医用生物材料——骨组织界面研究

已有一系列医用生物材料应用于骨科临床治疗和基础研究体系，材料的生物相容性和物理相容性是应用的最关键内容，而材料－骨组织界面这一相互作用最活跃的部位最能体现二者的程度。本文就界面研究的方法学、影响因素及应用指导意义作一综述。     

3D打印羊椎骨粉/聚乙烯醇支架、纳米级羟基磷灰石/聚乙烯醇支架、羊椎骨粉/聚乙烯醇无孔骨板的性能比较

BACKGROUND: With the promotion of 3D printing technology, 3D printing scaffolds for bone tissue engineering have become the new ideas for jaw bone repair. OBJECTIVE: To compare the physical and biological properties of sheep vertebral bone meal/polyvinyl alcohol (PVA) scaffold, nano-hydroxyapatite (nHA)/PVA scaffold, and sheep vertebral bone meal/PVA nonporous bone plate. METHODS: 3D printing technology was used to print sheep vertebral bone meal/PVA scaffold, nHA/PVA scaffold, and sheep vertebral bone meal/PVA nonporous bone plate. Porosity, morphology, water absorption rate and mechanical properties of different scaffolds were detected. Three kinds of scaffolds were all used to culture bone marrow mesenchymal stem cells, and cell proliferation ability was detected using cell counting kit-8 at 1, 4, 7 days of culture. RESULTS AND CONCLUSION: Under scanning electron microscope, the sheep vertebral bone meal/PVA scaffold and nHA/PVA scaffold exhibited regular and interconnected pores with good continuity and clear network structure; the sheep vertebral bone meal/PVA nonporous bone plate had no obvious pores; however, it had dense and evenly distributed micropores with different sizes on its surface. The porosity of nHA/PVA scaffold was lower than that of the sheep vertebral bone meal/PVA scaffold (P < 0.05). The water absorption rate was highest for the nHA/PVA scaffold followed by the sheep vertebral bone meal/PVA scaffold and the sheep vertebral bone meal/PVA nonporous bone plate (P < 0.05). In contrast, the scaffold toughness was highest for the sheep vertebral bone meal/PVA nonporous bone plate, followed by the sheep vertebral bone meal/PVA scaffold and nHA/PVA scaffold. In addition, the cell proliferation activity of cells cultured on the sheep vertebral bone meal/PVA scaffold was significantly higher than that cultured on the other two kinds of scaffolds. Taken together, the 3D printing sheep vertebral bone/PVA scaffold has good physical and chemical performance.     

磷酸钙的固有骨诱导性及其应用

BACKGROUND: With good biocompatibility, osteoconduction and biodegradability, calcium phosphate ceramics is considered as a substitute of autologous bone; furthermore, it also has the potentiel of osteoinduction after structure optimization.     

骨移植材料及其传导机理

骨移植材料起到了骨传导的作用。骨传导作用与三维材料的结构、化学特性有关。多孔珊瑚陶瓷、羟基磷灰石颗粒、羟基磷灰石－胶原复合物以及金属和生物可降解聚合物都具有骨传导特性。同时模仿骨的结构和组成设计骨移植材料,可得到最佳的传导特性。钙盐和胶原的引入能增强新骨在移植材料中的形成。     

异种煅烧骨材料的研究进展

煅烧骨是一种以羟基磷灰石为主要成分，拥有天然骨结构和形态的生物材料。它所具有的天然的多孔结构以及孔隙大小适合肉芽组织长入和骨、软骨组织的分化形成，并可被机体吸收降解，是一种理想的骨缺损修复材料。本就近年来有关煅烧骨的理化性质，生物相容性，以及煅烧骨同锌离子、成骨细胞、BMP等的复合材料的基础研究进行了综述。     

聚乳酸及其复合材料的性能研究

作者以ZnO为催化剂研制了聚乳酸,测定聚乳酸的力学性能和在磷酸盐缓冲液中的降解性能,以及聚乳酸和羟基磷灰石复合材料的力学性能。了解其用作医用内固定材料和“人工骨”的可行性。     

