The Preparation And Properties Of PLGA/HA Bone Scaffold Composites

Bone scaffold materials is the most important factor for bone tissue engineering. In this paper , the porous HA interlayer was prepared by immersion method, using PU foam as template. The effects of pretreatment, type and content of PVA agglomerant and content of HA solid phase on the porosity of this material are investigated. Then the poly lactic-co-glycolic acid/hydroxyapatite (PLGA/HA) composites were prepared by gel-casting. The filling performance, mechanical properties and degradation performance of the composites were also studied. The results are shown as follows:1.The foam was firstly pretreated in NaOH solution at 30℃, then modified with CMC solution. The hydrophilicity capacity , infiltration capability and the increase of slurry are increased. After sintering , the mechanical properties of the scaffold were improved.2.The porous HA has high porosity and the pore is reciprocally connective. The porosity increases with the increase of PVA content. The porosity of the scaffold first increase , and then reduce as the function of the HA content. The suitable content of HA is about 70 vol.%, as its porosity is the maximum. The compressive strength of porous HA decreases as the porosity increases, but the mechanical properties is lower than that of the adult.3. The influences of concentration, time, temperature and PH value on the viscosity of the PLGA sol are rather obvious. When the concentration of PLGA is under 50g/l, the viscosity changes a little as the function of the time expand (<40℃). But when the concentration of PLGA is about 50g/l and the temperature is above 40℃, the viscosity value sharply rise.4. The viscosity is relative to the filling properties. The PLGA bond easily with pore with a viscosity of 50mPa·s .After filled, the mechanical properties of the composite were improved significantly.5.The weight of samples decreases linearly with the increase of time and the degradation rate of the materials accelerates as the increase of HA content when the composites was immersed in simutation body fluid at 37℃. Hydroxyapatite was formed on the surface of the composites, which indicates the composites have excellent biocompatibility.