Fig. 6From: The co-culture of ASCs and EPCs promotes vascularized bone regeneration in critical-sized bone defects of cranial bone in ratsImmunostaining of VEGF in the newly formed bone (a–d) (a blank control group, b HA/Col group, c HA/Col+ASC group, d HA/Col+ASC+EPC group). e Quantitative analysis of blood vessel density. *p < 0.05Back to article page