title: Microenvironment-dependent respiration of T-47D cells cultured in alginate biostructures.
abstract: OBJECTIVE
  The main objective of this paper was to investigate whether the oxygen consumption rate (OCR) of cells entrapped in alginate hydrogels depends on presence of soluble factors present in foetal bovine serum (FBS).
  
  
  METHODS
  Pericellular oxygen concentrations were measured using a photochemical oxygen sensor inserted into bioconstructs made from different formulations of alginate, containing T-47D cells. Cell count was corrected for viability as determined by cell uptake and exclusion of standard live/dead fluorophores, in sections of freshly prepared biostructures. Based on concentration data, OCR of the embedded cells was calculated according to a simple algorithm.
  
  
  RESULTS
  OCR was found to vary significantly between the different formulations investigated. Inclusion of high concentrations of FBS in the biostructure matrices elicited significantly higher OCRs, in guluronate-rich gels similar to those previously found in monolayer culture. Guluronate-rich gels also generally permitted highest OCR. Respiration also had a falling tendency with increasing alginate concentration and elastic modulus.
  
  
  CONCLUSIONS
  Presence of FBS in biostructure matrices elicited higher OCR in T-47D cells. Formulation of biostructures must consider differential diffusion of macromolecular substances.
authors: School of Pharmacy, University of Oslo, Oslo, Norway.
authors: Benjamin Endré
authors: BE
authors: Larsen
authors: Erik Olai
authors: EO
authors: Pettersen
authors: Hanne Hjorth
authors: HH
authors: Tønnesen
authors: Jan Egil
authors: JE
authors: Melvik
mesh_terms: D000464:Alginates / Q000737:chemistry / Q000494:pharmacology*; D000465:Algorithms; D000818:Animals; D015374:Biosensing Techniques; D002417:Cattle; D002452:Cell Count; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D019069:Cell Respiration / Q000187:drug effects* / Q000502:physiology; D002470:Cell Survival; D018914:Cells, Immobilized; D055119:Elastic Modulus; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005333:Fetus; D005782:Gels; D020723:Glucuronic Acid / Q000737:chemistry / Q000494:pharmacology; D006603:Hexuronic Acids / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D010101:Oxygen Consumption / Q000187:drug effects* / Q000502:physiology; D044967:Serum / Q000737:chemistry
chemical_list: D000464:Alginates; D005782:Gels; D006603:Hexuronic Acids; C007896:guluronic acid; D020723:Glucuronic Acid