不同烧结温度下三维打印成型多孔钛植入体的实验研究

目的 评价三维打印成型技术(3DP)用于多孔钛植入体制备的可行性,研究不同烧结温度对其组织结构和力学性能的影响.方法 设计试件大小为25×20 mm圆柱体,设定每层的黏结面积为80％.选择纯度98.5％、颗粒直径约75 μm的钛粉为原料,聚乙烯醇粉作为黏结剂,聚乙烯吡咯烷酮粉作为辅助黏结剂.通过三维打印获得多孔钛植入体试件初胚,在氩气保护下,将试件分别烧结至1 200、1 300、1 400℃;对烧结完成的试件进行性能检测,包括孔隙率、显微硬度、扫描电镜观察试件的显微结构、抗压强度及弹性模量.结果 最终获得的多孔钛植入体试件,其收缩均匀、无明显变形、细节清晰、肉眼可见排列整齐的微孔结构、表面无裂纹,呈现金属光泽.在1 200、1 300、1 400℃的烧结温度下,孔隙率分别为(65.01±1.03)％、(46.73±0.73)％、(41.06±0.31)％,显微硬度为115.2±0.6、148.6±1.1、182.8±2.1,弹性模量为(5.9±0.5)、(16.2±0.9)、(34.8±1.5) GPa,抗压强度为(81.3±4.3)、(135.4±8.5)、(218.6±7.1)MPa.扫描电镜观察其孔隙相互连通成三维网状结构.结论 证实了应用三维打印成型技术制备多孔钛植入体的可行性,得到的多孔钛植入体具有与骨组织相匹配的良好的生物力学相容性.     

新型三维连通多孔钛的制备及特性*

目的将具有良好生物相容性的钛制成类似松质骨结构,具有较高的强度和良好的生物性能的多孔材料。方法聚氨酯泡沫海棉做成孔径200～600μ,孔隙率50%～70%的三维连通多孔结构,作为钛粉载体。烧结,制成具有三维连通结构的多孔钛,测定生物力学性能。结果制成的多孔钛,具有三维、连通结构,与人股骨头松质骨结构相似。孔径300～600μ,孔隙率50%～60%。三维连通多孔钛的平均弹性模量为0．6～0．7GPa。结论①本实验三维连通多孔钛,达到了理想的孔径和孔隙率,弹性模量适中,可以广泛应用在骨科各个领域。②三维连通多孔钛还存在着连通孔的闭塞率较高,整体强度不均匀问题。     

基于3D打印多孔支架和植入体的结构设计研究进展

支架或植入体的弹性模量过高会产生应力遮挡效应,引发骨吸收以及后期支架或植入体松动等问题。多孔支架和植入体可以根据需要调整其孔隙率和弹性模量,从而减小应力遮挡,同时多孔结构有利于骨组织的长入,利于骨整合。分别介绍3D打印多孔支架和植入体3种基本结构(均匀多孔结构、类骨小梁结构和功能梯度结构)的设计方法,以及基于计算机辅助设计、隐式曲面、图像、拓扑优化的设计方法,为解决应力遮挡问题和设计3D打印多孔支架和植入体提供参考建议。     

新型3D打印多孔钛人工椎体在猪脊柱模型置换前后的生物力学测试研究

目的通过对新型3D打印多孔钛人工椎体在猪脊柱模型置换前后的生物力学测试比较研究,评价该新型3D打印人工椎体的活动范围情况和即刻的生物力学稳定性。方法选取18具新鲜相近的猪脊柱标本(L1-L6),根据L3椎体置换前后,分为置换前组和置换后组。分别测试前屈、后伸、左右侧屈、左右旋转的位移角度变化。结果在0~8N.m逐级加载中,置换后组运动节段在前屈、后伸、左右侧屈各向量的位移角度变化明显小于置换前组,差异有统计学意义(0.05),而在轴位旋转位上,两者无显著性差异(0.05)。结论新型3D打印人工椎体的设计具有合理性和创新性,在猪脊柱模型L3椎体置换后,即刻可获得良好的生物力学稳定性。     

