BACKGROUND:Vital pulp therapy is one of the main treatments for common oral diseases such as deep caries.The antibacterial properties of pulp-capping materials are crucial to the efficacy of the treatment.Currently,commonly used pulp-capping material has weak antibacterial properties and may induce a certain degree of inflammatory response in the pulp tissue,leading to treatment failure.OBJECTIVE:To investigate the antibacterial effects of nanosilver-reduced graphene oxide/polydopamine/methacrylated gelatin@Gap19(AgNPs-rGO/PDA/GelMA@Gap19)hydrogel material.METHODS:Nanosilver-reduced graphene oxide was prepared.Human dental pulp stem cells were cultured in complete medium containing different mass concentrations of nanosilver-reduced graphene oxide.Cell proliferation was detected by CCK-8 assay.The inhibition zone assay was used to detect the inhibitory effect of different mass concentrations of nanosilver-reduced graphene oxide on Staphylococcus aureus.The nanosilver-reduced graphene oxide mass concentration with the most obvious cell proliferation and antibacterial effects was screened by the results of CCK-8 and inhibition zone assays,and loaded into hydrogels.Human dental pulp stem cells were cultured in complete medium containing different concentrations of Gap19(a specific inhibitor of connexin 43 hemichannels),and cell proliferation was detected by CCK-8 assay.The Gap19 concentration with the most obvious cell proliferation effect was screened and loaded into hydrogels.AgNPs-rGO/PDA/GelMA@Gap19 hydrogel was prepared,and the physicochemical properties of the hydrogel material were characterized.The suspension of Staphylococcus aureus(or Escherichia coli,Streptococcus mutans,Lactobacillus)was co-cultured with mineral trioxide aggregates,polydopamine/methacrylated gelatin hydrogel,nanosilver-reduced graphene oxide/polydopamine/methacrylated gelatin hydrogel and AgNPs-rGO/PDA/GelMA@Gap19 hydrogel.The bacterial suspension cultured alone was used as the blank control group to detect the antibacterial rate of each group of hydrogels.RESULTS AND CONCLUSION:(1)The optimal mass concentration of nanosilver-reduced graphene oxide was determined to be 12.5 μg/mL by CCK-8 assay and inhibition zone test results,and the optimal concentration of Gap19 was determined to be 20 μmol/L by CCK-8 assay.(2)Scanning electron microscopy showed that AgNPs-rGO/PDA/GelMA@Gap19 hydrogel was wrinkled and porous,and nanosilver was loaded on the surface and inside of the hydrogel.Energy spectrum analysis results showed that nanosilver-reduced graphene oxide and Gap19 were successfully loaded on the hydrogel.(3)The four hydrogels had obvious inhibitory effects on Staphylococcus aureus,Escherichia coli,Streptococcus mutans,and Lactobacillus,and the antibacterial effects of nanosilver-reduced graphene oxide/polydopamine/methacryloyl gelatin hydrogel and AgNPs-rGO/PDA/GelMA@Gap19 hydrogel were the most significant,indicating that AgNPs-rGO/PDA/GelMA@Gap19 hydrogel,as a new type of pulp capping material,has an obvious antibacterial effect.

BACKGROUND:Vital pulp therapy is one of the main treatments for common oral diseases such as deep caries.The antibacterial properties of pulp-capping materials are crucial to the efficacy of the treatment.Currently,commonly used pulp-capping material has weak antibacterial properties and may induce a certain degree of inflammatory response in the pulp tissue,leading to treatment failure.OBJECTIVE:To investigate the antibacterial effects of nanosilver-reduced graphene oxide/polydopamine/methacrylated gelatin@Gap19(AgNPs-rGO/PDA/GelMA@Gap19)hydrogel material.METHODS:Nanosilver-reduced graphene oxide was prepared.Human dental pulp stem cells were cultured in complete medium containing different mass concentrations of nanosilver-reduced graphene oxide.Cell proliferation was detected by CCK-8 assay.The inhibition zone assay was used to detect the inhibitory effect of different mass concentrations of nanosilver-reduced graphene oxide on Staphylococcus aureus.The nanosilver-reduced graphene oxide mass concentration with the most obvious cell proliferation and antibacterial effects was screened by the results of CCK-8 and inhibition zone assays,and loaded into hydrogels.Human dental pulp stem cells were cultured in complete medium containing different concentrations of Gap19(a specific inhibitor of connexin 43 hemichannels),and cell proliferation was detected by CCK-8 assay.The Gap19 concentration with the most obvious cell proliferation effect was screened and loaded into hydrogels.AgNPs-rGO/PDA/GelMA@Gap19 hydrogel was prepared,and the physicochemical properties of the hydrogel material were characterized.The suspension of Staphylococcus aureus(or Escherichia coli,Streptococcus mutans,Lactobacillus)was co-cultured with mineral trioxide aggregates,polydopamine/methacrylated gelatin hydrogel,nanosilver-reduced graphene oxide/polydopamine/methacrylated gelatin hydrogel and AgNPs-rGO/PDA/GelMA@Gap19 hydrogel.The bacterial suspension cultured alone was used as the blank control group to detect the antibacterial rate of each group of hydrogels.RESULTS AND CONCLUSION:(1)The optimal mass concentration of nanosilver-reduced graphene oxide was determined to be 12.5 μg/mL by CCK-8 assay and inhibition zone test results,and the optimal concentration of Gap19 was determined to be 20 μmol/L by CCK-8 assay.(2)Scanning electron microscopy showed that AgNPs-rGO/PDA/GelMA@Gap19 hydrogel was wrinkled and porous,and nanosilver was loaded on the surface and inside of the hydrogel.Energy spectrum analysis results showed that nanosilver-reduced graphene oxide and Gap19 were successfully loaded on the hydrogel.(3)The four hydrogels had obvious inhibitory effects on Staphylococcus aureus,Escherichia coli,Streptococcus mutans,and Lactobacillus,and the antibacterial effects of nanosilver-reduced graphene oxide/polydopamine/methacryloyl gelatin hydrogel and AgNPs-rGO/PDA/GelMA@Gap19 hydrogel were the most significant,indicating that AgNPs-rGO/PDA/GelMA@Gap19 hydrogel,as a new type of pulp capping material,has an obvious antibacterial effect.

