Microenvironment-dependent respiration of T-47D cells cultured in alginate biostructures.

Abstract

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). 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. 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. Presence of FBS in biostructure matrices elicited higher OCR in T-47D cells. Formulation of biostructures must consider differential diffusion of macromolecular substances.