Objectives Skin serves as the major interface between the external environment and body which is liable to many kinds of injuries. Mesenchymal stem cell (MSC) therapy has been widely used and became a promising strategy. Pre‐treatment with chemical agents, hypoxia or gene modifications can partially protect MSCs against injury, and the pre‐treated MSCs show the improved differentiation, homing capacity, survival and paracrine effects regard to attenuating injury. The aim of this study was to investigate whether the exosomes from the educated MSCs contribute to accelerate wound healing process. Materials and methods We extracted the exosomes from the two educated MSCs and utilized them in the cutaneous wound healing model. The pro‐angiogenetic effect of exosomes on endothelial cells was also investigated. Results We firstly found that MSCs pre‐treated by exosomes from neonatal serum significantly improved their biological functions and the effect of therapy. Moreover, we extracted the exosomes from the educated MSCs and utilized them to treat the cutaneous wound model directly. We found that the released exosomes from MSCs which educated by neonatal serum before had the more outstanding performance in therapeutic effect. Mechanistically, we revealed that the recipient endothelial cells (ECs) were targeted and the exosomes promoted their functions to enhance angiogenesis via regulating AKT/eNOS pathway. Conclusions Our findings unravelled the positive effect of the upgraded exosomes from the educated MSCs as a promising cell‐free therapeutic strategy for cutaneous wound healing.

Adult stem cell therapy for the treatment of tendon injuries is a growing area of research. This study is aimed to investigate the efficacy of human adipose-derived stem cell (hADSC) injection on the tendon during its healing process in a rat model of rotator cuff injury. hADSCs were injected 3 days after collagenase-induced rotator cuff injuries in experimental groups, while the control group received saline as a placebo. Histological and biomechanical analyses were performed 7, 14, 21, and 28 days after collagenase injection. Compared to the control group, it was found that inflammatory cells were significantly decreased in the hADSC-treated group after collagenase injection for 7 and 14 days. In the hADSC-injected group, the fiber arrangement and tendon organization had also been improved. On the seventh day after collagenase injection, the load to failure of the hADSC-injected group (15.87 ± 2.20 N) was notably higher than that of the saline-injected group (11.20 ± 1.35 N). It is suggested that the tensile strength of the supraspinatus tendon was significantly enhanced. Local administration of hADSCs might have the possibility to restore the tensile strength and attenuate the progression of tendinitis. Taken together, these findings demonstrate that the recovery processes in damaged tendons can be facilitated architecturally and functionally after hADSC injection.

BackgroundSkeletal muscle plays an important role in the body’s physiology but there are still no effective treatments for volumetric muscle loss (VML) resulting from severe traumatic injury or tumor excision. Recent studies show that a tissue engineering strategy using a compound containing mesenchymal stem cells (MSCs) and decellularized extracellular matrix (ECM) scaffold generates significant regenerative effects on VML injury, but the underlying mechanisms are not fully understood.MethodsThe characteristics of human umbilical cord MSCs, including multiplication capacity and multidifferentiation ability, were determined. We constructed a compound containing MSCs and decellularized ECM scaffold which was used for tissue regeneration in a VML model.ResultsWe found that MSCs and decellularized ECM scaffold generated synergistic effects on promoting skeletal muscle tissue regeneration. Interestingly, both MSCs and decellularized ECM scaffold could promote macrophage polarization toward the M2 phenotype and suppress macrophage polarization toward the M1 phenotype, which is widely regarded as an important promoting factor in tissue regeneration. More importantly, MSCs and decellularized ECM scaffold generate synergistic promoting effects on macrophage polarization toward the M2 phenotype, not just an additive effect.ConclusionsOur findings uncover a previously unknown mechanism that MSCs and decellularized ECM scaffold promote tissue regeneration via collaboratively regulating macrophage polarization.Electronic supplementary materialThe online version of this article (10.1186/s13287-018-0821-5) contains supplementary material, which is available to authorized users.

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The total synthesis of ganglioside 2, an analogue of the ganglioside Hp-s1 (1) which displays neuritogenic activity toward the rat pheochromocytoma cell line PC-12 cell in the presence of nerve growth factor (NGF) with an effect (34.0%) greater than that of the mammalian ganglioside GM 1 (25.4%), was accomplished by applying a chemoselective-activation glycosylation strategy. Moreover, we also demonstrate that the synthesized ganglioside 2 exhibited neuritogenic activity toward the human neuroblastoma cell line SH-SY5Y without the presence of NGF.