RESUMO
Cerebral ischemic preconditioning (CIP) has been shown to improve brain ischemic tolerance against subsequent lethal ischemia. Reactive astrocytes play important roles in cerebral ischemia-reperfusion. Recent studies have shown that reactive astrocytes can be polarized into neurotoxic A1 phenotype (C3d) and neuroprotective A2 phenotype (S100A10). However, their role in CIP remains unclear. Here, we focused on the role of N-myc downstream-regulated gene 2 (NDRG2) in regulating the transformation of A1/A2 astrocytes and promoting to brain ischemic tolerance induced by CIP. A Sprague Dawley rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) was used. Rats were divided into the following six groups: (1) sham group; (2) CIP group: left middle cerebral artery was blocked for 10 min; (3) MCAO/R group: left middle cerebral artery was blocked for 90 min; (4) CIP + MCAO/R group: CIP was performed 72 h before MCAO/R; (5) AAV-NDRG2 + CIP + MCAO/R group: adeno-associated virus (AAV) carrying NDRG2 was administered 14 days before CIP + MCAO/R; (6) AAV-Ctrl + CIP + MCAO/R group: empty control group. The rats were subjected to neurological evaluation 24 h after the above treatments, and then were sacrificed for 2, 3, 5-triphenyltetraolium chloride staining, thionin staining, immunofluorescence and western blot analysis. In CIP + MCAO/R group, the neurological deficit scores decreased, infarct volume reduced, and neuronal density increased compared with MCAO/R group. Notably, CIP significantly increased S100A10 expression and the number of S100A10+/GFAP+ cells, and also increased NDRG2 expression. MCAO/R significantly decreased S100A10 expression and the number of S100A10+/GFAP+ cells yet increased C3d expression and the number of C3d+/GFAP+ cells and NDRG2 expression, and these trends were reversed by CIP + MCAO/R. Furthermore, over-expression of NDRG2 before CIP + MCAO/R, the C3d expression and the number of C3d+/GFAP+ cells increased, while S100A10 expression and the number of S100A10+/GFAP+ cells decreased. Meanwhile, over-expression of NDRG2 blocked the CIP-induced brain ischemic tolerance. Taken together, these results suggest that CIP exerts neuroprotective effects against ischemic injury by suppressing A1 astrocyte polarization and promoting A2 astrocyte polarization via inhibiting NDRG2 expression.
Assuntos
Astrócitos , Isquemia Encefálica , Infarto da Artéria Cerebral Média , Precondicionamento Isquêmico , Ratos Sprague-Dawley , Animais , Precondicionamento Isquêmico/métodos , Masculino , Astrócitos/metabolismo , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Isquemia Encefálica/metabolismo , Ratos , Proteínas do Tecido NervosoRESUMO
Our previous study has proved that the Klotho up-regulation participated in cerebral ischemic preconditioning (CIP)-induced brain ischemic tolerance. However, the exact neuroprotective mechanism of Klotho in CIP remains unclear. We explored the hypothesis that STAT4-mediated Klotho up-regulation contributes to the CIP-induced brain ischemic tolerance via inhibiting neuronal pyroptosis. Firstly, the expressions of pyroptosis-associated proteins (i.e., NLRP3, GSDMD, pro-caspase-1, and cleaved caspase-1) in hippocampal CA1 region were determined during the process of brain ischemic tolerance. We found the expression of pyroptosis-associated proteins was significantly up-regulated in the ischemic insult (II) group, and showed no significant changes in the CIP group. The expression level of each pyroptosis-associated proteins was lower in the CIP + II group than that in the II group. Inhibition of Klotho expression increased the expression of pyroptosis-associated proteins in the CIP + II group and blocked the CIP-induced brain ischemic tolerance. Injection of Klotho protein decreased the expression of pyroptosis-associated proteins in the II group, and protected neurons from ischemic injury. Secondly, the transcription factor STAT4 of Klotho was identified by bioinformatic analysis. Double luciferase reporter gene assay and chromatin immunoprecipitation assay showed STAT4 can bind to the site between nt - 881 and - 868 on the Klotho promoter region and positively regulates Klotho expression. Moreover, we found CIP significantly enhanced the expression of STAT4. Knockdown STAT4 suppressed Klotho up-regulation after CIP and blocked the CIP-induced brain ischemic tolerance. Collectively, it can be concluded that STAT4-mediated the up-regulation of Klotho contributed to the brain ischemic tolerance induced by CIP via inhibiting pyroptosis.
