Study On The Oxygen Diffusion Model In The Capillary And Its Application

Using the porous silk fibroin film (PSFF) to protect the wound in the animal experiments, we found that it was avirulent and not irritant to the organism, and has good biocompatibility. So the PSFF is a medical biomaterial of great developing value. And the former researches also indicated that the capillaries and the fibroblasts could grow into the pores of the PSFF, but the growth of the cells and the capillaries had obvious selectivity to the porosity and the pore size of the PSFF, and that different types of tissue have different capillary densities. In the organism of the animals the capillary net is a huge micro-vessel network system which transports nutritive matter and oxygen to the tissue and removes metabolite. Every capillary supplies nutritive matter and oxygen for the metabolic requirement of the cells of the surrounding tissue, and takes away the cellular metabolic waste, such as lactic acid,CO₂ etc. Therefore the capillary system is one of the most essential components in an animal body to maintain its normal metabolism.Researching on the biomaterials, the first thing to qualify a good biomaterial is the extension and growth of the capillary network in the biomaterials. In order to design a more rational PSFF with its porous structure more suitable to the growth of the cells and tissue, especially in order to obtain different PSFF materials suitable to the repair of different tissue and organs, it's important to study and discuss the microcosmic action that the capillaries grow into the PSFF, and it is also very significant to find out and establish the growth model of the cells and capillaries in the PSFF.The paper mainly includes three parts. In the first part, we analyzed the process that the endothelial cells expanded, transferred and united one another to form a new capillary on the basis of the existed capillary network. And we summarized the common characteristics of the growth of capillaries, such as with bounds, with limitation, within a degree and unification between order and disorder. Based on the characteristics, we established a model of the formation of the capillaries net. In the second part, we presented a model of the oxygen diffusion in the capillary. Based on the model of the oxygen diffusion, we discussed the influencing factors of the capillaries density, and drew some conclusions in accordance with the recent experimental results. In the third part, we built the model of the oxygen distribution in the opening capillary and the model of the oxygen concentration change in the closed capillary, which would provide basal tools for the further research on the oxygen distribution in the tissue, in addition, we analyzed the certain abnormal action induced by the change of the parameters in the former model.Through these researches, we tried to elucidate the relation between the growth of the capillaries and the structure of the biomaterials. And the paper also provided the basic theoretical analysis for designing the PSFF.