Controllable Macroscopic Chirality of Coordination Polymers through pH and Anion-Mediated Weak Interactions.

Helical architectures with controllable helical sense bias have recently attracted considerable interest for mimicking biological helices and developing novel chiral materials. Coordination polymers (CPs), composed of metal ion nodes and organic linkers, are intriguing systems showing tunable structures and functions. However, CPs with helical morphologies have rarely been explored so far. Particularly, chirality inversion through external stimulus has not been achieved in helical CPs. In this work, we carried out an in-depth investigation on the self-assembly of 1D gadolinium(III) phosphonate CPs using GdX3 (X=Cl, Br, I) and Gd(RSO3 ) (R=CH3 , C6 H5 , CF3 ) as metal sources and R-(1-phenylethylamino)methyl phosphonic acid (R-pempH2 ) as ligand. Superhelices were formed by precise control of the interchain interactions through different intercalated anions. Furthermore, the twisting direction of superhelices could be controlled by synergistic effect of anions and pH. This study may provide a new route to fabricate helical nanostructures of CPs with a desirable chiral sense and help understand the inner mechanism of the self-assembly process of macroscopic helical structures of molecular systems.

[A five-year experience for treating patients with chronic apical periodontitis with root canal treatment: a retrospective cohort study].

PURPOSE: To investigate the clinical outcomes, including survival and periapical healing rates and failure causes, of root canal treatment for patients with periapical lesion. METHODS: A retrospective cohort study was conducted which enrolled patients admitted for the evaluation and management of periapical lesion with root canal treatment. The primary predictor variables were difficulty assessment of root canal therapy (DARCT),which was divided into lower（DARCT =3-4）, medium (DARCT =5-7) and higher (DARCT =8-9) difficulty root canal, in terms of canal length, curvature and calcification. The primary outcome measurement was the incidence of periapical healing and survival rate. Potential confounders included patient demographics, canal number, root canal filling, and coronal restoration. SPSS 21.0 software package was used for data analysis. RESULTS: The 5-year survival rate was 81.4%(83/102) and healing rate was 77.1% (64/83). DARCT was significantly associated with the survival rate(P=0.017). Root fracture, deep pockets lesions and periodontal abscess were observed in DARCT with a value of 8-9(P=0.027), leading to tooth extraction. The teeth with multiple root canals were extracted due to recurrent or persistent periapical lesion (P=0.004). Chi-square test showed that root canal number (P=0.021), quality of root canal filling (P=0.006) as well as DARCT (P=0.000) were significantly correlated with the final healing rate. Multivariate logistic regression analysis showed that DARCT (P=0.000) and the quality of root canal filling (P=0.033) were associated with the final healing rate. CONCLUSIONS: DARCT and the quality of root canal filling play key roles in the clinical prognosis of periapical lesion, DARCT and number of root canal are more likely to be correlated with failure.

Hematopoietic stem and progenitor cells can be enriched by implanting biomaterial into spatium intermusculare.

Hematopoietic stem and progenitor cells (HSPCs) have been used successfully to treat patients with cancer and disorders of the blood and immune systems. In this study, we tried to enrich HSPCs by implanting biomaterials into the spatium intermusculare of mice hind limbs. Gelatine sponges were implanted into the spatium intermusculare of mice and then retrieved after 12 days. The presence of HSPCs in the migrating cells (MCs) was detected by phenotypically probing with CD34(+)Sca-1(+) and functionally confirming the presence of using colony-forming cell assay and assessing the long-term reconstitution ability. The frequency of CD34(+), Sca-1(+), and CD34(+)Sca-1(+) cells and colony formation unit in the MCs was much higher than that in the bone marrow (BM). Moreover, transplanted MCs were able to home to BM, muscle, and spleen, which induced an efficient long-term hematopoietic reconstitution in vivo. In addition, HSPCs within the MCs originated from the BM. Furthermore, the administration of G-CSF greatly reduced the time of implantation, and increased the number of MCs and frequency of HSPCs in the MCs. These data provide compelling evidence that HSPCs can be enriched by implanting biomaterial into spatium intermusculare. Implantation of biomaterial may be seen as the first step to a proof of their applicability to clinical practice in enriching HSPCs.

[Effect of NF-κB on the expression of interleukin-6 induced by lipopolysaccharides of Porphyromonas endodontalis in MC3T3-E1 cells].

