体内磷酸钙沉积晶体结构的透射电镜研究

羥基磷灰石(HA)和磷酸八鈣(OCP)是生物陶瓷植入體表面磷酸鈣沉積的兩種常見晶型。由于HA和OCP具有相似的晶體結構,利用X射線衍射法(XRD)標定二者時,極易引起混淆。本文利用透射電鏡(TEM)電子衍射和高分辨電子顯微(HRTEM)技術,對狗和兔子體內磷酸鈣沉積進行了比較研究,通過兩套典型的電子衍射圖證實狗和兔體內沉積物分別具有HA和OCP晶體結構。另外,分析比較了兩套電子衍射圖的相似之處,發現在進行高分辨觀察時,OCP晶體內部由于含有結晶水更容易發生輻照損傷。 Hydroxyapatite(HA) and octacalcium phosphate(OCP) are two commonly reported calcium phosphate precipitates formed on bioceramic implants.It likely leads to misidentification of HA and OCP by X-ray diffraction(XRD) due to their structure similarity.In this report,the calcium phosphate precipitates in dog and rabbit bodies were comparatively studied by electron diffraction and highresolution transmission electron microscopy(HRTEM).The precipitates in dog and rabbit bodies were confirmed to be HA and OCP respectively by two typical sets of electron diffraction patterns.The similarity of these sets of patterns were compared and discussed.Moreover,it was found that OCP crystals were more likely to be damaged by electron beam irradiation during TEM observations because OCP contains structural water

Ti6Al4V表面HAP／聚乙酸乙烯酯杂化陶瓷膜层的电化学合成

應用電化學共沉積技術制備HAP 聚乙酸乙烯酯雜化陶瓷膜層 ,XRD、XPS、SEM表征結果指出 ,由電化學共沉積制備的復合膜層中無機相以HAP為主 ,有機物含量達 4% .HAP陶瓷膜層的表面結構形貌因引入有機高聚物而發生顯著改變 .力學拉伸實驗表明HAP 聚合物陶瓷膜層與金屬基體的結合力比單一HAP相有明顯提高. An electrochemical co-deposition method was developed to successfully prepare the hybrid bioceramic coating of hydroxyapatite (HAP) / Poly (vinyl acetate) on the surface of Ti alloy. The characterization of XRD, XPS and SEM showed that the composition of inorganic phase in the hybrid bioceramic coatings was mainly HAP and the content of organic phase was more than 4% (w/w) . It was noted that there was remarkable change on the surface morphology of hybrid ceramic coating because of adding organic monomer vinyl acetate. The binding-pulling experiments indicated that the bonding force of the hybrid coating to metal substrate was increased as high as 2.43 MPa

电化学共沉积制备有机高聚物／钙磷复合陶瓷膜层Ⅱ XPS、SIMS表征及力学性能研究

通過電化學共沉積方法制備具有生物活性的有機高聚物 /鈣磷陶瓷復合膜層。用 XPS、SIMS等對復合膜層的化學組分進行表征 ,證明少量有機高聚物可能在分子層次上摻雜形成有機高聚物 /羥基磷灰石復合膜層。對電沉積 HAP陶瓷膜層進行微刮痕實驗表明 ,陶瓷膜層與金屬基體的結合力得到顯著改善. Electrodeposition hydroxyapatite (HAP) coatings of ceramics were studied by Nano Indent. The bonding force between the coating and metal substrate was distinctly increased. The experiments about XPS and SIMS showed that there is the act of organic polymer enriching at negative. It ensues that minor organic polymer is compounded to HAP coatings at molecular level and forms that HAP/Organic polymer compound coating

