The present study is an investigation of the properties of poly(vinyl alcohol),which would be a better contact lens mate- rial than conventional HEMA in some ways.A transparent PVA hydrogel was prepared from a PVA sol...The present study is an investigation of the properties of poly(vinyl alcohol),which would be a better contact lens mate- rial than conventional HEMA in some ways.A transparent PVA hydrogel was prepared from a PVA solution in a mixed solvent consisting of water and a water-miscible organic solvent,DMSO,by the freezing-thawing method.The water content,visible light transmittance,mechanical and swelling properties of the hydrogels were evaluated as a function of PVA concentration and number of freeze-thaw cycles.The results show that the properties of PVA hydrogels depend on the polymer concentration,the number of freeze-thaw cycles and the addition of the organic solvent.展开更多
Objective： To search for the best procedure on preparation ofacellular bovine pericardium,so to provide scaffolds for constructing tissue-engineering Methods： The bovine pericardiums were treated with 5 methods, whi...Objective： To search for the best procedure on preparation ofacellular bovine pericardium,so to provide scaffolds for constructing tissue-engineering Methods： The bovine pericardiums were treated with 5 methods, which were divided into 6 groupsGroup A： Fresh bovinepericardium; Group B： Trypsin-detergent group;Group C： Freeze-thaw-detergent 24 h group; Group I）： Freeze-thaw-detergent 48 h group; Group Fz Freeze-thaw-nuclease group; Group F： Detergent-nuclease group. Then, by HE staining and scanning electron microscope to observe the effects ofdecellularization and fibrous changes among the 6 groups; by water content testingonechanical testing to observe the changes in physical properties of the matrix; by detecting the DNA content of each group to determine the effect of deeellularization qualitatively; by eytotoxieity test to detect the biocompatibility of bovine pericardium in each group. Results： The 5 methods can all remove the cellular components effectively, compared with the fresh bovine pericardium,the water content of each deeellularized group were increased （P〈0.05）, while the DNA content decreased （P〈0.05）, with statistically significant differences. Of group E, the fibers were a little disorder, with the largest tension and the elastic modulus increased, while the rupture tensile rate decreased. Compared with fresh bovine pericardium,the largest tension of the other decellularization groups were all decreased （P〈0.05）. The fibers of group B, group D were irregularly arranged and also with ruptures, both the elastic modulus and the rupture tensile rate decreased（P〈0.05）. In group C and F, the fibers were dense and their direction was normal, the elastic modulus and the rupture tensile rate were similar to the fresh bovine pericardium （P〉0.05）. Cytotoxicity results showed that the cell toxicity of group B, group C, group D, group E and group F were respectively 0.9, 0.6, 1.0, 1.0 and 0.5, each group were qualified toxicity test, in which group C and group F were with the lowest eytotoxieity. Conclusion： Group C and group F can remove the cell components of bovine pericardium successfully,while maintaining the major structural components and the histological and biological properties of bovine pericardium,and with low cytotoxicity.However, group C is more economical than group F,and easier to operate. So the method on freeze-thaw-detergent 24 h can be the best choice to produce a decellularized bovine pericardium.展开更多
基金Projects 50575106 supported by the National Natural Science Foundation of ChinaBG2007046 by the High Technology Project of Jiangsu Province
文摘The present study is an investigation of the properties of poly(vinyl alcohol),which would be a better contact lens mate- rial than conventional HEMA in some ways.A transparent PVA hydrogel was prepared from a PVA solution in a mixed solvent consisting of water and a water-miscible organic solvent,DMSO,by the freezing-thawing method.The water content,visible light transmittance,mechanical and swelling properties of the hydrogels were evaluated as a function of PVA concentration and number of freeze-thaw cycles.The results show that the properties of PVA hydrogels depend on the polymer concentration,the number of freeze-thaw cycles and the addition of the organic solvent.
文摘Objective： To search for the best procedure on preparation ofacellular bovine pericardium,so to provide scaffolds for constructing tissue-engineering Methods： The bovine pericardiums were treated with 5 methods, which were divided into 6 groupsGroup A： Fresh bovinepericardium; Group B： Trypsin-detergent group;Group C： Freeze-thaw-detergent 24 h group; Group I）： Freeze-thaw-detergent 48 h group; Group Fz Freeze-thaw-nuclease group; Group F： Detergent-nuclease group. Then, by HE staining and scanning electron microscope to observe the effects ofdecellularization and fibrous changes among the 6 groups; by water content testingonechanical testing to observe the changes in physical properties of the matrix; by detecting the DNA content of each group to determine the effect of deeellularization qualitatively; by eytotoxieity test to detect the biocompatibility of bovine pericardium in each group. Results： The 5 methods can all remove the cellular components effectively, compared with the fresh bovine pericardium,the water content of each deeellularized group were increased （P〈0.05）, while the DNA content decreased （P〈0.05）, with statistically significant differences. Of group E, the fibers were a little disorder, with the largest tension and the elastic modulus increased, while the rupture tensile rate decreased. Compared with fresh bovine pericardium,the largest tension of the other decellularization groups were all decreased （P〈0.05）. The fibers of group B, group D were irregularly arranged and also with ruptures, both the elastic modulus and the rupture tensile rate decreased（P〈0.05）. In group C and F, the fibers were dense and their direction was normal, the elastic modulus and the rupture tensile rate were similar to the fresh bovine pericardium （P〉0.05）. Cytotoxicity results showed that the cell toxicity of group B, group C, group D, group E and group F were respectively 0.9, 0.6, 1.0, 1.0 and 0.5, each group were qualified toxicity test, in which group C and group F were with the lowest eytotoxieity. Conclusion： Group C and group F can remove the cell components of bovine pericardium successfully,while maintaining the major structural components and the histological and biological properties of bovine pericardium,and with low cytotoxicity.However, group C is more economical than group F,and easier to operate. So the method on freeze-thaw-detergent 24 h can be the best choice to produce a decellularized bovine pericardium.
