Figure 4. In order to examine whether CCCL matrices without islets can be vascularized in vivo the CCCL matrixes were implanted subcutaneously in immunoincompetent BALB/c mice and retrieved after 7 (A), 14 (B), 21 (C) and 28 d (D). The grafts were fixed and paraffin-embedded; sections were stained for von Willebrand Factor (vWF), hemotoxylin, and eosin. All scale bars are 100 µm. Arrows indicate vWF positive cells (A) and capillaries (B–D).