Pressurized Solid Reaction Route to Synthesizing Carbonated Hydroxyapatite and Its Adsorption to Mn2+

羟基磷灰石因与骨骼、牙齿极其相似，在医学和材料学领域被广泛研究。人体骨骼并不完全等同羟基磷灰石，比如骨骼中碳酸根离子含量在4~8wt%。羟基磷灰石发生碳酸根离子取代，即形成碳酸化羟基磷灰石（CHAp）。CHAp比羟基磷灰石有更高的骨骼再生率和骨传导性。其制备方法很多，最常用的液相法存在外来离子掺杂、有机溶剂残留等问题。本研究提出加压固相法，即采用加压CO2作为碳源，同钙、磷源的固体盐合成CHAp；分析研究CO2嵌入反应机理；将合成的CHAp应用于Mn2+的吸附。 采用CO2介入的加压固相法，考察不同钙源和磷源在加压固相法中的反应效果，以Ca(OH)2(蛋壳)为钙源，以Na2HPO4·12H2...Hydroxylapatite similar to bone and teeth, is widely used in medical and material areas.But biological apatite is not just hydroxylapatite, for example, the carbonate content in bone is about 4–8 wt%. If the replacement of carbonate ions happened, it forms carbonated hydroxyapatite (CHAp). CHAp has higher bone regeneration ratio and bone conductivity. Several techniques have been advanced to synth...学位：工学硕士院系专业：化学化工学院_化学工程学号：2062013115148

FTIR-ATR Spectrometry of BSA Adsorption on Hydroxyapatite

采用傅里叶变换红外衰减全反射(FTIR-ATR)光谱法对牛血清白蛋白(BSA)在羟磷灰石(HA)[Ca_(10)(OH)_2(PO_4)_6]表面不同时间的相互吸附作用进行了表征。在BSA溶液作用下,羟磷灰石表面的Ca~(2+)、PO_4~(3-)和OH~-离子初始的溶解和再沉淀使得BSA与HA相互作用层层叠加,在HA表面形成从表层到次表层分子都包含有吸附的BSA的覆盖层,从而加深两者之间的相互作用。经红外差谱法处理过的相关ATR数据表明,BSA与HA之间的相互作用是快速的,并随时间变化进一步加强;来自HA上PO_4~(3-)的P=O基团对蛋白质肽键的酰胺Ⅱ带(-CNH)、多肽链的甲基(-CH_3)和亚甲基(-CH_2)上氢的吸附作用要比P-O快速而且强烈。Ca~(2+)在该吸附过程中起了极其重要的作用,其快速与蛋白质肽键的羰基氧发生作用,并诱导该蛋白质二级结构由β-折叠向α-螺旋和β-转角构象转变;伴随着这一构象变化,蛋白质多肽链上大多数肽键的-C=O和H-N-活性基团从链间氢键交联中释放出来,带动众多的氢分别参与同HA表面的Ca~(2+)、PO_4~(3-)和OH~-离子的相互吸附作用,并牢牢地结合于HA表面;这对硬组织的再生起着重要作用,促进了HA的生物矿化过程。The microcosmic process of bovine serum albumin(BSA) adsorbing onto hydroxyapatite(HA) for different time intervals was investigated by Fourier transform infrared attenuated total internal reflectance(FTIRATR) spectrometry.The initial dissolution and re-precipitation of PO_4~(3-),Ca~(2+),and OH~- ions from the HA coating led to the occurrence of the coating including adsorbed BSA on the HA from surface-to subsurface-molecular layers and to in-depth interaction between BSA and HA.The subtraction results gained in the adsorption regions of HA and BSA reveal that the binding of P=O,from the phosphate(PO_4~(3-)),to the hydrogen of amide Ⅱ,methyl and methene of the BSA appears to be considerably more rapid and stronger than that of the P—O group.In addition,it is very likely that Ca~(2+) plays an important role in the interaction of BSA with HA.It appears that the binding of Ca~(2+) to the carbonyl-oxygen of the peptide bond in BSA caused a significant,molecular,conformational rearrangement of polypeptide backbones from β-pleated sheet to helical circles of α-helix and β-turn.This change appears to have been followed by much hydrogen of polypeptides being driven to bind PO_4~(3-) and OH~-effectively and much-C=O and H-N- groups of the peptide bond being freed from inter-chain hydrogenbonding to act on Ca~(2+) and combine strongly with the HA surface.This might reasonably be expected to promote hard tissue regeneration.BSA seems to be activated by the inductive effect of Ca~(2+) via the molecular rearrangement of polypeptide backbones from pleated sheet to helical circles and in turn reacts strongly on the HA,resulting in profound effects on the course of biomineralization.国家自然科学基金(51571169)资助项目~