新型氯化锂复合磷酸钙骨水泥的理化性能及成骨特性

BACKGROUND: Lithium chloride is a widely used inorganic ion inhibitor of glycogen synthase kinase-3β, and it can be combined with glycogen synthase kinase-3β to activate the classical Wnt/β-catenin pathway, thereby promoting human bone marrow mesenchymal stem cells and osteoblasts proliferation and accelerating bone repair. OBJECTIVE: To observe the physicochemical properties of novel lithium chloride/calcium phosphate cement, and to explore its osteoinductive biological property. METHODS: Calcium phosphate cement served as control group, and lithium chloride/calcium phosphate cement containing different lithium content as experimental groups. The setting time and compressive strength of bone cement in each group were detected, and the microstructure of the material surface observed under scanning electron microscopy. Bone cement and MC3T3-E1 cells were co-cultured in vitro, and the growth and adhesion morphology of MC3T3-E1 cells on the surface of bone cement were observed under the scanning electron microscope. Effect of bone cement extracts on cell proliferation was determined through MTT assay, and alkaline phosphatase kit used for determining alkaline phosphatase activity. RESULTS AND CONCLUSION: Lithium chloride/calcium phosphate cement had the same physicochemical properties to the calcium phosphate cement. Initial and final setting time, compressive strength and morphology of bone cement had no significant differences among groups. MC3T3-E1 cells grew and adhered well on the material surface. Results of MTT assay showed that compared with the calcium phosphate cement, the lithium chloride/calcium phosphate cement was better to improve osteoblast proliferation in vitro. In addition, the alkaline phosphatase activity in MC3T3-E1 cells was higher in experimental groups than the control group. These findings indicate that lithium chloride/calcium phosphate cement can maintain good physicochemical properties, and release lithium ions to promote bone formation.       

微晶玻璃人工骨材料的研究

本文描述了一种新型微晶玻璃人工骨材料的制备方法。一系列的试验表明新材料具有良好的力学性能及生物活性。采用扫描电镜及电子探针等分析技术研究了材料与骨结合界面的结构。新材料适合作为各种复杂形状的人工骨材料。     

多孔材料应用在组织工程中的现状及前景CSCD

背景:近年来多孔材料体内植入的基础研究和临床应用均展示了良好的应用前景。目的:回顾近10年来组织工程多孔材料的基础与临床研究进展,总结存在的问题并展望未来。方法:由作者检索PubMed数据库和中国知网数据库获得文献,英文检索词为porous material,bone implantation",中文检索词为"多孔材料,骨移植"。纳入用于体内外及临床研究的多孔材料及其复合材料,以及与骨缺损修复或骨组织工程密切相关的多孔材料。结果与结论:目前研究较多的多孔材料有羟基磷灰石、钛及其合金、聚乙烯、磷酸钙类等,从大量的体内外实验结果来看,多孔材料展示了其良好的组织相容性和骨诱导特性,但有利于组织最快和最有效长入的孔隙尺寸尚无统一的标准,不规则异形多孔材料的孔隙率怎样获得和控制,材料的弹性模量如何调控,以及如何获得材料100%的有效孔隙率等问题尚未有明确的标准答案,另外临床应用过程中发生的炎症和暴露等并发症的问题是否与前述问题相关还无法确定。     

A new electrochemically graded hydroxyapatite coating for osteosynthetic implants promotes implant osteointegration in a rat model

