不同配方CPC/DBM/rhBMP-2复合材料的抗压性能和超微结构特征

目的:探讨脱钙骨基质颗粒(DBM)/磷酸钙骨水泥(CPC)/重组人骨形成蛋白-2(rhBMP-2)复合材料的抗压性能和超微结构特征,找出该复合材料的最佳配方.方法:预制兔DBM,用吸附法将rhBMP-2与DBM复合后,再按不同的质量比与CPC复合.复合材料行体外抗压强度测定和扫描电镜观察.结果:DBM的质量比在0.2～0.4的范围内,复合材料中存在较多100μm以上的不规则裂隙.DBM的质量比≤0.1时,材料内部的大部分间隙<100μm.DBM的质量比≥0.5时,DBM和CPC丧失结合及塑型能力.随DBM质量比的增加,材料抗压极限强度递减,质量比为0.1,0.2,0.3,0.4的抗压极限强度分别为(8.12±0.79)MPa,(5.46±1.13)MPa,(5.13±1.18)Mpa和(1.49±0.61)MPa.各组数据经方差分析,差异具有统计学意义(P<0.05),其中质量比为0.2,0.3,两组比较差异无统计学意义(P>0.05),而(1.49±0.61)MPa小于人体松质骨的平均抗压强度.结论:随着DBM质量比的增加,孔隙越丰富而材料力学强度逐渐降低.DBM质量比为0.2～0.3的复合材料可用于修复低承重部位松质骨的骨缺损.

槲皮素对大鼠废用性骨质疏松的预防作用及ERK1/2-MAPK信号通路的影响

目的探讨槲皮素对大鼠废用性骨质疏松的预防作用及细胞外调节蛋白激酶1/2(ERK1/2)-丝裂原活化蛋白激酶(MAPK)信号通路的影响。方法选取清洁级SD大鼠80只随机分成对照组、模型组、强骨胶囊组、槲皮素低、高剂量组,每组16只。模型组、强骨胶囊组、槲皮素低、高剂量组建立大鼠废用性骨质疏松模型。从造模第1天开始,强骨胶囊组给予强骨胶囊250 mg/kg灌胃,槲皮素低、高剂量组分别给予槲皮素100、200 mg/kg灌胃,对照组及模型组给予等体积生理盐水灌胃,1/d,给药4周。显微CT扫描大鼠股骨形态,测定大鼠股骨骨密度、骨小梁数量、骨小梁厚度、骨小梁分散度及股骨ERK1/2、MAPK mRNA和蛋白水平。结果与对照组比较,模型组股骨骨密度、骨小梁数量、骨小梁厚度显著降低,骨小梁分散度、ERK1/2、MAPK mRNA和蛋白表达水平显著升高(P<0.05);与模型组比较,强骨胶囊组、槲皮素低、高剂量组股骨骨密度、骨小梁数量、骨小梁厚度显著升高,骨小梁分散度、ERK1/2 mRNA和蛋白表达水平、MAPK mRNA和蛋白表达水平显著降低(P<0.05)。与槲皮素低剂量组比较,强骨胶囊组和槲皮素高剂量组股骨骨密度、骨小梁数量、骨小梁厚度升高,骨小梁分散度、ERK1/2、MAPK mRNA和蛋白表达水平降低(P<0.05);槲皮素高剂量组与强骨胶囊组上述指标比较差异无统计学意义(P>0.05)。模型组股骨骨小梁结构疏松、数量较对照组减少,且各骨小梁互相独立、网状结构减少;槲皮素低剂量与模型组比较变化不明显,强骨胶囊组及槲皮素高剂量组骨小梁结构较模型组密集,数量增加,且网状结构也增加。结论槲皮素能显著改善骨小梁结构数量,增加骨密度,对废用性骨质疏松有明显预防作用;其机制与槲皮素可抑制ERK1/2、MAPK mRNA和蛋白的表达,从而抑制ERK1/2-MAPK信号通路的传导有关。