Assuntos
Isquemia Encefálica , Precondicionamento Isquêmico , Ratos , Animais , Ratos Wistar , Regulação para Cima , Piroptose , Fator de Transcrição STAT4/metabolismo , Isquemia Encefálica/metabolismo , Região CA1 Hipocampal/metabolismo , Neurônios/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismoRESUMO
The morbidity rate of ischemic stroke is increasing annually with the growing aging population in China. Astrocytes are ubiquitous glial cells in the brain and play a crucial role in supporting neuronal function and metabolism. Increasing evidence shows that the impairment or loss of astrocytes contributes to neuronal dysfunction during cerebral ischemic injury. The mitochondrion is increasingly recognized as a key player in regulating astrocyte function. Changes in astrocytic mitochondrial function appear to be closely linked to the homeostasis imbalance defects in glutamate metabolism, Ca2+ regulation, fatty acid metabolism, reactive oxygen species, inflammation, and copper regulation. Here, we discuss the role of astrocytic mitochondria in the pathogenesis of brain ischemic injury and their potential as a therapeutic target.
Assuntos
Lesões Encefálicas , Isquemia Encefálica , Humanos , Idoso , Astrócitos/metabolismo , Isquemia Encefálica/patologia , Encéfalo/metabolismo , Lesões Encefálicas/metabolismo , Mitocôndrias/metabolismoRESUMO
Cerebral ischemic preconditioning (CIP)-induced brain ischemic tolerance protects neurons from subsequent lethal ischemic insult. However, the specific mechanisms underlying CIP remain unclear. In the present study, we explored the hypothesis that peroxisome proliferator-activated receptor gamma (PPARγ) participates in the upregulation of Klotho during the induction of brain ischemic tolerance by CIP. First we investigated the expression of Klotho during the brain ischemic tolerance induced by CIP. Lethal ischemia significantly decreased Klotho expression from 6 h to 7 days, while CIP significantly increased Klotho expression from 12 h to 7 days in the hippocampal CA1 region. Inhibition of Klotho expression by its shRNA blocked the neuroprotection induced by CIP. These results indicate that Klotho participates in brain ischemic tolerance by CIP. Furthermore, we tested the role of PPARγ in regulating Klotho expression after CIP. CIP caused PPARγ protein translocation to the nucleus in neurons in the CA1 region of the hippocampus. Pretreatment with GW9962, a PPARγ inhibitor, significantly attenuated the upregulation of Klotho protein and blocked the brain ischemic tolerance induced by CIP. Taken together, it can be concluded that Klotho upregulation via PPARγ contributes to the induction of brain ischemic tolerance by CIP.
