Evaluation of bovine pericardium performance after liquid nitrogen freezing and thinning / 生物医学工程学杂志

In the present study, the performance of the liquid nitrogen frozen and thinned bovine pericardium was studied and compared with the porcine pericardium. The microstructure and mechanical properties of the bovine pericardium were observed and tested by hematoxylin-eosin (HE) staining and tensile test respectively. In all conditions, porcine pericardium was selected as a control group. The results showed that there was little difference in the performance of bovine pericardium after being frozen by liquid nitrogen. The secant modulus and ultimate strength of the thinned bovine pericardium were similar to those of porcine pericardium, however, the elastic modulus was a little higher than porcine pericardium. The study suggested that the performance of the thinned bovine pericardium was similar to those of porcine pericardium. It was easy for the thinned bovine pericardium to obtain a relatively ideal thickness and expected performance, therefore, the thinned bovine pericardium can be used as the materials of transcatheter aortic valve leaflets.

Application of high hydrostatic pressure in development of melanoma vaccine / 中国免疫学杂志

Objective: To explore the application of high hydrostatic pressure in the development of melanoma vaccine.Methods:The high hydrostatic pressure,liquid nitrogen freezing and thawing were used to break the murine B16 melanoma cells and then the cell suspension was mixed with Freund's adjuvant to prepare vaccine for immunizing the mice.Results:After immu-nization,the murine B16 melanoma cells were injected intravenously and subcutaneously.The immune results of the vaccines were evaluated,by comparing survival time of the mice, subcutaneous tumor volume, DTH experiments and the fluorescence imaging of tumors.Conclusion:Compared with the method of liquid nitrogen freeze-thaw broken,high hydrostatic pressure crushing cells has more advantages in the development of tumor vaccine.

The Experimental Study of Liquid Nitrogen Refrigeration Induced Osteonecrosis of the Femeral Head in Rat / 医学研究杂志

Objective To establish animal models of avascular necrosis of the femoral head. Methods Rat models of avascular necrosis of the femoral heads with liquid nitrogen freezing left femoral head were made. After operations, we accessed behaviors and regular observed X - ray graphy. we observed the femoral head after the rats were killed one monthe later. Results The rats in model group presented "new month syndrom" two weeks after operation,and became more and more worse. Conclusion The rat models of avascular necrosis of the femoral heads made by liquid nitrogen is economic and of low mortality. We can use it in making large - scale mordels, particularly in drug treatment' study.