Effect Of New Au Nanostars/Collagen Matrix Material On Oxidative Stress Damage In Newborn Rat Ventricular Myocytes

ObjectiveTo verify Au nanostars/collagen?AuNSs/Col?^?s antioxident activity for newborn rat ventricular myocyte?NRVM?by in vitro studies,thereby to protect the original cells and transplanted cells from injury.Methods1)Building different concentration of Au nanostar/collagen composite substrate materials,using transmission electron microscopy?TEM?to observe dispersion of AuNSs in Col;and the conductivity was evaluated by electrochemical workstation.2)The biocompatibility of AuNSs/Col composites to NRVM was evaluated through Live/dead,CCK-8 assay and the optimal concentration selected out and Col were used for subsequent experiments.3)When cell growth is 3 days?about 70%to 80%of cover glass?,oxidative stress injury?high ROS?model was induced by H₂O₂ induction cells in vitro.Four groups of AuNSs/Col groups and Col groups were induced 0h,6h,12h and 24h?0h and 6h were the same treatment time?.,Observing the cell apoptosis in the AuNSs/Col composites;Using DCFH-DA staining and NO content determination,the effects of AuNSs/Col composites on total ROS and NO levels in cells were observed;The antioxidative capacity of the cells in AuNSs/Col composites was evaluated by the enzyme activity of catalase.The effect of AuNSs/Col composite on lipid oxidation in cells was evaluated by the determination of mda content.Finally,the activation level of apoptosis-related proteins?Bcl-2 and Bax?was detected by Western blotting experiment,and the effect of AuNSs/Col on myocardial apoptosis was analyzed and evaluated under H₂O₂.Results1)TEM showed that lower concentrations of AuNSs in Col solution can be uniformly dispersed comparing with the high concentration of AuNSs?0.2mg/ml?;The electrochemical workstation showed that the conductivity of the composite matrix increases with the increase of AuNSs concentration.Both Live/dead and CCK-8 experiments showed that the Au NSs/Col composites with 0.1mg/ml had the lowest cytotoxicity and the most proliferative capacity.2)the apoptosis experiment showed that the early apoptosis of H₂O₂ induced 6h was significantly increased compared with that of 0h,indicating that the oxidative stress damage model had been established.In any induction time,the early apoptosis ratio of the AuNSs/Col group of 0.1mg/ml was significantly reduced with the Col group.And the early apoptosis ratio decreases with time.Compared with the Col group,the AuNSs/Col composites in the H₂O₂ induced oxidative stress damage model can effectively remove redundant ROS from the myocardium cells,and the removal effect is more obvious with the prolonged time.On the basis of reducing intracellular ROS,AuNSs/Col composites can reduce the activity of antioxidant enzymes in cells.At the same time,AuNSs/Col composites can reduce the content of malondialdehyde generated by ROS reaction in cells,reduce lipid oxidation level and reduce oxidative stress damage.In addition,AuNSs/Col composites inhibited the apoptosis of myocardial cells by influencing the apoptosis-related protein Bcl-2/Bax ratio..Conclusion1)The optimum concentration of AuNSs/Col composite was not toxic to cells,which could further promote the proliferation of NRVM compared with Col.2)Compared with Col materials,AuNSs/Col composites have a further protective effect on the oxidative stress damage induced by H₂O₂.