用于人体关节植入物的多孔纯钛/钛合金研究

目的研究Ti6Al4V合金基体上经钎焊制得的多孔纯钛／钛合金,并对其各项性能进行表征,探讨其是否适用于人体关节植入物。方法制备钎焊多孔纯钛／钛合金表面多孔层,采用SEM观察其形貌及孔径,采用重量法计算其孔隙率,采用Instron 4057材料试验机进行结合强度测试,并根据国家标准GB／T16886-3完成遗传毒性实验。结果纯钛／钛合金多孔层孔径为100μm以上,孔隙率6％以上;多孔层与基体的结合强度达到27MPa。遗传毒性试验结果为阴性。结论经钎焊可制得纯钛／钛合金球形粉末多孔层,其孔隙率和孔径允许骨细胞长入;多孔层与基体的结合强度能够满足植入要求,并具有较好生物相容性;经钎焊制得的纯钛／钛合金多孔层是一种可用于人体关节植入物的表面结构形式。     

微弧氧化表面改性3D打印多孔钛合金支撑棒治疗羊距骨骨坏死的研究

目的 探讨微弧氧化（MAO）表面改性3D打印多孔钛合金支撑棒对羊距骨坏死的治疗作用,为其进一步临床应用提供基础。方法 观察3D打印多孔钛合金支撑棒通过MAO表面改性后,其表面形态、元素变化及晶像情况。通过体外细胞实验,研究大鼠成骨细胞在材料表面的黏附、增殖及分化情况。建立羊距骨坏死模型基础,并置入3D打印多孔钛合金支撑棒,探究其在距骨内的稳定性及其成骨修复情况。结果 通过MAO改性,材料表面形成大小均一的多孔微米结构,Ca、P、O元素分布在材料表面,同时表面形成TiO₂晶像。在体外细胞实验中,MAO改性组和对照组均表现出良好的生物相容性,但是MAO改性组在细胞接种后8 h黏附能力优于对照组、接种1、4、7 d后细胞增殖能力均优于对照组,同时接种7 d时细胞分化能力也优于对照组,差异具有统计学意义（P＜0.05）。羊距骨植入实验表明,术后12周两组支撑棒都有骨长入,但是MAO改性组与对照组相比其周围有更多的新生骨长入。定量结果显示MAO组的骨体积分数、骨小梁厚度也优于对照组,差异具有统计学意义（P＜0.05）。结论 仿生的3D打印多孔结构为支撑棒提供了优良的力学性能,MAO表面改性进一步提高了其生物活性,使其在治疗羊距骨早期骨坏死过程中充分发挥了力学和生物学的优势。本临床前研究效果满意,并为其未来临床应用提供了理论和研究基础。     

电子束熔融制造医用Ti6Al4V在人工模拟体液中耐腐蚀行为

目的 研究电子束熔融技术（EBM）3D打印制备的医用Ti6Al4V不同打印截面在Hank''s模拟人工体液中的电化学腐蚀行为。方法 采用开路电位和动电位极化曲线方法研究了Ti6Al4V不同打印截面,分别记为EBM-XOY面（垂直于打印方向的钛合金截面）和EBM-YOZ面（平行于打印方向的钛合金截面）,在Hank''s模拟人工体液中的电化学腐蚀行为,利用SEM、XRD和金相显微镜分析了其表面形貌和物相组成及其腐蚀机理,并与传统医用锻造Ti6Al4V进行了对比研究。结果 与传统医用锻造Ti6Al4V合金相比,EBM-YOZ面钛合金在Hank’s模拟人工体液中的开路电位、腐蚀电位和腐蚀电流与之相当,显示出与之接近的耐腐蚀性能;EBM-XOY面钛合金的耐腐蚀性能较EBM-XOZ面和传统锻造钛合金稍差,主要原因是EBM-XOY面的α+β相界面积大,α相含量较高,且被优先溶解,因此,耐腐蚀性能较差。结论 电子束熔融制造的Ti6Al4V不同截面的耐腐蚀性能不同,EBM-YOZ面的耐腐蚀性能与传统医用锻造钛合金相当,EBM-XOY面的耐腐蚀性能稍差。     

