The skin is one of the most vital organs in the human body, and skin wounds caused by various factors can severely impact patients’ physical and mental health. Among the therapeutic strategies for skin wound repair, mesenchymal stem cell-derived exosomes (MSC-Exos) have emerged as a promising biological therapy, attracting significant attention in related research. As critical mediators of stem cell biological effects, MSC-Exos fuse with target cells and transfer bioactive proteins and nucleic acids from stem cells into recipient cells. These exosomes modulate inflammatory responses, promote cell proliferation, migration, and angiogenesis, and regulate extracellular matrix remodeling, thereby accelerating wound healing. In recent years, studies on the mechanisms by which exosomes promote skin wound repair have advanced and refined continuously. This article summarized the key signaling pathways through which MSC-Exos participate in skin wound repair, aiming to enhance the understanding of their roles in facilitating wound healing.

The skin is one of the most vital organs in the human body, and skin wounds caused by various factors can severely impact patients’ physical and mental health. Among the therapeutic strategies for skin wound repair, mesenchymal stem cell-derived exosomes (MSC-Exos) have emerged as a promising biological therapy, attracting significant attention in related research. As critical mediators of stem cell biological effects, MSC-Exos fuse with target cells and transfer bioactive proteins and nucleic acids from stem cells into recipient cells. These exosomes modulate inflammatory responses, promote cell proliferation, migration, and angiogenesis, and regulate extracellular matrix remodeling, thereby accelerating wound healing. In recent years, studies on the mechanisms by which exosomes promote skin wound repair have advanced and refined continuously. This article summarized the key signaling pathways through which MSC-Exos participate in skin wound repair, aiming to enhance the understanding of their roles in facilitating wound healing.

Objective To evaluate the therapeutic effect of poloxamer hydrogel loaded with exosomes derived from human dental pulp stem cells genetically modified with human hepatocyte growth factor against radiation skin injuries.Methods Human dental pulp stem cells derived exosomes(DPSC-Exo)and hepatocyte growth factor modified DPSC-Exo(HGF-DPSC-Exo)were extracted via ultracentrifugation separation,identified in terms of particle size and morphology,and analyzed separately by means of nanoparticle tracking analysis and scanning electron microscopy(SEM),while exosome marker proteins were determined by Western blot.Then,the effect of exosomes on radiation-damaged skin cells was assessed.The poloxamer hydrogel was prepared and its safety was evaluated with CCK-8.A mouse model of injury combined with radiation injury was established,and the therapeutic effect of hydrogel loaded with exosomes was determined based on wound size,HE and Masson staining.Furthermore,the underlining therapeutic mechanism was explored with Tunnel assay,malondialdehyde content and peroxidase activity.Results The diameter exosomes ranged from 30 to 150 nm and their morphology was a disc-shaped vesicle under SEM.Moreover,CD9,CD63 and TSG101 were expressed.The results of cellular experiments showed that exosomes significantly promoted the proliferation and migration of radiation-damaged skin keratinocytes and fibroblasts,and reduced their apoptosis.HGF modification enhanced the healing effect of exosomes.Poloxamer hydrogel showed good temperature-sensitive properties and biocompatibility.The results of animal experiments showed that exosomes significantly accelerated the healing of radiation-combined injuries in mice,inhibited inflammatory infiltration and mitigated collagen deposition in the wound.Interestingly,the healing effect in the group treated with hydrogel loaded with exosomes was the best.The underlining mechanism was possibly related to promotion of cell proliferation and inhibition of apoptosis and oxidative stress.Conclusion A novel poloxamer hydrogel loaded HGF-DPSC-Exo has been prepared and its therapeutic effect against radiation combined injury has been proved,thus providing a new strategy for the treatment of radiation skin injury in clinic.

