title: Biochemical consequences of alginate encapsulation: a NMR study of insulin-secreting cells.
abstract: In this study we explore the biochemical consequences of alginate encapsulation on betaTC3 cells. (13)C NMR spectroscopy and isotopomer analysis were used to investigate the effects of encapsulation on several enzymatic processes associated with the TCA cycle. Our data show statistically significant differences in various enzymatic fluxes related to the TCA cycle and insulin secretion between monolayer and alginate-encapsulated cultures. The principal cause for these effects was the process of trypsinization. Embedding the trypsinized cells in alginate beads did not have a compounded effect on the enzymatic fluxes of entrapped cells. However, an additional small but statistically significant decrease in insulin secretion was measured in encapsulated cells. Finally, differences in either enzymatic fluxes or glucose consumption as a function of bead diameter were not observed. However, differences in T(2), assessed by (1)H NMR microimaging, were observed as a function of bead diameter, suggesting that smaller beads became more organized with time in culture, while larger beads displayed a looser organization.
authors.affiliation: Department of Medicine, University of Florida, Gainesville, 32610, USA.
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Simpson
authors.forename: Samuel C
authors.initials: SC
authors.lastname: Grant
authors.forename: Lenita
authors.initials: L
authors.lastname: Gustavsson
authors.forename: Vilje-Mia
authors.initials: VM
authors.lastname: Peltonen
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Blackband
authors.forename: Ioannis
authors.initials: I
authors.lastname: Constantinidis
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000818:Animals; D021522:Bioartificial Organs; D018929:Cell Culture Techniques / Q000379:methods; D002478:Cells, Cultured; D002952:Citric Acid Cycle / Q000502:physiology*; D004339:Drug Compounding; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000378:metabolism*; D050417:Insulin-Secreting Cells / Q000166:cytology / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010316:Particle Size
chemical_list: D000464:Alginates; D007328:Insulin; D005947:Glucose