简介概要

新型可降解生物医用镁合金JDBM的研究进展

来源期刊:中国有色金属学报2011年第10期

论文作者:袁广银 章晓波 牛佳林 陶海荣 陈道运 何耀华 蒋垚 丁文江

文章页码:2476 - 2488

关键词:可降解生物医用镁合金;骨内植物;心血管支架;生物相容性;生物降解性能

Key words:degradable biomedical magnesium alloys; bone implants; cardiovascular stents; biocompatibility; biodegradation properties

摘    要:镁合金因具有与人体骨头接近的密度和弹性模量、高比强度和比刚度、生物可降解性以及生物相容性等优点,近10年来国内外研究人员对其应用于骨内植物、骨组织工程支架和心血管支架等领域进行了广泛的研究。然而,目前大多数研究均以现有商用镁合金为对象,如含Al元素的AZ31、AZ91以及含重稀土元素的WE43等,并未考虑到作为生物材料的安全性等问题。本文作者阐述镁合金作为生物医用材料的优势、面临的挑战以及应对策略;重点介绍上海交通大学轻合金精密成型国家工程研究中心近年来围绕自行研发的新型生物医用镁合金JDBM开展的研究工作;最后展望可降解生物医用镁合金的应用前景和发展方向。

Abstract: Mg alloys have been extensively studied in the last decade in the fields of bone implants, bone tissue engineering scaffolds and cardiovascular stents due to their excellent properties, such as close density and elastic modulus to those of nature bone, high specific strength and rigidity, biodegradation and biocompatibility. However, most of the Mg alloys studied for biodegradable materials are aluminium-containing alloys, such as AZ31 and AZ91 and some heavy rare earth elements-containing alloys such as WE43. These alloys were originally developed for structural materials which did not consider the bio-safety as biomaterials. In this work, the advantages, challenges and strategies of the Mg alloys as biomedical materials are briefly introduced. The work on biomedical Mg alloys of the National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, is highlighted. Finally, the application prospects and direction of the biodegradable biomedical Mg alloys are prospected.



详情信息展示

文章编号:1004-0609(2011)10-2476-13

新型可降解生物医用镁合金JDBM的研究进展

袁广银1,章晓波1,牛佳林1,陶海荣2,陈道运3,何耀华3,蒋  垚3,丁文江1

(1. 上海交通大学 材料科学与工程学院 轻合金精密成型国家工程研究中心,上海 200240;

2. 上海交通大学 附属第三人民医院骨科,上海 201900;

3. 上海交通大学 附属第六人民医院骨科,上海 200233)

摘  要:镁合金因具有与人体骨头接近的密度和弹性模量、高比强度和比刚度、生物可降解性以及生物相容性等优点,近10年来国内外研究人员对其应用于骨内植物、骨组织工程支架和心血管支架等领域进行了广泛的研究。然而,目前大多数研究均以现有商用镁合金为对象,如含Al元素的AZ31、AZ91以及含重稀土元素的WE43等,并未考虑到作为生物材料的安全性等问题。本文作者阐述镁合金作为生物医用材料的优势、面临的挑战以及应对策略;重点介绍上海交通大学轻合金精密成型国家工程研究中心近年来围绕自行研发的新型生物医用镁合金JDBM开展的研究工作;最后展望可降解生物医用镁合金的应用前景和发展方向。

关键词:可降解生物医用镁合金;骨内植物;心血管支架;生物相容性;生物降解性能

中图分类号:R318.08       文献标志码:A

Research progress of new type of degradable

 biomedical magnesium alloys JDBM

YUAN Guang-yin1, ZHANG Xiao-bo1, NIU Jia-lin1, TAO Hai-rong2, CHEN Dao-yun3,

HE Yao-hua3, JIANG Yao3, DING Wen-jiang1

(1. National Engineering Research Center of Light Alloy Net Forming, School of Materials Science and Engineering,

Shanghai Jiao Tong University, Shanghai 200240, China;

2. Department of Orthopedics, the Third People’s Hospital Affiliated to Medical College, Shanghai Jiao Tong University, Shanghai 201900, China;

3. Department of Orthopedics, Shanghai Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233, China)

Abstract: Mg alloys have been extensively studied in the last decade in the fields of bone implants, bone tissue engineering scaffolds and cardiovascular stents due to their excellent properties, such as close density and elastic modulus to those of nature bone, high specific strength and rigidity, biodegradation and biocompatibility. However, most of the Mg alloys studied for biodegradable materials are aluminium-containing alloys, such as AZ31 and AZ91 and some heavy rare earth elements-containing alloys such as WE43. These alloys were originally developed for structural materials which did not consider the bio-safety as biomaterials. In this work, the advantages, challenges and strategies of the Mg alloys as biomedical materials are briefly introduced. The work on biomedical Mg alloys of the National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, is highlighted. Finally, the application prospects and direction of the biodegradable biomedical Mg alloys are prospected.

