载银二氧化钛纳米羟基磷灰石/聚酰胺66复合材料的生物相容性及其安全性

背景:理想的修复材料是既具有良好生物相容性,又具有成骨能力.任何一种生物材料必须具备使用安全性和良好的生物相容性,这是生物材料获准临床使用的前提.目的:探讨载银二氧化钛纳米羟基磷灰石/聚酰胺66(TiO_2-Ag-nHA/PA66)骨修复材料的体内生物相容性及安全性.设计、时间及地点:随机对照,重复测量设计,于2008-07/2009-07在重庆医科大学完成.材料:清洁级3周龄昆明小鼠40只,同窝同系健康成年新西兰大白兔32只,均由重庆医科大学实验动物中心提供.粉末状TiO_2-Ag-nHA/PA66复合材料10 g,直径5 mm×长度25 mm和直径3 mmx长度5 mm的TiO_2-Ag-nHA/PA66复合材料各32根,由四川大学纳米生物材料研究中心提供.方法:①急性全身毒性试验:40只小鼠随机分为实验组和对照组,选择粉末状复合材料制各材料浸提液,将浸提液注入实验组小鼠腹腔内,对照组注入等量生理盐水.②肌内埋植实验:16只兔随机分为实验组和对照组,实验组每只兔左、右竖脊肌各植入2根直径5 mm×长度25 mm复合材料,对照组行相同的手术操作但不植入任何材料.③骨内埋植试验:取剩余16只兔,每只兔左、右外上髁各植入1根直径3 mm×长度5 mm柱状复合材料.④溶血试验:取抗凝兔血8 mL,分别加入复合材料粉末0.1,0.15,0.2 g.主要观察指标:TiO_2-Ag-nHA/PA66的体内生物相容性及安全性.结果:急性全身毒性试验结果表明,两组小鼠活动及进食良好,呼吸正常,无瘫痪、惊厥及死亡发生,小鼠体质量稳定.肌内埋植试验和骨内埋植试验结果显示,植入前及植入后4 d,1周,2周,两组丙氨酸氨基转移酶、天门冬酸氨基转移酶、尿素氮、肌酐水平及白细胞数量均无明显差异(P>0.05),且实验组内各时相点比较亦无明显差异(P>0.05).肌内埋植中,实验组的组织切片示材料周围的包裹组织,材料周围炎性演变转归与对照组基本相似;骨内埋植中,实验组的组织切片示围绕材料出现新骨.溶血试验结果显示,3种浓度梯度的TiO_2-Ag-nHA/PA66复合材料其溶血率均未超过5%,达到标准要求.结论:TiO_2-Ag-nHA/PA66复合材料具有良好的生物相容性及生物安全性.

Biocompatibility and biological security of the TiO_2-Ag-nano-hydroxyapatite/polyamide66 composite

BACKGROUND: An ideal repairing material characterizes by both great biocompatibility and osteogenesis ability. Any biomaterials should meet excellent biological security and biocompatibility prior to clinical application.OBJECTIVE: To evaluate the biocompatibility and the biological security of the TiO_2-Ag-nano-hydroxyapatite/polyamide66 (TiO_2-Ag-nHA/PA66) composite.DESIGN, TIME AND SETTING: A randomized controlled duplicated design was performed in Chongqing Medical University from July 2008 to July 2009.MATERIALS: A total of 40 Kunming mice aged 3 weeks and of clean grade and 32 healthy adult New Zealand rabbits were provided by Experimental Animal Center of Chongqing Medical University. TiO_2-Ag-nHA/PA66 composite powder (10 g),TiO_2-Ag-nHA/PA66 composites (n=32, 5 mm ×25 mm), and TiO_2-Ag-nHA/PA66 composites (n=32, 3 mm × 5 mm) were provided by Research Center of Nano-Biomaterials of Sichuan University.METHODS: General toxicity test: Forty mice were randomly divided into experimental and control groups. Composite powder was used to prepare leaching liquor which was treated on experimental mice by an intraperitoneal injection. While, an equal amount saline was inserted into the control mice. Intramuscular implanting test: The 16 rabbits were randomly divided into experimental and control groups. Two TiO_2-Ag-nHA/PA66 composite (5 mm × 25 mm) were implanted into left and right erector spinae, respectively. A similar surgery with the exception of implantation was performed on the control rabbits. Intrabony implanting test: The resting 16 rabbits were implanted one TiO_2-Ag-nHA/PA66 composite (3 mm × 5 mm) into left and right lateral epicondyle, respectively. Hemolytic test: A 8-mL anti-coagulation blood was obtained and added with composite powder (0.1,0.15, and 0.2 g).MAIN OUTCOME MEASURES: Biocompatibility and biological security of TiO_2-Ag-nHA/PA66 composite.RESULTS: General toxicity test demonstrated that mice in the two groups had good activity and eating, normal breathing, stable body mass, no paralysis, convulsion, and death. Intramuscular implanting test and intrabony implanting test showed that there was no significant difference in levels of alanine aminotransferase, aspartate transaminase, urea nitrogen, and creatinine and leukocyte numbers between the two groups before implantation and at day 4,1 week, and 2 weeks after implantation (P> 0.05).In particular, there was no significant difference in the experimental group at varying time points (P> 0.05). Intramuscular implanting test indicated that tissue sections in the experimental group displayed coated tissue of materials. The inflammatory variation in the experimental group was generally similar to that in the control group. Intrabony implanting test indicated that tissue sections in the experimental group displayed new bone formation. Hemolytic test suggested that hemolytic ratio of three varying concentrations of TiOrAg-nHA/PA66 composites was less than 5%, which met the normal criterion.CONCLUSION: TiO_2-Ag-nHA/PA66 composite has a good biocompatibility and biological security.