Hydroxyapatite (HAP) is widely used as an osteoconductive coating for orthopedic implants. So far standard coating methods like plasma spraying produce a relatively thick coating layer (>30 microm). In addition, the chemical structure of the HAP may be altered because of the heating throughout the coating process. This may have negative effects on the coating stability, implant fixation, and induction of bone formation. The relatively thick layer may detach from the implant with the risk of wear debris. In the present study the potential of a newly developed HAP coating of implants on osteointegration was investigated in a rat model. The coating method, based on an electrochemical process, is applied in a graded manner and results in a biodegradable HAP coating with a thickness of approximately 2 mum. Coated versus uncoated titanium Kirschner wires (1.4-mm diameter) were inserted into the medullary cavity of the right femora of 5-month old female Sprague Dawley rats (n=36) in a retrograde fashion. Throughout an experimental period of 2 months the osteointegration was traced radiologically. After this time the animals were sacrificed and the implant integration was tested biomechanically with the use of a push-out test. To analyze the bone-implant interface, histological sections (80 mum) were investigated with an image analyzing system. The biomechanical testing revealed a significantly higher implant fixation in the group treated with the HAP-coated implant (shear strength: 27.8 +/- 6.7 MPa) compared to control (shear strength: 8.08 +/- 3.4 MPa). The histological analyses demonstrated a better ingrowth of the implants in the HAP group with significantly more direct bone-implant contacts compared to the control group. The results demonstrate that the HAP coating promotes implant osteointegration in a rat model.     

功能梯度牙种植体三维有限元力学分析与结构优化

背景：将生物活性陶瓷与钛进行整体的梯度设计,从而能最大程度地起到增强种植体早期骨结合与长期稳定的作用。 目的：通过三维有限元方法分析功能梯度牙种植体生物力学特性。 方法：建立功能梯度牙种植体及部分颌骨三维有限元模型。整个功能梯度牙种植体从头部到底部的弹性模量梯度变化分别设计为线性、指数函数、对数函数变化3种情况,以钛种植体为对照组。在Abaqus软件中进行三维有限元应力分析。 结果与结论：与对照组相比,功能梯度牙种植体每一层面上及相应骨界面上的应力均有减小。从种植体头部到底部,种植体表面应力下降为3%~50%,骨界面上应力下降为10%~30%,均以指数函数变化组下降最为明显。提示功能梯度牙种植体的设计能减小种植体与骨界面之间的应力,尤以指数函数变化的设计方案更为明显。     

血管化人工骨的体外构建和体内异位成骨

背景：血管化在骨形成和改建中起重要作用,目前大的组织块难以获得充足的氧气和营养供应,因此组织工程中就出现了需要适当血管化的问题。 目的：建立体外血管化人工骨模型并且体内异位成骨的实验体系。 方法：分离培养鼠骨髓间充质干细胞和肾血管内皮细胞,体外构建鼠骨髓间充质干细胞和鼠肾血管内皮细胞直接接触培养血管化人工骨组,以间接接触三维培养体系和两种细胞单独培养体系作为对照。体外通过测定蛋白质含量,碱性磷酸酶活性和骨钙素,分析骨髓间充质干细胞在不同混合培养模型中的成骨能力。建立鼠骨髓间充质干细胞和肾血管内皮细胞的三维培养体系,再将两种细胞直接接触组材料和骨髓间充质干细胞单独培养组的材料分别植入鼠左右腿肌肉内,通过软X射线摄影和苏木精-伊红染色检测分析不同植入方法的血管形成和成骨能力。 结果与结论：当两种细胞混合培养时,具有很好的细胞兼容性。两种细胞单独培养碱性磷酸酶活性和骨钙素较间接接触混合培养降低,而两种细胞混合培养时,体系中碱性磷酸酶活性和骨钙素水平增加。动物实验结果显示在混合培养体系中的骨髓间充质干细胞的成骨能力高于单独培养(P < 0.05)。体内实验表明在血管化人工骨中的软X射线骨密度,血管数量和新形成的骨量均高于对照组(P < 0.05)。提示在两种细胞混合培养时骨髓间充质干细胞的成骨能力可以被细胞因子和细胞膜蛋白质调节,和传统的人工骨比较,血管化人工骨有加速骨髓间充质干细胞分化,增加了局部的血管微循环生存率,以及加速成骨和更好的抗感染能力。     

Detachment of titanium and fluorohydroxyapatite particles in unloaded endosseous implants

