国产钛镍合金血管支架的生物相容性研究

采用国产钛镍形状记忆合金制成４ｍｍ内径的血管支架,通过导管置入８只正常犬的双侧髂动脉。观察１－６个月,发现支架表面业层新生内膜覆盖,光镜及电观察新生内膜表层为血管内皮样细胞,国产钛镍合金血管要有很好的生物相容性     

单节段颈椎人工椎间盘置换术早中期临床疗效探讨

目的探讨单节段颈椎人工椎间盘置换术早、中期临床疗效。方法对我院28例颈椎病患者分别经单节段颈椎人工椎间盘置换术、颈椎前路减压钛网植入内固定融合术治疗,13例患者行单节段颈椎人工椎间盘假体置换（B ryan置换组）,15例行传统颈前路单节段椎间盘切除减压钛网植骨融合内固定（钛网植入内固定融合组）。术后6周、3个月、6个月、12个月、18个月、24个月进行随访,平均随访21个月。并适时复查拍摄颈椎前屈后伸动力位X线片,观察置换组假体稳定性及融合组融合节段骨性融合情况。同时进行术后系列调查评分,统计并发症发生率,对治疗结果进行回顾性统计分析。结果单节段钛网植入内固定融合手术组术后早期吞咽困难、颈痛、上肢疼痛等发生率比单节段B ryan人工颈椎间盘置换手术组明显要高（P〈0.05）,单节段钛网植入内固定融合组术后邻近节段的活动度较术前明显增大（P〈0.05）;而单节段B ryan人工颈椎间盘置换组置换前后邻近节段活动范围无显著性差异（P〉0.05）。结论单节段颈椎人工椎间盘置换术后早期并发症减少,中期能保护相邻节段退变,与传统减压钛网植入内固定融合术相比治疗效果有一定提高。     

腰椎椎体间镍钛记忆合金支架的生物力学分析

目的 测试镍钛记忆合金支架的力学性能及用于腰椎间融合术的体外生物力学性能。方法 通过力学测试机测试支架的力学性能,并在新鲜腰椎标本上模拟腰椎间融合术,对比分析镍钛记忆合金支架及其配套的骨粒-可吸收骨水泥混凝物浇注植骨方法、传统盒状融合器用于腰椎间融合术的生物力学性能。结果 镍钛记忆合金支架最大抗压强度为(12 964±962) N,记忆特性有效范围内最大形变为(4.68±0.03) mm,形状恢复率为99.86%。相比于正常腰椎模型,单独使用镍钛记忆合金支架植入模拟腰椎间融合术后手术节段稳定性在前屈、后伸、侧屈、旋转方向上均有增加,与采用传统盒状融合器相当(P>0.05)。而在复合使用配套设计的自体骨粒-可吸收骨水泥混凝物植骨后,手术节段活动度进一步降低(P<0.05),节段稳定性与附加椎弓根螺钉内固定组相当(P>0.05)。镍钛记忆合金支架植入后的抗拔出强度弱于传统盒状融合器(P<0.05),在配合使用自体骨粒-可吸收骨水泥混凝物植骨时的抗拔出强度显著强于传统盒状融合器(P<0.05)。结论 本研究的镍钛记忆合金支架同时配套设计了相匹配的骨粒-骨水泥混凝...     

不同材料和结构食管支架置入恶性食管狭窄患者围手术期的普适性和特异性生活质量问卷评估

背景：目前食管内支架较多使用Z型不锈钢支架和记忆合金网状支架,两者疗效是否存在差异呢？ 目的：用生活质量问卷评估不同材料及不同结构食管支架置入治疗恶性食管狭窄者效果的差异。 方法：79例晚期食管癌患者,其中38例分别置入国产Z型不锈钢支架,41例置入镍钛记忆合金网状支架,分别在支架置入前,置入后1,3个月进行生活质量普适性问卷和食管癌特异性问卷评估。 结果与结论：生活质量普适性问卷比较,置入后1,3个月时两组患者躯体功能、角色功能、情绪功能、社会功能评分及总体健康分均明显高于置入前(P < 0.05),但组间比较差异无显著性意义(P > 0.05);食管癌特异性问卷比较,两组患者各症状条目评分及总症状分置入前差异无显著性意义(P >0.05),置入后1,3个月时均明显降低,且记忆合金组部分症状分及总症状分明显低于Z型不锈钢组(P < 0.05)。说明国产Z型不锈钢和镍钛记忆合金网状支架均可改善恶性食管狭窄的生活质量,但镍钛记忆合金网状支架改善食管癌特异性生活质量评分更显著一些。     