电子束熔融法制备的医用Ti6Al4V在人工模拟体液中的耐腐蚀行为

目的研究电子束熔融技术(EBM)3D打印制备的医用Ti6Al4V不同打印截面在Hank's模拟人工体液中的电化学腐蚀行为。方法采用开路电位和动电位极化曲线方法研究了Ti6Al4V不同打印截面,分别记为EBMXOY面(垂直于打印方向的钛合金截面)和EBM-YOZ面(平行于打印方向的钛合金截面),在Hank's模拟人工体液中的电化学腐蚀行为,利用SEM、XRD和金相显微镜分析了其表面形貌和物相组成及其腐蚀机理,并与传统医用锻造Ti6Al4V进行了对比研究。结果与传统医用锻造Ti6Al4V合金相比,EBM-YOZ面钛合金在Hank's模拟人工体液中的开路电位、腐蚀电位和腐蚀电流与之相当,显示出与之接近的耐腐蚀性能;EBM-XOY面钛合金的耐腐蚀性能较EBM-XOZ面和传统锻造钛合金稍差,主要原因是EBM-XOY面的α+β相界面积大,相含量较高,且被优先溶解,因此,耐腐蚀性能较差。结论电子束熔融制造的Ti6Al4V不同截面的耐腐蚀性能不同,EBM-YOZ面的耐腐蚀性能与传统医用锻造钛合金相当,EBM-XOY面的耐腐蚀性能稍差。     

图像分析方法研究DLC膜/Ti6Al4V梯度材料的血液相容性稳定性

对 DL C膜 / Ti6Al4V梯度材料和 Ti6Al4V钛合金进行了血液相容性稳定性研究。用数字图像分析方法分别测定了材料生物摩擦磨损实验前后的血小板消耗率。研究表明 ,在 Hank' s溶液润滑条件下 ,经过 2 0 0 0 m摩擦磨损实验后 ,Ti6Al4V钛合金血小板消耗率显著增加约 5 0 % ,而 DL C膜 / Ti6Al4V梯度材料血小板消耗率没有明显增加。说明 DL C膜 / Ti6Al4V梯度材料在使用条件下具有很好的血液相容性稳定性     

基于Weaire-Phelan结构的Ti6Al4V多孔支架力学性能研究及数值模拟

目的 研究基于lattice Weaire-Phelan（LWP）结构支架的力学性能,并利用有限元方法精确模拟多孔支架的整个压缩过程。方法 采用选择性激光熔融（selective laser melting,SLM）技术制造具有不同孔隙率的Ti6Al4V（TC4）多孔支架。通过单轴压缩试验测试样件力学属性,并与人体骨骼及其他支架结构进行对比。验证4种材料模型对多孔支架压缩仿真结果 的影响。结果 LWP支架展现出与人体松质骨十分接近的弹性模量以及高于大多数皮质骨的屈服强度。与其他支架结构相比,LWP支架具有几乎最小的弹性模量和最大的屈服强度。利用本文提出的材料模型,即Johnson-Cook本构模型和动态几何应变失效模型（Johnson-Cook constitutive model and failure model based on dynamic geometric strain,JCDG）,模拟出的结果 与试验数据非常接近。结论 作为骨修复材料,LWP支架展现出比其他支架结构更优秀的力学性能。与其他材料模型相比,JCDG更有利于构建出合理的多孔支架压缩仿真模型。     

单侧椎体后外上方入路与双侧椎弓根入路行椎体成型术治疗骨质疏松性椎体压缩骨折的生物力学对比研究

目的 比较单侧椎体后外上方入路与双侧椎弓根入路行椎体成型术后的单椎体生物力学效能。方法 收集老年女性尸体的骨质疏松脊柱椎体（L₁）共20个,采用随机数字表法将样本随机分为两组,分别为单侧椎体后外上方组（A组）、双侧椎弓根组（B组）。首先测量椎体高度、垂直压缩状态下的单椎体弹性模量。在力学测试仪上将每个椎体制备成压缩骨折模型,记录其失效强度、刚度、失效位移。按每组对应的穿刺入路行椎体成型术,术后行X线扫描观察骨水泥在椎体内的弥散情况。再次测量椎体高度、垂直压缩运动状态下的单椎体弹性模量及失效强度、刚度、失效位移。结果 A组、B组椎体内骨水泥弥散类型差距不大,均能达到椎体内对称均匀分布。成型后两组的椎体前缘高度恢复率相当,差异无统计学意义（P＞0.05）。骨折前两组椎体的失效强度、刚度及失效位移比较,差异均无统计学意义（P＞0.05）;成型后,两组的失效强度、刚度及失效位移相当,差异无统计学意义（P＞0.05）;但在椎体垂直压缩时的弹性模量方面A组优于B组,差异有统计学意义（P＜0.05）。结论 单侧椎体后外上方穿刺入路行椎体成型术后的单椎体生物力学效能与传统双侧椎弓根入路相当,值得在临床进一步推广。     