3D打印多孔钛支架微观孔隙结构和力学性能

目的研究3D打印技术制造的钻石分子结构多孔钛支架的微观孔隙结构和力学性能,指导3D打印多孔钛骨科植入物的开发。方法采用选择性激光熔化(selective laser melting,SLM)和电子束熔化(electron beam melting,EBM)两种金属3D打印制造工艺,制造钻石分子结构多孔Ti6Al4V支架。使用光学显微镜和扫描电镜观察其微观孔隙结构,并使用万能材料试验机对这些支架进行压缩测试。结果两种3D打印制造工艺都会存在加工误差,并且在表面存在半熔融金属颗粒。SLM工艺相对误差为20.9%~35.8%。EBM工艺相对误差为-9.1%~46.8%,且制造不出杆件宽度为0.2 mm的支架。SLM工艺制造的支架抗压强度为99.7~192.6 MPa,弹性模量为2.43~4.23 GPa。EBM工艺制造的支架抗压强度为39.5~96.9 MPa,弹性模量为1.44~2.83 GPa。结论 SLM工艺比EBM工艺制造精度高。支架的孔隙率是影响其抗压强度和弹性模量的主要因素,相同工艺的情况下,孔隙率越大,抗压强度越小,弹性模量也越小;相近孔隙率的情况下,SLM工艺比EBM工艺强度高,弹性模量也高。     

影像实物建模的医学应用价值与局限

评估基于快速成型技术的影像实物建模在医学中的应用价值,并讨论其进一步应用增长的限制因素与未来前景。     

不同孔隙率多孔钛铌合金的生物力学强度及细胞生物相容性

BACKGROUND: Titanium-niobium alloy holds high biomechanical strength and low elastic modulus that is close to the human cortical bone, so it has been extensively used as implant materials of dental, orthopedics and artificial hip joints. OBJECTIVE: To observe the biomechanical strength and cytocompatibility of porous titanium-niobium alloys with different porosities. METHODS: Porous titanium-niobium alloys with the porosity of 40% and 70% were prepared using powder metallurgy technology. Afterwards, the pore size, elasticity modulus and compressive strength of the two alloys were detected. Then the rabbit bone marrow mesenchymal stem cells were seeded onto the 40% and 70% porous titanium-niobium alloys, and cell adhesion and proliferation were observed at 3, 24 and 72 hours after inoculation, respectively. RESULTS AND CONCLUSION: Pore size of porous titanium-niobium alloys with rough surface was 200-500 μm, and both main pore size was 350 and 400 μm, and there was three-dimensional connectivity between the pores; in the 70% group, honeycombed pores were partly fractured, and connected mutually; pores distributed unevenly and there was little communication between the pores in the 40% group. In addition, both groups had high compressive strength and low elastic modulus, but there was no difference between the two groups. Furthermore, both two alloys promoted cell adhesion, and the number of cell adhesion in the 70% group was significantly higher than that in the 40% group (P < 0.05), and extracellular matrix could be found in the 70% group. These results show that porous titanium-niobium alloy with the porosity of 70% is significantly conducive to cell adhesion.     

微弧氧化技术在骨科钛植入体生物功能改性中的应用进展

微弧氧化是用于增强钛植入体的生物相容性和抗菌性的有效表面处理技术。在钛植入体表面制备生物活性元素组成的多孔涂层,是微弧氧化技术最具吸引力的特征。本研究主要介绍了微弧氧化的基本原理,阐述了该方法的技术优势,并总结了几种微弧氧化涂层的国内外研究进展;对含钙磷、银、铜、锌、硅的微弧氧化涂层,重点关注了对该类型涂层的骨整合性、抗菌性以及毒性的研究报道,旨在为研究者提供较为全面的视角,评估微弧氧化在骨科钛植入体上的应用进展,为后续临床研究提供参考。     

