3D打印载PaMZ/BMP-2的nHA抗结核人工骨在体内成骨效果及药物缓释性能研究

Study on osteogenic properties and sustained release of 3D printed PaMZ/BMP-2-loaded nHA artificial bone in vivo

中文关键词:  脊柱结核  3D打印  人工骨  PaMZ  体内缓释

英文关键词:Spinal tuberculosis  3D printing  Artificial bone  PaMZ  Sustained release in vivo

中文摘要:

  【摘要】 目的：评估3D打印的载普托马尼（Pa）、莫西沙星（M）、吡嗪酰胺（Z）组合抗结核药物（PaMZ）和骨形态发生蛋白-2（bone morphogenetic protein-2，BMP-2）的纳米羟基磷灰石（nano-Hydroxyapatite，nHA）抗结核人工骨在体内的成骨效果及药物缓释性能。方法：取40只新西兰兔，随机分为4组，每组10只，构建脊柱骨缺损模型。其中A组植入载PaMZ/BMP-2的nHA人工骨（实验组）；B组植入空白nHA人工骨（阴性对照组）；C组植入自体髂骨（阳性对照组）；D组不植骨（空白组）。观察动物一般情况，监测体温、体重、肝肾功能；术后4、8、12周行螺旋CT三维重建观察骨缺损修复情况，并进行CT-Hedberg评分；术后8、12周行组织大体观察及植入物-骨缺损界面组织病理学观察。取SD大鼠100只，随机分为2组，实验组植入载PaMZ/BMP-2的nHA人工骨，对照组植入空白nHA人工骨，采用高效液相色谱法分别检测材料周围肌肉组织和血浆中术后不同时间点的药物浓度。结果：所有动物模型构建成功，无切口感染、死亡等情况发生。兔模型中各组动物的体温、体重及肝肾功能指标正常，组间比较均无统计学差异（P＞0.05）；CT-Hedberg评分显示在术后4、8、12周时，A组与C组相比均无统计学差异（P＞0.05），其余各组间在不同时间点相比均存在统计学差异（P<0.05）。大体标本显示12周时A组人工骨完全被新骨包埋或替代，但B组仍有部分人工骨裸露。对植入物-骨缺损界面的骨小梁总面积定量分析显示在术后8、12周时，A组和C组相比无统计学差异（P＞0.05），其余各组间相比均有统计学差异（P＜0.05）。SD大鼠模型对照组未测出药物成分，实验组Pa、M、Z三种药物在局部组织中均能缓释至少84d，血药浓度在植入载药人工骨后的初始时间点未测出，随后测得结果远低于局部组织药物浓度，二者具有正相关关系。结论：载PaMZ/BMP-2的nHA人工骨在体内具有良好的成骨性能，修复脊柱骨缺损的效果与自体髂骨相当，优于单纯的nHA人工骨支架；其在体内的缓释性能满意，血药浓度远低于局部组织药物浓度。

英文摘要:

  【Abstract】 Objectives: To observe the osteogenic properties and sustained release of 3D printed nano-hydroxyapatite(nHA) artificial bone loaded with a novel triple anti-tuberculosis drug combination(PaMZ) of Pretomanid(Pa), Moxifloxacin(M), Pyrazinamide(Z) and bone morphogenetic protein 2(BMP-2) in vivo. Methods: 40 New Zealand rabbits were divided into four groups randomly and constructed spinal bone defect models. Group A(experimental group) implanted with 3D-printed PaMZ/BMP-2-loaded nHA artificial bone; group B(negative control group) implanted with blank nHA artificial bone; group C(positive control group) implanted with autologous iliac bone; group D(blank group) without bone grafting. The general conditions were observed, body temperature, weight, and liver and kidney function were monitored. The bone defect restoration was observed by spiral CT 3D reconstruction at the 4th, 8th and 12th week postoperatively and was evaluated with CT-Hedberg scale; the gross observation of tissues and histopathological observation of the implants-bone defect interface were carried out at the 8th and 12th week postoperatively. 100 SD rats were divided into two groups randomly, experimental group implanted with 3D-printed PaMZ/BMP-2-loaded nHA artificial bone, control group implanted with blank nHA artificial bone. The drug concentrations in the plasma and muscle tissue around the material at different time points was tested with high performance liquid chromatography. Results: All animal models were successfully constructed without incision infection or death. The body temperature, weight and liver and kidney function indexes of the experimental groups in the rabbit models were normal, with no statistical differences from those of the control groups(P>0.05). The CT-Hedberg score showed that there was no statistical difference between group A and group C at the 4th, 8th and 12th week(P>0.05), however, there was statistical difference between all the other groups at different time points(P<0.05). The observation of the gross specimens at the 12th week after surgery showed that the artificial bone in group A was completely encapsulated or replaced by new bone, but there was still some artificial bone exposed in group B. Quantitative analysis of the total trabecular area at the implant-bone defect interface showed no statistical difference between groups A and C at the 8th and 12th week postoperatively(P>0.05), and a statistical difference between the remaining groups(P<0.05). No drug components were detected in the SD rat model control group, the three drugs Pa, M, Z in experimental group can be sustained-released in local tissues for at least 84d. The blood drug concentration was not detected at the initial time point after local implantation of the drug-loaded artificial bone, and the subsequent measured results were much lower than the local tissue drug concentration, and the two had a positive correlation. Conclusions: The 3D printed PaMZ/BMP-2-loaded nHA artificial bone has good osteogenic properties in vivo, the effect of restoring spinal bone defects is comparable to that of autologous iliac bone, which is better than that of HA artificial bone scaffold alone. Its sustained release behavior in vivo is satisfactory, and the blood drug concentration is much lower than the local tissue drug concentration.