Assuntos
Isquemia Encefálica , Precondicionamento Isquêmico , Animais , Ratos , Isquemia Encefálica/metabolismo , Região CA1 Hipocampal , Isquemia , PPAR gama/metabolismo , Ratos Wistar , Regulação para CimaRESUMO
Several studies indicated that autophagy activation participates in brain ischemic tolerance (BIT) induced by cerebral ischemic preconditioning (CIP). However, the mechanism of autophagy activation during the process still remains unclear. The present study aimed to evaluate the role of p38 MAPK-peroxisome proliferator-activated receptor γ (PPARγ) signaling cascade in autophagy during the CIP-induced BIT. The results shown that, initially, autophagy activation was observed after CIP in the model of global cerebral ischemia in rats, as was indicated by the upregulation of Beclin 1 expression, an increase in LC3-II/LC3-I ratio, the enhanced LC3 immunofluorescence, and a rise in the number of autophagosomes in the neurons of the hippocampal CA1 area. Besides, the inhibitor of autophagy 3-methyladenine obliterated the neuroprotection induced by CIP. Furthermore, the upregulation of p-p38 MAPK and PPARγ expressions was earlier than autophagy activation after CIP. In addition, pretreatment with SB203580 (the inhibitor of p38 MAPK) reversed CIP-induced PPARγ upregulation, autophagy activation, and neuroprotection. Pretreatment with GW9662 (the inhibitor of PPARγ) reversed autophagy activation and neuroprotection, while it had no effect on p-p38 MAPK upregulation induced by CIP. These data suggested that the p38 MAPK-PPARγ signaling pathway participates in autophagy activation during the induction of BIT by CIP.
Assuntos
Isquemia Encefálica , Precondicionamento Isquêmico , Animais , Autofagia , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Precondicionamento Isquêmico/métodos , PPAR gama/genética , PPAR gama/metabolismo , Ratos , Ratos Wistar , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Long noncoding RNAs (lncRNAs) play an important regulatory role in various diseases. However, the role of lncRNAs in brain ischemic tolerance (BIT) induced by cerebral ischemic preconditioning (CIPC) is still unknown. The lncRNA profile of rat cortical astrocytes pretreated with ischemic preconditioning was analyzed by high-throughput sequencing. The results of Cell-Counting Kit-8 (CCK-8) assay showed that a novel lncRNA, NONRATT009133.2, which we referred to as brain ischemia-related factor (BIRF), was highly correlated with BIT. Through bioinformatics analysis, we predicted that BIRF, miR-330-5p, and GLT-1 (also named Slc1a2) might constitute a ceRNA regulatory network in the induction of BIT. We found that BIRF was upregulated by CIPC, which promoted GLT-1 expression and BIT induction. BIRF could directly bind to miR-330-5p. Furthermore, miR-330-5p directly targeted GLT-1, and miR-330-5p inhibited both GLT-1 expression and BIT induction in vitro and in vivo. Moreover, BIRF acts as a molecular sponge to competitively bind to miR-330-5p with GLT-1 mRNA, while the miR-330-5p inhibitor reversed all the effects of BIRF siRNA on GLT-1 expression and neuronal vitality. Taken together, our results demonstrate the important roles of the BIRF/miR-330-5p/GLT-1 axis in the induction of BIT by CIPC. BIRF may be a potentially effective therapeutic strategy against stroke injury.
Assuntos
Isquemia Encefálica , Transportador 2 de Aminoácido Excitatório , Precondicionamento Isquêmico , MicroRNAs , RNA Longo não Codificante , Animais , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Isquemia Encefálica/genética , Isquemia Encefálica/metabolismo , Clorprofam , Transportador 2 de Aminoácido Excitatório/genética , Transportador 2 de Aminoácido Excitatório/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , RatosRESUMO
Carbon black (CB) has been demonstrated to have adverse effects on the lung tissue. Few studies explored the effects of CB on the cerebellum, widely recognized to contribute to gait and balance coordination and timing in the motor domain. Some studies have reported that inflammatory response and damaged autophagy are important mechanisms of CB toxicity and can be repaired after the recovery. The present study aimed to determine whether long-term CB exposure could induce the inflammation and damaged autophagy of the cerebellum. The rats were randomly divided into four groups. The control group received the filtered air for 90 days; the carbon black (CB) group received CB particles for 90 days; the recovery (R) group received CB for 90 days and recovered for another 14 days; the recovery control (RC) group received filtered air for 104 days. The purpose of the R group was to test whether neuroinflammation and autophagy could be repaired after short-term recovery. The western blot and immunohistochemistry revealed that long-term CB exposure induced augmented level of pro-inflammatory cytokines (Interleukin-1ß, IL-1ß; Interleukin-6, IL-6; and Tumor Necrosis Factor-α, TNF-α) and anti-inflammatory cytokine (Interleukin-10, IL-10). The autophagic markers (Beclin1 and LC3) were increased in both CB group and R group. These findings clearly demonstrated that long-term CB exposure induced inflammation and autophagy in the cerebellum, which were not obviously improved after short-term recovery.
