Unconjugated Bilirubin Attenuates DSS-Induced Colitis Potentially via Enhancement of Bilirubin Reabsorption.

Studies increasingly show that ulcerative colitis (UC) is a consequence of an imbalance between oxidative stress and antioxidant capacity. Bilirubin exerts an anti-inflammatory effect by scavenging reactive oxygen species (ROS), although the exact mechanism is not completely understood. The aim of this study was to determine the role of serum bilirubin in UC using patient data and a mouse model of dextran sodium sulfate (DSS)-induced colitis. We found that low levels of serum bilirubin correlated to a higher risk of UC in a retrospective case-control population. Pre-treatment with exogenous unconjugated bilirubin (UCB) significantly enhanced colonic bilirubin absorption in mice, and attenuated the DSS-induced body weight loss, colon shortening and histopathological damage. Mechanistically, bilirubin prevented the infiltration of inflammatory cells, and decreased the levels of myeloperoxidase and pro-inflammatory cytokines in the serum and colon. Moreover, bilirubin inhibited ROS and malondialdehyde production, scavenged superoxide anions (O2 ·-) from the colon and enhanced the total antioxidant capacity. In conclusion, exogenous UCB attenuated DSS-induced colitis by directly scavenging O2 ·- and enhancing bilirubin reabsorption in the colon via enterohepatic cycling.

[Effect of hemostatic agent on bonding strength of deciduous tooth dentin].

PUPPOSE: To investigate the effect of hemostatic agent on bonding strength of deciduous tooth dentin. METHODS: Forty deciduous molars were used to make dentin grinding model and randomly divided into observation group and control group, 20 teeth in each group. Teeth in the observation group were covered with hemostatic agent for 30s, and then washed, followed by processing; while teeth in the control group were subjected to bonding directly. Micro tensile bond strength and micro leakage were measured and compared in the two groups. SPSS19.0 software package was used to analyze the data. RESULTS: Micro tensile bond strength of the observation group was (12.84±2.10) MPa, significantly lower than that of the control group (P<0.05); most resin protrusion in the observation group was > 35 µm and long and dense, extending into the open dentinal tubules; while resin protrusion in the control group was about 7 to 35 µm, with obvious collateral communication. There was no significant difference in the degree of micro leakage between the two groups (P>0.05). CONCIUSIONS: Hemostatic agent has certain impact on the dentin bonding strength of deciduous tooth, special attention should be paid during clinical application.

Synthesis and characterization of triethylene glycol dimethacrylate nanocapsules used in a self-healing bonding resin.

OBJECTIVES: To date, the production of highly durable dentine bonding is still a challenge. Self-healing bonding resins may provide a new direction for the improvement of the bonding durability. The objective of the current study was to synthesize polyurethane nanocapsules encapsulated with the core material triethylene glycol dimethacrylate (TEGDMA) for use as a major component in a self-healing bonding resin. METHODS: TEGDMA nanocapsules were synthesized via interfacial polycondensation in a miniemulsion, and the TEGDMA nanocapsules were then characterized via Fourier-transform infrared (FTIR) spectrometer, field emission scanning electron microscopy (FESEM), and high-performance liquid chromatography (HPLC) to investigate the morphology, the average TEGDMA loading (DL%), and encapsulation efficiency (EE%). The mechanical property of dental adhesive with different concentrations (0, 3, 6, 9, and 12 wt%) of the TEGDMA nanocapsules were also measured, and the cytotoxicity was investigated using an MTT assay. RESULTS: FTIR confirmed that the TEGDMA nanocapsules were successfully synthesized. These nanocapsules showed a high drug load. The bond strength of the dental adhesive incorporated with 9 wt% TEGDMA nanocapsules was significantly higher compared with those of the other groups (P<0.001). Moreover, the biocompatibility of the dental adhesive was not affected by the incorporation of the TEGDMA nanocapsules. CONCLUSIONS: The current study demonstrated the successful synthesis of TEGDMA nanocapsules, and the overall properties of the dental adhesive were not compromised.