Preparation And Property Research On Porous Phosphate Glass-fiber Scaffolds

In this project, a novel10Na2O-10K2O-20CaO-5MgO-5SrO-10B2O3-40P2O5(mol%) phosphate glass was prepared by melting method and glass fibers with same composition were drawn as well. Two kinds of scaffolds were prepared by binding and sintering methods. For the binding method, chitosan solution was selected as binding agent. The prepared scaffold is3D porous and interconnected, having a porosity of86.8±1.4%and pore size of300-500μm. The scaffold has a compressive strength of1.2MPa when its compressive strain is70%. The compressive strength of scaffolds decreases after immersed in the simulated body fluid. For the sintering method, the sintering temperature was550℃and sintering time was30min. The porosity of the scaffold is89.36±2.1%, and the pore size is200-600μm. It should be pointed out that the compressive strength of the sintering scaffolds is apparently lower than that of the binding scaffolds. Hydroxyapatite deposited on the surface of phosphate glass fibers and these two kinds of scaffolds after they were immersed in the simulated body fluid for7d. The cytotoxicity of phosphate glass and scaffolds were determined by MTT test. The results showed the cytotoxicity of all samples were acceptable under biomaterials standard. Phosphate glasses and the binding scaffolds (with or without incorporating rhBMP-2) were implanted in mouse hindlimb muscle pocket model for2weeks to investigate the ectopic bone formation. The results showed that three kinds of samples all could induce ectopic bone formation and not induced inflammation in mouse. The quantities and distribution of ectopic bone in mouse were different, scaffolds incorporated rhBMP-2had better bone generation than scaffolds without rhBMP-2and phosphate glasses. The phosphate glassfiber/chitosan scaffolds have good biodegradability and bone generation, which is potential to be used in bone tissue engineering and as the carrier of growth factors such as rhBMP-2.