新型β钛合金Ti_(35)Nb_3Zr_2Ta在人工关节假体应用中的生物相容性

背景:目前被广泛应用于人体关节置换的钛合金为Ti6Al4V,但其弹体模量高于人体骨,导致人工关节假体的稳定性差。而新型β钛合金Ti35Nb3Zr2Ta弹性模量较低,或许能成为新一代生物相容性较好的人体关节假体材料。目的:探讨新型β钛合金Ti35Nb3Zr2Ta在人工关节假体应用的生物相容性。方法:应用计算机检索自万方数据库、中国知网和Pub Med文献数据库,检索时间范围2010至2015年,以"新型β钛合金;人工关节假体;生物相容性"为检索词,检索医用人工关节假体材料的应用现状及新型β钛合金Ti35Nb3Zr2Ta在人工关节假体应用的生物相容性的研究。结果与结论:与Ti6Al4V相比,Ti35Nb3Zr2Ta表面粗糙度较高,表面接触角较小,碱性磷酸酶活性以及成骨细胞的钙沉积量明显高于Ti6Al4V,具有良好的生物相容性,可以考虑在人工关节假体领域中进一步广泛应用。     

HA/ZrO2 不同复合材料对MSCs贴壁、增殖及成骨分化影响的差异

目的: 观察间充质干细胞(MSCs)在不同生物材料表面的生长及成骨分化情况。方法: 采用干铺法制备氧化锆(ZrO₂)单层复合羟基磷灰石(HA)及ZrO₂梯度复合HA 两种复合材料,观察复合材料表面形貌特征。分离和培养兔MSCs,分别培养于HA/ZrO₂单层复合材料、HA/ZrO₂梯度复合材料、纯HA及ZrO₂材料薄片上,观察细胞贴壁、增殖情况和碱性磷酸酶活性,提取细胞总RNA并检测Ⅰ型胶原、骨钙蛋白和骨桥蛋白mRNA 表达情况。结果: 制备的HA/ZrO₂单层复合材料具有不连续的HA表面层,可以清晰地观察到部分ZrO₂基体。而HA/ZrO₂梯度复合材料表面较为粗糙,呈多孔状。X射线衍射分析显示,经高温烧结后,两种复合材料表面的ZrO₂相依旧存在,HA相转变为β-Ca₃(PO₄)₂(β-TCP)、α-Ca₃(PO₄)₂(α-TCP)和CaZrO₃相。细胞培养显示,HA/ZrO₂梯度复合材料更有利于细胞贴壁。细胞在纯HA上碱性磷酸酶活性较其它组显著升高;细胞在复合材料和纯HA上Ⅰ型胶原、骨钙蛋白和骨桥蛋白表达较对照组均有不同程度升高,其中Ⅰ型胶原表达升高更为明显。结论: HA/ZrO₂梯度复合材料可促进MSCs的增殖,并可促进MSCs的成骨分化。     

3D打印PEEK材料假体置入CT表现：骨肿瘤患者10例

目的 阐述3D打印PEEK材料置入后随访的CT特征及改变。方法 回顾性分析2020年2月至2021年6月间骨肿瘤患者行瘤段切除3D打印PEEK材料假体置入后的CT图像10例,通过多平面重组观察、测量CT值等方法分析假体形态、密度改变及假体－骨界面的情况。结果 10例假体均未发生变形及折断,各个假体与骨接触面密度均无较大改变,残留骨与假体接触面发生不同程度骨质吸收。10例中有5例残留骨表面出现骨膜新生骨,2例出现感染,1例出现脱位表现。均未见肿瘤复发征象。结论 CT可以评估假体的位置、形态、密度改变及与自体骨间关系,可以发现相应的并发症,是这类手术患者术后首选的随访方法。     