多孔纯钛种植体表面快速沉积钙磷涂层的研究

商业纯钛片经磨平、喷砂、清洗、酸洗后分成A、B两组。A组不作任何处理,B组用H2SO4和HCl混合液酸蚀,然后两组钛片同时置于37℃的仿生液SBF-A中1d及SBF-B中2d。结果两组钛片表面均可沉积磷灰石涂层,涂层为多孔片状结构,X射线衍射分析证实其为碳酸化羟基磷灰石和磷酸八钙的混合物,钙磷原子量比约1.51。这说明在多孔纯钛表面可以快速仿生沉积碳酸化磷灰石涂层。     

3D打印技术在复杂骨盆骨折个体化治疗中的应用

目的 探讨个体化治疗复杂骨盆骨折运用3D打印技术的可行性及临床应用价值。方法 以本院2015年7月至2018年7月收治的30例复杂骨盆骨折手术患者为研究对象,通过CT扫描得到的数据进行计算机三维建模,3D打印模型,研究制定手术方案,在模型上进行模拟手术,并针对拟用固定钢板进行预塑形,指导手术治疗。术后12个月骨盆骨折复位Matta评分及骨盆骨折功能Majeed评分作为术后随访评价标准。结果 患者均随访12个月以上。手术时间65～150 min,平均(85.25±18.45) min;术中出血量400～1 000 mL,平均(617.50±265.32)m L。切口均甲级愈合,未发生感染、神经损伤及深静脉血栓等并发症。骨盆骨折复位Matta评分:优22例,良6例,中2例,差0例,优良率93%。骨盆骨折功能Majeed评分:优24例,良3例,中3例,差0例,优良率90%。结论 骨盆骨折治疗中应用3D打印技术可以全面、精确了解骨折形态,准确分型,个体化制定骨折手术治疗方案,有利于更好地进行术前评估及规划。     

New depowdering-friendly designs for three-dimensional printing of calcium phosphate bone substitutes

Powder-based three-dimensional printing (3DP) is a versatile method that allows creating synthetic calcium phosphate (CaP) scaffolds of complex shapes and structures. However, one major drawback is the difficulty of removing all remnants of loose powder from the printed scaffolds, the so-called depowdering step. In this study, a new design approach was proposed to solve this problem. Specifically, the design of the printed scaffolds consisted of a cage with windows large enough to enable depowdering while still trapping loose fillers placed inside the cage. To demonstrate the potential of this new approach, two filler geometries were used: sandglass and cheese segment. The distance between the fillers was varied and they were either glued to the cage or free to move after successful depowdering. Depowdering efficiency was quantified by microstructural morphometry. The results showed that the use of mobile fillers significantly improved depowdering. Based on this study, large 3DP scaffolds can be realized, which might be a step towards a broader clinical use of 3D printed CaP scaffolds.     

Printability of calcium phosphate powders for three-dimensional printing of tissue engineering scaffolds

Three-dimensional printing (3DP) is a versatile method to produce scaffolds for tissue engineering. In 3DP the solid is created by the reaction of a liquid selectively sprayed onto a powder bed. Despite the importance of the powder properties, there has to date been a relatively poor understanding of the relation between the powder properties and the printing outcome. This article aims at improving this understanding by looking at the link between key powder parameters (particle size, flowability, roughness, wettability) and printing accuracy. These powder parameters are determined as key factors with a predictive value for the final 3DP outcome. Promising results can be expected for mean particle size in the range of 20-35 μm, compaction rate in the range of 1.3-1.4, flowability in the range of 5-7 and powder bed surface roughness of 10-25 μm. Finally, possible steps and strategies in pushing the physical limits concerning improved quality in 3DP are addressed and discussed.     