补肾壮督方对中老年骨质疏松性椎体骨折的影响

目的:探讨补肾壮督方联合阿仑膦酸钠对中老年骨质疏松性椎体骨折临床疗效和骨形态发生蛋白质-2(BMP-2)、B细胞淋巴瘤-2(Bcl-2)的影响。方法:选取2019年1月至2021年6月在海口市中医医院住院治疗的骨质疏松性椎体骨折患者69例作为研究对象,将患者按照随机数字表分为观察组(n=35)和对照组(n=34)。对照组给予阿仑膦酸钠口服,观察组加用补肾壮督方口服治疗。记录2组中医证候临床疗效。采用骨密度T值评估骨密度改善情况,采用骨痂生长评分量表评估患者骨痂生长情况。采用血清骨形态发生蛋白质-2(BMP-2)和B细胞淋巴瘤2(Bcl-2)评估骨生长情况。结果:治疗后2组患者中医证候临床疗效差异有统计学意义(P<0.05);与对照组比较,观察组治疗后和随访结束腰椎、股骨颈、粗隆间和Wards三角区骨密度T值均明显高于对照组,差异有统计学意义(P<0.05);观察组治疗后和随访结束断端边缘、骨痂密度、骨痂量和骨痂边缘评分明显高于对照组,差异有统计学意义(P<0.05);观察组治疗后BMP-2和Bcl-2明显高于对照组,差异有统计学意义(P<0.05)。结论:补肾壮督方联合阿仑膦酸钠治疗中老年骨质疏松性椎体骨折可加速中老年骨质疏松性椎体骨折愈合,提高骨密度,改善生命质量。

Effect of nano-hydroxyapatite/collagen composite and bone morphogenetic protein-2 on lumbar intertransverse fusion in rabbits

Objective: To investigate the effect of nano hydroxyapatite/collagen (nHA/collagen) composite as a graft extender and enhancer when combined with recombinant human bone morphogenetic protein 2 (rhBMP 2) on lumbar intertransverse fusion in rabbits. Methods: Sixty four adult female New Zealand white rabbits, aged 1 year and weighing 3.5 4.5 kg, underwent similar posterolateral intertransverse process arthrodesis and were randomly divided into 4 groups based on different grafts: autogenous cancellous bone alone (ACB group), nHA/collagen alone (HAC group), half autogenous cancellous bone and half nHA/collagen (ACB+HAC group) and nHA/collagen combined with rhBMP 2 (HAC+BMP group). The fusion masses were analyzed by manual palpation, radiography, biomechanical testing and histological examination. Results: Fusion was observed in 4 cases in the 6th week and in 5 cases in the 10th week after surgery in ACB group. No case showed fusion in HAC group. In ACB+HAC group, there was fusion in 3 cases in the 6th week and in 4 cases in the 10th week after surgery. In HAC+BMP group, fusion in 1 case was found in the 4th week, in 5 cases in the 6th week and in 6 cases in the 10th week after surgery. It suggested that ACB, ACB+HAC and HAC+BMP groups showed similar fusion ratio and mechanical strength in the 6th and 10th week after surgery. According to the microstructure analysis of the samples, nHA/collagen had no negative effect when implanted together with ilium autograft. In HAC+BMP group, new bone like tissue was observed in the 2nd week postoperatively, and nearly all of the implanted composites were replaced by mature bone matrix and new bones in 10th week postoperatively. Conclusions: The nHA/collagen, especially combined with rhBMP 2, is a promising bone substitute, for it has quick biodegradation, fine bone bending ability, and high osteoconductivity on posterolateral spinal fusion in rabbits.

Role of adsorbed proteins on hydroxyapatite-coated titanium in osteoblast adhesion and osteogenic differentiation

The method of plasma-spray coating of hy- droxyapatite （HA） onto pure titanium has been demon- strated to be effective to enhance the osteogenic differentiation and accelerate bone regeneration. Yet it is still a big challenge to figure out the interplay among im- plant surface properties, adsorbed proteins and cell-surface interactions. In this study, the plasma-sprayed HA-coated titanium （HA-Ti） surface was compared with the titanium substrate in terms of protein adsorption, cell adhesion and differentiation. The phase composition, wettability and to- pography were characterized. Compared to the Ti substrate, the HA-Ti had a smaller water contact angle, but larger micro-scale roughness, and showed a poorer ability to ad- sorb fibronectin （Fn）, bovine serum albumin （BSA） and serum proteins. However, it could adsorb larger amount of recombinant human bone morphogenetic protein 2 （BMP- 2）. The osteoblasts and bone marrow mesenchymal stem cells （BMSCs） tended to adhere on the Ti substrate. By contrast, the BMSCs cultured on the HA-Ti showed a stronger tendency toward osteogenesis differentiation.