BACKGROUND:Skin damage caused by radiation therapy and nuclear accidents is still a serious medical problem.It is difficult to achieve effective treatment results with single prevention and treatment methods.It is an important research direction to find new comprehensive treatment methods. OBJECTIVE:To observe the protective effect and the underlying mechanism of 1,2-propanediol combined with hepatocyte growth factor-modified exosomes derived from dental pulp stem cells on human epidermal radiation damage cell models. METHODS:(1)After infection of human dental pulp stem cells using recombinant adenovirus of human hepatocyte growth factor gene,exosomes,i.e.,Ad.HGF DPSC-Exo,were isolated with ultracentrifugation.(2)HaCat cells were irradiated with X-ray.The cells were treated with 1,2-propanediol before irradiation and Ad.HGF DPSC-Exo after irradiation.Cell proliferative activity was determined by CCK-8 assay.Cell apoptosis was detected by flow cytometry.Cell migration was detected by cell scratch assay.The expression levels of P21 and P53 were detected by PCR. RESULTS AND CONCLUSION:1,2-Propanediol,Ad.HGF.DPSC-Exo,Ad.HGF.DPSC-Exo + 1,2-propanediol could significantly improve the growth inhibition of HaCaT cells,reduce cell apoptosis,elevate cell proliferation and migration,and exhibit a good radiation protection effect.Moreover,the combined effect of Ad.HGF.DPSC-Exo + 1,2-propanediol was better.Furthermore,Ad.HGF.DPSC-Exo + 1,2-propanediol alleviated the cellular G2/M phase block and decreased the expression of cell cycle genes P53 and P21.In conclusion,1,2-propanediol pretreatment combined with Ad.HGF.DPSC-Exo had significant protective effects on radiation-induced HaCaT cell injury and it provided novel ideas and potential methods for the prevention and treatment of radiation-induced skin damage.

The clinical data of a case of adrenal alveolar echinococcosis treated and misdiagnosed in our hospital were reported retrospectively. The pre-operative CT examination of this patient showed that the liver S7 segment-the right adrenal gland area showed irregular masses of mixed density lesions, the boundary was unclear, consider the possibility of liver hydatid. During the operation, hydatid was found to only invade the liver capsule, and the primary lesion was the adrenal gland. The right adrenal gland and lesion were resected by urological surgeons. The pathological diagnosis was adrenal alveolar echinococcosis. When the imaging examination considers hepatic alveolar echinococcosis, and the lesion is mainly in the right adrenal gland area, it should be considered that the primary lesion could be in the adrenal gland.

Objective: To evaluate the efficacy and safety of reduced volume hepatectomy in treatment of advanced hepatic alveolar echinococcosis. Methods: The clinical data of 90 patients with advanced hepatic alveolar echinococcosis treated at the Qinghai Provincial People's Hospital from January 2017 to January 2019 were retrospectively analyzed. There were 41 males and 49 females, with an average age of 32 (range 11 to 58) years. The locations of the lesions, operations, complications and follow-up were analyzed. Results: 90 patients were treated with reduced volume focal hepatectomy, 38 with radical resection and 52 with quasi radical resection. The operation time was (361±22) min. The hospital stay was (22±2) day, and the blood loss was (781±37) ml. Red blood cells were transfused in 19 patients and plasma in 39 patients. Pringle’s maneuver was used in 12 patients, regional hepatic blood flow occlusion in 42 patients, and Glisson sheath occlusion in 26 patients. The total bilirubin, alanine aminotransferase and aspartate aminotransferase returned to normal in 3 to 14 days after operation. There were 12 patients who developed bile leakage, 41 pleural effusion and 26 effusion in the operation sites. A total of ninety patients were followed up for 2 to 24 months. There was no recurrence of echinococcosis after radical resection and no enlargement of residual lesions after quasi-radical resection. Conclusion Reduced-volume hepatectomy reduced the risk and difficulty of operation. The follow-up results were good. This approach provides a feasible scheme for treatment of advanced hepatic alveolar echinococcosis.

