In vivo study of liposome-modified polyetheretherketone implant on bacteriostasis and osseointegration / 北京大学学报(医学版)

OBJECTIVE@#To develop dexamethasone plus minocycline-loaded liposomes (Dex/Mino liposomes) and apply them to improve bioinert polyetheretherketone (PEEK) surface, which could prevent post-operative bacterial contamination, enhance ossification for physiologic osseointegration, and finally reduce implant failure rates.@*METHODS@#Dex/Mino liposomes were covalently grafted onto the PEEK surface using polydopamine (pDA) coating as a medium. Confocal laser scanning microscopy was used to confirm the binding of fluorescently labeled liposomes onto the PEEK substrate, and a microplate reader was used to semiquantitatively measure the average fluorescence intensity of fluorescently labeled liposome-decorated PEEK surfaces. Moreover, the mouse subcutaneous infection model and the beagle femur implantation model were respectively conducted to verify the bioactivity of Dex/Mino liposome-modified PEEK in vivo, by means of micro computed tomography (micro-CT) and hematoxylin and eosin (HE) staining analysis.@*RESULTS@#The qualitative and quantitative results of fluorescently labeled liposomes showed that, the red fluorescence intensity of the PEEK-pDA-lipo group was stronger than that of the PEEK-NF-lipo group (P < 0.05); the liposomes were successfully and uniformly decorated on the PEEK surfaces due to the pDA coating. After mouse subcutaneous implantation of PEEKs for 24 hours, HE staining results showed that the number of inflammatory cells in the PEEK-Dex/Mino lipo group were lower than that in the inert PEEK group (P < 0.05), indicating a lower degree of infection in the test group. These results suggested that the Mino released from the liposome-functionalized surface provided an effective bacteriostasis in vivo. After beagle femoral implantation of PEEK for 8 weeks, micro-CT results showed that the PEEK-Dex/Mino lipo group newly formed more continuous bone when compared with the inert PEEK group; HE staining results showed that more new bones were formed in the PEEK-Dex/Mino lipo group than in the inert PEEK group, which were firmly bonded to the functionalized PEEK surface and extended along the PEEK interface. These results suggested that the Dex released from the liposome-functionalized surface induced effective bone regeneration in vivo.@*CONCLUSION@#Dex/Mino liposome modification enhanced the bioactivity of inert PEEK, the functionalized PEEK with enhanced antibacterial and osseointegrative capacity has great potential as an orthopedic/dental implant material for clinical application.

Study on time-toxicity relationship and mechanism of Gardeniae Fructus extract on hepatoxicity in rats based on proteomics / 中国中药杂志

To study the time-toxicity relationship and mechanism of Gardeniae Fructus extract on the hepatoxicity in rats. Rats were randomly divided into C group(0 day), D5 group(5 days), D12 group(12 days), D19 group(19 days), and D26 group(7 days recovery after 19 days of administration). The rats in normal group received normal saline through intragastric administration, and the rats in other groups received 10 g·kg~(-1 )Gardeniae Fructus extract through intragastric administration. After the final administration, the livers were collected. Hematoxylin-eosin staining was used to observe the histopathological changes in the liver tissue. Total liver proteins were extracted for proteomic analysis, detected by the Nano-ESI liquid-mass spectrometry system and identified by Protein Disco-very software. SIEVE software was used for relative quantitative and qualitative analysis of proteins. The protein-protein interaction network was constructed based on STRING. Cytoscape software was used for cluster analysis of differential proteins. Kyoto encyclopedia of genes and genomes(KEGG) database was used to perform enrichment signal pathway analysis. Pearson correlation analysis was performed for the screened differential protein expression and liver pathology degree score. The results showed that the severity of liver injury in D5, D12 and D19 groups was significantly higher than that in group C. The degree of liver damage in D5 group was slightly higher than that in D12 and D19 groups, with no significant difference between group D26 and group C. Totally 147 key differential proteins have been screened out by proteomics and mainly formed 6 clusters, involving in drug metabolism pathways, retinol metabolism pathways, proteasomes, amino acid biosynthesis pathways, and glycolysis/gluconeogenesis pathways. The results of Pearson correlation analysis indicated that differential protein expressions had a certain temporal relationship with the change of liver pathological degree. The above results indicated that the severity of liver damage caused by Gardeniae Fructus extract did not increase with time and would recover after drug with drawal. The above pathways may be related to the mechanism of liver injury induced by Gardeniae Fructus extract.

