Objective To investigate the effect of dexamethasone on proliferation of human periodontal ligament fibroblasts(hPDLF) cultivated in vitro,and search for optimal culture condition for hPDLF in vitro,and provide basis for further study on regeneration of periodontinum.Methods The hPDLF cultivated in vitro were divided into 5 groups and cultivated in 5 different culture media separately which all included 10% fetal bovine serium: ①control group(no DEX);②5 mg?L-1DEX;③10 mg?L-1 DEX;④20 mg?L-1 DEX;⑤50 mg?L-1 DEX.The proliferation of hPDLF was assyed by MTT method.The phase contrast microscope was used to observe the morphological changes of the cells.Results The PDLF appeared aggregation and cells on bottom of culture bottle showed squamae-shape after inoculated on plate with 24 hole for 3 d.There were more layers of smaller hPDLF with blunt prominency came forth after cultivated in DEX culture media.MTT method showed that DEX promoted the proliferation of hPDLF obviously compared with control group(P

Objective To investigate the effect of insulin-like factor-I(IGF-Ⅰ)on the proliferation activity of human periodontal ligamental fibroblasts(PDLF).Methods The PDLF transfected with IGF-Ⅰ and PDLF untransfected with IGF-Ⅰ prepared in our lab were digested by 0.25% trypsin and prepared into cell suspension.The two sorts of cells were counted after being vaccinated,then the growth curves of the two cells were mapped and the growth speeds were compared.The PDLF transfected with IGF-Ⅰ and PDLF untransfected with IGF-Ⅰ were digested by 0.25% trypsin and then cultivated.The proliferation activities of the PDLF transfected with IGF-Ⅰ and PDLF untransfected with IGF-Ⅰ were observed using MTT methods.The activity of alkaline phosphatase(ALP) was determined by using ALP kit.Results The growth curves of the two cells showed that the growth speed of the PDLF transfected with IGF-Ⅰ was significantly faster than that of the PDLF untransfected with IGF-Ⅰ(P

Chitooligosaccharides(COS),as the degradation products of the natural polysaccharide chitosan(CS),retain the good biocompatibility,non-toxicity,and biodegradability of CS.Additionally,due to the shortened sugar chains and reduced molecular weight,their water solubility and bioactivity are improved,making them more easily absorbed and utilized by organisms.In recent years,COS has received increasing attention.While there are numerous studies on the biological functions of CS and its applications in the biomedical field,the research on the functions and applications of COS is relatively limited.This study summarizes and analyzes the main biological functions of COS(anti-inflammatory,anti-tumor,antibacterial,and tissue regeneration promotion)and their possible mechanisms.It also discusses the research progress in the applications of COS in the biomedical field,in order to provide the theoretical basis and reference for the further research and broader application of COS in biomedicine.

objective:To prepare a composite photocrosslinked hydrogel containing zeolite imidazole framework-8(ZIF-8),and to evaluate its in vitro cytotoxicity,drug release capability,and antimicrobial propertie.Methods:The ZIF-8 particles were synthesized by hydrothermal method,and the microstructure characteristic was observed under scanning electron microscope(SEM).The particles were mixed with the gelatin methacryloyl(GelMA)with the mass fraction of 0.2%to obtain the composite hydrogel GelMA-Z.The atomic absorption spectroscope was used to detect the cumulative zinc ion(Zn2+)release amounts in GelMA-Z at different time points.The NIH-3T3 cells were co-cultured with GelMA-Z for 1,3,and 7 d;the viabilities of the cells in various groups were detected by CCK-8 assay;the GelMA-Z was co-cultured with Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)for 6,12,and 24 h and divided into control group,GelMA group,and GelMA-Z group.The bacterial activities of the cells in various groups at different time points were detected by microplate reader;the bacterial formation and the presence of live/dead becterial staining condition were detected by plate antibacterial experiment and live/dead bacterial staining method.Results:The SEM observation results showed that the hydrothermally synthesized ZIF-8 particles had the uniform particle sizes.The atomic absorption spectroscope results showed that Zn2+ in GelMA-Z showed an initial burst phase within 1 d,followed by a slow release,and reached the equilibrium around 7 d.Compared with control group,the viabilities the cells in GelMA group and GelMA-Z group were above 90%on the 1st,3rd,and 7th days,but there was no significant difference(P>0.05).The bacterial activity detection results showed that when co-cultured with bacteria for 6,12,and 24 h,compared with control group and GelMA group,the bacterial activities of the E.coli and S.aureus in GelMA-Z group were decreased(P<0.05).The plate antibacterial experiment results showed that the number of bacterial formation in GelMA-Z group was fewer than those in control group and GelMA group.The live/dead bacterial staining results showed that in GelMA-Z group,there was a large number of red fluorescence stained dead bacteria;in control group and GelMA group,there was a large number of green fluorescence stained live bacteria.Conclusion:The GelMA hydrogel loaded with ZIF-8 particles can achieve the in situ photocrosslinking and possesses good Zn2+ release capability and antimicrobial activity,and it is a novel hydrogel dressing for treatment of the infected wounds.

