degree at Gannon University and his Master’s of Science at Old Dominion University.  He has been a scientist at the University of Florida since 1986 and presently serves as the technical, research and administrative staff of the laboratory.  Mark’s research interests and expertise are diverse, and he shares his knowledge and enthusiasm with the students who work within the lab.  He has enjoyed his time working in Dr. Simpson’s lab.

 

Selected Publications

For the most updated list of publications, please follow this link.

Volland NA, Mareci TH, Constantinidis I, Simpson NE.  Development of an inductively-coupled MR coil system for imaging and spectroscopic analysis of an implantable bioartificial construct at 11.1T.  Mag. Reson. Med., in press, 2009.

Constantinidis I, Grant SC, Simpson NE, Oca-Cossio JA, Sweeney CA, Mao H, Blackband SJ, Sambanis A.  Use of magnetic nanoparticles to monitor alginate encapsulated cells.  Mag. Reson. Med., 61:282-290, 2009.

Tsai YY, Oca-Cossio J, Agering K, Simpson NE, Atkinson MA, Wasserfall CH, Constantinidis I, Sigmund W.  Novel synthesis of cerium oxide nanoparticles for free radical scavenging.  Nanomedicine, 2:321-328, 2007.

Constantinidis I, Grant SC, Celper S, Gauffin-Holmberg I, Agering K, Oca-Cossio JA, Bui JD, Flint J, Hamaty C, Simpson NE, Blackband SJ. Non-invasive evaluation of alginate/poly-L-lysine/alginate microcapsules by magnetic resonance microscopy.  Biomaterials, 28:2438-2445, 2007.

Simpson NE, Han Z, Berentzen KM, Sweeney CA, Oca-Cossio J, Constantinidis I, Stacpoole PW.  Magnetic resonance spectroscopic investigation of mitochondrial fuel metabolism and energetics in cultured human fibroblasts: Effects of pyruvate dehydrogenase complex deficiency and dichloroacetate.  Mol. Genet. Met., 89:97-105, 2006.

Simpson NE, Khokhlova N, Oca-Cossio J, Constantinidis I.  Insights into the role of anaplerosis in insulin secretion: a 13C NMR study.  Diabetologia, 49:1338-1348, 2006.

Simpson NE, Grant SC, Gustavsson L, Peltonen V-M, Blackband SJ, Constantinidis I. Biochemical consequences of cell encapsulation a NMR study of insulin-secreting cells.  Biomaterials, 27:2577-2586, 2006.

Simpson NE, Khokhlova N, Oca-Cossio JA, McFarlane SS, Simpson CP, Constantinidis I.  Effects of growth regulation on conditionally-transformed alginate-entrapped insulin secreting cell lines in vitro.  Biomaterials.  26:4633-4641, 2005.

Simpson NE, Stabler CL, Sambanis A, Constantinidis I.  The role of CaCl2-guluronic acid interaction on alginate encapsulated bTC3 cells.  Biomaterials.  25:2603-2610, 2004.

Simpson NE, Grant SC, Blackband SJ, Constantinidis I.  NMR properties of alginate microbeads.  Biomaterials.  24:4941-4948, 2003.

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