Wang Song, Yang Han, Yang Jian, Kang Jianping, Wang Qing, Song Yueming
Department of Spine Surgery, the Affiliated Hospital of Southwest Medical University, Luzhou Sichuan, 646000, P.R.China.
Department of Orthopedics, West China Hospital, Sichuan University, Chengdu Sichuan, 610041,
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2017 Dec 15;31(12):1462-1467. doi: 10.7507/1002-1892.201707097.
To investigate the effect of a porous calcium phosphate/bone matrix gelatin (BMG) composite cement (hereinafter referred to as the "porous composite cement") for repairing lumbar vertebral bone defect in a rabbit model.
BMG was extracted from adult New Zealand rabbits according to the Urist's method. Poly (lactic-co-glycolic) acid (PLGA) microsphere was prepared by W/O/W double emulsion method. The porous composite cement was developed by using calcium phosphate cement (CPC) composited with BMG and PLGA microsphere. The physicochemical characterizations of the porous composite cement were assessed by anti-washout property, porosity, and biomechanical experiment, also compared with the CPC. Thirty 2-month-old New Zealand rabbits were used to construct vertebral bone defect at L in size of 4 mm×3 mm×3 mm. Then, the bone defect was repaired with porous composite cement (experimental group, =15) or CPC (control group, =15). At 4, 8, and 12 weeks after implantation, each bone specimen was assessed by X-ray films for bone fusion, micro-CT for bone mineral density (BMD), bone volume fraction (BVF), trabecular thickness (Tb. Th.), trabecular number (Tb.N.), and trabecular spacing (Tb. Sp.), and histological section with toluidine blue staining for new-born bone formation.
The study demonstrated well anti-washout property in 2 groups. The porous composite cement has 55.06%±1.18% of porosity and (51.63±6.73) MPa of compressive strength. The CPC has 49.38%±1.75% of porosity and (63.34±3.27) MPa of compressive strength. There were significant differences in porosity and compressive strength between different cements ( =4.254, =0.006; =2.476, =0.034). X-ray films revealed that the zone between the cement and host bone gradually blurred with the time extending. At 12 weeks after implantation, the zone was disappeared in the experimental group, but clear in the control group. There were significant differences in BMD, BVF, Tb. Th., Tb. N., and Tb. Sp. between 2 groups at each time point ( <0.05). Histological observation revealed that there was new-born bone in the cement with the time extending in 2 groups. Among them, bony connection was observed between the new-born bone and the host in the experimental group, which was prior to the control group.
The porous composite cement has dual bioactivity of osteoinductivity and osteoconductivity, which are effective to promote bone defect healing and reconstruction.
在兔模型中研究多孔磷酸钙/骨基质明胶（BMG）复合骨水泥（以下简称“多孔复合骨水泥”）修复腰椎骨缺损的效果。
按照Urist法从成年新西兰兔中提取BMG。采用W/O/W双乳化法制备聚乳酸-羟基乙酸共聚物（PLGA）微球。通过将磷酸钙骨水泥（CPC）与BMG和PLGA微球复合来研制多孔复合骨水泥。通过抗冲刷性能、孔隙率和生物力学实验对多孔复合骨水泥的物理化学特性进行评估，并与CPC进行比较。选用30只2月龄新西兰兔构建L节段大小为4 mm×3 mm×3 mm的椎体骨缺损。然后，用多孔复合骨水泥（实验组，n = 15）或CPC（对照组，n = 15）修复骨缺损。植入后4、8和12周，通过X线片评估各骨标本的骨融合情况，通过显微CT评估骨密度（BMD）、骨体积分数（BVF）、骨小梁厚度（Tb.Th.）、骨小梁数量（Tb.N.）和骨小梁间距（Tb.Sp.），并通过甲苯胺蓝染色的组织学切片评估新生骨形成情况。
研究表明两组均具有良好的抗冲刷性能。多孔复合骨水泥的孔隙率为55.06%±1.18%，抗压强度为（51.63±6.73）MPa。CPC的孔隙率为49.38%±1.75%，抗压强度为（63.34±3.27）MPa。不同骨水泥之间的孔隙率和抗压强度存在显著差异（F = 4.254，P = 0.006；F = 2.476，P = 0.034）。X线片显示，随着时间延长，骨水泥与宿主骨之间的区域逐渐模糊。植入后12周，实验组该区域消失，而对照组仍清晰可见。各时间点两组之间的BMD、BVF、Tb.Th.、Tb.N.和Tb.Sp.存在显著差异（P < 0.05）。组织学观察显示，两组中随着时间延长骨水泥内均有新生骨形成。其中，实验组新生骨与宿主骨之间可见骨连接，且早于对照组。
多孔复合骨水泥具有骨诱导性和骨传导性的双重生物活性，对促进骨缺损愈合和重建有效。