Objective:To establish an animal model of trichloroethylene (TCE) -induced liver cancer following chronic exposure and to understand the changes in SET expression and histone acetylation, potentially serving as a molecular mechanism for TCE-induced hepatocarcinogenesis.Methods:B6C3 mice at 6 weeks were treated with TCE at a series of doses (500, 1000 and 2000 mg/kg) by gastric gavage, with corn oil used as the negative control and carbon tetrachloride (CCl 4) as the positive control. The serum and liver were sampled for the determination of biochemical indexes and pathological examination after 56 weeks of chemical exposure. Western blot was used to determine the levels of SET, H2AK9ac and HDAC1 expression. Results:The overall survival rate of the mice in various groups was 90.4% (141/156) , with no statistical difference between groups ( P>0.05) . Compared with the negative control, the organ coefficient for the liver in the high dose TCE group and the positive control group were significantly increased ( P<0.05) . The levels of ALT, AST, LDH and BUN in the all the three TCE groups and the positive control were significantly higher than those in the negative control ( P<0.01) . CREA levels in the 1000 and 2000 mg/kg TCE groups were significantly higher than those in the negative control ( P<0.05) . Statistical increases in the incidence of hepatocellular carcinoma and the activities of ALT and AST in various doses of TCE-exposed mice as compared with the control were observed ( P<0.01) , in a dose-dependent manner. In the 1000 and 2000 mg/kg of TCE treated mice, levels of SET and H2AK9ac were increased ( P<0.05) , while HDAC1 was decreased ( P<0.05) , Compared to the tissue adjacent to liver cancer, in the 1000 and 2000 mg/kg TCE groups, the levels of SET were increased ( P<0.05) , while HDAC1 was decreased ( P<0.05) , and H2AK9ac increased in the 2000 mg/kg group. Conclusion:The hepatocellular carcinoma mouse model induced by chronic exposure to trichloroethylene was successfully established, with enhanced SET protein expression and H2AK9ac in the hepatic tissue.

Objective:To discuss the effect of temperature-controlled shrinkage polytrimethylene carbonate(PTMC)/polyvinylpyrrolidone(PVP)nanofiber membrane on the biological behavior of mouse fibroblasts and the repairment effect on full-thickness skin defects in the rats,and to clarify the potential mechanism.Methods:The murine L929 fibroblast cells were used in the in vitro experiments and were divided into control group and experimental group(treated with PTMC/PVP nanofiber membranes).The proliferation activities of the cells in two groups were detected by CCK-8 assay;the numbers of live/dead cells in two groups were observed by live/dead cell staining;the morphology of the cells was observed by cytoskeletal staining.A total of 12 six-week-old male SD rats were selected in the in vivo experiment,and were randomly divided into control group and experimental group,and there were six rats in each group.The full-thickness skin defect model was established,and the rats in experimental group were treated with PTMC/PVP nanofiber membranes.The photographs were taken after operation,and the wound healing rates of the cells in two groups were calculated on the 0,3rd,6th,and 12th days.On the 6th and 12th days after operation,the skin samples around the wound of the rats in two groups were taken,and the histopathology of the would skin and adjacent tissue was detected by HE staining;the collagen deposition in wound skin tissue of the rats in two groups was observed by Masson trichrome staining;the numbers of angiogenesis in wound skin tissue of the rats were detected by CD31 immunohistochemical staining.Results:The CCK-8 assay results showed that the proliferation activity of the cells in experimental group showed an increasing trend on the 1st,3st,and 5st days,and there was no significant difference in the proliferation activities of the cells bewteen experimental group and control group(P＞0.05).The live/dead cell staining experiment results showed that compared with control group,the cell density and number of the cells in experimental group had no significant changes,and were predominantly live cells.The cytoskeletal staining results showed that the cells in experimental and control groups appeared spindle-shaped and well-spread.In the in vivo experiments,on the 3rd,6th,and 12th days,compared with control group,the wound healing rates of the cells in experimental group were increased(P＜0.01),and the wound healing rate of the cells was 95.45％on the 12th day,indicating nearly complete healing of the wound.The HE staining showed that on the 12th day,the wound skin structure of the cells in experimental group was more similar to the normal skin,and there was abundant granulation tissue,regular epidermal structure,and new blood vessel formation.The Masson trichrome staining results showed that compared with control group,the collagen deposition in wound tissue of the rats in experimental group was increased.The immunohistochemical staining results showed that the expression of CD31 in wound tissue of the rats in experimental group was increased,indicating the increasing of the number of angiogenesis.Conclusion:The PTMC/PVP thermoresponsive nanofiber membranes exhibit good biocompatibility and can promote the repairment of full-thickness skin defects in the rats;its mechanism may be related to the enhancement of proliferation activity of the basal cells.