Assuntos
Autofagia/efeitos dos fármacos , Cerebelo/efeitos dos fármacos , Doenças Neuroinflamatórias/induzido quimicamente , Fuligem/toxicidade , Animais , Western Blotting , Cerebelo/patologia , Masculino , Doenças Neuroinflamatórias/patologia , Ratos , Ratos Sprague-Dawley , Fuligem/administração & dosagemRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Aconitum carmichaelii Debeaux is a well-known Chinese herb that has been used to treat liver diseases for many years in China. We investigated the effects of aqueous extract from Aconitum carmichaelii Debeaux (AEACD) on acute liver failure and identified the possible mechanisms of these effects. MATERIAL AND METHODS: Specific pathogen-free (SPF) male Wistar rats were used to establish acute liver failure model by intraperitoneal injection of D-galactosamine (D-GalN) and treated with Stronger Neo-Minophagen C (SNMC) and AEACD by gavage. Then, the serum biochemical parameters, the pathological scores in the liver tissue, the mRNA expressions of toll- like receptor 4 (TLR4), nuclear factor kappa B (NF-κB), high mobility group box 1 (HMGB1) and caspase-3, the proliferating cell nuclear antigen (PCNA) positive rates were analyzed. RESULTS: The liver function was improved, the pathological scores were decreased, the expressions the TLR4, NF-κB, HMGB1, and caspase-3 were inhibited, and the PCNA positive rates were increased by both SNMC and AEACD, but AEACD induced greater effects. CONCLUSIONS: AEACD protected liver function by inhibiting inflammatory reaction, apoptosis and promoting liver tissue regeneration in the acute liver failure rats induced by D-galactosamine.
Assuntos
Aconitum/química , Caspase 3/metabolismo , Proteína HMGB1/metabolismo , Hepatopatias/tratamento farmacológico , NF-kappa B/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Cisteína/metabolismo , Combinação de Medicamentos , Galactosamina/efeitos adversos , Glicina/metabolismo , Ácido Glicirretínico/análogos & derivados , Ácido Glicirretínico/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Hepatopatias/metabolismo , Masculino , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacosRESUMO
For tooth segmentation problem on the three-dimensional computed tomography(CT)volume data,this paper proposes a regional adaptive deformable model for tooth structure measurement of CT images.The proposed method combines the automatic thresholding segmentation,CV active contour model,and graph-cut.Firstly,we achieved the segmentation and location of dental crowns by automatic thresholding segmentation.And then by using the above segmentation result as the initial contour,we utilized active contour method to slice gradually the segment of remaining tooth.By incorporating active contour and graph-cut then,we realized the accurate segmentation for tooth root,which is the most difficult to be segmented.The experimental results showed that the proposed tooth structure measurement accurately and automatically segmented dental crowns from CT data,and then rapidly and accurately segmented the tooth neck and tooth root.The structure of tooth could be effectively segmented from CT data by using the proposed method.Experimental results indicated that the proposed method was rather robust and accurate,and could effectively assist the doctor for diagnosis in clinical treatment.
