For some amphiphilic molecules like natural synthetic surfactant can not simply associate the synthesis of micelle phospholipids, dispersed in water will spontaneously form a kind of closed bilayer structure molecular ordered combination, known as vesicles also known as liposome. The meaning of the terms giant unilamellar vesicles and liposome is somewhat ambiguous in the literature. It is generally believed that if these amphiphilic molecules are natural surfactant lecithin, the structure formed is called liposome. When composed of a synthetic surfactant, it is called a vesicle. Therefore, liposome refer to a special class of vesicles formed by phospholipids, which is the first vesicle system discovered by human beings. Some people also use liposome to represent a system with multi-layer closed double-layer structure.

The cell membrane that is carrier by vesicle has permeability, the permeability of cell membrane to some molecules inside body can be divided into the following three kinds of situations roughly: those that pass freely have water molecules, those that can pass freely have glucose, amino acid, urea, chloride ion and so on. Proteins, sodium, potassium, etc. The existence of permeability, the movement of water inside and outside the cell, the exchange of various substances, the maintenance of ph and osmotic pressure, all have important physiological significance. In some pathological conditions, it may destroy the normal structure and function of cell membrane and increase the effect of cell membrane isolation, resulting in tissue edema and other reactions.

Structure characteristics and physiological characteristics of the membrane are respectively has a certain fluidity and choose through sex, there are three: the main function of the membrane separating the cell and its environment, control of material in and out of the cell and the exchange of information between cells, renal tubular epithelial cells in patients with renal diabetes membrane transport carrier protein, glucose to renal tubular reabsorption of glucose reduced capacity. In a diabetic patient, the blood glucose level did not decrease after insulin injection, which may be caused by the damage or absence of insulin receptors on the surface of the cell membrane.

Vesicles play an important role in the efflux of secreted proteins. One of the most important applications of vesicles is to simulate biofilms. The main body of biofilm is a closed bilayer vesicle structure composed of phospholipid and protein oriented arrangement. Biofilms play an important role in living organisms, such as ion migration and immune recognition. Through the research on vesicles, it can deepen people's understanding of biofilm and provide a new way for people's bionic research, especially for research content like what is enzyme engineering.

What is directed evolution? The mutant original protein can be used as the research object, and the mutant protein variant can be used as the carrier to select the protein variant that shows improved or more ideal function. These selected proteins are then mutated again to produce another round of protein variants for another round of selection. Repeat this cycle until the final mutant protein has optimized performance compared to the original protein. These nanoparticles are used as optical biosensors - tiny devices that use light to detect biological molecules in air, water or blood. Optical biosensors are widely used in biological research, drug development and medical diagnosis, such as real-time monitoring of insulin and glucose in diabetic patients.

Immune electron microscopy is a product of the combination of immunochemical technology and electron microscope technology. It is a method to study and observe the binding location of antigen and antibody at the level of ultrastructure. Immunoelectron microscopy technology can be divided into two categories: one is immune agglutination electron microscopy technology, that is, after the antigen antibody agglutination reaction, negative staining directly observed under the electron microscopy; The other is immunoelectron microscopy. This technique USES antibodies with special marks to combine with corresponding antigens and observe under an electron microscope, so as to indicate the location of corresponding antigens due to the formation of a certain electron density of the standard substance. The application of immunoelectron microscopy brings the study of antigen and antibody localization to the subcellular level.

The principle of immune electron microscopy and immunohistochemistry in basically the same, but the final requirements for immune electron microscopy  immune reaction product is electron density of the material, such as the DAB chromogenic agent or colloidal gold, be applied in both immune electron microscopy , the former reaction products to make the fine granular material of electron density, the latter for the high electron density of particles, colloidal gold can according to the different preparation methods, it also have different diameter, can be used in the double standard or standard.

Enzyme plays an important role in modern biological production, as a kind of biocatalyst enzyme, due to its catalysis with high specificity and mild catalytic conditions, no pollution, and enzyme engineering technical breakthrough unceasingly, makes the enzyme in the development of industry, agriculture, medicine and health care, energy and environmental engineering applications of more and more widely. With the development of enzyme production, the application of enzyme is more and more extensive. Now, enzyme engineering has been widely used in medicine, food industry, agriculture, feed, environmental protection, energy, scientific research and other fields. It has become an irreplaceable tool in the scientific research and technology development of new technology fields such as gene engineering, cell engineering and protein engineering.