The preparation and characterization of nano-Ag/HAp bioceramic coating on titanium surface

目的:在纯钛表面构筑羟基磷灰石/纳米银涂层并进行各种性能表征。方法:采用恒电位电化学法在纯钛表面构建纳米银/羟基磷灰石(nAnO-Ag/HAP)涂层。采用扫描电子显微镜(SEM),X射线衍射仪(Xrd)、等检测手段对涂层进行理化性能的表征。考察了涂层的结构组分和表面的微观形貌,而后将l-929细胞培养于涂层表面,采用细胞毒性评价,分析比较涂层表面对l-929细胞黏附率及增殖率的影响。结果:涂层纳米银粒子直径在200~400nM时体外细胞培养显示其具有良好的生物活性。结论:本实验构筑的涂层具有良好的性能和应用前景。Objective:This research was aimed at the electrochemical deposition employed to deposit a Nano-Ag/HAp composite coating on titanium surface.Methods:A Nano-Ag/Hap composite coating was deposited on the surface of pure titanium by electrochemical deposition.Scanning electromicroscope(SEM) and X-ray diffraction(XRD) were employed to characterize the obtained coating.In vitro celluar responses of the L-929 to the coating were also evaluated by MTT assay.Conventional Hap coatings and commercially pure titanium were taken as control.Results:The Nano-Ag/Hap bioceramic coating has good crystallization and homogeneous on nano-Scale surface morphology.The L-929 culture exhibits satisfactory bioactivity.Conclusion:The Nano-Ag/HAp bioceramic coating on titanium surface has promising prospects in the future clinical application

Core-shell Hydroxyapatite Combined with Bone Morphogenetic Protein 2 in Periodontal Regeneration Treatment in Dogs

目的初步评估贝壳多孔羟基磷灰石基骨修复材料及该材料和骨形成蛋白-2联合应用引导比格犬牙周组织再生的效果。方法选取18月龄比格犬6只,牙周基础治疗后1周,在下颌第二、三、四前磨牙,建立急性牙周骨缺损模型,依照分组情况进行不同治疗。实验组(T组)植入骨修复材料和骨形成蛋白-2;阴性对照组(nC组)植入骨修复材料;空白对照组(bC组)不植入任何材料。实验设计采取同颌同名牙对照,同一只比格犬的3对同颌同名牙分别为:空白对照组和阴性对照组,阴性对照组和实验组,空白对照组和实验组。术后12周,处死动物,MICrO-CT检查并对数据进行统计学分析。结果材料植入后,未见材料溢出,植入局部和全身都未见明显不良反应。3组缺损都有一定程度骨再生,以T组再生组织量最多,bC组最少。MICrO-CT结果显示:T组、nC组和bC组的骨再生平均高度为(4.50±0.47)MM(、1.75±0.42)MM和(0.87±0.31)MM。nC组和bC组相比,差异有统计学意义(P<0.05)。T组与nC组和bC组相比,差异均有统计学意义(P<0.05),且有临床意义。结论贝壳多孔羟基磷灰石基骨修复材料和骨形成蛋白-2联合应用于比格犬,可以获得更好的引导组织再生效果。Objective To evaluate the ability of core-shell hydroxyapatite bone graft material alone and combined with bone morphogenetic protein 2(BMP-2) in periodontal regeneration treatment in dogs.Methods Thirty-six defects were created in six 18-months male beagle dogs at the sites of the second,third and fourth mandibular premolars one week later after the dogs were treated with non-surgical periodontal therapy.Different treatments were carried out according to which group the teeth belonged.There are 3 groups.The test group(group T) was treated with core-shell hydroxyapatite bone graft material combined with BMP-2;the negative control group(group NC) was treated with core-shell hydroxyapatite bone graft material alone and the blank control group(group BC) was treated with no graft material.When a tooth was selected into one of the 3 groups randomly,the tooth with the same name on the other side in the same jaw was selected into another group.6 defects in the same dog were made and divided into 3 groups.The animals were sacrificed 12 weeks after surgery and analyzed by Micro-CT.Results There was no adverse reaction after material was planted.There were bone regenerations in all groups.Group T got the best bone regeneration while group BC got the least bone regeneration.The biggest height of bone regeneration for group T,group NC and group BC were(4.50±0.47) mm、(1.75±(0.42) mm) and(0.87±0.31) mm according to Micro-CT evaluation.There were statistical difference of bone regeneration height between group NC and group BC.There were statistical differences between group T and group NC and between group T and group BC.Conclusion More periodontal tissue regeneration could be got when core-shell hydroxyapatite bone graft material was used with bone morphology protein 2.南京市医学科学技术发展专项项目(ZKX07022);天津市生物医学材料重点实验室开放课题;南京市医学科技发展青年人才启动项目(QYK10166

