Figure 2.

Effects of accurate and proactive immunomodulation via IL-4 on DBM-mediated osteogenesis and angiogenesis in large cranial bone defects. Four doses of IL-4 (0 ng, 10 ng, 50 ng and 100 ng) were used. (A) 3D and coronal micro-CT images of the cranial bone defects at 6 and 12 weeks showing the best defect healing outcome, with complete defect bridging at 12 weeks, in the 10 ng group. This was followed by the 50 ng and 0 ng group, with partial defect bridging; the 100 ng group exhibited non-union healing. Bar = 1 mm. (B) Ratio of bone volume/total volume (BV/TV) and (C) bone mineral density (BMD) showing that the 10 ng group had the highest amount of bone tissue. (D) Micro-CT angiography. The blood vessels were perfused with Microfil. Yellow circles indicate bone defect regions. Bar = 1 mm. (E-G) Summary of micro-CT angiography results. Bar charts showed that the (E) volume of newly-formed vasculature, (F) microvessel connectivity and (G) vascular thickness were greater in the 10 ng group, indicating the most vascular development, compared with the other groups. For all charts, the groups designated by different uppercase letters or lowercase letters were significantly different (p < 0.05).