BACKGROUND:Mn can participate in oxidation-reduction reactions in various organisms.For example,as a metal-assisted group in superoxide dismutase 2,Mn plays a role in helping to remove reactive oxygen species.Therefore,the development of novel anti-oxidative stress materials containing Mn has become a research focus in recent years.OBJECTIVE:To investigate the protective effect of Mn bioceramic powder material on oxidative stress damage to chondrocytes by reducing the reactive oxygen species pathway.METHODS:Bioceramic powders containing Mn were prepared by molten salt method.Primary mouse chondrocytes were isolated and cultured.Bioceramic powder containing 0,0.15,and 0.30 mg/mL of Mn was added into H2O2 solution.The H2O2 clearance rate was detected after incubation without light.The passage 2 to passage 4 chondrocytes were co-cultured with complete media containing Mn-containing bioceramic powder with different mass concentrations(0,0.15,and 0.30 mg/mL).Cell viability was detected by cell live/dead staining.The passage 2-4 chondrocytes(or cartilage tissue)were divided into four groups for intervention:Complete culture medium was added to the blank control group.The H2O2 group was added and cultured with complete medium containing H2O2.H2O2+low mass concentration Mn powder group was cultured by adding H2O2+0.15 mg/mL Mn-containing bioceramic powder.The complete medium containing H2O2+0.30 mg/mL Mn-containing bioceramic powder was added to the H2O2+high mass concentration Mn powder group.Viability of chondrocytes was detected by CCK-8 assay.Generation of reactive oxygen species of chondrocytes was detected by 2,7-dichlorofluorescein diacetate probe.Expression of chondrocyte-related factors was detected by qRT-PCR.The tissue structure and function of cartilage were detected by toluidine blue staining.RESULTS AND CONCLUSION:(1)Both doses of Mn-containing bioceramic powders could significantly remove H2O2 in vitro,and they were concentration dependent.The results of cell live/death staining showed that 0.15 mg/mL bioceramic powder containing Mn had chondrocyte safety,and 0.30 mg/mL bioceramic powder containing Mn had chondrocytotoxicity.(2)The results of CCK-8 assay showed that the two mass concentrations of Mn-containing bioceramic powders could significantly reduce the inhibitory effect of H2O2 on chondrocyte viability,and inhibit the generation of reactive oxygen species induced by H2O2 in chondrocytes in a mass concentration dependent manner.Both kinds of Mn-containing bioceramic powders could reverse the H2O2-induced increase of mRNA expression of a disintegrin and metalloproteinase with thrombospondin motifs-5 and decrease of proteoglycan mRNA expression in chondrocytes.(3)Toluidine blue staining results showed that both concentrations of Mn-containing bioceramic powder could protect the integrity of cartilage tissue structure under oxidative stress,and 0.30 mg/mL of Mn-containing bioceramic powder could also reduce the functional damage of cartilage tissue.(4)The results indicate that the Mn-containing bioceramic powder can protect chondrocytes under oxidative stress by clearing reactive oxygen species,maintaining the extracellular matrix homeostasis.However,0.30 mg/mL Mn-containing bioceramic powder has certain chondrocytotoxicity,so 0.15 mg/mL Mn-containing bioceramic powder is preferred for follow-up studies.

BACKGROUND:Mn can participate in oxidation-reduction reactions in various organisms.For example,as a metal-assisted group in superoxide dismutase 2,Mn plays a role in helping to remove reactive oxygen species.Therefore,the development of novel anti-oxidative stress materials containing Mn has become a research focus in recent years.OBJECTIVE:To investigate the protective effect of Mn bioceramic powder material on oxidative stress damage to chondrocytes by reducing the reactive oxygen species pathway.METHODS:Bioceramic powders containing Mn were prepared by molten salt method.Primary mouse chondrocytes were isolated and cultured.Bioceramic powder containing 0,0.15,and 0.30 mg/mL of Mn was added into H2O2 solution.The H2O2 clearance rate was detected after incubation without light.The passage 2 to passage 4 chondrocytes were co-cultured with complete media containing Mn-containing bioceramic powder with different mass concentrations(0,0.15,and 0.30 mg/mL).Cell viability was detected by cell live/dead staining.The passage 2-4 chondrocytes(or cartilage tissue)were divided into four groups for intervention:Complete culture medium was added to the blank control group.The H2O2 group was added and cultured with complete medium containing H2O2.H2O2+low mass concentration Mn powder group was cultured by adding H2O2+0.15 mg/mL Mn-containing bioceramic powder.The complete medium containing H2O2+0.30 mg/mL Mn-containing bioceramic powder was added to the H2O2+high mass concentration Mn powder group.Viability of chondrocytes was detected by CCK-8 assay.Generation of reactive oxygen species of chondrocytes was detected by 2,7-dichlorofluorescein diacetate probe.Expression of chondrocyte-related factors was detected by qRT-PCR.The tissue structure and function of cartilage were detected by toluidine blue staining.RESULTS AND CONCLUSION:(1)Both doses of Mn-containing bioceramic powders could significantly remove H2O2 in vitro,and they were concentration dependent.The results of cell live/death staining showed that 0.15 mg/mL bioceramic powder containing Mn had chondrocyte safety,and 0.30 mg/mL bioceramic powder containing Mn had chondrocytotoxicity.(2)The results of CCK-8 assay showed that the two mass concentrations of Mn-containing bioceramic powders could significantly reduce the inhibitory effect of H2O2 on chondrocyte viability,and inhibit the generation of reactive oxygen species induced by H2O2 in chondrocytes in a mass concentration dependent manner.Both kinds of Mn-containing bioceramic powders could reverse the H2O2-induced increase of mRNA expression of a disintegrin and metalloproteinase with thrombospondin motifs-5 and decrease of proteoglycan mRNA expression in chondrocytes.(3)Toluidine blue staining results showed that both concentrations of Mn-containing bioceramic powder could protect the integrity of cartilage tissue structure under oxidative stress,and 0.30 mg/mL of Mn-containing bioceramic powder could also reduce the functional damage of cartilage tissue.(4)The results indicate that the Mn-containing bioceramic powder can protect chondrocytes under oxidative stress by clearing reactive oxygen species,maintaining the extracellular matrix homeostasis.However,0.30 mg/mL Mn-containing bioceramic powder has certain chondrocytotoxicity,so 0.15 mg/mL Mn-containing bioceramic powder is preferred for follow-up studies.

Third-grade class A hospitals undertake three tasks-medical service,scientific research and teaching.scientific research is the motivation for third-grade class A hospitals' continuous development and also an important symbol of their medical and academic level.On the purpose of evaluating overall scientific level of such hospitals this thesis analyze the scientific projects and the outcomes of 34 hospitals by using the method of literature research and questionnaire,extracting advantages for scientific research,seeking their problems and coming up with corresponding strategy.have analyzed the achievements we acquired as well as the problems still existing.According to the reality of Fujian Province,some suggestions are coming up with so as to improve the scientific research.