Fig. 2.

Module-associated vascularization. (A) Module-associated vasculature was characterized by staining with CD31 and SMA in serial sections at day 21. CD31⁺ vessels (black arrows, Upper Row) were present in all groups, including the without-HUVEC group, and many of these vessels were also positive for SMA, suggesting that the vessels were mature. (Scale bars: 200 μm.) (B) CD31 vessel counts. There were significantly more vessels when islet modules were coated with HUVEC (n = 6) than without HUVEC (n = 5) at days 7 and 14 (two-sided t test). At day 21 the density of CD31⁺ vessels was similar between the two module groups (P > 0.05). Islet modules without HUVEC degraded over time, and not many implants could be found at day 21. n = 5 for islet modules with HUVEC and n = 2 for islet modules without HUVEC at day 21. *P < 0.05, **P < 0.01; error bars indicate SEM.