Objective:intrahepatic portocaval shunt (TIPS) in the treatment of hepatic sinusoidal obstruction syndrome (HSOS).Methods:A retrospective analysis was performed on 27 patients with HSOS who were treated with TIPS in our center from July 2018 to July 2020. The changes of portal vein pressure (PVP), portal vein pressure gradient (PPG) and liver function were observed, so as to evaluate the efficacy. Paired t test was adopted to evaluate the quantitative parameters, while χ2 test was used to analyze qualitative parameters, with P < 0.05 as statistical difference. Results:PVP decreased from (4.41 ± 0.18) kPa before shunt to (2.69 ± 0.11) kPa after shunt ( t = 82.41, P < 0.001), PPG decreased from (3.23 ± 0.18) kPa before shunt to (1.46 ± 0.23) kPa after shunt ( t = 32.41, P < 0.001). The liver function improved significantly after operation. After 24 months of follow-up, 3 patients developed stent restenosis and recanalized after balloon dilation. Three patients developed hepatic encephalopathy, which was improved after drug treatment. One patient underwent liver transplantation due to liver failure. Conclusion:TIPS is effective in the treatment of HSOS in the short and medium term, and can provide time for liver transplantation patients to wait for liver source.

Objective:To explore the correlation between portal vein pressure gradient (PPG) and hepatic vein pressure gradient (HVPG) in patients with portal hypertension (PHT).Methods:752 cases with portal hypertension (PHT) who underwent transjugular intrahepatic portosystemic shunt (TIPS) and met the enrollment criteria between January 2016 to December 2019 were analyzed for hepatic vein, inferior vena cava and portal vein pressure. Paired t-test was used for analysis. Pearson correlation test was used to estimate correlation coefficient and coefficient of determination. P<0.05 were considered statistically significant. Results:Wedged hepatic vein pressure (WHVP), portal vein pressure (PVP), correlation coefficient, and coefficient of determination were 27.98±8.95 mmHg, 33.85±7.33 mmHg, 0.329 ( P<0.001), and 0.108, respectively. HVPG, PPG,correlation coefficient, and coefficient of determination were 16.84±7.97 mmHg, 25.11±6.95 mmHg ( P<0.001), 0.145, and 0.021 ( P<0.001), respectively. The difference between HVPG and PPG was greater than 5 mmHg in 524 cases, accounting for 69.7%. The difference between HVPG and PPG was within 5 mmHg or basically equal in 228 cases, accounting for 30.3%. The correlation coefficient between free hepatic venous pressure (FHVP) and inferior vena cava pressure (IVCP) was 0.568 ( P<0.001), and the coefficient of determination was 0.323. According to the presence or absence of hepatic venous collaterals after balloon occluded hepatic angiography, they were divided into two groups: 157 (20.9%) cases in the group with hepatic venous collaterals, and 595 (79.1%) cases in the group without hepatic venous collaterals. The parameters of the two groups were compared: WHVP (15.73±3.63) mmHg vs. (31.22±6.90) mmHg, P<0.001; PVP (31.69±8.70) mmHg vs. (34.42±6.81) mmHg, P<0.001; HVPG (7.18±4.40) mmHg vs. (19.40±6.62) mmHg, P<0.001; PPG (24.24±8.11) mmHg vs. (25.34±6.60) mmHg, P<0.001; free hepatic venous pressure (FHVP) (8.58±3.37) mmHg vs. (11.82±5.07) mmHg , P<0.001; inferior vena cava pressure (IVCP) (7.45±3.29) mmHg vs. (9.09±4.14) mmHg, P<0.001. Conclusion:The overall correlation is poor between HVPG and PPG. HVPG of most patients is not an accurate representation of PPG, and the former is lower than the latter. Hepatic venous collateral formation is one of the important reasons for the serious underestimation of HVPG values.

Objective:By using balloon occlusive hepatic angiography in cirrhotic portal hypertension to evaluate contrast doses on the detection rate of intrahepatic venous-lateral branch shunt (HVVC), and the effect on hepatic venous pressure gradient (HVPG) and portal vein pressure gradient (PPG).Methods:From Jan 2018 to Jun 2021, 131 patients received transjugular intrahepatic portosystemic shunt (TIPS) at Beijing Shijitan Hospital.Results:A positive correlation between PVP and weged hepatic venous pressure (WHVP) ( r=0.241, P=0.001) was found when only by right hepatic vein approach. Ten ml of iodine contrast medium when compared to 5ml doses found more cases of intrahepatic venous-venous lateral branch shunt. The mean PPG of patients with HVVC was significantly higher than the mean of HVPG( P<0.05).The right hepatic vein was the only reliable vein by which WHVP was measured. Conclusions:Right hepatic vein manometry,adequate ballon occlusion and using 10ml of iodine contrast help get reliable WHVP and found HVVC; HVVC can affect the consistency of HVPG and PPG.