Fig. 5
Microencapsulated islets maintain regulated insulin secretion. a, b Phase contrast images of Alg-PEG microencapsulated islets (104 IEQ/ml Alg-PEG) (a) and islets coencapsulated with 8 × 105 MSC (b). c Insulin secretion by microencapsulated islets (islets Alg-PEG) and islets coencapsulated with MSC (islets-MSC Alg-PEG) at 3 days after encapsulation. Microencapsulated islets (150 IEQ) were incubated at basal glucose (2.8 mM, white bars), high glucose concentration (16.7 mM, striped bars), and high glucose plus theophylline (16.7 and 5 mM, respectively, black bars) for 1 h. Values of secreted insulin are normalized to the total insulin amount and expressed as fold increase where the basal level was set at 1. Data presented as mean value ± SEM of three islet donors, and for each donor the assay was performed in triplicate. Wilcoxon signed-rank test: ***p < 0.001