| Appropriate physiological environment for bone repairs and growth of new bone can be offered by ideal bone scaffolds,which is important for atraumatic restorative treatment towards bone defects.This article adopted poly(lactic acid)as matrix and hydroxyapatite after modification as fillers,hydroxyapatite/poly(lactic acid)composites were prepared and extruded into filaments to form the porous scaffolds through fused deposition modeling.Surface modification of nano-hydroxyapatite were conducted by using citric acid and stearic acid,respectively,to realize the improvement of adhesion between inorganic/organic phase interfaces.The results of FTIR and XPS showed that modifiers were grafted to the surface of hydroxyapatite successfully,and the concentration of modifiers should be controlled.The consequences of TGA showed that the grafted efficiencies of citric acid and stearic acid were fairly equal.The influence of modified hydroxyapatite addition towards the properties of composites were investigated.The results showed that the addition of particles should be controlled under 20wt% to prevent the drop of mechanical properties and bad dispersion.Surface modification could improve the adhesion between hydroxyapatite and the matrix.Epoxidized soybean oil was added into the system of composites to improve the dispersion of particles and the compatibility of particle and resin,the effect was identified as positive.Porous scaffolds made by composites of the best formula and poly(lactic acid)respectively were prepared through fused deposition modeling.The results showed that porous scaffolds made by composites presented larger pore sizes than poly(lactic acid)porous scaffolds,and the porosity of composites scaffolds was higher than poly(lactic acid)scaffolds.However,mechanical properties of scaffolds made by poly(lactic acid)were better than scaffolds made by composites.The porous scaffolds made by composites prepared possessed potential prospect of application in repairs for bone defects. |
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