镍钛形态记忆合金与骨组织相容性的形态学

目的：观察镍钛形态记忆合金植入动物骨组织后局部组织的反应、骨缺损的修复情况，研究镍钛合金与骨的组织相容性，为镍钛合金作为生物医学材料在临床上广泛应用提供理论依据。方法：纯系日本白性兔，实验组在股骨下1／3处植入镍钛合金。于术后4、8、16w，在植入区上下0．5cm处横断取材。将骨块置于4％多聚甲醛-2．5％戊二醛混合液内固定。制作半薄切片，经1％甲苯胺蓝染色，光镜观察；制作超薄切片，透射电镜观察。结果：实验组表现出与对照组相似的骨缺损修复过程。结论：此镍钛形态记忆合金与骨组织具有良好的相容性。     

CRTER杂志放射科方面生物材料研究的发稿方向

<正>○气道内金属支架植入疗法在支气管结核治疗中的应用○经纤维支气管镜球囊定位及生物材料填塞治疗顽固性气胸○镍钛合金支气管封堵器的研制及其实验研究○镍钛记忆合金支架治疗气道狭窄的临床应用○形状记忆合金医用内支架的系统研究○记忆镍钛合金支架在气管狭窄中的应用     

典型胸主动脉裸支架的力学性能

目的 研究两种胸主动脉镍钛裸支架（Ze、Fa支架）的力学性能,为裸支架的设计和临床选择提供理论依据。方法建立两种裸支架的有限元模型和实物模型。分别完成两种裸支架弯曲、径向力和模拟使用的有限元分析,并进行对应的实物模型测试。通过实测结果验证有限元分析的准确性,预测支架植入后血管的应力和应变。结果 有限元分析表明,Ze、Fa支架弯曲90°时截面扁平率分别为3.83%和18.83%（实测为8.57%和14.27%）,弯曲180°时截面扁平率分别为12.02%和23.72%（实测为14.37%和23.35%）。Ze、Fa支架在心脏收缩期最大径向力分别为33、429 N/m（实测为31、433 N/m）,在心脏舒张期最大径向力分别为27、146 N/m（实测为29、179 N/m）。Ze、Fa支架在植入后对血管造成的最大应力分别为4、18 kPa,最大应变分别为4.17%和13.92%,最大直径扩张率分别为103%和898%。有限元分析和实测结果无显著性差异（P>0.05）。结论Ze、Fa支架植入后对健康血管造成的最大应力、应变在许可范围内。Ze支架的弯曲性能较优,适合被植入弯曲血管。Ze支架径向力较弱,适合被作为仅提供内膜支撑的Petticoat支架。较强的径向力有助于加强Fa支架在血管内的稳定性,降低脊髓缺血风险,故Fa支架适合被作为限制性裸支架。     

支架-骨粒-可吸收骨水泥式腰椎间融合术的有限元分析

目的采用有限元分析方法研究镍钛记忆合金支架-自体骨粒-可吸收骨水泥式腰椎间融合术的生物力学性能。方法依次建立正常L3～5节段有限元模型(M0)、盒状融合器模拟植入的L4～5椎间融合术模型(M1)、镍钛记忆合金支架模拟植入的L4～5椎间融合术模型(M2)以及镍钛记忆合金支架模拟植入复合骨粒-可吸收骨水泥混凝物浇注植骨的L4～5椎间融合术模型(M3)。对模型进行力学加载,分析各模型生物力学稳定性和L4椎体下终板的峰值应力。结果 M1、M2模型L4～5节段在前屈、后伸、侧屈、轴向旋转方向上的活动度较M0模型明显降低。在M3模型中,手术节段稳定性进一步提高,且L4下终板峰值应力远小于M1、M2模型。结论镍钛记忆合金支架与传统盒状融合器在单独用于腰椎间融合术时具有生物力学等效性,在复合应用骨粒-可吸收骨水泥混凝物浇注植骨后能进一步提升稳定性及降低终板应力。     

