X射线不透性体温固化聚氨酯髓核假体材料的研究

STUDY OF BODY TEMPERATURE CURABLE AND RADIOPAQUE POLYURETHANE FOR PROSTHETIC DISC NUCLEUS

为了制备X光可显影且可以体温固化的聚氨酯,合成了N,N'-双(1,3-二羟基丙基)-2,3,5,6-四碘对苯二甲酰胺(BDTIP)含碘四元醇,将其作为聚氨酯固化的交联剂和X光显影剂,与聚氨酯预聚物混合反应得到一种新的可用于人工髓核假体的材料.利用红外光谱监测BDTIP的反应程度;利用X射线对不同BDTIP含量的聚氨酯材料的显影效果进行评定;利用噻唑蓝(MTT)比色法测试材料细胞毒性,并对具有不同碘含量聚氨酯材料的力学性能进行了对比研究.结果表明,碘的加入对聚氨酯的显影效果有很好的促进作用,较低碘含量(0.2 wt%)的聚氨酯材料即有较好的X光显影效果,而且此时聚氨酯依然保持较好的力学性能;MTT法测试表明含BDTIP的聚氨酯材料不具有细胞毒性.

A series of radiopaque polyurethanes used for prosthetic disc nucleus were prepared via polycondensation between polyurethane prepolymer and N,N′-bis（1,3-dihydroxypropyl）-2,3,5,6-tetra iodoterephthalamide（BDTIP）,which was synthesized as crosslinker and X-ray contrast agent.The structure of BDTIP was characterized by 1H-NMR.Infrared spectroscopy was used to monitor the reaction degree of BDTIP.The developing effect of modified polyurethane was characterized by X-radiography.Meanwhile,the cytotoxicity was tested by the method of thiazolyl blue tetrazolium bromide（MTT） colorimetric assay using mouse fibroblast,and the mechanical properties of radiopaque polyurethanes with different iodine contents were also studied.The results of 1H-NMR showed that the hydrogen atoms on benzene ring were replaced by iodine completely and expected structure was obtained.Polyether polyurethane structure,demonstrated by FTIR,was also obtained.The X-radiography results showed that polymer had a good radiopacity which is almost equivalent to that of a 2 mm thick aluminum wedge when the iodine content was very small,while the mechanical properties were still excellent.There was nearly no change of compression modulus when the iodine content is low and within half an hour after the compression test the shape of prosthetic disc nucleus were restored to the state before compression,which demonstrated that the addition of BDTIP had little effect on the mechanical properties of prosthetic disc nucleus of polyurethane.The cell proliferation rate（RGR） of all modified polyurethanes was more than 75%,they were all biomaterials without cytotoxicity.This study provides a new modification way for preparing radiopaque polyurethane used for prosthetic disc nucleus.