基于三维打印技术的多药控释型载药人工骨生物学评价

目的 评价三维打印技术制备的多药控释型载药人工骨的生物相容性.方法 利用三维打印技术制备多药控释型载药人工骨,并进行急性毒性试验、热源试验、皮肤刺激试验、溶血试验、微核试验和肌肉埋植试验等检测评价其生物相容性.结果 该多药控释型载药人工骨无全身急性毒性反应、无热源效应;皮肤刺激实验局部皮肤未见红斑、水肿反应;溶血率为0.29%,有良好的血液相容性;微核实验未见致突变现象.无细胞遗传毒性作用;肌肉埋植实验未见局部组织变性、坏死或排斥现象.结论 三维打印技术制备的多药控释型载药人工骨具有良好的生物相容性,符合医用生物材料的性能要求. Abstract： Objective To evaluate the biocompatibility of porous drug implant scaffolds prepared by 3D printing technique. Methods Porous drug implant scaffolds were fabricated by 3D printing technique, and a series of tests were carried out to validate the biocompatibility, including acute systemic toxicity, hot source test, local irritation reaction, micronucleus test, muscle implant test and so on. Results The porous drug implant scaffolds showed no acute systemic toxicity, no pyrogenetic effect, no local erythema and edema in local irritation re-action, hemolysis rate of 0.29%, no cellular genetoxic. No local tissue denaturation, necrosis and exclusion were found in intramuscular implant test. Conclusion With good biocompatibility, the porous drug implant scaffold fabricated by 3D printing technique can meet the clinical requirement for biomaterial.     

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。     

骨科个体化治疗与3D打印技术

个体化治疗是骨科发展的一个重要方向,无论是个体化假体的应用还是常规假体的个体化植入,理论上均可改善骨关节假体与邻近骨性结构的匹配,从而改善病患功能状态。个体化治疗理论上的优越性无法代偿其在术前规划、设计、制造等方面程序上复杂及时限上滞后的缺陷,因而,个体化治疗常常停留在一种曲高和寡的概念。伴随图像技术的发展及3D打印技术的成熟,个体化设计及制造的生产效率有望显著提高,从而弥补传统个体化治疗效率上的不足,将个体化从概念落地为治疗理念。     

3D打印ACT钛金骨小梁椎间融合器行颈椎前路减压融合后颈椎的矢状位平衡变化

文题释义：3D打印ACT钛金骨小梁椎间融合器：以钛合金为原料,通过电子束熔融快速成型技术进行三维精准构建建立互相连接的微孔而制成的多孔植入物,其类似骨小梁的多孔贯通的微孔结构,利于骨细胞的迁移和增殖,可提供良好的生物组织相容性和可靠的骨整合,同时类皮质骨的弹性模量,可以避免应力遮挡及骨吸收。 C_2⁃7 Cobb角：C₂,C₇下终板垂线之间的夹角。 C_2-7矢状面轴向距离：经过C₂椎体几何中心作铅垂线,该线与C₇椎体后上角的水平距离。 背景：颈前路椎间盘切除减压融合是目前临床上常用的手术入路,但对于其植入物的选择,临床上存在较大争议。3D打印钛金骨小梁材料具有优越的生物学特性,十分适合作为骨植入物材料。 目的：观察应用3D打印ACT钛金骨小梁椎间融合器行颈前路减压融合患者术后临床疗效及矢状位影像学参数的变化。 方法：回顾性分析行单节段颈前路椎间盘切除减压融合的颈椎病患者60例,根据融合器类型分组,对照组30例应用聚醚醚酮融合器,试验组30例应用3D打印ACT钛金骨小梁椎间融合器。记录手术时间、术中出血量以及术中C臂透视次数,临床评价指标记录日本骨科协会评分、疼痛目测类比评分及颈椎功能障碍指数;测量术前、术后3 d、术后3个月及末次随访时颈椎侧位X射线的矢状面参数,包括手术节段椎间隙高度、椎间隙角度、C_2-7 Cobb角、C_2-7矢状位轴向距离及T₁倾斜角;根据美国FDA和Kandziora标准判断椎间融合器的融合率;分析患者各时间点影像学参数间的相关性采用 Pearson相关性分析。结果与结论：①术后随访15-49个月;②试验组的手术时间、术中出血量及术中C臂透视次数均小于对照组,末次随访时2组日本骨科协会评分均较术前显著增加,疼痛目测类比评分及颈椎功能障碍指数评分显著减少(P < 0.05),2组之间差异无显著性意义;③2组手术节段椎间隙高度、椎间隙角度、C2-7 Cobb角及T1倾斜角在术后3 d、3个月及末次随访时较术前均有增加(P < 0.05);术后3个月及末次随访时,试验组手术节段椎间隙高度、C2-7 Cobb角、椎间隙角度及T1倾斜角均高于对照组(P < 0.05);④C2-7 Cobb角与椎间隙角度及T1倾斜角,椎间隙角度与T1倾斜角,T1倾斜角与C2-7矢状面轴向距离在各时间点均呈正相关(P < 0.01),而C2-7矢状面轴向距离与C2-7 Cobb角呈负相关(P < 0.01);⑤故应用3D打印ACT钛金骨小梁椎间融合器及聚醚醚酮融合器行颈前路椎间盘切除减压融合均可缓解临床症状,恢复手术节段椎间隙的高度、角度以及颈椎曲度,其中3D打印ACT钛金骨小梁椎间融合器可缩短手术时间,减少术中出血量及C臂透视次数,且对维持手术节段术后椎间隙高度、角度及颈椎生理性前凸更具优势。 ORCID: 0000-0003-3469-9836(杨旭) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