Effect of the vacuum-formed retainer on preventing the proximal contact loss between implant supported crown and adjacent natural teeth / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the effect of the vacuum-formed retainer on preventing the proximal contact loss between the implant supported crown and its adjacent natural teeth.@*METHODS@#Forty-six posterior implant crowns in the mandible including 92 interproximal contacts in 46 patients (19 men, 27 women) aged from 25 to 66 years were included. The participants in experimental group (22 cases) were vacuum-formed retainers at night, while participants in control group (24 cases) only received routine examination. The two groups were not different in age, gender, the time interval of the tooth loss and tooth position at baseline. Mesial and distal proximal contact tightness was measured using the orthodontic dynamometer and metallic articulating film immediately after crown delivery, and 1-month, 3-month, 6-month, and 1-year follow-up respectively. The articulating film was inserted interdentally from the occlusal direction, and then it was slowly removed in the buccallingual direction by the dynamometer. Increasing the number of films (N) piece by piece until the frictional force (F) was great than 0, and the number of films (N) was recorded. At each follow-up, proximal contact between implant crown and its adjacent teeth was considered to be loss if the number of films (N) used at immediate crown delivery passed without frictional force (F=0). Besides, the periodontal conditions [scored according to the probing depth (PD), bleeding index (BI), mobility (M)] and complaint of food impaction were recorded. The mesial and distal proximal contact loss rates were compared between the two groups at different times. Chi-square test or Fisher's exact test was used for statistical analysis.@*RESULTS@#The proximal contact loss rate on the mesial surface of the implant supported crown continuously increased over the follow-up periods. At the end of the 1-, 3-, and 6-month follow ups, 18.2%, 22.7% and 27.3% were identified for the contact loss rates on the mesial surface of the implant supported crown in the experimental group, respectively. Meanwhile in control group, the rates were 20.8%, 37.5% and 45.8%. No significant differences were observed at the end of the 1-, 3-, and 6-month follow ups(1-month: χ2=0.000, P=1.000; 3-month: χ2=1.183, P=0.277; 6-month: χ2=1.697, P=0.193). The proximal contact loss rate on the mesial surface in control group (62.5%) was significantly higher than that in the experimental group (31.8%, χ2=4.330, P=0.037) at the end of the 1-year follow-up. However, no statistical difference was found on the distal surfaces between the two groups during the whole follow-up periods. The first open contact was noted 1 month after crown insertion.@*CONCLUSION@#By wearing vacuum-formed retainer for one year, the incidence of open contacts between the posterior implant prostheses and mesial adjacent teeth in the mandible has been reduced.

Proteomics research of intervention effect of "Qi enriching" herbs on "Qi deficiency" rats based on technology of NanoLC-LTQ-Orbitrap / 中国中药杂志

Proteomics method, based on NanoLC-LTQ-Orbitrap technology, was applied to explore the biological basis of intervention effect of "Qi enriching" herbs on "Qi deficiency" rats. The "Qi deficiency" rat model was established with caloric restriction combined with excessive swimming. Muscle proteins of vastus lateralis from the blank group, the model group and the ginseng group were detected by NanoLC-LTQ-Orbitrap system. The data were imported into Protein Discovery software to identify the proteins and all the raw datum were analyzed by SIEVE software. Compared with model group, 26 significant difference proteins were found in ginseng group, which the variation trend was consistent with the blank group. Through the biological function analysis, the found proteins could be classified into proteins involved in energy metabolism, proteins involved in glucose metabolism, electrolyte balance and material transfer related proteins, inflammation related protein and cytoskeleton protein. The above target proteins and their regulation pathways may be the biological basis which ginseng played a role of tonifying "Qi" of "Qi deficiency" symptom.