载药复合支架的抗血管组织增生的研究

在氧化钛表面改性的国产不锈钢支架上涂覆一定量药物,制备出新型复合的抗增生载药支架.观察支架植入猪冠状动脉3个月后血管的开通情况及血管的内膜反应.将7枚国产的普通不锈钢支架和7枚制备的新型载药支架植入14头小型猪冠状动脉内,3个月后对支架植入段血管进行血管造影、光镜及电镜检查并进行免疫组织化学分析.冠状动脉造影显示动物处死前支架段血管开通率100%,支架X光下清晰可见,未经特殊抗血栓治疗,支架段血管内无血栓形成.扫描电镜显示两组支架表面都完全被血管内膜覆盖,表面光滑,无血栓形成.覆盖的血管内膜中内皮细胞沿血流方向成典型的铺路石状排列.组织学形态分析显示植入支架3个月后,所有支架植入段血管内膜都有明显的增生,增生内膜主要由细胞外基质和平滑肌细胞构成.结论:含有新型载药支架的冠状动脉血管段内膜增生厚度比普通不锈钢支架的冠状动脉血管段内膜增生厚度小,这种载药复合支架具有良好的应用前景,需扩大样本进行深入研究.     

镍钛记忆合金网状支架植入治疗喉气管狭窄

目的探讨镍钛记忆合金网状支架在喉气管狭窄的治疗及颈段气管重建术中的作用。方法回顾分析6例喉气管狭窄病例用镍钛记忆合金网状支架治疗及2例颈段气管肿瘤行气管切除术后用镍钛网状支架重建气管的临床资料。结果6例喉气管狭窄患者安放网状支架后,均呼吸畅顺,2例行颈段气管重建术的患者同样获良好疗效。随访1～18个月,呼吸道无狭窄征。近期有效率100%。结论镍钛记忆合金网状支架可使狭窄的喉气管迅速扩张,明显地改善呼吸困难,具有使用方便、见效快、疗效可靠的优点熏可作为喉气管狭窄的常规治疗手段之一熏在颈段气管重建术中也有独特的应用效果。     

Plasma-immersion ion-implanted nitinol surface with depressed nickel concentration for implants in blood

Ion implantation into nitinol had been shown previously to decrease the surface nickel concentration of this alloy and produce a titanium oxide layer. Nothing is known yet about the blood compatibility of this surface and the suitability for implants in the blood vessels, like vascular stents. Nickel depletion of superelastic nitinol was obtained by oxygen or helium plasma-immersion ion implantation. The latter leads to the formation of a nickel-poor titanium-oxide surface with a nanoporous structure, which was used for comparison. Fibrinogen adsorption and conformation changes, blood platelet adhesion, and contact activation of the blood clotting cascade have been checked as in vitro parameters of blood compatibility; metabolic activity and release of cytokines IL-6 and IL-8 from cultured endothelial cells on these surfaces give information about the reaction of the blood vessel wall. The oxygen-ion-implanted nitinol surface adsorbed less fibrinogen on its surface and activated the contact system less than the untreated nitinol surface, but conformation changes of fibrinogen were higher on the oxygen-implanted nitinol. No difference between initial and oxygen-implanted nitinol was found for the platelet adherence, endothelial cell activity, or cytokine release. The nanoporous, helium-implanted nitinol behaved worse than the initial one in most aspects. Oxygen-ion implantation is seen as a useful method to decrease the nickel concentration in the surface of nitinol for cardiovascular applications.     

镍钛合金听泡植入对豚鼠耳蜗及听功能的毒性

背景：镍钛合金多作为自膨胀支架和封堵器的材料应用已很成熟,但镍钛合金作为听骨链重建材料的相关研究及临床应用至今少有报道。 目的：观察镍钛合金植入体在豚鼠听泡中的耳毒性。 方法：健康听敏纯白红目豚鼠50只,每只豚鼠其中一侧耳为镍钛合金植入组,其中25只对侧耳为钛植入组,另25只对侧耳为空白植入组。分别于植入后7,14,28,56,112 d随机处死含钛植入组和空白植入组的豚鼠各5只,对各组行近中轴位耳蜗石蜡切片苏木精-伊红染色观察耳蜗组织的形态变化,行耳蜗毛细胞核丫啶橙-碘化丙啶双重荧光染色观察毛细胞凋亡和缺失情况,行耳蜗基底膜扫描电镜观察毛细胞纤毛排列情况,透射电镜观察毛细胞细胞器形态,对各组的豚鼠植入前、不同时间点处死前均行听性脑干反应及畸变反应耳声发射检测。 结果与结论：各组植入后各时间点耳蜗组织形态无明显变化,未发现耳蜗毛细胞发生凋亡,基底膜耳蜗毛细胞纤毛排列整齐,外耳蜗毛细胞的细胞器未见明显异常。植入前及植入后7,14,28,56,112 d听性脑干反应阈值差异无显著性意义,且畸变反应耳声发射检测通过率均为100%。结果证实,镍钛合金听泡植入对豚鼠耳蜗形态及听功能无明显影响,提示镍钛合金无明显耳毒性。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

