Human amniotic epithelial cells (hAECs) are nontumorigenic, highly abundant, and low immunogenic and possess multipotent differentiation ability, which make them become ideal alternative stem cell source for regenerative medicine. Previous studies have demonstrated the therapeutic potential of hAECs in many tissue repairs. However, the therapeutic effect of hAECs on diabetic wound healing is still unknown. In this study, we injected hAECs intradermally around the full-thickness excisional skin wounds of db/db mice and found that hAECs significantly accelerated diabetic wound healing and granulation tissue formation. To explore the underlying mechanisms, we measured inflammation and neovascularization in diabetic wounds. hAECs could modulate macrophage phenotype toward M2 macrophage, promote switch from proinflammatory status to prohealing status of wounds, and increase capillary density in diabetic wounds. Furthermore, we found that the hAEC-conditioned medium promoted macrophage polarization toward M2 phenotype and facilitated migration, proliferation, and tube formation of endothelial cells through in vitro experiments. Taken together, we first reported that hAECs could promote diabetic wound healing, at least partially, through paracrine effects to regulate inflammation and promote neovascularization.

Hypertrophic scar pain, pruritus, and paresthesia symptoms are major and particular concerns for burn patients. However, because no effective and satisfactory methods exist for their alleviation, the clinical treatment for these symptoms is generally considered unsatisfactory. Therefore, their risk factors should be identified and prevented during management. We reviewed the medical records of 129 postburn hypertrophy scar patients and divided them into two groups for each of three different symptoms based on the University of North Carolina "4P" Scar Scale: patients with scar pain requiring occasional or continuous pharmacological intervention (HSc pain, n = 75) vs. patients without such scar pain (No HSc pain, n = 54); patients with scar pruritus requiring occasional or continuous pharmacological intervention (HSc pruritus, n = 63) vs. patients without such scar pruritus (No HSc pruritus, n = 66); patients with scar paresthesia that influenced the patients' daily activities (HSc paresthesia, n = 31) vs. patients without such scar paresthesia (No HSc paresthesia, n = 98). Three multivariable logistic regression models were built, respectively, to identify the risk factors for hypertrophic burn scar pain, pruritus, and paresthesia development. Multivariable analysis showed that hypertrophic burn scar pain development requiring pharmacological intervention was associated with old age (odds ratio [OR] = 1.046; 95% confidence interval [CI], 1.011-1.082, p = 0.009), high body mass index (OR = 1.242; 95%CI, 1.068-1.445, p = 0.005), 2-5-mm-thick postburn hypertrophic scars (OR = 3.997; 95%CI, 1.523-10.487, p = 0.005), and 6-12-month postburn hypertrophic scars (OR = 4.686; 95%CI, 1.318-16.653, p = 0.017). Hypertrophic burn scar pruritus development requiring pharmacological intervention was associated with smoking (OR = 3.239; 95%CI, 1.380-7.603; p = 0.007), having undergone surgical operation (OR = 2.236; 95%CI, 1.001-4.998; p = 0.049), and firm scars (OR = 3.317; 95%CI, 1.237-8.894; p = 0.017). Finally, hypertrophic burn scar paresthesia development which affected the patients' daily activities was associated with age (OR = 1.038; 95%CI, 1.002-1.075; p = 0.040), fire burns (OR = 0.041; 95%CI, 0.005-0.366; p = 0.004, other burns vs. flame burns), and banding and contracture scars (OR = 4.705; 95%CI, 1.281-17.288, p = 0.020).