Study on discrimination mode of cold and hot properties of traditional Chinese medicines based on biological effects / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of cold or hot properties of traditional Chinese medicines (TCM) on biological effect indexes, and analyze the contribution of variables on cold or hot properties, in order to preliminarily establish the discrimination mode for the biological effects of cold or hot properties.</p><p><b>METHOD</b>Rats were randomly divided into the blank control group, cold TCM groups (Coptidis Rhizoma, Scutellariae Radix, Phellodendri Cortex, Gardeniae Fructus, Sophorae Flavescentis Radix and Gentianae Radix) and hot TCM groups (Aconiti Lateralis Preparata Radix, Zingiberis Rhizoma, Alpiniae Officinarum Rhizoma, Zanthoxyli Pericarpium, Cinnamomi Cortex and Evodiae Fructus), and orally administered with 10 mL x kg(-1) of corresponding TCM water decoctions for 30 d, twice a day. Altogether 53 biological effect indexes correlated to cold or hot properties of traditional Chinese medicines were founded by searching literatures. The data warehouse were established by using data-mining software Clementine12.0. Data of the blank control group, cold TCM groups (Coptidis Rhizoma, Phellodendri Cortex, Gardeniae Fructus, Sophorae Flavescentis Radix, Gentianae Radix) and hot TCM groups (Aconiti Lateralis Preparata Radix, Zingiberis Rhizoma, Alpiniae Officinarum Rhizoma, Zanthoxyli Pericarpium, Cinnamomi Cortex) were selected into a training set. C5.0 algorithm and C&R classification and regression algorithm were adopted to define the importance of variable, create the decision trees, and test hot or cold properties of Evodiae Fructus and Scutellariae Radix.</p><p><b>RESULT</b>According to C&R classification and regression algorithm, SDH activity of livers was the most important hot or cold property, with the significance closed to 30%. It was followed by triglyceride, liver Na' -K' -ATPase enzyme, muscle glycogen and platelet distribution width, with the accuracy up to 97.39% in models. C5.0 algorithm showed that liver SDH activity was the most important hot or cold property, with the significance closed to 40%. It was followed by triglyceride, GOT, muscle glycogen and liver Na(+)-K(+)-ATPase enzyme, with the accuracy up to 98.26% in models. The possibilities that Evodiae Fructus is in hot property and Scutellariae Radix is in cold property were 100. 00% and 77.78% by using both C&R classification and regression algorithm and C5.0 algorithm.</p><p><b>CONCLUSION</b>The SDH activity of liver is the most important biological effect index to distinguish cold and hot properties of TCMs. The discrimination pathway or mode of cold and hot properties is closely related to energy metabolism.</p>

Effect of euodiae fructus on hepatic energy metabolism-related mechanisms of reserpine-induced asthenia cold syndrome rats / 中国中药杂志

<p><b>OBJECTIVE</b>To discuss the effect of Euodiae Fructus on hepatic energy metabolism-related mechanisms of mitochondria of hepatic tissues of asthenia cold syndrome rats.</p><p><b>METHOD</b>Rats were subcutaneously injected with Reserpine to establish the model. After the oral administration with Euodiae Fructus for 12 d, the oxygen electrode method was adopted to determine the respiration efficiency. The expressions of Cox4, Atp5b, Ucp2,Pgc-1alpha, Nrf1, Tfam mRNA were assayed by using RT-PCR method.</p><p><b>RESULT</b>Euodiae Fructus 4.2 g x kg(-1) could obviously increase ST3 and RCR of asthenia cold syndrome rats, and expressions of Cox4, Ucp2 Nrf1 mRNA. It could also increase expressions of Atp5b and Pgc-1alpha mRNA, but with no statistical significance. No obvious change was observed in Tfam mRNA expression. Euodiae Fructus 4.2 g x kg(-1) could significantly increase ST3 and RCR of asthenia cold syndrome rats and Pgc-1alpha mRNA and Nrf1 mRNA expressions, and significantly decrease P/O, with no obvious impact on Cox4, AtpSb, Ucp2, Tfam mRNA expressions.</p><p><b>CONCLUSION</b>Euodiae Fructus can promote mitochondrial respiratory function and oxidative phosphorylation efficiency by improving Pgc-1alpha mRNA and Nrf1 mRNA expressions and regulating Cox4 and Atp5b mRNA in mitochondrial respiratory chain. It can also strengthen mitochondrial uncoupling respiration and add heat production by activating Ucp2 mRNA expression in liver.</p>

Silver-ion release and particle distribution of denture base resin containing nanometer-sized silver-supported antimicrobial agent / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the distribution of antimicrobial agent STR-1 of nanometer level which was incorporated with ball-grinding method in the polymethylmethacrylate (PMMA) denture base, and to study the release mode of silver ions from the base.</p><p><b>METHODS</b>The distribution of the antimicrobial agent in the PMMA denture base containing STR-1 at concentrations of 0 g/L, 5 g/L, and 10 g/L was examined with scanning electronic microscopy. Then, PMMA resin bases containing STR-1 at the three concentrations were respectively immersed in artificial saliva at 37 degrees C for 54 days. The release of silver ions from the resin bases was surveyed with inductively coupled plasma-mass spectroscopy (ICP-MS) every 24 hours.</p><p><b>RESULTS</b>The antimicrobial agent incorporated by ball-grinding method was even-distributed with individual particles of nanometer level in the PMMA resin base. The release of silver ions from the PMMA resin with antimicrobial agent was extremely slow during the test, a very small fraction of the silver ions released. At the beginning of the test, the release speed was extremely slow, the speed increased rapidly in the middle of the test, and at the end of the test, the speed returned to slow and steady. The cumulative release curve of silver ions was of "S" type.</p><p><b>CONCLUSIONS</b>STR-1 can be even-distributed in the denture base, and the silver ions release from the base with extremely slow speed. It also indicates that biological safety and long-term antimicrobial efficacy of denture base containing silver-supported antimicrobial agents of nanometer level are possibly obtained based on their slow release of silver ions.</p>