Assuntos
Processamento de Imagem Assistida por Computador , Tomografia Computadorizada por Raios X , Dente/diagnóstico por imagem , Algoritmos , HumanosRESUMO
OBJECTIVE: To develop novel polyetheretherketone (PEEK) based nanocomposites which possess the favorable antibacterial property, and to investigate the oral microbial adhesion and biofilm formation on the surfaces of PEEK, nano-fluorohydroxyapatite (n-FHA)-PEEK and nano-hydroxyaptite (n-HA)-PEEK. METHODS: The bacterial adhesion and biofilm formation on the surfaces of n-FHA-PEEK, n-HA-PEEK were investigated via microbial viability assay kit and laser scanning confocal microscope (LSCM), respectively, with pure PEEK as control group. RESULTS: No significantly statistical difference were found in the bacterial adhesion amounts on the surfaces of n-FHA-PEEK, n-HA-PEEK and PEEK at 1 h and 4 h. However, the number of bacteria on the n-FHA-PEEK surface decreased dramatically at 2 h (0.496 ± 0.008) compared with n-HA-PEEK groups (0.543 ± 0.015, P < 0.01). Although the biofilms formation on surfaces observed by LSCM had similar morphology and thickness at 3, 7, 14 d, that on the n-FHA-PEEK surface showed the highest dead-to-live bacteria ratio among the three materials at 14 d. CONCLUSIONS: The combination of n-HA, especially for the n-FHA could inhibit the bacteria adhesion and accelerate the bacterial death, eventually may have an influence on the structure of biofilms and reduce the risk of peri-implantitis. Therefore, n-FHA-PEEK nanocomposites presented a good prospect for clinical applications as dental implant materials.
Assuntos
Aderência Bacteriana/fisiologia , Biofilmes , Implantes Dentários/microbiologia , Hidroxiapatitas , Cetonas , Nanocompostos/microbiologia , Polietilenoglicóis , Carga Bacteriana , Benzofenonas , PolímerosRESUMO
PURPOSE: To evaluate the epidemiology and the treatment of infected fractures of the mandible. METHODS: Thirty-five cases of infected mandible fractures treated by extra oral open reduction and rigid internal fixation with reconstructive plates were retrospectively investigated. RESULTS: The fracture healing and occlusion recovery of 34 cases were satisfied without any nonunion or deformity, except 1 case healed after bone grafting for bone defect. CONCLUSIONS: The reconstructive plate fixation is applicable to the treatment of infected mandible fractures by its excellent stability and reliability.
Assuntos
Placas Ósseas , Fixação Interna de Fraturas , Infecções , Fraturas Mandibulares , Transplante Ósseo , Consolidação da Fratura , Fraturas Ósseas , Humanos , Mandíbula , Estudos RetrospectivosRESUMO
PURPOSE: To evaluate the effectiveness and safety of nitrous oxide/oxygen inhalation sedation in the treatment of acute pulpitis. METHODS: The study population comprised 72 patients of acute pulpitis treated from September 2012 to March 2013. They were randomly divided into 2 groups, which included experimental group (37 cases) and control group (35 cases). Venham clinical anxiety, cooperative behavior level and WHO clinical pain level evaluation were conducted for the patients. Wilcoxon and Chi-square test were used respectively for statistical analysis with SPSS 14.0 software package. RESULTS: In the experimental group, 86.5% cases behaved comfortable, while in the control group the rate was only 42.9%. 94.6% of the patients in the experimental group felt painless after therapy. The proportion of that in the control group was 68.6%. There was significant difference between the 2 groups (P<0.01). CONCLUSIONS: The technique of nitrous oxide/oxygen inhalation sedation provides a safe and effective way to release pain and anxiety during treatment of acute pulpitis, while the long-term clinical result still needs further investigation.