PURPOSE: To investigate the effect of NF-κB signaling on the expression of interleukin-6(IL-6) induced by lipopolysaccharides(LPS) extracted from Porphyromonas endodontalis(P.e) in MC3T3-El cells. METHODS: MC3T3-E1 cells were pretreated with BAY-117082 for 1 h, and then were treated with 10 mg/L P.e-LPS for different times. The translocation of NF-κB was observed by immunofluorescence. The expression of IL-6 was detected by reverse transcription polymerse chain reaction (RT-PCR) and enzyme-linked immuno sorbent assay (ELISA). Statistical analysis was performed using multi-way ANOVA and Dunnett's t test with SPSS 13.0 software package. RESULTS: The staining of NF-κB was mostly in cytoplasm in untreated cells. Rapid translocation of NF-κB into nucleus was observed in the cells stimulated for 30 min and mostly relocalization of NF-κB from nucleus to cytoplasm was observed after 60 min. Pretreatment with 10 µmol/L BAY-117082 for 1h significantly inhibited P.e-LPS-induced translocation of NF-κB .The mRNA and proteins of IL-6 decreased significantly after pretreatment with 10 µmol/L BAY-117082 and the expression of IL-6 proteins was reduced from (774.983±6.585) ng/L to (377.384±14.620) ng/L (P<0.01). The group of treatment with BAY-117082 alone had no significant difference from the blank control group. CONCLUSIONS: P.e-LPS can induce translocation of NF-κB in mouse osteoblast MC3T3-El, and P.e-LPS may induce the expression of IL-6 in mouse osteoblast through the signaling of NF-κB.

[Antimicrobial effect of various calcium hydroxide on Porphyromonas endodontalis in vitro].

PURPOSE: To compare the antimicrobial activity of Endocal, calcium hydroxide paste, Calxyl, Vitapex on Porphyromonas endodontalis(P.e). METHODS: (1) The antimicrobial activity of different calcium hydroxide on P.e was examined at different exposure times by dynamic nephelometry. (2) 85 freshly extracted single-rooted human teeth were selected and cut at the amelocemental junction. All roots were randomly divided into five groups. The bacteria were incubated in each canal and were sampled and counted before and after enveloping five kinds of intercanal medicine seeded. Student's t test, One-way ANOVA were used with SPSS11.0 software package for statistical analysis. RESULTS: The bacteria from each group were reduced significantly after intracanal medication (P<0.05). The antibacterial efficacy of Endocal and calcium hydroxide paste were superior to others under dynamic nephelometry test (P<0.05). Endocal, calcium hydroxide paste, Calxyl, Vitapex had strong inhibitory effect on P.e from infected root canals, and the rate of bacteria clearance was 95%. The antimicrobial activity of Endocal was significantly greater than others (P<0.05). CONCLUSIONS: Endocal, calcium hydroxide paste, Calxyl and Vitapex were effective for intercanal disinfection. The antibacterial activity of Endocal is greater than Vitapex.

[Effect of lipopolysaccharides extracted from Porphyromonas endodontalis on the expression of p38 and ERK1/2 in osteoblast].

PURPOSE: To investigate the effect of lipopolysaccharides (LPS) extracted from Porphyromonas endodontalis(P.e) on the expression of p38 and ERK1/2 in osteoblast. METHODS: MC3T3-E1 cells were stimulated with 10 µg/mL P.e-LPS for 0,5,15,30,60,180 min. The phosphorylation of p38 and ERK1/2 was measured by Western blot. Statistical analysis was performed using one- way ANOVA and Dunnett t test with SPSS11.0 software package. RESULTS: 10 µg/mL LPS could significantly activate p38 MAPK. The peak of phosphorylated p38 was detected at 5 to 30 min(P<0.01) and returned to baseline within 60 min; the level of phosphorylated ERK1/2 increased after the stimulation of LPS for 5 min and reached maximum at 15 min (P<0.01) and declined after 30 min. CONCLUSIONS: P.e-LPS can induce the expression of p38 and ERK1/2 in osteoblast MC3T3-E1, which indicates that P.e-LPS may play an important role in osteoblast through p38 and ERK1/2.

[Effects of lipopolysaccharides from various Porphyromonas on the expression of CD14 and TLRs in mouse osteoblast].

