Study On Regulation Of Cell-membrane Microvesicles Multicompartment Structures

The vesicles are a bilayer spherical structures formed by amphiphilic molecule,such as lipids or surfactants,which are mainly composed of synthetic vesicles and extracellular vesicles secreted from living cells.Extracellular vesicles are a subcellular component produced by the secretion from diverse types of living cells under spontaneous or certain conditions,including microvesicles,exosomes,and apoptotic blebs.Taking into account of the unique properties and structures of vesicles,they have broaden application prospects in the fields of biomedical,biomimetic simulation and bio-sensing.With the development of the vesicles preparation technology,vesicle a cell membrane model has become an important platform to study the structure and properties of cell membrane.Vesicles can be used as cell membrane models to study the cell division,fusion,budding and other life phenomena,and then reveal the evolution of early life on earth.In this thesis,we obtained giant vesicles made by cell membrane from living cells,which can play an excellent role of cell membrane model.The structures of these plasma membrane vesicles were regulated in the addition of chemical reagents,in order to obtain the multicompartment structures with good stability.In the second chapter,we used micro vesicles of extracting from mammals living cells that inherits the natural properties of plasma membrane.By adding the sodium chloride and magnesium chloride mixed with vesicles incubated for 1 hour at 37?,the monolayer vesicles deformed into large number of multicompartment structures with possess good stability.There are several stages in the process of monolayer microvesicles deformation into multicompartment vesicles.Firstly,the osmotic pressure gradient was formed around the vesicle membrane by adding salt ion solution.The result showed that the vesicles would exhibit unique transformation in response to osmotic pressure.Driven by osmotic pressure,giant vesicles from the single-layer spherical to prolate,the prolate vesicle kept its shape for a moment and then transformed into a stomatocyte shape via an oblate shape.Subsequently,the stomatocyte vesicle deformed to a sphere with regressing invagination and then formed into double spherical vesicles.In this chapter,we used the laser scanning confocal microscopy to monitor the deformation process of vesicular morphology and used Image J software to perform statistical analysis of the yielding of multi-chamber structures.These results showed that the method of inducing multicompartment vesicles formation with the salt ion solution is simple and high yielding,which lays the foundation for the application of plasma membrane multi-chamber structures in the field of drug delivery,construction of artificial cells,mimicking cell metabolism and so on.In the third chapter,we studied the deformation of surface membrane structure induced by action of surfactants in cell membrane vesicles.In this experiment,CTAB,SDS,Tween-20 and TX-100 were selected to study the morphologic changes of the vesicles membrane.These results showed that the vesicles membrane structure changed to form heterogeneous structures under the surfactant of TX-100 and CTAB.In the late stage of heterogeneous structure,vesicles produced budding and fission.This study provides reference for exploring the structure and properties of cell membrane surface.