Osteogenic Potential of Porous Titanium. An Experimental Study in Sheep

The search for osteoinductive as well as osteoconductive materials has led to the novel idea of using titanium in bone augmentations of the alveolar crest. Due to its excellent biocompatibility and favorable osteogenic properties, highly porous TiO₂ granules has been proposed as a promising material for non-resorbable synthetic bone grafts in the restoration of large bone defects, and for bone augmentation in dental applications.ObjectivesThe aim of this study was to investigate the osteoconductive properties and biological performance of porous titanium granules used in osseous defects adjacent to the maxillary sinus in sheep. The experimental animal study involved 15 yearling sheep with a focus on the osteogenic potential of porous titanium used for subantral augmentation.Material and methodsCalibrated defects were prepared in the subantral region of sheep. The defects were randomized into tests and control group. The test defects were grafted with porous titanium granules (PTG), whereas control defects were left empty (sham). Defects were left for healing for 30, 60, and 90 days. After healing, the grafted areas were removed and finally osteoconductivity was analyzed by an orthopantograph (OPG} and histology.ResultsSignificantly more new bone formed in PTG grafted defects compared with sham. The control group showed significantly less expression of key inflammation cells, but with no significant difference in key inflammation cells compared with the experimental groups.ConclusionPorous titanium can offer as an effective alternative to calcium phosphate and bone collagen-based materials used for subantral augmentation of the maxillary bone in cases of dental implantation.     

杆状和片状三周期极小曲面模型孔隙特征与力学性能对比

目的分析对比杆状与片状三周期极小曲面(triply periodic minimal surface,TPMS)模型孔隙特征与力学性能,构建高比表面积、低刚度和高强度的多孔结构。方法构建相同孔隙率的D、G、P 3种单元杆状TPMS与片状TPMS模型,对比模型的孔径、杆径、比表面积等孔隙特征;利用有限元方法分析模型的力学性能;采用增材制造技术制作多孔钛样件,利用显微镜和扫描电镜观测多孔钛孔隙特征,通过压缩试验检测多孔钛力学性能。结果同种单元片状结构的比表面积均显著高于杆状结构,同种单元片状结构的力学性能明显优于杆状结构。其中,D单元片状TPMS模型的优势最显著,比表面积为13.00 mm~(-1),多孔钛样件的弹性模量、屈服强度和抗压强度分别为(5.65±0.08) GPa、(181.03±1.30) MPa和(239.83±0.45) MPa,比杆状多孔钛样件分别提高43.87%、55.08%和67.21%。结论相同单元的片状TPMS模型在保留有多孔结构低刚度的同时,有更大的比表面积,更有利于细胞的黏附生长,其低刚度、更高强度的力学特性能有效降低应力遮挡,提供足够的力学支撑,是一种理想的骨缺损修复替代物孔隙结构模型。     

Effect of process control agent on the porous structure and mechanical properties of a biomedical Ti–Sn–Nb alloy produced by powder metallurgy

The influence of different amounts and types of process control agent (PCA), i.e., stearic acid and ethylene bis-stearamide, on the porous structure and mechanical properties of a biomedical Ti–16Sn–4Nb (wt.%) alloy was investigated. Alloy synthesis was performed on elemental metal powders using high-energy ball milling for 5 h. Results indicated that varying the PCA content during ball milling led to a drastic change in morphology and particle-size distribution of the ball-milled powders. Porous titanium alloy samples sintered from the powders ball milled with the addition of various amounts of PCA also revealed different pore morphology and porosity. The Vickers hardness of the sintered titanium alloy samples exhibited a considerable increase with increasing PCA content. Moreover, the addition of larger amounts of PCA in the powder mixture resulted in a significant increase in the elastic modulus and peak stress for the sintered porous titanium alloy samples under compression. It should also be mentioned that the addition of PCA introduced contamination (mainly carbon and oxygen) into the sintered porous product.     

应用三维打印成型技术制备个体化多孔纯钛植入体的研究

三维打印(3DP)成型技术适合成型形状复杂、结构精细的个体化多孔医用生物植入材料,能满足不同患者的不同需求。本文应用3DP成型技术制备直径为25mm×20mm的多孔纯钛植入体生柸,于500℃真空脱粘后,在氩气保护下烧结至1 300℃,利用扫描电镜(SEM)观察其孔径大小介于50～150μm,其孔隙率、体积密度、维氏硬度、抗压强度及弹性模量测试结果分别为(44.26±2.43)%、(2.59±0.81)g/cm3、134.2～151.6、(61.2±3.2)MPa、(3.25±1.08)GPa。结果表明,3DP成型技术在制备个体化多孔纯钛植入体方面有着广阔的应用前景。     

