Preliminary Research On Angiogenesis Modes In Porous Silk Fibroin Materials

Because of fine biocompatibility,biodegradability and processible attribute,there have been a great many researches on biomedical application of the silk fibroin materials in recent years.The porous silk fibroin materials which are designed and made up of silk fibroin,are invaluable in wound protection and repair.In wound healing,it requires rapid and effective neovascularization in biomaterials after implantation to satisfy the metabolism requirement of tissue cells entering into these biomaterials.The former researches indicate the capillaries and fibroblast can grow into the pores of porous silk fibroin materials.It is of great value to study the modes or mechanism of angiogenesis in porous silk fibroin materials,for designing the porosity structure which can be propitious to neovascularization of silk fibroin materials.The paper aims at exploring the angiogenesis modes in porous silk fibroin materials.Firstly,it is analyzed the conclusion that the more serious the hypoxia,the larger the VEGF concentration is during this hypoxia area,Then,it put forward the conclusion that there are three different angiogenesis reaction of ECs depending upon the VEGF concentration.Furthermore,it is explored the angiogenesis modes in porous silk fibroin materials.And the modes are that the preliminary capillarie network come into being by means of the division,proliferation,remotion and sprouting of ECs not long after implantation,then there will be intussusceptive angiogenesis which can regulate and remode the preliminary capillarie network with degradation of the silk fibroin.Finally,the porous silk fibroin materials are implanted in the back skin and femoral muscle of hind limb in rats during animal experiments.It is observed and analysed the neovascularization process in these materials after the operation,and deduced that there are sprouting angiogenesis around and into materials which were implanted both in back skin and femoral muscle no more 10 days after operation.The intussusceptive angiogenesis come into being in these materials on the 10^th day.The experiments primarily confirme the forementioned angiogenesis modes in porous silk fibroin material.