The shape, surface composition and morphology of orthopaedic and endosseous dental titanium implants are key factors to achieve post-surgical and long-term mechanical stability and enhance implant osteointegration.In this study a comparison was made between 12 titanium screws, plasma-spray-coated with titanium powders (TPS), and 12 screws with an additional coating of fluorohydroxyapatite (FHA-Ti). Screws were implanted in the femoral and tibial diaphyses of two mongrel sheep and removed with peri-implant tissues 12 weeks after surgery.The vibrational spectroscopic, ultrastructural and morphological analyses showed good osteointegration for both types of implants in host cortical bone. The portion of the FHA-Ti implants in contact with the medullary canal showed a wider area of newly formed peri-implant bone than that of the TPS implants.Morphological and EDAX analyses demonstrated the presence of small titanium debris in the bone medullary spaces near the TPS surface, presumably due to the friction between the host bone and the implant during insertion. Few traces of titanium were detected around FHA-Ti implants, even if smaller FHA debris were present.The present findings suggest that the FHA coating may act as a barrier against the detachment of titanium debris stored in the medullary spaces near the implant surface.     

钛微粒诱导破骨细胞活化中信号素7A siRNA的抑制作用

背景：信号素7A是一种细胞表面蛋白,可在促进破骨细胞融合的同时促进成骨细胞的迁移,影响骨的动态平衡。 目的：观察信号素7A siRNA对钛微粒诱导骨溶解过程中的破骨细胞活化是否具有抑制作用。 方法：将细胞浓度为4×109 L-1的前体破骨细胞接种于含玻璃盖玻片的96孔板上,分4组培养：空白对照组加入细胞培养液,阳性对照组加入未转染siRNA的上清液20 μL,实验组加入转染信号素7A siRNA的上清液20 μL,阴性对照组加入转染对照siRNA的上清液20 μL。上清液为钛合金微粒溶液与小鼠单核巨噬细胞株RAW264.7共培养24 h的上清液,其中siRNA转染于小鼠单核巨噬细胞株RAW264.7中。 结果与结论：培养7 d时,阳性对照组、阴性对照组、实验组炎症因子白细胞介素1、白细胞介素1β、肿瘤坏死因子α、基质金属蛋白酶9、核因子κB受体活化因子水平高于空白对照组(P < 0.05),实验组各因子水平低于阳性对照组、阴性对照组(P < 0.05)。培养8 d时,阳性对照组、阴性对照组、实验组破骨细胞增殖活性、抗酒石酸酸性磷酸酶染色阳性细胞数量高于空白对照组(P < 0.05),实验组破骨细胞增殖活性、抗酒石酸酸性磷酸酶染色阳性细胞数量低于阳性对照组、阴性对照组(P < 0.05)。结果表明信号素7A siRNA对钛颗粒诱导的破骨细胞活化具有一定的抑制作用。 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      

羟基磷灰石涂层改善骨内植物界面促进骨整合

BACKGROUND: We have designed and manufactured a novel artificial cervical vertebra and intervertebral complex (ACVC) which combines the cervical titanium cage with the artificial cervical disc, and also developed the ACVC with a hydroxyapatite biocoating (ACVC-HA). OBJECTIVE: To evaluate biomechanical properties of the joint system, and the role of HA coating in promoting osseointegration and long-term stability. METHODS: Twenty-four goats were randomly divided into three groups and underwent the anterior C _2/3 and C _3/4 discectomy, and C₃ subtotal corpectomy, followed by ACVC implantation (group 1) and ACVC-HA implantation (group 2), and given no intervention (black control group), respectively. group. At 12 weeks after surgery, C _1-5 samples were collected to undergo biomechanical tests and histological staining. RESULTS AND CONCLUSION: Prior to the fatigue test, compared with the blank control group, the range of motion and neural zone of groups 1 and 2 in the directions of flexion-extension and lateral bending showed no significant differences, but the above indicators were significantly increased in the direction of rotation (P < 0.05). Additionally, the stiffness in all three directions was significantly lower than that in the blank control group (P < 0.05). There were no significant differences in the range of motion and neural zone in all directions between groups 1 and 2. Similar results were found after the fatigue test. The histological staining showed that both two implants had good biocompatibility and abradability, but more new bone formed on the ACVC-HA. These results suggest that ACVC can effectively reconstruct the motor function of the cervical spine after decompression. Furthermore, HA coating can markedly improve bone-implant interface to promote osseointegration.     

