Molecular dynamics simulation of interaction between nanorod and phospholipid molecules bilayer

Natural and artificially prepared nanorods'surfaces have proved to have good bactericidal effect and self-cleaning property.In order to investigate whether nanorods can kill the enveloped virus,like destroying bacterial cell,we study the interaction between nanorods and virus envelope by establishing the models of nanorods with different sizes as well as the planar membrane and vesicle under the Dry Martini force field of molecular dynamics simulation.The results show that owing to the van der Waals attraction between nanorods and the tail hydrocarbon chain groups of phospholipid molecules,the phospholipid molecules on virus envelope are adsorbed to nanorods on a large scale.This process will increase the surface tension of lipid membrane and reduce the order of lipid molecules,resulting in irreparable damage to planar lipid membrane.Nanorods with different diameters have different effects on vesicle envelope,the larger the diameter of nanorod,the weaker the van der Waals effect on the unit cross-sectional area is and the smaller the degree of vesicle deformation.There is synergy between the nanorods in the nanorod array,which can enhance the speed and scale of lipid adsorption.The vesicle adsorbed in the array are difficult to desorb,and even if desorbed,vesicle will be seriously damaged.The deformation rate of the vesicle adsorbed in the nanorod array exceeds 100%,implying that the nanorod array has a strong destructive effect on the vesicle.This preliminarily proves the feasibility of nanorod array on a surface against enveloped virus,and provides a reference for the design of corresponding nanorods surface.

Numerical Simulation of Microcarrier Motion in a Rotating Wall Vessel Bioreactor

Objective To analyze the forces of rotational wall vessel （RWV） bioreactor on small tissue pieces or microcarrier particles and to determine the tracks of microcarrier particles in RWV bioreactor. Methods The motion of the microcarrier in the rotating wall vessel （RWV） bioreactor with both the inner and outer cylinders rotating was modeled by numerical simulation. Results The continuous trajectory of microcarrier particles, including the possible collision with the wall was obtained. An expression between the minimum rotational speed difference of the inner and outer cylinders and the microcarrier particle or aggregate radius could avoid collisions with either wall. The range of microcarrier radius or tissue size, which could be safely cultured in the RWV bioreactor, in terms of shear stress level, was determined. Conclusion The model works well in describing the trajectory of a heavier microcarrier particle in rotating wall vessel.

Immunohistochemical analysis of PD-L1 and tumor-infiltrating immune cells expression in the tumor microenvironment of primary signet ring cell carcinoma of the prostate

Primary signet ring cell carcinoma(SRCC)of the prostate is a rare neoplasm.However,its potential tumorigenic mechanism,clinicopathological features,and prognostic outcome have not been systematically described.To determine the pathogenic mechanism,we detected distributions of programmed cell death-ligand 1(PD-L1),programmed death 1(PD-1),and cellular components in the tumor microenvironment,including tumor-infiltrating lymphocytes(CD4 and CD8),tumor-associated macrophages(TAMs;CD163 and CD68),and tumor-associated fibroblasts(vimentin and alpha-smooth muscle actin[α-SMA]),in tumor tissues from four patients with primary prostatic SRCC compared with corresponding adjacent tissues and tumor tissues from 30 patients with prostate adenocarcinoma(PCa)by immunohistochemical staining.We found higher expression of PD-L1,CD163,and CD68 in primary SRCC specimens than that in both corresponding adjacent nontumor specimens and PCa specimens with different Gleason scores,indicating that TAMs may participate in the malignant biological behavior of primary SRCC of the prostate.For further analysis,we searched electronic journal databases and Surveillance,Epidemiology,and End Results(SEER)to identify 200 eligible patients including our four cases.According to Kaplan–Meier survival curve analysis,patients<68 years old,with radical prostatectomy(RP),Gleason score of 7–8,and lower clinical stage had longer overall survival(OS).Moreover,Cox multivariate analysis indicated that race(hazard ratio[HR]=1.422),surgical approach(HR=1.654),and Gleason score(HR=2.162)were independent prognostic factors for OS.Therefore,primary SRCC of the prostate represents a distinct and aggressive subtype of prostate cancer associated with a higher distribution of PD-L1 and TAMs,which warrants further clinical investigation.