Figure 1. Glucose stimulated insulin secretions of control and collagen embedded NPIs were measured following 1 and 4 d in culture. The stimulation indices (SI) were determined by dividing the amount of insulin released at high glucose (20.0 mM) by that at low glucose (2.8 mM). The stimulation indices were subsequently normalized to the non-embedded control values. The stimulation indices for the control Ham's F10 condition after 1 and 4 d in culture were 1.42 ± 0.48 and 1.05 ± 0.18, respectively. Data are expressed as mean ± SEM (n = 6 per time point).