电化学共沉积制备有机高聚／钙磷复合陶瓷膜层－Ⅰ XRD、SEM表征及生物活性研究

首次提出在 NH4H2 PO4- Ca( NO3) 2 溶液中添加水溶性乙烯類有機高聚物 ,實現了通過電化學共沉積法制備具有生物活性的有機高聚物 /鈣磷陶瓷復合膜層。用 XRD、SEM等對膜層的組分和形貌進行表征 ,證明陶瓷膜層表面形貌發生明顯的變化。有機高聚物的引入 ,并不影響電沉積制備的羥基磷灰石 ( HAP)晶體在 ( 0 0 2 )晶面生長存在的晶面擇優取向。體外細胞實驗表明 ,HAP/有機高聚物復合膜層具有優良的生物活性 An electrochemical co-deposition technique has been developed to prepare a hydroxyapatite (HAP)/organic polymer composite coatings on Ti surface as new biomaterial of hard tissue. The composite coating of organic polymer and calcium phosphate is formed by adding a water soluble polymer of the ethylene series to NH4H2PO4 - Ca(NO3)2 solution when conducting an appropriate electrochemical co-deposition experiment. The XRD, SEM, XPS, SIMS and nano indent measurements were performed to characterize the morphology, composition, structure and surface stiffness of the composite coating. It was found that the morphology and surface hardness of the coatings showed a remarkable modification when introducing a minor polymer to HAP coating, and the bonding force between the coating and metal substrate was distinctly increased. The incorporation of minor organic polymer into the HAP compound at molecular level will improve the mechanical properties and morphology of the composite coatings, and this may be helpful to raising its bio-activity

生物材料表面微納結構對成骨相關細胞的影響

生物醫用材料表面性能,包括表面形貌與化學組成,對誘導骨組織形成并形成骨整合具有重要作用。細胞行為對基底表面形貌和組成的依賴性決定了設計不同功能表面的重要性。作者小組多年來從事生物材料表面微納結構相關研究。在微圖形方面,結合微加工和磁控濺射技術制備出的羥基磷灰石微溝槽;采用溶膠-凝膠與復制微模塑相結合的方法制備了TiO2微圖形;采用掩模曝光電化學微加工技術和噴射電化學微加工技術,在鈦基底上制備多孔微圖形;通過轉移微模塑法與自組裝技術相結合,得到殼聚糖與牛血清蛋白復合微圖形。在納米結構方面,采用電化學陽極氧化處理,獲得一定管徑和管長的二氧化鈦納米管。在微納多級結構方面,結合高壓微弧氧化和低壓陽極氧化制備了微納多級結構鈦表面。除了考慮微納結構單獨效應之外,還考慮了微納結構化與生物功能化的協同效應,即在具有微納結構的生物材料表面通過層層自組裝等手段進行生物化學修飾。最后通過成骨相關細胞培養實驗及體內植入實驗,考察各試樣的生物活性。研究表明,微米尺度表面促進骨細胞粘附、增殖、分化等,而納米尺寸結構以及微納多級結構對細胞功能具有進一步促進作用。微納結構化與表面功能化修飾存在有協同效應。這些研究結果為微納米技術應用于人體植入研究提供了新方向。Surface properties including topography and chemistry are of great significance in deciding the response of tissue to implants. Our group has been engaged in researches on micro/nano structured biomaterial surfaces for a long time. This article reviews our series works on osteogenetic cells behavior on biomaterial surfaces with micro-and nano-structures. For micro-patterns, hydroxyapatite microgrooves were prepared by combining micro-fabrication technology and magnetron sputtering technology; TiO2 micropatterns were obtained by combining sol-gel and replica molding; Micro-patterned Ti substrates were prepared by using a through mask electrochemical micromachining and a jet electrochemical micromachining technology; chitosan/bovine serum albumin micropatterns were prepared on functionalized Ti surfaces by micro-transfer molding combined with self-assembly. For nanostructures, titania nanotubes with various diameters and lengths were prepared by a electrochemical anodic oxidation treatment. For micro-nano hierarchical structures, titania micropores modified with nanotubes were obtained by high voltage micro-arc oxidation and low voltage anodization. In addition to considering the effects of micro-nano structure alone, the synergistic effects of struturalization and biofunctionalization of biomaterial surfaces were investigated, which were realized through layer-by-layer self-assembly and other means of biochemical modification on micro/nano structured surfaces. Finally, in vitro osteogenetic cell culture and in vivo study were conducted to investigate the biological activity of various sample. The results indicate that micro-scale topographical features promote cell adhesion, bone ingrowth and the formation of mechanical interlocking between the implant surfaces and bone tissue. The nano-scale features, including nanotubes, nanofibers and nanodots, can generate preferential interactions with a biological system at protein and cellular levels, such as cell proliferation, differentiation, and gene expression. The micro/nano hierarchical surface structures further enhance cell activity. The micro/nano structures and biofuctionalization with biomolecules and biofilms have synergistic effects on cell behaviors. These studies provide a potential new direction for the application of micro/nano technology on implant surface modification