Preparation and Modification of Chitosan-based composite Rods

本文在原位沉析法制备壳聚糖棒材的基础上，通过加入聚乳酸纤维、壳聚糖纤维、羟基磷灰石等方法对壳聚糖基体进行力学性能改性，并利用SEM对复合材料的微观形貌进行分析，结合红外、XRD等探讨了复合材料的改性机理；本文还采用化学改性和物理涂覆的方法改善棒材的湿态力学性能。 为了提高壳聚糖棒材的力学性能，本文利用原位沉析法制备了聚乳酸纤维/壳聚糖复合棒材，对复合棒材的微观形貌进行分析发现，应用此成型方法，聚乳酸纤维和壳聚糖基体间形成良好的界面连接，在棒材沉析过程中，聚乳酸纤维的表面还会因氢键等作用和壳聚糖基体产生一定的物理吸附作用。复合棒材的弯曲强度和弯曲模量得到有效提高。 研究了壳聚糖纤维增强壳聚糖...In this paper, on the base of chitosan rod prepared by in-situ precipitation, the mechanical propertiesof chitosan rod were improved by adding chitosan fibers,polylactic acid fibers or hydroxyapatite. The fracture surface morphologies of the composites were observed by SEM, and combined with IR and XRD, the modification mechanisms of the composite materials were discussed. The anti-water of chitos...学位：理学硕士院系专业：材料学院材料科学与工程系_高分子化学与物理学号：2072007115002

Preparation and Modification of Chitosan-based composite Rods

本文在原位沉析法制备壳聚糖棒材的基础上，通过加入聚乳酸纤维、壳聚糖纤维、羟基磷灰石等方法对壳聚糖基体进行力学性能改性，并利用SEM对复合材料的微观形貌进行分析，结合红外、XRD等探讨了复合材料的改性机理；本文还采用化学改性和物理涂覆的方法改善棒材的湿态力学性能。 为了提高壳聚糖棒材的力学性能，本文利用原位沉析法制备了聚乳酸纤维/壳聚糖复合棒材，对复合棒材的微观形貌进行分析发现，应用此成型方法，聚乳酸纤维和壳聚糖基体间形成良好的界面连接，在棒材沉析过程中，聚乳酸纤维的表面还会因氢键等作用和壳聚糖基体产生一定的物理吸附作用。复合棒材的弯曲强度和弯曲模量得到有效提高。 研究了壳聚糖纤维增强壳聚糖...In this paper, on the base of chitosan rod prepared by in-situ precipitation, the mechanical propertiesof chitosan rod were improved by adding chitosan fibers,polylactic acid fibers or hydroxyapatite. The fracture surface morphologies of the composites were observed by SEM, and combined with IR and XRD, the modification mechanisms of the composite materials were discussed. The anti-water of chitos...学位：理学硕士院系专业：材料学院材料科学与工程系_高分子化学与物理学号：2072007115002

原位增强羟基磷灰石/壳聚糖复合棒材

利用低温水溶液均相沉积法制备了磷酸钙盐微纤维;应用原位沉析法制备了壳聚糖(CS)三维棒材及羟基磷灰石(HA*)/CS复合棒材。XRD证实应用原位沉析法制备HA*/CS复合棒材过程中,磷酸钙盐转化为羟基磷灰石结构,尺寸为10~60μm,并用SEM对晶体形貌进行了表征,分析了转化机制。HA*/CS复合材料的微观形貌表明,HA*晶体在CS凝胶棒原位沉析的过程中析出而与CS基体形成镶嵌、相互咬合结构,且在基体中分散均匀,有效地提高了HA*与CS基体的界面连接作用,使力学性能显著提高。所制备的HA*/CS棒材随HA*含量的增大(在其饱和溶解度3.3 wt%范围内),复合材料的弯曲性能逐渐提高,当羟基磷灰石质量分数为3.3%时,复合材料的弯曲强度达到159.6 MPa,弯曲模量达到5.1 GPa,比CS基体分别提高85.6%和54.5%。HA*/CS复合棒材的弯曲强度和弯曲模量远高于松质骨,弯曲强度也比密质骨高

