骨水泥对椎间盘细胞凋亡、基质蛋白多糖及胶原代谢的影响

Influence of bone cements on apoptosis,metabolism of proteoglycan and collagen of the intervertebral disc

目的探讨骨水泥材料对藻酸盐凝胶系统中的椎间盘细胞凋亡、细胞外基质蛋白多糖和胶原代谢的影响。方法兔椎间盘标本于藻酸盐凝胶系统中分别使用普通培养液(对照组)、聚甲基丙烯酸甲酯骨水泥(PMMA组)、磷酸钙骨水泥(CPC组)及丝素复合磷酸钙骨水泥(SF/CPC组)浸出培养液培养至1、2、3周时,对各组标本行Hoechst33342和PI染色,检测细胞死亡率;免疫组化检测Ⅱ型胶原的表达;番红O染色检测基质多糖含量。结果第1周时,PMMA组及CPC组细胞死亡率均高于对照组及SF/CPC组,PMMA组高于CPC组(P<0.05);第3周时,CPC组高于对照组和SF/CPC组(P均<0.05)。第1、2周时,PMMA组及CPC组Ⅱ型胶原含量明显降低(P<0.05),第3周时,CPC组有一定恢复,SF/CPC组与对照组近似(P>0.05)。各组基质蛋白多糖平均光密度值均随时间呈下降趋势,PMMA组下降最明显(P<0.05)。结论PMMA对藻酸盐凝胶系统培养的椎间盘细胞活性、Ⅱ型胶原及基质蛋白多糖代谢影响最明显,SF/CPC较CPC对椎间盘组织有更好的生物相容性。骨水泥材料可加速椎间盘的退变,影响程度与材料的类型有关。

Objective To investigate the influence of bone cements on apotosis, metabolism of proteoglycan and collagen of the intervertebral disc cultured in an alginate gel system. Methods The discs taken from rabbits were cultured in the alginate gel system with ordinary complete medium （control group） and mediums in which cements samples had been extracted, including polymethylmethacrylate bone cement （ PMMA group）, calcium phosphate cement （ CPC group） and silk fibroin/CPC composite （SF/CPC group）. After 1,2 and 3 weeks, cell viability was measured by Hoeehst 33342 and PI cocktail nuclear staining; the expressions of type Ⅱ collagen was detected by immunohistochemistry; proteoglyean content measurement was done by Safranin O staining. Results At 1 week, the dead cells in PMMA and CPC group were higher than that in control and SF/CPC group（P 〈0.05）. At 3 weeks, the dead cells in CPC group were higher than that in control and SF/CPC group（ P 〈 0.05）. The content of type Ⅱ collagen of PMMA and CPC group were markedly lower than that in SF/CPC group（ P 〈 0.05 ）. At 3 week, there was some restore in CPC group. The value of SF/CPC group was similar to the control group（ P 〉 0.05 ）. The integrated option density value was dropped in all groups, however, the decline rate in PMMA group was the most（P 〈 0.05）. Conclusions PMMA significantly inhibits the cell viability, metabolism of proteoglycan and collagen of the intervertebral disc cultured in the alginate gel system. Compared to CPC, SF/CPC presents a better biocompatibility with intervertebral disc. The bone cements can accelerate the degeneration of intervertebral disc with different degree depending on the cement type.