Simvastatin Nanoparticles Protect Human Umbilical Vein Endothelial Cells Against Lipopolysaccharide-induced Cell Injury

ObjectiveSimvastatin nanoparticles were developed and its protective effect on LPS-induced HUVECs injury was observed from cell activity, cytoskeletal and vascular function. Then,explore the mechanism of its protective effect on mitochondrial membrane potential changes and balance between eNOS and iNOS.Methodsimvastatin nanoparticles were prepared and zeta potential analyzer was used to measure the particle size of nanoparticles. Drug encapsulation efficiency and drug loading of nanoparticles were measured. HUVECs divided into control group (control), lipopolysaccharide group (LPS), simvastatin intravenous group (SIM iv) and simvastatin nanoparticles (SIM np) group.Use CCK-8method to detect the cell activity, immunofluorescence to assay changes in cytoskeletal structure, and ECMatrixTM was used to detect angiogenesis.JC-1was used to detect Mitochondrial transmembrane potential, concentration of nitric oxide was tested, western-blot was used to detect the express of eNOS and iNOS in HUVECs.Result1) Simvastatin nanoparticles particle size was significantly higher than the blank nanoparticles particle size (350.3±156.9) vs (214.3±103.1), P<0.05; simvastatin nanoparticles encapsulation efficiency was65.71±2.45%drug loading the amount of3.41±0.23%.2) Cell activity in LPS group was lower than control group (0.524±0.039) vs (0.943±0.050),P<0.05. Both simvastatin intravenous group and simvastatin nanoparticles group have higher Cell activity than LPS group. Compared with simvastatin intravenous group, simvastatin nanoparticles group has higher cell activity (0.849±0.052) vs (0.750±0.061),P<0.05. Skeleton structure in LPS group become disorder, and cytoskeletal structural damage in simvastatin intravenous group and simvastatin nanoparticles group reduced, with more obvious in simvastatin nanoparticles group.LPS group has reduced angiogenesis function than then control group,(14794.66±286.99) vs (20306.97±1684.12), P<0.05; simvastatin intravenous group (16475.10±1582.79)and simvastatin nanoparticles group (16729.19±1010.98) have moderately angiogenesis function compared with LPS group large, but with no statistically significant.3)Mitochondrial membrane potential in LPS group was lower than the control group,(0.257±0.034) vs (0.363±0.033) p<0.05. Mitochondrial membrane potential in simvastatin intravenous group was higher than the LPS group,(0.275±0.014) vs (0.257±0.034), but with no statistical significance. Simvastatin nanoparticles group is also higher than the LPS group,(0.298±0.048) vs (0.257±0.034), P<0.05, and with statistical significance. Relating to concentration of nitric oxide in culture supernatant, LPS group is higher than control group (14.647±0.79) vs (3.418±0.453) P<0.05.Both simvastatin intravenous group and simvastatin nanoparticles group were lower than LPS group.Compared to the intravenous group, simvastatin nanoparticles has lower nitric oxide in culture supernatant (12.168±0.936) vs (13.429±0.609), with statistically significant. Cells in LPS group had less eNOS and more iNOS then control group,(0.343±0.011vs1.072±0.071) and (1.050±0.049vs0.295±0.062), with statistically significant. Both simvastatin intravenous group and simvastatin nanoparticles group had more eNOS and less iNOS than LPS group. Compared to the intravenous group, simvastatin nanoparticles has more eNOS and less iNOS express in cells,(0.644±0.061vs0.493±0.072) and (0.795±0.057vs0.894±0.084),with statistically significant.ConclusionSimvastatin nanoparticles have protective effect on LPS-induced HUVECs.The mechanism may relate to change of mitochondrial membrane potential and balance between eNOS and iNOS, and further studies are needed.