Biologic effects of surface roughness and fluorhydroxyapatite coating on osteointegration in external fixation systems: an in vivo experimental study

The concomitant influence of surface roughness and fluorhydroxyapatite (FHA) coating of titanium (Ti) implants on bone response was investigated. For this purpose, titanium screw-shaped implants with a lower degree (Y371) and a higher degree (TiPore300) of surface roughness, coated with FHA and uncoated, were transversally inserted into the diaphyses of sheep tibiae for 12 weeks. Four sheep received Y371 (group A) and Y371 + FHA (group B) screws and four sheep received TiPore300 (group C) and TiPore300 + FHA (group D) screws. For each type of material, the morphology and microstructure of implant-facing bone were evaluated. The host bone of each tibia was used as a control. In all groups the bone tissue did not reach a complete maturation. The higher degree of roughness, perhaps due to an excessive irregularity of the surface, induced the worst osteointegration: a fibrous tissue layer between screw and new bone tissue was often present. Nevertheless, as viewed by XRD, no crystallographic change of the apatite lattice was observed in any of the implants. In contrast, the microhardness value, an index of bone mineralization, was higher in the uncoated screws and decreased progressively in the following order: group C > group A > group B > group D. The association of plasma spraying with roughness treatment constitutes a complex system that seems to interfere with bone mineralization. A chemical change of the surface, perhaps with more Ti release or more coating degradation, could be responsible for such impairment. The authors emphasize the necessity for simultaneous evaluation of surface topography and chemistry as well as an improvement in plasma-spraying and post-processing techniques and in standard procedures for materials characterization.     

钙磷涂层镁合金植入体周围组织中骨形成蛋白2的表达*****☆

背景：改变合金构成可以改善镁合金的耐腐蚀性和机械性能。 目的：观察钙磷涂层对镁合金植入体周围软组织中骨形成蛋白2表达的影响。 方法：将27只兔随机分成3组,分别在兔下颌骨内植入钙磷涂层镁合金螺钉、镁合金螺钉及钛合金,植入后1,2,3个月,采用反转录聚合酶链技术检测植入体周围软组织中骨形成蛋白2 mRNA的表达情况。 结果与结论：钙磷涂层镁合金螺钉组、镁合金螺钉组周围软组织中骨形成蛋白2 mRNA的表达,随时间的增加逐渐增高,钙磷涂层镁合金螺钉组内各时间点间骨形成蛋白2 mRNA的表达水平差异有显著性意义(P < 0.05),且镁合金螺钉组植入后1,2个月周围软组织中骨形成蛋白2 mRNA的表达水平高于钙磷涂层镁合金螺钉组(P < 0.05)。显示钙磷涂层能够促进骨形成蛋白2 mRNA的表达,并抑制其过度表达,有利于早期成骨过程,表现出良好的生物活性。      