Objective:To establish an animal model of trichloroethylene (TCE) -induced liver cancer following chronic exposure and to understand the changes in SET expression and histone acetylation, potentially serving as a molecular mechanism for TCE-induced hepatocarcinogenesis.Methods:B6C3 mice at 6 weeks were treated with TCE at a series of doses (500, 1000 and 2000 mg/kg) by gastric gavage, with corn oil used as the negative control and carbon tetrachloride (CCl 4) as the positive control. The serum and liver were sampled for the determination of biochemical indexes and pathological examination after 56 weeks of chemical exposure. Western blot was used to determine the levels of SET, H2AK9ac and HDAC1 expression. Results:The overall survival rate of the mice in various groups was 90.4% (141/156) , with no statistical difference between groups ( P>0.05) . Compared with the negative control, the organ coefficient for the liver in the high dose TCE group and the positive control group were significantly increased ( P<0.05) . The levels of ALT, AST, LDH and BUN in the all the three TCE groups and the positive control were significantly higher than those in the negative control ( P<0.01) . CREA levels in the 1000 and 2000 mg/kg TCE groups were significantly higher than those in the negative control ( P<0.05) . Statistical increases in the incidence of hepatocellular carcinoma and the activities of ALT and AST in various doses of TCE-exposed mice as compared with the control were observed ( P<0.01) , in a dose-dependent manner. In the 1000 and 2000 mg/kg of TCE treated mice, levels of SET and H2AK9ac were increased ( P<0.05) , while HDAC1 was decreased ( P<0.05) , Compared to the tissue adjacent to liver cancer, in the 1000 and 2000 mg/kg TCE groups, the levels of SET were increased ( P<0.05) , while HDAC1 was decreased ( P<0.05) , and H2AK9ac increased in the 2000 mg/kg group. Conclusion:The hepatocellular carcinoma mouse model induced by chronic exposure to trichloroethylene was successfully established, with enhanced SET protein expression and H2AK9ac in the hepatic tissue.

Objective: To investigate alteration of proteins profile in malignant transformation bronchial epithelial cells(16HBE-T) induced by hexavalent chromium[(Cr(VI))] and analyze the expression level of SET protein, then to provide some new insights for the carcinogenesis mechanism of Cr(VI). Methods: Total protein was extracted from 16HBE cells and was alkylated and desalinated before digested into peptides. The products were labeled with Tandem Mass Tag (TMT) and identified using LC-ESI-MS/MS. Results: A total of 3 517 proteins were found, expression differences greater than 1.5 or less 0.67 times were to found have 185 and 201 proteins, respectively. Gene enrichment analysis revealed that differential proteins were mainly involved in autophagy, DNA damage repair, RNA processing and other biological processes. Western blot results showed the expression level of SET was significantly increased while downregulated in histone H3K18/27 acetylation and p53 protein. Conclusion Proteins involved in multiple biological processes altered in 16HBE-T cells and regulation mode of SET inhibiting histone H3K18/27 acetylation regulating transcriptional activity of p53 may paly an important role in Cr(VI)-association carcinogenesis.