In vivo degradation behavior and biocompatibility of Mg-Nd-Zn-Zr alloy at early stage

The neotype magnesium alloy, Mg-Nd-Zn-Zr (NZK) alloy, was implanted into the rabbit femur to investigate its in vivo degradation behavior and biocompatibility. Seventy-two New Zealand white rabbits were randomly divided into the NZK alloy group, titanium alloy group and sham-operated group. Then NZK alloy rods were embedded in the rabbit femur in the NZK alloy group, titanium alloy rods were embedded in the titanium alloy group, and only bone tunnel was established in the sham-operated group. Prior to surgery and at 1, 7, 14, 28 and 56 days after operation, the serum alanine transaminase, creatinine, creatine kinase and magnesium ion concentration were examined in each group. An X-ray of the implanted region was taken at 7, 14, 28 and 56 days after implantation. The pathological changes in heart, liver, kidney and bone from the implant region were examined at 28 and 56 days postoperatively. The degradation behavior of the NZK alloy was observed using scanning electron microscope with an energy dispersive spectroscopy system. There were no significant differences in serum alanine transaminase, creatinine, creatine kinase and magnesium ion concentrations among each group at the same time point (P>0.05). The histology of heart, liver, kidney and bone from implant region was altered. The results demonstrate that the NZK alloy implanted into the rabbit femur could be absorbed gradually, and that the NZK alloy has excellent biocompatibility in vivo.     

The wear behavior of ion-implanted Ti-6A1-4V against UHMW polyethylene

Nitrogen-ion-implanted Ti-6A1-4V against UHMW polyethylene was tested on a joint simulator to evaluate the wear behavior under different conditions. It was concluded that the polymer wear rate was not affected by ion implantation. The metallic wear, on the other hand, was substantially reduced by this treatment. It was also found that ion implantation resulted in good protection of the metal surface against third-body wear by PMMA, while the introduction of C.P. titanium particles in the joint initiated tremendous wear. Although ion implantation improved the wear of titanium alloy against UHMW polyethylene, the durability of the implanted layer needs further study.     

Corrosion behavior of titanium nitride coated Ni-Ti shape memory surgical alloy

Nickel-titanium (NiTi, nitinol) shape memory alloy was nitrided using an original powder immersion reaction assisted coating (PIRAC) method in order to modify its surface properties. PIRAC nitriding method is based on annealing the samples in the atmosphere of highly reactive nitrogen supplied by decomposition of unstable nitride powders or, alternatively, by selective diffusion of the atmospheric nitrogen to the sample surface. Being a non-line-of-sight process, PIRAC nitriding allows uniform treatment of complex shape surgical implants. Hard two-layer titanium nitride (TiN)/Ti2, Ni coatings were obtained on NiTi surface after PIRAC anneals at 900 and 1000 degrees C. PIRAC coating procedure was found to considerably improve the corrosion behavior of NiTi alloy in Ringer's solution. In contrast to untreated nitinol, no pitting was observed in the samples PIRAC nitrided at 1000 degrees C, 1 h up to 1.1 V. The coated samples were also characterized by very low anodic currents in the passive region and by an exceedingly low metal ion release rate. The research results suggest that PIRAC nitriding procedure could improve the in vivo performance of NiTi alloys implanted into the human body.     

Bone ingrowth in porous titanium implants produced by 3D fiber deposition

3D fiber deposition is a technique that allows the development of metallic scaffolds with accurately controlled pore size, porosity and interconnecting pore size, which in turn permits a more precise investigation of the effect of structural properties on the in vivo behavior of biomaterials. This study analyzed the in vivo performance of titanium alloy scaffolds fabricated using 3D fiber deposition. The titanium alloy scaffolds with different structural properties, such as pore size, porosity and interconnecting pore size were implanted on the decorticated transverse processes of the posterior lumbar spine of 10 goats. Prior to implantation, implant structure and permeability were characterized. To monitor the bone formation over time, fluorochrome markers were administered at 3, 6 and 9 weeks and the animals were sacrificed at 12 weeks after implantation. Bone formation in the scaffolds was investigated by histology and histomorphometry of non-decalcified sections using traditional light- and epifluorescent microscopy. In vivo results showed that increase of porosity and pore size, and thus increase of permeability of titanium alloy implants positively influenced their osteoconductive properties.     

