A 3D hydrogel loaded with exosomes derived from bone marrow stem cells promotes cartilage repair in rats by modulating immunological microenvironment / 南方医科大学学报

OBJECTIVE@#To assess the efficacy of GelMA hydrogel loaded with bone marrow stem cell-derived exosomes for repairing injured rat knee articular cartilage.@*METHODS@#The supernatant of cultured bone marrow stem cells was subjected to ultracentrifugation separate and extract the exosomes, which were characterized by transmission electron microscopy, particle size analysis and Western blotting of the surface markers. The changes in rheology and electron microscopic features of GelMA hydrogel were examined after loading the exosomes. We assessed exosome release from the hydrogel was detected by BCA protein detection method, and labeled the exosomes with PKH26 red fluorescent dye to observe their phagocytosis by RAW264.7 cells. The effects of the exosomes alone, unloaded hydrogel, and exosome-loaded hydrogel on the polarization of RAW264.7 cells were detected by q-PCR and immunofluorescence assay. We further tested the effect of the exosome-loaded hydrogel on cartilage repair in a Transwell co-culture cell model of RAW264.7 cells and chondrocytes in a rat model of knee cartilage injury using q-PCR and immunofluorescence assay and HE and Masson staining.@*RESULTS@#GelMA hydrogel loaded with exosomes significantly promoted M2-type polarization of RAW264.7 cells (P < 0.05). In the Transwell co-culture model, the exosome-loaded GelMA hydrogel significantly promoted the repair of injured chondrocytes by regulating RAW264.7 cell transformation from M1 to M2 (P < 0.05). HE and Masson staining showed that the exosome-loaded hydrogel obviously promoted cartilage repair in the rat models damage.@*CONCLUSION@#GelMA hydrogel loaded with bone marrow stem cell-derived exosomes can significantly promote the repair of cartilage damage in rats by improving the immune microenvironment.

Analysis of the efficacy of postoperative radiotherapy in gallbladder cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To summarize the experiences in gallbladder cancer treatment, evaluate the efficacy of postoperative radiotherapy, and investigate the method of improving the survival of gallbladder cancer patients.</p><p><b>METHODS</b>One hundred and twenty-seven gallbladder cancer patients, treated in our center by radical resection (84 cases) and combined with postoperative radiotherapy (43 cases), between June 2003 to December 2009 were included in this study. Their clinical data and follow-up results were retrospectively analyzed. According to AJCC staging criteria, the survival time and 1-, 3- and 5-year survival rates of the surgery group and the postoperative radiotherapy group at the different pathological stages and resection margin status were compared.</p><p><b>RESULTS</b>The median survival time of postoperative radiotherapy patients in stage III was 16.9 months, and the 1-year, 3-year, and 5-year survival rates were 55.7%, 23.5% and 18.2%, respectively, significantly higher than that of the simple operation group ( median survival time 14.3 months, and 1-year, 3-year, 5-year survival rates 42.7%, 22.6% and 16.7%, respectively) (P<0.05). The median survival time of postoperative radiotherapy patients in stage IV, the median survival time was 9.7 months in the postoperative radiotherapy group and 6.3 months in the simple surgery group, and the 1-year survival rates were 14.2% and 9.8%, the 3-year survival rates were 7.2% and 3.9%, the 5-year survival rates were 7.2% and 1.9%, respectively, all showing a statistically significant difference (P<0.05). Among the stage III and IVpatients, all the 1-, 3- and 5-year survival rates of the postoperative radiotherapy group were higher than that of the simple R0 and R1 surgical resection group (all P<0.05), but with a non-significant difference between the stageIandIIpatients (P>0.05). The main side effects in postoperative radiotherapy patients including nausea, vomiting and abdominal pain, all were successfully alleviated by symptomatic and supportive therapy, and the radiotherapy was successfully completed.</p><p><b>CONCLUSIONS</b>With regard to the gallbladder cancer patients in stage III and IV, the survival rate can be obviously increased by postoperative radiotherapy. However, for patients in stageIand II, whether postoperative radiotherapy significantly improves the survival or not, needs to be further validated in larger scale studies.</p>