基于选区激光熔融技术制备的多孔钛合金支架的力学性能及成骨能力评价

目的评价选区激光熔融(selective laser melting,SLM)技术制备的多孔钛合金支架的力学性能及成骨能力。方法通过SLM技术制备两种多孔钛合金(Ti6-Al4-V)支架,分别为均一多孔组和复合多孔组,简称均一组与复合组,并对其力学性能、体外细胞相容性和体内骨整合能力进行评价。结果与传统锻件相比,多孔钛合金支架的弹性模量更接近人体正常骨组织,且复合组的弹性模量高于均一组,差异具有统计学意义(0.05)。细胞相容性方面,随着时间的推移,间充质干细胞数量在两组多孔支架上均有增加,但复合组钛合金支架在5 d和7 d的细胞数量高于均一组(0.05)。该组在成骨分化实验的7 d也具有更高的ALP活性(0.05)。诱导14 d后两组ALP活性无差异。体内植入实验表明,3个月时,复合组的骨体积分数与均一组比较差异无统计学意义(0.05)。结论本研究表明,基于SLM制备的多孔钛合金支架弹性模量适宜,具有骨整合能力,适合做骨缺损修复材料。     

Development and characterisation of novel cross-linked bio-elastomeric materials

Recombinantly-engineered elastin-like polypeptides (ELPs) possess many of the favourable attributes of the native elastin protein, making them an attractive option for designing biomaterials for tissue-engineering applications. The focus of this study was to synthesize and characterise the bulk material properties of two ELP sequences, ELP2 and ELP4, cross-linked with lysine diisocyanate (LDI). The two distinct ELPs consist of repeating hydrophobic and hydrophilic cross-linking domains in a block co-polymer structure, however, differ by the number of respective domains. Depending on the conditions sets for the cross-linking reactions, two different ELP-based materials were synthesized: a gel-like relatively non-porous material and a porous foam-like material, from both ELP sequences. The physical material properties were characterised by scanning electron microscopy, compression testing, differential calorimetry analysis and swelling analysis. The bulk material properties were found to vary depending on the ELP sequence investigated. ELP gels were also found to have a more dense solidified morphology, lower compressive moduli, higher melting temperature and greater swelling capacity than the porous ELP foams. These novel cross-linked bio-elastomeric materials show promising properties for soft tissue replacement, particularly in load-bearing applications.     

Fabrication of Chitosan Scaffolds with Tunable Porous Orientation Structure for Tissue Engineering

Chitosan, as an example of natural macromolecular biomaterials, was used to fabricate highly porous chitosan scaffolds with microtubules having a tubular orientation structure using the unidirectional freeze-drying method. The porous structure of the scaffolds was characterized via scanning electron microscopy. The factors that affect the porous structure of the scaffolds, such as the concentration of chitosan solution and addition of glutaraldehyde as cross-linking agent, have been extensively studied in order to find a facile and efficient way to control the porosity, tubular morphology and orientation of the microtubules. The properties of the chitosan scaffolds, including water absorption ability, compressive strength, protein adsorption and in vitro enzymatic biodegradation in the presence of lysozyme, were also investigated. In vitro cell-culture results showed that the chitosan scaffold was non-toxic to cartilage cells and the cells could spread and grow well on the scaffolds.     

Porous titanium and silicon-substituted hydroxyapatite biomodification prepared by a biomimetic process: Characterization and in vivo evaluation

Porous titanium with a pore size of 150–600 μm and a porosity of 67% was prepared by fiber sintering. The porous titanium had a complete three-dimensional (3D) interconnected structure and a high yield strength of 100 MPa. Si-substituted hydroxyapatite (Si-HA) was coated on the surface by a biomimetic process to improve the surface bioactivity. X-ray diffraction results showed that Si-HA coating was not well crystallized. New bone tissue was found in the uncoated porous titanium after 2 weeks of implantation and a significant increase (p < 0.05) in the bone ingrowth rate (BIR) was found after 4 weeks of implantation, indicating the good osteoconductivity of the porous structure. The HA-coated and Si-HA-coated porous titanium exhibited a significantly higher BIR than the uncoated titanium at all intervals, highlighting the better surface bioactivity and osteoconductivity of the HA- and Si-HA coatings. Also, the Si-HA-coated porous titanium demonstrated a significantly higher BIR than the HA-coated porous titanium, showing that silicon plays an active role in the surface bioactivity. For Si-HA-coated porous titanium, up to 90% pore area was covered by new bone tissue after 4 weeks of implantation in cortical bone. In the bone marrow cavity, the pore spaces were filled with bone marrow, displaying that the interconnected pore structure could provide a channel for body fluid. It was concluded that both the 3D interconnected pore structure and the Si-HA coating contributed to the high BIR.