Assuntos
Anestesia Dentária , Óxido Nitroso , Oxigênio , Pulpite , HumanosRESUMO
AIMS: To investigate whether ginkgolide B (a platelet-activating factor inhibitor) affects vascular inflammation in atherosclerosis-prone apolipoprotein E-deficient (ApoE(-/-)) mice. METHODS AND RESULTS: Human platelets were used to evaluate the effects of ginkgolide B on platelet aggregation and signal transduction. Ginkgolide B attenuated platelet aggregation and inhibited phosphatidylinositol 3 kinase (PI3K) activation and Akt phosphorylation in thrombin- and collagen-activated platelets. ApoE(-/-) mice were administered a high-cholesterol diet for 8 weeks. Plasma platelet factor 4 (PF4) and RANTES (regulated upon activation, normal T-cell expressed, and secreted protein) were then measured using an enzyme-linked immunosorbent assay. Scanning electron microscopy and immunohistochemistry were used to determine atherosclerotic lesions. Ginkgolide B decreased plasma PF4 and RANTES levels in ApoE(-/-) mice. Scanning electron microscopic examination showed that ginkgolide B reduced aortic plaque in ApoE(-/-) mice. Immunohistochemistry analysis demonstrated that ginkgolide B diminished P-selectin, PF4, RANTES, and CD40L expression in aortic plaque in ApoE(-/-) mice. Moreover, ginkgolide B suppressed macrophage and vascular cell adhesion protein 1 (VCAM-1) expression in aorta lesions in ApoE(-/-) mice. Similar effects were observed in aspirin-treated ApoE(-/-) mice. CONCLUSION: Ginkgolide B significantly reduced atherosclerotic lesions and P-selectin, PF4, RANTES, and CD40L expression in aortic plaque in ApoE-/- mice. The efficacy of ginkgolide B was similar to aspirin. These results provide direct evidence that ginkgolide B inhibits atherosclerosis, which may be associated with inhibition of the PI3K/Akt pathway in activated platelets.
Assuntos
Apolipoproteínas E/genética , Aterosclerose/genética , Ginkgolídeos/farmacologia , Lactonas/farmacologia , Vasculite/genética , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Aorta/patologia , Apolipoproteínas E/deficiência , Aterosclerose/tratamento farmacológico , Plaquetas/efeitos dos fármacos , Ligante de CD40/metabolismo , Quimiocina CCL5/sangue , Quimiocina CCL5/metabolismo , Ginkgolídeos/administração & dosagem , Humanos , Lactonas/administração & dosagem , Lipídeos/sangue , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Selectina-P/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Placa Aterosclerótica/metabolismo , Ativação Plaquetária , Agregação Plaquetária/efeitos dos fármacos , Fator Plaquetário 4/sangue , Fator Plaquetário 4/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo , Vasculite/tratamento farmacológicoRESUMO
OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Assuntos
Anti-Infecciosos/farmacocinética , Materiais Dentários/química , Íons/farmacocinética , Prata/farmacocinética , Bases de Dentadura , Prótese Parcial , Teste de Materiais , Nanoestruturas , Polimetil Metacrilato/químicaRESUMO
OBJECTIVE: To evaluate the biocompatibility of polymethylmethacrylate(PMMA) denture base resin containing silver-supported antimicrobial agent STR-1 of nanometer level in vitro. METHODS: According to the national standards for biological evaluation of dental materials, the cytotoxicity of denture base resin containing STR-1 at concentrations of 5 g/L and 10 g/L was examined by molecular filtrating method, and the hemolysis of STR-1, denture base resin containing STR-1 at concentrations of 5 g/L and 10 g/L was also surveyed. RESULTS: The control denture base resin without containing STR-1 and the denture base resins containing STR-1 at concentrations of 5 g/L and 10 g/L were not cytotoxic to L929 cells. Two hours and 24 hours after cell culturing, the filter membranes of the control and experimental groups were stained evenly with blue color. The staining intensity was not decreased and the fading areas were 0 mm2 during the culturing. The cytotoxicity grades were 0. The hemolysis rates of the antimicrobial agent STR-1 and the denture base resins containing STR-1 at concentrations of 5 g/L and 10 g/L were 1.7%, 3.5% and 3.7% respectively. They were less than the national guild standard 5% which represent no hemolysis. CONCLUSION: The PMMA denture base resins containing silver-supported antimicrobial agents STR-1 of nanometer level at concentrations of 5 g/L and 10 g/L exhibit good biocompatibility.