PURPOSE: To observe the effect of lipopolysaccharides(LPS) extracted from Porphyromonas endodontalis(P.e) and Porphyromonas gingivals(P.g) on the expression of CD14 and TLRs in osteoblast. METHODS: MC3T3-E1 cells were stimulated with 10µg/mL P.e-LPS and P.g-LPS. The change of CD14,TLR2 and TLR4 mRNA was observed at different time point (0,1,3,6,12,24h) using RT-PCR,and the expression of CD14,TLR2 and TLR4 protein was measured by flow cytometry at 24-hour. Statistical analysis was performed using one-way ANOVA and Dunnett t test with SPSS11.0 software package. RESULTS: MC3T3-E1 cells were stimulated with 10µg/mL P.e-LPS for 1h,the expression of CD14 and TLR4 mRNA increased significantly. There was no increase of TLR2 mRNA with stimulation of P.e-LPS. The CD14,TLR2 and TLR4 mRNA expression increased significantly after stimulation with 10µg/mL P.g-LPS. Flow cytometry showed that CD14 and TLR4 protein increased significantly after stimulation with 10µg/mL P.e-LPS. CD14,TLR2 and TLR4 protein increased significantly after treatment with 10µg/mL P.g-LPS. CONCLUSIONS: CD14,TLR4 receptors are involved in P.e-LPS effect and CD14,TLR2 and TLR4 receptors are involved in P.g-LPS effect in mouse osteoblast.

[Effect of CD-14 and toll like receptors on the expression of interleukin-6 induced by lipopolysaccharides of Porphyromonas endodontalis].

OBJECTIVE: To evaluate the effect of cluster of differentiation 14 (CD-14) and Toll like receptors (TLR) on the expression of interleukin-6 (IL-6) mRNA induced by Porphyromonas endodontalis (Pe) lipopolysaccharides (LPS). METHODS: MC3T3-E1 cells were treated with 10 mg/L Pe-LPS for different hours, and the cells uninvolved by anything as the blank group. The expression of IL-6 was detected by reverse transcription polymerse chain reaction (RT-PCR) and enzyme-liked immunosorbent assay (ELISA). The expression of CD-14, TLR-2 and TLR-4 mRNA was observed at different time point (0 - 24 h) by RT-PCR. The protein of CD-14, TLR-2 and TLR-4 was analyzed with a flow cytometer. MC3T3-E1 cells were pretreated with anti-CD-14, anti-TLR-2 and anti-TLR-4 antibody for 1 h, and then cells were stimulated with 10 mg/L Pe-LPS for 6 h. The expression of IL-6 mRNA was examined by RT-PCR. Statistical analysis was performed using one-way ANOVA Dunnett-t test with SPSS 11.0 software package. RESULTS: The IL-6 mRNA and proteins increased significantly after treatment with Pe-LPS. When MC3T3-E1 cells treated by Pe-LPS for 6 h, the expression of proteins soared from (11.696 ± 0.672) ng/L to (36.534 ± 0.574) ng/L (P < 0.01); In the control group, the CD-14 and TLR-4 mRNA are ambly-expression, and the ratios of CD-14 and TLR-4 positive cells were (39.038 ± 3.131)% and (11.438 ± 0.385)% respectively in MC3T3-E1. After treatment by Pe-LPS, the expression of CD-14 and TLR-4 mRNA increased significantly, and the ratios of CD-14 and TLR-4 positive cells markedly increased to (62.407 ± 1.800)% and (21.367 ± 2.271)%. TLR-2 expression did not change apparently after Pe-LPS treatment. The expression of IL-6 mRNA was partly inhibited by anti-CD-14 or anti-TLR-4 antibody, but not by TLR-2. CONCLUSIONS: Pe-LPS can induce the expression of IL-6 in osteoblast MC3T3-E1 through CD-14 and TLR-4, but not TLR-2.

[Effect of lipopolysaccharides extracted from Porphyromonas endodontalis on the expression of CD14 in osteoblast].

PURPOSE: To investigate the effect of lipopolysaccharides(LPS) extracted from Porphyromonas endodontalis(P.e) on the expression of CD14 in osteoblast. METHODS: Under the condition with or without serum, MC3T3-E1 cells were stimulated with 10 µg/mL P.e-LPS for 24 hours, then the expression of CD14 was measured using flow cytometry; the membrane CD14 mRNA was detected at different time point (0, 1, 3, 6, 12, 24 h) by RT-PCR. Statistical analysis was performed using two-sample t test, one-way ANOVA and Dunnett t test with SPSS13.0 software package. RESULTS: Flow cytometry showed that CD14 protein increased after the stimulation of P.e-LPS for 24 h, while the non-serum group demonstrated more increase; the membrane CD14 mRNA level was up-regulated by 10 µg/mL P.e-LPS at 1 hour, and reached the maximum at 3 h and declined after 6 h. CONCLUSIONS: P.e-LPS can induce the expression of CD14 in osteoblast MC3T3-E1, which indicates that P.e-LPS may play an important role in osteoblast through CD14.