Key words: degradable biomedical magnesium alloys; bone implants; cardiovascular stents; biocompatibility; biodegradation properties

从21世纪初开始,以生物可降解镁合金为主要代表的具有生物可降解特性的新一代医用金属材料的研究发展迅速,受到了人们的特别关注[1-2]。这类新型医用金属材料改变人们通常将金属植入材料作为生物惰性材料使用的传统思想,巧妙地利用镁基金属材料在人体环境中易发生腐蚀(降解)的特性,来实现金属植入物在体内逐渐降解直至最终消失的医学临床目的。

与其他医用金属材料相比,镁合金具有如下的优势:

1) 可降解性。镁合金具有较低的腐蚀电位,在含有氯离子的体内环境下易发生腐蚀,并以缓慢腐蚀的方式在体内完全降解,可实现镁在人体中的降解吸收。

2) 生物安全性高。Mg作为人体必需的营养元素,在人体内含量仅次于Ca、K、Na,排第4位。目前,许多发达国家已将镁列为人体必需元素,补镁的重要性并不亚于补钙。世界卫生组织建议成人每天需要的摄镁量为280~300 mg,少年儿童为250 mg,婴幼儿为80 mg。Mg的生理功能主要体现在它能催化或激活机体325种酶系,参与体内所有能量代谢。对肌肉收缩、神经运动机能、生理机能及预防循环系统疾病和缺血性心脏病均具有重要作用[3-4]。镁的排泄主要通过泌尿系统,它在人体内吸收不会导致血清镁含量的明显升高。图1所示为人体内Mg的吸收和排泄动态平衡分布[5]。通常食物中所含镁的30%~50%由肠胃吸收。另外,肾脏是Mg代谢调节的中心,血浆中自由Mg离子和Mg盐每天由肾小球进行过滤,其中,95%~98%由肾小管进行再吸收。由于肾小管的再吸收将影响血浆中Mg的浓度,如果从肠胃吸收的Mg的吸收量增加,则肾小管的再吸收量就会减少,排泄量增加,使得血浆中的Mg浓度保持一定。因此,采用镁合金作为医用可降解生物材料具有良好的医学安全性基础[3]

3) 生物力学相容性好。表1所列为几种常见植入材料及镁与人体骨物理机械性能的对比结果[6]。从表1可见,镁是目前所有金属材料中生物力学性能与人体骨最接近的金属材料,传统医用不锈钢的弹性模量E=200 GPa左右, 传统医用钛合金(Ti-6Al-4V)弹性模量也高达110 GPa,而天然骨的弹性模量则为3~20 GPa(不同部位,骨的弹性模量不同)。骨内固定修复材料的弹性模量如果与骨的弹性模量相差较大,就会导致“应力遮挡”[7],而影响骨的修复愈合。而镁的弹性模量E=45 GPa,最接近骨的弹性模量,可有效缓解“应力遮挡”。此外,镁合金的密度通常为1.74~2.0 g/cm3,与自然骨密度1.8~2.1 g/cm3也最相近。由此可见,镁的物理机械性能比其他医用金属材料更接近于生物骨,是最理想骨内固定修复材料。

4) 成本低。镁是包括海洋在内地球表层最为丰富的金属元素,价格低廉。目前金属镁锭的市场价格在2万元(RMB)/t左右,而钛锭的价格在8万元(RMB)/t以上。

图1  人体内Mg的吸收和排泄动态平衡分布图[5]

Fig.1  Distribution of dynamic absorption and excretion equilibrium of Mg in human body

表1  几种植入材料在物理力学性能方面同人骨的对比概括[6]

Table 1  Summary of physical and mechanical properties of various implant materials in comparison to natural bone