脂肪干细胞来源的外泌体促进肉芽组织来源的成纤维细胞增殖的初步研究

目的研究脂肪干细胞来源的外泌体(ADSC-Exo)能否促进肉芽组织来源的成纤维细胞的增殖。 方法取内蒙古医科大学第三附属医院术后废弃脂肪组织,分离培养脂肪干细胞(ADSC),超滤浓缩离心方法收集ADSC-Exo,电子显微镜下观察其形态,Western Blotting测定表面标志物,Nanosight分析仪检测粒径和浓度;取烧伤创面的肉芽组织,分离培养肉芽组织成纤维细胞,进行波形蛋白免疫组织化学染色。成纤维细胞划痕实验设立空白组和ADSC-Exo组,检测ADSC-Exo在培养24、48 h对成纤维细胞的迁移作用。Transwell共培养实验设立空白对照组、ADSC-Exo共培养组和ADSC共培养组,检测ADSC-Exo与ADSC在培养24、48、72、96 h对成纤维细胞的增殖作用。成纤维细胞划痕实验结果比较采用独立样本t检验;Transwell共培养实验结果采用单因素方差分析。 结果电子显微镜下ADSC-Exo可见囊泡结构,直径在40～100 nm之间,ADSC-Exo标志物CD81、CD63的蛋白表达阳性,Nanosight检测显示其直径峰值聚集于55 nm。成纤维细胞镜下外形呈多角形或长梭形,波形蛋白免疫组织化学染色示细胞质呈棕黄色。培养24 h,ADSC-Exo组划痕迁移面积(46.2±9.8)%与空白组(31.7±8.6)%比较,差异有统计学意义(t＝2.72, P<0.05);培养48 h,ADSC-Exo组迁移面积(85.5±5.3)%与空白组(71.2±8.9)%比较,差异有统计学意义(t＝3.37, P<0.01)。Transwell共培养结果示培养48 h ADSC共培养组吸光度值(0.37±0.05)与空白对照组(0.29±0.06)比较差异有统计学意义(P<0.05);培养72 h,ADSC-Exo共培养组吸光度值(0.51±0.05)和ADSC共培养组吸光度值(0.53±0.08)显著高于空白对照组(0.38±0.06),培养96 h,ADSC-Exo共培养组吸光度值(0.68±0.07)和ADSC共培养组吸光度值(0.72±0.11)显著高于空白对照组(0.54±0.07),差异均有统计学意义(P值均小于0.05)。 结论超滤浓缩离心方法能够分离ADSC-Exo;ADSC-Exo可显著促进肉芽组织来源成纤维细胞的增殖和迁移能力。     

载三联抗痨药硫酸钙/聚氨基酸人工骨植入脊柱结核病灶内：植骨界面的组织学改变

BACKGROUND: Most researchers have devoted to study the control-release system in spinal tuberculosis focus and implant material for bone defects, but the effective combination to obtain a novel implant material and its treatment outcomes are rarely reported. OBJECTIVE: To observe the histological change of the implant-bone interface after implantation of the calcium sulfate/polyaminoacid artificial bone carrying triple-anti-tuberculosis drugs including isoniazid, rifampicin and pyrazinamide in a rabbit model of spinal tuberculosis, and to assess the fusion ability of the material. METHODS: Thirty-six New Zealand rabbits were randomly divided into experiment, control and blank control groups (n=12 per group). Models of spinal tuberculosis were established in the rabbits and randomly assigned into either experiment or control groups, followed by implantation with the calcium sulfate/polyaminoacid artificial bone carrying triple-anti-tuberculosis drugs including isoniazid, rifampicin and pyrazinamide, or the calcium sulfate/polyaminoacid artificial bone, respectively. Healthy controls received the implantation with calcium sulfate/polyaminoacid artificial bone only. RESULTS AND CONCLUSION: Hematoxylin-eosin staining showed that the artificial bone was covered by fibers and tightly adhered to the wound in each group at 2 weeks after implantation, the graft started to degrade obviously at the 4th week, degraded mostly at the 8th week, and disappeared completely at the 16th week. There was obvious callus formation at 4 weeks after implantation in the experiment group, but the bone healing was later than that of the blank control group. The bone healing ended in the control group. In the blank control group, callus formation and early osteogenesis appeared at the 4th week, and healed completely at the 16th week. Transmission electron microscope and scanning electron microscope revealed that osteoblasts could crawl through the gap of materials to form new bone. These results suggest that the calcium sulfate/polyaminoacid artificial bone carrying triple-anti-tuberculosis drugs can be used as a scaffold, and osteocytes in the bone defect area can crawl through the gap of materials, thereby promoting bone osseointegration at the bone-implant interface.