Research Of Evaluation On Its Biocompatibility And Safty Of A Non-woven Silk Fibroin And Poly L-lactic Acid Net

It has already become the focus studied to repair defects by means oftissue engineering in the domain of defects repair and regeneration.It is the firstdifficult problem for us to prepare ideal scaffolds. So far,it’s urgent to ownscaffolds with good physical and biological properties,which are suitable forcell growth. After years of experimental research, we prepare SF/PLLAnanocomposite with silk fibroin and poly L-lactic acid by static spinning inChemical College of Jilin University.In our experimental group,we evaluate the biological compatibility andsafety of the material by the experments of in vivo implantation test,observation after the rabbit knee joint cartilage cells seeded to the surface ofmaterials,acute systemic toxicity test,and cytotoxicity test.The main content of this research are as follows:1.The materials were implanted into the back of the mice,and3-0suturewas used as control.Tissues were collected at1,2,3,4weeks after operation,dyed by HE staining and then photos were taken.The tissue reactions inexperimental group and control group were observed.Result: There were littlefibroblasts and a little of lymphocytes and macrophage cells in the materialswhich were implanted into the back of the mice at the beginning.Then thenumber of the fibroblasts increased,but the number of the lymphocyte andmacrophage cells did not change obviously.The materials degraded slowly,andthe material degraded obviously at4weeks. The inflammation of tissue aroundthe material reduced gradually from2nd week. And the inflammation oftissue around the material was the same to the suture,sometimes was slighterthan the suture. After seeding24h,there were cells attaching to the fibers of thematerial.More and more cells attached to the fibers.2.The rabbit knee joint cartilage cells were separated and cultured, and then subculture cells were seeded to the surface of materials. After culturing invitro, the adhesion and growth of the cells were observed with inverted opticalmicroscope. Result: After seeding24h,there were cells attaching to the fibersof the material.More and more cells attached to the fibers.3. Physiological saline as control,the leaching solution was prepared andinjected into the mice,then the rates were observed for72h. Result:Afterinjection，he body status of the mice was the same to the control group.4．The bioactivities of the rabbit knee joint cartilage cells in negativecontrol group(DMEM culture media), experimental group(DMEM containmaterials) and positive control group(DMEM contain phenol solution)weredetermined by MTT Tassay after coculture for24and48h. Result: The reasultof MTT Tassay showed that the cytotoxicity in experimental groups were all onLevel Ⅰ at24and48h.Except for positive control group,the A values wereincreased in other groups with the extended response time.At the same time,there was no significant difference in cytotoxicity between experimental groupand negative control group(P>0.05)and the A values of experimental group washigh than positive control group(P<0.01).This showed that material has goodsafety.In conclusion,the materials prepared with silk fibroin and poly L-lacticacid by static spinning have good biocompatible,which are suitable for cellgrowth and belong to safe implant materials.The article provide experimentbasis for studying how to repair defective articular cartilage with the materials.