Preliminary Study On Biocompatibility Of SF/PLLA Composite Fibrous Scaffold

In recent years, with the constant progress of the bioscience, engineering and materialsscience, research on tissue engineering has been developed rapidly and had wide applicationprospect especially in the field of regenerative medicine. Extracellular matrix scaffoldmaterial which is one of the three elements of tissue engineering is gradually causingwidespread concern. The kernel content of the tissue engineering is to create athree-dimensional space composite material, to bind with cell and biological material, to formviable living tissue and achieve the goal of impairment tissue replacement.Tissue engineering scaffolds must satisfy several conditions such as idealbiocompatibility, appropriate scaffold porosity, scaffold degradation rate and certain degree ofmechanical strength. Use silk fibroin (SF) which has excellent biocompatibility and polylacticacid (PLLA) as the major scaffold. Utilization electrostatic pinning technology and preparethe scaffold which has three-dimensional structure, porous, degradable and well-fibrous. Thephysical properties and chemical properties of scaffold are controllable. SF/PLLA haveunique physical, chemical and biological properties so that would serve as a scaffold fortissue engineering in the field of regenerative medicine.In study, biocompatibility of SF/PLLA fiber scaffold material under the sameconcentration and different mass quality via to the experiment preliminary research, whichconcluded acute toxicity test, pyrogen test, systemic allergy test and hemolysis test.Meanwhile, epithelial cells and fibroblasts were cultured at the same time. Used the methodsof compound culture which respectively added mass ratio30:70,40:60and50:50SF/PLLA(S30P70, S40P60and S50P50) fiber scaffolds and investigated biocompatibility of SF/PLLAfiber scaffold material under the same concentration and different mass quality. We providedfeasibility evidence that SF/PLLA could be served as the tissue engineering scaffolds.The main content of this research are as follow:1. Preliminary investigated the S30P70, S40P60and S50P50fiber scaffolds under thesame concentration and different mass quality through the toxicity test, pyrogen test, systemicanaphylaxis test and hemolysis test. It had no difference between the biocompatibility of S30P70, S40P60and S50P50fiber scaffold materials. Injected the SF/PLLA fiber membranein the form of extracts into mice, rabbit and guinea pig to determine whether the SF/PLLAfiber membrane had toxicity, pyrogenicity and sensitizing. In mice injection group, the statusand body weight of the mice had no difference and had no acute toxicity after injection72h.In robbit injection group, the temperature of robbit elevated sum of less than1.4℃afterinjection3h. It had non-pyrogenicity and accorded with regulation.In guinea pig injectiongroup, it had no tremble, dyspnea and shock symptoms. It had non-pyrogenicity and accordedwith regulation. In hemolysis test, contacted fresh anticogulated rabbit blood with SF/PLLAfiber membrane. Measured absorbance value in the wave length of545nm to determinewhether the SF/PLLA fibrous membrane would caused hemolytic reaction. The resultsshowed that the SF/PLLA fiber membranes hemolysis rate is less than5%and accorded withregulation in hemolysis test.2. Isolated and cultured both epithelial and fibroblast cells successfully. Compoundcultured epithelial cells and fibroblasts. Scanned the compound culture cell by confocal laserscanning microscope and electric mirror. The results showed that cells would closely attachedto the SF/PLLA fiber bracket and cells were well-grown. Compound cultured several days,the cells were getting closely connected. The cells firmly adhered to the stand. It explainedthat SF/PLLA fiber membrane had well cell compatibility which would promoted celladhesion and proliferation. Meanwhile, scanned the results of three ratios S30P70, S40P60and S50P50fiber membrane from the epithelial cells and fibroblasts by comfocal laserscanning microscope. Cells number was more in the S40P60fiber membrane group. Whenthe mass ratio SF/PLLA was40:60, was most conductive to the growth of cell proliferation.In summary, the scaffold materials have good cell compatibility and biocompatibilityand have the possibility of becoming new scaffolds in tissue engineering applications.