Objective To establish an aging model of mesenchymal stem cells (MSCs) and to investigate aging related biological mechanism for the purpose of studying the senesence of MSCs .Methods MSCs were separated and purified from human placenta, and the cells of the third passage(P3-MSCs) were cultured in the medium for 2 hours, then 100,200 and 300 μmol/L hydrogen peroxide ( H2 O2 ) was added to the cells for 2 hours to establish the MSCs aging model in vitro. Biological characteristics of aging MSCs were evaluated by cell cycle assay and senescence associated β-galactosidase staining.The expression of p16,p21 and p53 genes was further measured using quantitative real-time PCR (RT-PCR).Re-sults Compared with the control , the number of MSCs treated with 200μmol/L H2 O2 for 2 hours was significantly decreased and the cells displayed less adipogenic ,osteogenic and chondrogenic differentiation .Moreover ,after exposure to 200 μmol/L H2 O2 , the majority of the cells were in the G 0/G1 phase as showed by cell cycle analysis .The percentage of senescence-associated β-galactosidase-positive cells was increased , and the expression of p 16 , p21 and p53 mRNA and protein was significantly increased.Conclusion The results of this study has demonstrated that the H 2 O2 (200 μmol/L) can be used to establish the aging model of MSCs in vitro, and the cellular phenotypic alteration may attribute to the cell cycle associated gene expression (p16, p21, and p53).

BACKGROUND:Placenta is a valuable source of mesenchymal stem cels for stem cel therapy and future application in the field of regenerative medicine. However, conventional methods cannot acquire a large amount of purified human placenta-derived mesenchymal stem cels. Here, we present a new method for isolating human placenta-derived mesenchymal stem cels suitable for banking strategies and for future clinical applications. OBJECTIVE:To analyze the biological characteristics of human placenta-derived mesenchymal stem cels cultured by tissue dissociating and colagenase digestion. METHODS: Human placenta-derived mesenchymal stem cels were obtained from human placenta by tissue dissociating and colagenase digestion method. Immunophenotype was analyzed by flow cytometry. Growth curve was determined by MTT assay, and differentiation ability was evaluated byin vitro adipogenic, osteogenic and chondrogenic induction as wel. RESULTS AND CONCLUSION:Human placenta-derived mesenchymal stem cels could be passaged stablyin vitro. Furthermore, the cels expressed CD73, CD90, CD105, but were negative for the markers of CD11b, CD19, CD34, CD45, and HLA-DR. Human placenta-derived mesenchymal stem cels proliferated actively and began to grow logarithmicaly at days 3-5 folowed by a plateau period at day 6. In addition, the isolated cels could be induced into adipocytes, osteocytes, chondrocytesin vitro. In a word, the results of this study demonstrated that the tissue dissociating and colagenase digestion method is an efficient method for obtaining a large amount of human placenta-derived mesenchymal stem cels that can be stably cultured in vitro and have strong proliferative ability.

Objective To compare two sources of mesenchymal stem cells ( MSCs) from human placenta and umbilical cord, and to optimize a technical solution for bench or clinical studies of MSCs.Methods MSCs were isolated from human placenta and umbilical cord and expanded for analysis.The cell morphology was observed under invert microscope, the immunophenotypic feature of MSCs was analyzed with flow cytometer, the cell proliferation ability was determined by cell cycle assay and cell doubling time, the cell differentiation potential was evaluated by osteogenic and adipogenic induction in vitro as well.Results Both sources of MSCs were adherent cells and exhibited fusiform and fibrous morphology. Furthermore, both MSCs high expressed CD90 and CD105, and were negative for the markers of CD34, CD45 and HLA-DR.The population doubling time of MSCs form human placenta and umbilical cord was 39.5 h and 40.8 h separately, and the results of cell cycle analysis showed that the percent of the two sources of MSCs in G0/G1 phase was 52.12%and 57.50% respectively. The above results demonstrated that both sources of MSCs possessed the similar biological characteristics in morphology, phenotype and as well as proliferation ability.In addition, both of them could be induced into osteoblasts and adipocytes in vitro.Conclusion MSCs from human placenta have the similar biological characteristics to these from human umbilical cord, and both of them are better candidates for bench and clinical research.