多孔氮氧生物玻璃骨修复支架的制备及性能

Preparation and properties of porous nitrogen oxygen bioglass scaffold for bone repair

背景:生物玻璃脆性高、机械强度差,限制了其在承重部位骨缺损中的应用,氮氧玻璃具有更高的强度和硬度,因此氮化处理有望改善生物活性玻璃机械强度差的致命弱点。目的:分析氮化处理对多孔生物玻璃支架的孔隙率、抗压强度、抗弯强度、降解性能及体外矿化活性的影响。方法:以硅酸盐玻璃(Si O2-Ca O-P2O5-Na2O-Zn O)为基础,对其进行氮化处理(分别用质量百分比0%,2%,4%,6%的Si3N4取代Si O2),采用熔融法制备氮氧基础玻璃(Si O2-Ca O-P2O5-Na2O-Zn O-Si3N4),然后以聚氨酯海绵为模板,采用有机泡沫浸渍法制备多孔氮氧生物活性玻璃支架。检测4组支架的孔隙率、抗压强度、抗弯强度、体外降解性能。将4组支架分别浸泡于模拟体液中7 d,扫描电镜观察支架表面形貌。结果与结论:(1)4组支架的孔隙率比较差异无显著性意义(P>0.05);(2)随着Si3N4含量的增加,多孔生物活性玻璃支架的抗压强度与抗弯强度逐渐增加,组间比较差异有显著性意义(P<0.05);(3)随着Si3N4含量的增加,多孔生物活性玻璃支架的体外降解性能逐渐下降;(4)扫描电镜显示,未经氮化处理多孔生物活性玻璃支架与含2%Si3N4多孔生物活性玻璃支架表面形成了典型的羟基磷灰石膜,其余两组未见羟基磷灰石膜形成;(5)结果表明,氮化处理可显著增强生物玻璃的机械强度,但会降低其降解性能和体外矿化活性。

BACKGROUND:Bioglass has high brittleness and poor mechanical strength,which limits its application in bone defect of bearing part.Nitrogen oxide glass has higher strength and hardness.Therefore,nitriding treatment is expected to improve the mechanical strength of bioglass.OBJECTIVE:To analyze the effects of nitridation on the porosity,compressive strength,bending strength,degradation performance and mineralization activity of porous bioglass scaffolds.METHODS:This experiment was based on silicate glass(Si O2-Ca O-P2O5-Na2O-Zn O),and nitriding it(Si O2 was replaced by 0%,2%,4%,6%Si3N4,respectively).The basic glass(Si O2-Ca O-P2O5-Na2O-Zn O-Si3N4)was prepared by melting method.The polyurethane foam was used as template and organic foam impregnation method was used to prepare porous bioglass scaffolds.The porosity,compressive strength,bending strength,and degradation performance in vitro of the porous bioglass scaffolds were measured in four groups.Four groups of scaffolds were immersed in simulated body fluid for 7 days.The surface morphology of the scaffold was observed with the scanning electron microscope.RESULTS AND CONCLUSION:(1)The porosity of the four groups had no statistical difference(P>0.05).(2)With increased Si3N4 content,compressive strength and bending strength of porus bioglass scaffold increased,and there was statistical difference between each group(P<0.05).(3)With increased Si3N4 content,the degradation performance of porous bioglass scaffolds decreased gradually in vitro.(4)Scanning electron microscope revealed that typical hydroxyapatite membrane was formed on the surface of porous bioglass scaffold without nitriding treatment and porous bioglass scaffold containing 2%Si3N4,but no hydroxyapatite membrane was formed in the other two groups.(5)Nitriding treatment can significantly enhance the mechanical strength of bioglass,but can reduce its degradation performance and mineralization activity in vitro.