The promotion of osteointegration under diabetic conditions using chitosan/hydroxyapatite composite coating on porous titanium surfaces

Composited Chitosan/Hydroxyapatite (CS/HA) material coated on titanium surface (cTi) is a promising approach to produce biomaterials with better osseointegration capacity, but its bio-performance under diabetic conditions and the mechanisms involved remain elusive. We propose that the alterations in the Wnt/β-catenin pathway may play a role in mediating the improvement effect of cTi on diabetes-induced impaired implant osteointegration. To confirm the hypothesis, primary rat osteoblasts incubated on Ti and cTi were subjected to normal serum (NS), diabetic serum (DS), DS + Wnt3a (a specific Wnt agonist) and DS + Dkk1 (a specific Wnt antagonist) treatment. In vivo study was performed on diabetic sheep implanted with Ti or cTi into the bone defect on crista iliaca. Results showed that diabetes depressed osteoblast function evidenced by impaired cell adhesion and morphology, decreased cell proliferation and ALP activity, and higher apoptotic rate on Ti. Importantly, both cTi and Wnt3a treatment ameliorated osteoblastic dysfunction and apoptosis under diabetic condition. Implantation with cTi significantly improved osteointegration evidenced by Micro-CT and histological examinations compared with Ti. Moreover, the aforementioned promotive effects afforded by cTi were abolished by blocking Wnt pathway with Dkk1. Our study explicitly demonstrates that CS/HA composite material improves diabetes-induced impaired osteointegration of Ti via the reactivation of Wnt/β-catenin pathway and provides a target point for biomaterial modification to attain better clinical performance in diabetic patients.     

3D打印个体化骨盆假体多孔结构物理性能检测方法研究

目的提出针对三维(3D)打印个体化骨盆假体多孔结构部分物理性能的检测方法并通过实验验证方法的可行性。方法设计3D打印个体化骨盆假体多孔结构孔径、丝径、孔隙率和抗压强度的检测方法。使用3D打印个体化骨盆假体样品和同等工艺制造的致密样件、多孔样件,对其各个项目分别进行了验证实验,并对实验结果进行了分析。结果根据文中提出的检测方法,测得实验样品的平均孔径为464.95μm,平均丝径为601.13μm,平均孔隙率为62.47%,平均抗压强度为48.0 MPa。结论提出了针对3D打印个体化骨盆假体多孔结构多项物理性能的检测方法,验证实验表明方法可行性,并且重复操作性良好,具有较高的应用价值。