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In recent years, problems such as the devitalization of dental pulp and the increased brittleness and fragility of teeth after root canal treatment have attracted more and more attention. Therefore, pulp regeneration has become the focus of research in endodontics and periapical disease, in which vascularization is of paramount importance. It is found that peptide hydrogel scaffolds have been widely applied because of their properties of impacting cell behavior, promoting angiogenesis, and being adaptable. In this review paper, the research progress of the application of peptide hydrogel in the vascularization of pulp regeneration and the properties of various peptide hydrogels were summarized to provide a reference for the further application of peptide hydrogel in pulp regeneration.
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【Objective】 To evaluate the efficacy and safety of human coagulation factor Ⅷ developed by Shenzhen Weiguang Biological products Co, Ltd in the treatment of patients with hemophilia A. 【Methods】 A prospective, multi-center, open, single-group clinical study was conducted. A total of 65 subjects with hemophilia A were enrolled, and human coagulation factor Ⅷ(FⅧ) was injected according to the patients’ bleeding severity. The improvement score of bleeding symptoms and signs after the first infusion of the first bleeding event and the transfusion efficiency of FⅧ activity at 10 min and 1 hour after infusion were taken as the main efficacy indexes. The improvement scores of bleeding symptoms and signs after the first infusion and the increase of FⅧ activity at 10 min and 1 hour after infusion were the secondary efficacy indexes. 【Results】 The 65 subjects were enrolled in safety analysis set (SS) and full analysis set (FAS), and 58 of them were enrolled in protocol analysis set (PPS). Ten minutes and one hour after the first infusion, the level of factor Ⅷ activity in the subjects increased significantly, and the FⅧ activity increased by 100% or more in more than 79% of the subjects. The average infusion efficiency of FⅧ activity in all subjects was more than 100%. In 70% of the subjects, the pain was relieved rapidly and /or the bleeding symptoms were significantly improved 8 hours after each bleeding infusion, and the improvement rate of bleeding symptoms and signs reached 100% 72 hours after infusion. 【Conclusion】 After infusion of human coagulation factor Ⅷ, the activity level of factor Ⅷ in patients with hemophilia A significantly increased. The infusion efficiency can reach a optimal level, and the bleeding symptoms can be significantly improved.
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Seamless modification is a popular genomic manipulation technique in genetic engineering. Selection stringency of the counter-selection system determines the efficiency of the seamless modification. Recently, a novel counter-selection system, kil, was constructed. It is reported that the selection selectivity of kil is higher in host bacteria harboring plasmid pSim6 than that harboring pKD46, indicating that recombinants could be selected out more efficiently by combining kil counter-selection system and plasmid pSim6. In order to confirm this speculation, four different loci (lacI, dbpa, ack, glk) in Escherichia coli strains W3110, MG1655 and DH10B were selected for testing: dsDNA fragments of different sizes (500 bp, 1 000 bp, and 2 000 bp) were used to substitute tet/kil. As expected, recombination efficiency was higher in host bacteria harboring plasmid pSim6 than that harboring pKD46, and the results were more obvious with the length of dsDNA increasing. Specifically, recombination efficiency was 1.2 to 2 fold higher in pSim6 harboring bacteria than in pKD46 harboring bacteria when dsDNA fragments were 1 000 bp in length. With the length of dsDNA increasing up to 2 000 bp, the gap increased to 2.2-5 fold. In conclusion, it is easier to perform seamless modification by combining kil counter-selection system and plasmid pSim6 than combining kil and pKD46. An alternative tool in genomic engineering is provided in this study.
Subject(s)
Escherichia coli , Escherichia coli Proteins , Genetic Engineering , Plasmids , Recombination, GeneticABSTRACT
Objective To investigate the effects of carbohydrate and its concentration,nitrogen source,and metal ions on suspension cell growth of Gentiana macrophylla and gentiopicroside accumulation. Methods The cell dry weight and gentiopicroside content were measured under factors of different carbohydrate,NH4+/NO3-,Ca2+,and Zn2+ at various concentration. Results The optimum culture conditions are as follows:3% sucrose,NH4+/NO3-of 20/40,3 mmol/L Ca2+,0.007 49 mmol/L Zn2+. Conclusion Different carbohydrates and their concentration have significant effects on cell growth and gentiopicroside accumulation while high concentration of carbohydrates does not have such effect. NO3-is better than NH4+ for the cell growth. Ca2+ Remarkably influences both cell growth and gentiopicroside accumulation while Zn2+ contributes only to gentiopicroside content.
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Objective To establish cell suspension culture system of Gentiana macrophylla.Methods Good cell line was selected by the methods of small cell aggregate and the effects of different media,inoculation age of cells,initial pH value,culture temperature,and rotation speed on cell growth and gentiopicroside accumulation were investigated.Results The eligible cell suspension culture conditions were:MS media as the basic medium,cells with inoculation age of 15 d,initial pH 7,and rotation speed of 110 r/min at 25 ℃,culturing in Erlenmeyer flasks.Conclusion Optimal cell suspension culture system of G.macrophylla has been established by shake flasks.The different effects of media on cell growth and gentiopicroside accumulation indicate that some inorganic ions have significant effects on regulation.