Department of Orthopedics, Yanan University Affiliated Hospital, Yan'an 716000, China.
Department of Orthopedics, Yan'an People's Hospital, Yan'an 716000, China.
Cell Mol Biol (Noisy-le-grand). 2022 Mar 31;68(3):86-95. doi: 10.14715/cmb/2022.68.3.11.
This study was to compare the effects of three-dimensional (3D) printed bioactive porous titanium alloy scaffolds (3DP-BPTAS) and rhBMP-2/PLA-loaded sustained-release nanospheres (SRNs) in the treatment of bone defects. In this study, the bioactive porous titanium alloy scaffolds (BPTAS) with different pore sizes were prepared by selective laser melting (SLM) technology. The rhBMP-2/PLA SRNs were prepared by the double emulsion solvent volatilization method. The morphology of the two nanomaterials was observed under a scanning electron microscope (SEM). The encapsulation rate (ER), drug loading (DL), and in vitro release rate of the SRNs were detected by enzyme-linked immunosorbent assay (ELISA); and the effects of different particle sizes of BPTAS and SRNs on the proliferation of BMSCs were measured using the Methyl Thiazolyl Tetrazolium (MTT) method. 42 healthy male rabbits were selected and rolled into a control group (no treatment), a model group (the femoral condyle defect model), an A800 group (model + 800 μm of BPTAS), and an A1000 group (model + 1000 μm of BPTAS), an A1200 group (model + 1200 μm of BPTAS), an A1500 group (model + 1500 μm of BPTAS), and an SNR group (model + rhBMP-2/PLA SRNs). There were 6 rabbits in each group, and they were sacrificed 4, 8, and 12 weeks after the surgery. They were performed with general observation, X-ray photography, and histological and biomechanical examinations. According to the Lane-Sandhu bone defect repair tissue X-ray and histological scoring standard, the effect of bone defect repair was evaluated. It was found that the actual pore structure of the scaffold prepared by the SLM process was consistent with the theoretical design. The observation under TEM showed that rhBMP-2/PLA SRNs were approximately round, with an average particle size of 835 nm, and its encapsulation efficiency and drug loading rate were 89.02 ± 5.14% and 0.033 ± 0.004%, respectively. The rhBMP-2/PLA SRNs and BPTAS had no statistically obvious increase in the number of cells after cell treatment compared with the control group (P> 0.05). At 12 weeks postoperatively, the stent bone tissue growing distance (SBTGD) in the SRN group was longer than that in the A1000 group (P< 0.01), and that in the A1000 group was better in contrast to the A800, A1200, and A1500 groups (P< 0.01). The Lane-Sandhu X-ray score of the SRN group was better than other groups (P< 0.05). It suggested that 3DP-BPTAS and rhBMP-2/PLA SRNs could repair the bone defects, and rhBMP-2/PLA SRNs were more conducive to the formation of new bone tissue.
本研究旨在比较三维（3D）打印生物活性多孔钛合金支架（3DP-BPTAS）和负载 rhBMP-2/PLA 的缓释纳米球（SRNs）在治疗骨缺损中的效果。本研究采用选择性激光熔化（SLM）技术制备具有不同孔径的生物活性多孔钛合金支架（BPTAS）。采用双乳液溶剂挥发法制备 rhBMP-2/PLA SRNs。通过扫描电子显微镜（SEM）观察两种纳米材料的形态。通过酶联免疫吸附测定（ELISA）检测 SRNs 的包封率（ER）、载药量（DL）和体外释放率；采用噻唑蓝（MTT）法测定不同粒径的 BPTAS 和 SRNs 对 BMSCs 增殖的影响。选择 42 只健康雄性家兔，随机分为对照组（无处理）、模型组（股骨髁缺损模型）、A800 组（模型+800μm 的 BPTAS）、A1000 组（模型+1000μm 的 BPTAS）、A1200 组（模型+1200μm 的 BPTAS）、A1500 组（模型+1500μm 的 BPTAS）和 SNR 组（模型+rhBMP-2/PLA SRNs），每组 6 只。术后 4、8、12 周处死每组动物，进行一般观察、X 线摄片和组织学及生物力学检查。根据 Lane-Sandhu 骨缺损修复组织 X 射线和组织学评分标准，评价骨缺损修复效果。结果发现，SLM 工艺制备的支架实际孔结构与理论设计一致。透射电镜观察显示，rhBMP-2/PLA SRNs 呈近似圆形，平均粒径为 835nm，其包封效率和载药量分别为 89.02%±5.14%和 0.033%±0.004%。rhBMP-2/PLA SRNs 和 BPTAS 与对照组相比，细胞处理后细胞数量无明显统计学增加（P>0.05）。术后 12 周时，SRN 组支架骨组织生长距离（SBTGD）长于 A1000 组（P<0.01），A1000 组优于 A800、A1200 和 A1500 组（P<0.01）。SRN 组 Lane-Sandhu X 射线评分优于其他组（P<0.05）。提示 3DP-BPTAS 和 rhBMP-2/PLA SRNs 均可修复骨缺损，rhBMP-2/PLA SRNs 更有利于新骨组织的形成。