Surface mechanical properties, corrosion resistance, and cytocompatibility of nitrogen plasma-implanted nickel-titanium alloys: a comparative study with commonly used medical grade materials

Stainless steel and titanium alloys are the most common metallic orthopedic materials. Recently, nickel-titanium (NiTi) shape memory alloys have attracted much attention due to their shape memory effect and super-elasticity. However, this alloy consists of equal amounts of nickel and titanium, and nickel is a well known sensitizer to cause allergy or other deleterious effects in living tissues. Nickel ion leaching is correspondingly worse if the surface corrosion resistance deteriorates. We have therefore modified the NiTi surface by nitrogen plasma immersion ion implantation (PIII). The surface chemistry and corrosion resistance of the implanted samples were studied and compared with those of the untreated NiTi alloys, stainless steel, and Ti-6Al-4V alloy serving as controls. Immersion tests were carried out to investigate the extent of nickel leaching under simulated human body conditions and cytocompatibility tests were conducted using enhanced green fluorescent protein mice osteoblasts. The X-ray photoelectron spectroscopy results reveal that a thin titanium nitride (TiN) layer with higher hardness is formed on the surface after nitrogen PIII. The corrosion resistance of the implanted sample is also superior to that of the untreated NiTi and stainless steel and comparable to that of titanium alloy. The release of nickel ions is significantly reduced compared with the untreated NiTi. The sample with surface TiN exhibits the highest amount of cell proliferation whereas stainless steel fares the worst. Compared with coatings, the plasma-implanted structure does not delaminate as easily and nitrogen PIII is a viable way to improve the properties of NiTi orthopedic implants.     

Investigation of surface endothelialization on biomedical nitinol (NiTi) alloy: Effects of surface micropatterning combined with plasma nanocoatings

Plasma nanocoated films with trimethylsilane-oxygen monomers showed outstanding biocompatibility in our previous studies. In this study, endothelialization on biomedical nitinol alloy surfaces was systematically investigated. Our study focuses on elucidating the effects of surface micropatternings with micropores and microgrooves combined with plasma nanocoating. Plasma nanocoatings with controlled thickness between 40 and 50 nm were deposited onto micropatterned nitinol surface in a direct current plasma reactor. Bovine aortic endothelial cells were cultured in vitro on these nitinol samples for 1, 3 and 5 days. It was found that rougher surfaces could enhance cell adhesion compared with the smoother surfaces; the surfaces patterned with micropores showed much more endothelialization than microgrooved surface after a 3 days culture. The cell culture results also showed that plasma nanocoatings significantly further increased cell proliferation and cell adhesion on the micropatterned nitinol surfaces, as compared with non-plasma nanocoated surface of nitinol samples. The surface micropatternings combined with plasma nanocoatings could improve the cell adhesion and accelerate surface endothelialization after implantation of intravascular stents, which is expected to reduce in-stent restenosis.     

双支架留置术治疗恶性气管、食管狭窄

目的探讨气管、食管双支架留置术治疗恶性气管、食管狭窄的安全性和临床疗效。方法 12例恶性肿瘤造成气管、食管狭窄患者,其中男性8例,女性4例;年龄38～66岁,平均年龄48.8岁。术前行食管造影及螺旋CT气道三维重建检查,明确气管、食管狭窄的部位、程度及是否存在气管食管瘘。7例以吞咽困难为主要症状患者首先置入食管支架,5例以呼吸困难为主要症状患者首先置入气管支架。食管支架选用覆膜镍钛合金支架,气管、支气管支架选用自膨胀网状镍钛合金支架。所有患者都留置气管、食管双支架。结果所有患者成功置入气管、食管双支架,手术成功率100%。7例首先留置食管支架者,5例在食管支架置入后立即出现呼吸困难,需马上留置气管、支气管支架,另2例在24h内逐渐出现呼吸困难,置入气管、支气管支架后缓解。5例首先留置气管支架者,支架留置后呼吸困难缓解,之后留置食管支架操作顺利。所有患者留置气管、食管双支架后呼吸困难、吞咽困难症状明显改善。2例合并气管食管瘘患者,双支架留置后瘘口闭合。12例患者术后生存1.5～6.2个月,1例因肿瘤的过度生长而发生食管再狭窄,再次置入食管支架后症状缓解。结论气管、食管双支架留置术是治疗恶性气管、食管狭窄安全、有效的治疗方法。对于同时伴有气管、食管狭窄的患者,应首先置入气管支架,以防止食管支架膨胀压迫气管,加重气管狭窄引起窒息。