羟基磷灰石纳米颗粒溶胶的抗癌及急性毒性作用研究

Anti-tumor Effect and Acute Toxicological Reaction of Hydroxyapatite Nanoparticle

目的 研究羟基磷灰石纳米颗粒（HAP）溶胶对小鼠的抗癌及其急性毒性作用机制。方法 经超声波作用和均匀沉淀法制备出直径达50～100nm的HAP超微粒溶胶，用不同浓度（0．50、0．10、0．05g／L）的HAP培养液行肿瘤细胞体外药效实验；以及经小鼠尾静脉和腹腔内注射后，观察小鼠死亡情况，分别将死亡小鼠的心、肺、肝、肾等器官行病理学检查，并用概率单位一对数图解法及直线回归法计算HAP的LD50值，分析死亡原因。结果 经肿瘤细胞体外药效试验检测发现，0．50g／L的HAP对人胃癌细胞的生长抑制率达76．8％，且抑癌率与作用的时间及使用的浓度呈正比例关系。HAP经小鼠尾静脉注射的LD50为0．443g／kg，当剂量为0．325g／kg时，无小鼠死亡；经腹腔内注射，无1例死亡。经病理检查发现：①小鼠肺泡间隔中毛细血管腔内广泛存在着HAP的聚合体，并有广泛的肺泡间隔内淤血及肺泡水肿；②肝中央静脉明显扩张、淤血，肝窦亦扩张、淤血；而肝实质无明显损害；③心肌无明显损害，无管腔堵塞；④肾小球无坏死、扩张、充血，肾小管形态结构无改变，肾小静脉可见中等淤血、扩张。结论 静脉内注射HAP在有效的体外抑瘤浓度下（0．50g／L）是安全的，腹腔内注射的安全性极高。其静脉内应用主要的致死原因是由于HAP发生团聚后，广泛栓塞肺毛细血管网，导致急性呼吸功能衰竭和右心功能衰竭。

Objective To evaluate the mechanism of anti cancer and acute toxicological reaction of hydroxyapatite nanopar ticle （HAP） on mice. Methods The nanoparticle solution of HAP, whose diameter ranged from 50-100 nm, was prepared through ultrasound vibration and uniform sediment. The in vitro pharmacodynamic test of HAP-solution was done with different concentrations （0.50, 0. 10, 0.05）. After injection of HAP-solution via mouse tail vein and intra-abdominal cavity, the mouse death was observed, and the heart, lung, liver, renal etc. in mice were resected for pathological examination. LD50 of HAP was calculated through probability unit-logarithmic table and linear regression methods. The causes of death were also analyzed. Results In vitro pharmacodynamic test revealed that 0. 50 g/L HAP could achieve 76. 8 G inhibitory rate to the growth of tumor cell, and the rate was time- and concentration-dependent. The LD50 of HAP by intravenous injection was 0. 443 g/kg, and no mouse was dead under the dosage of 0. 325 g/kg. Intraperitoneal injection of HAP caused no death of mice even under the highest dosage of 1. 658 g/kg. The pathological examination indicated that： ① There was large quantities of em bolism of HAP combined corps obstructed in the capillary vessels of lung, and the alveolar interval congestion and alveolar ede ma were found extensively; ② The central veins of liver were severely enlarged, but no damage to liver parenchyma was found; ③ No obvious injury was found in the myocardia and no embolism in the vessels; ④ Moderate congestion and enlargement of renal veins occurred. Conclusion Intravenous injection of HAP under the effective anti-cancer dosage of 0.50 g/L is still quite safe, more through intraperitoneal injection. The major cause of death by intravenous injection is the extensive embolism of capillary veins of lung due to HAP accumulation, subsequently resulting in acute pulmonary hypertension and acute pulmonary failure.