Objective To compare the characteristics of gelatin microspheres crossl inked by glutaraldehyde (GA) or geni pin (GP). Methods Gelatin microspheres, prepared by the improved emulsified cold-condensation method, were crossl inked by GP and GA, respectively. After being dispersed in PBS, two kinds of microspheres with 60% degree of cross l inking were compared in terms of morphology, swell ing and degrading properties. rhBMP-2 were loaded into the GP and GAmicrospheres, and the encapsulation rate, drug loading and releasing capacity were measured; 100%, 50% and 25% leaching l iquid of GP and GA microspheres were respectively cultured with rat osteoblast (DMEM group as the control), and cell prol iferation was measured by MTT method to grade the cell cytotoxicity. Results GP and GA microspheres were both spherical with the diameters of (78 ± 18) μm and (65 ± 10) μm, and there were no difference between both microspheres in drug loading and encapsulation rate. But, GP microspheres, with long degrading period (28 days) compared to GA microspheres (21 days), had better dispersibil ity, and swell ing rate (89.0% ± 4.8%), the percentage of cumulative drug releasing at 10 days (78.80% ± 4.96%) were both lower than GA microsphere (118.0% ± 7.6%, 90.50% ± 5.12%). The percentages of drug loading of GP and GA were (921 ± 73) and (965 ± 62) ng/g, and the encapsulation rates were 88.5% ± 2.1% and 89.7% ± 1.8%; showing no significant difference (P gt; 0.05). The cell cytotoxicity of 100%, 50% and 25% leaching l iquid of GP microspheres was all at the level I, but leaching l iquid of GA microspheres with corresponding concentration were at the levels of III, III and II. Conclusion GP crossl inked gelatin microspheres are superior to GA crossl inked gelatin microspheres and can be widely used in tissue engineering field.
Objective To investigate the osteogenesis effects of angiopoietin 1 (Ang-1) gene transfected bone marrow mesenchymal stem cells (BMSCs) seeded on β tricalcium phosphate (β-TCP) scaffolds (tissue engineered bone) with platelet-rich plasma (PRP). Methods BMSCs were isolated from bone marrow tissue of rabbits. The Ang-1 gene was transfected into the BMSCs at passage 2 by lentivector, which were seeded on β-TCP scaffolds with PRP (0.5 mL) after 48 hours of transfection. Bilateral radial segmental bone defects (15 mm in length) were created in 20 3-month-old New Zealand rabbits. Then the tissue engineered bone with the Ang-1 gene transfected BMSCs (experimental group) and untransfected BMSCs (control group) were implanted into the defects in the right and left radius, respectively. X-ray, histology, immunohistochemistry, and biomechanics observations were done at 2, 4, 8, and 12 weeks after operation. Results In vitro, the transfected rate was over 90% and RT-PCR showed that the Ang-1 expression were significantly increased after transfection. The X-ray films showed that some callus formed at 4 weeks, partial bony union was observed at 8 weeks, and complete union at 12 weeks in experimental group; and bone union was not observed at 12 weeks in control group. HE staining showed that capillary appeared at 8 weeks and more capillaries were observed in new bone at 12 weeks in experimental group; only a few capillaries were observed at 12 weeks in control group. At 8 and 12 weeks, the microvascular density were (50.1 ± 7.8) /mm2 and (66.1 ± 3.5) /mm2 in experimental group and were 0 and (30.3 ± 7.2)/mm2 in control group, showing significant differences between 2 groups at 12 weeks (Z= —2.107, P=0.031). Immunohistochemistry examination showed that the positive cells can be found at 8 weeks in experimental group. And the biomechanical analysis showed that maximum loads of experimental group were significantly higher than those of control group in three-point bending test and compression test at 12 weeks (P lt; 0.05). Conclusion The tissue engineered bone with PRP and Ang-1 can increase the osteogenic properties by enhancing capillary regeneration, thus it can be used to repair radial segmental bone defects of rabbit.
ObjectiveTo systematically review the relationship between Glasgow prognostic score (GPS) and prognosis of gastric cancer (GC) patients. MethodsPubMed, Web of Science, The Cochrane Library, CNKI, CBM and VIP databases were electronically searched to collect cohort studies on the relationship between GPS and prognosis of GC patients from inception to April, 2022. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies; then, meta-analysis was performed by using RevMan 5.3 software and Stata 16.0 software. ResultsA total of 9 cohort studies involving 2 395 patients were included. The results of meta-analysis showed that GPS was significantly associated with poor overall survival of GC patients (HR=2.01, 95%CI 1.55 to 2.61, P<0.000 01). It also was associated with deeper depth of tumor, positive lymph node metastasis, more advanced TNM stages, positive distant metastasis and older age. ConclusionCurrent evidence shows that GPS is associated with survival prognosis and clinical pathological features of GC patients. Due to limited quality and quantity of the included studies, more high-quality studies are needed to verify the above conclusion.
ObjectiveTo systematically review the relationship between cadmium (Cd) and childhood autism.MethodsPubMed, EMbase, Web of Science, The Cochrane Library, CNKI, VIP, WanFang Data and CBM were electronically searched to collect case-control studies on the relationship between Cd and childhood autism from inception to July 2019. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed by using RevMan 5.3 software.ResultsA total of 8 case-control studies were included. The results of meta-analysis showed that whether the specimen was from whole blood, urine or hair, there were no correlations between Cd and childhood autism (MDblood=0.17, 95% CI −0.06 to 0.39, P=0.15; MDurine=−0.43, 95%CI −1.44 to 0.58, P=0.4; MDhair=−0.08, 95%CI −0.52 to 0.36, P=0.72).ConclusionsCurrent evidence shows that Cd concentration is not correlated with autism in children. Due to limited quality and quantity of the included studies, more high quality studies are required to verify above conclusions.