Study on bio-safety for Nano-Ag/HAp as anti-bacterial materials

通信作者:史建陆Tel:(0576)85199572 E-mail: zmfjmu@ gmail．com[中文文摘]目的研究纳米银羟基磷灰石的细胞毒性。方法采用能快速、准确、敏感地评价细胞增殖率和细胞毒性的MTT比色法,以纳米羟基磷灰石为对照组,纳米银羟基磷灰石为实验组,在材料浸提液中,分别检测人牙周膜成纤维样细胞的相对增殖率。另观察细胞在扫描电镜中的形态,从而分析比较涂层表面对细胞的毒性。结果与纳米羟基磷灰石相比,纳米银羟基磷灰石涂层中的纳米银粒子直径在200～400nm时体外细胞培养显示表现出较高的细胞增殖率,细胞毒性趋于0级,显示其具有良好的生物活性。结论纳米银羟基磷灰石涂层无细胞毒性。[英文文摘]Objective To study the cytotoxicity of a Nano-Ag/HAp composite coating on titanium surface.Methods A Nano-Ag/HAp composite coating was deposited on the surface of pure titanium by electrochemical deposition.In vitro celluar responses of the PDLF to the coating were also evaluated by MTT assay.Conventional HAp coatings and commercially pure titanium were taken as control.Results The Nano-Ag/Hap bioceramic coating has good crystallization and homogeneity on nano-scale surface morphology.The PDLF culture exhibits satisfactory bioactivity．Conclusions The Nano-Ag /HAp bioceramic coating on titanium surface has promising prospects in the future clinical application

Synthesis and Characterization of Hydroxyapatite Nanoparticle with Amino Acids

羟基磷灰石（hydroxyapatite，HA）是人体和动物骨骼和牙齿的主要无机矿物成分。体内骨的形成主要是在生物分子（例如，胶原、骨形态蛋白等物质）调控下，生成具有特殊形貌和粒度大小的HA晶体。因此，制备具有特殊尺寸、形貌和物化性能的HA晶体是生物医学和材料科研人员的重要方向之一。本文研究了羟基磷灰石纳米棒不同尺寸的可控合成及其反应机理进行初步探讨，并利用X-射线衍射(XRD)、透射电镜(TEM)、高分辨透射电镜(HRTEM)、红外光谱(FT-IR)等分析测试手段对产物的化学组成和物化性能进行了表征。 在用沉淀法合成HA过程中，加入不同种类和含量的氨基酸，以考察氨基酸对生成的HA形貌及结构...Hydroxyapatite (HA) is the main inorganic mineral components of bones and teeth. HA in bone with special crystal morphology and grain size mainly is controlled by the biological molecules, for example, collagen and bone morphogenetic protein. Therefore, the focus of scientific research is preparation of HA crystals with special size, shape and physical and chemical properties. Controlled synthesis...学位：理学硕士院系专业：材料学院生物材料系_生物医学工程学号：3142008115062

Preparation of Hydroxyapatite Restoration Coating on Enamel Surface and Its Biocompatibility Evaluation

龋病是一种全世界范围内常见的口腔进行性疾病，龋病导致的牙齿功能的丧失严重影响着人们的生活与健康。阻止龋病发展的关键在于对早期龋齿的及时发现和有效的治疗。目前，对于龋病的治疗主要是通过填充从而达到修补龋洞的目的。但这种治疗方式需要磨除部分健康的牙组织，并且由于填充材料与牙齿具有不同的化学成分和微观结构，填充材料与基底之间难以实现完美的结合，在填充以后可能在牙齿与填充材料的界面上发生继发龋。因此，在发生浅龋的牙釉质表面构建与之成分、结构相仿的羟基磷灰石（HA）修复涂层，以达到对早期浅龋无损修复的目的，是解决这一问题的有效途径。 本文基于涂剂法制备牙釉质仿生修复涂层的思路，利用羟基磷灰石粉末在固化...Dental caries is a prevalent chronic and world-wide oral disease. The loss of teeth as a consequence of serious caries greatly reduces the quality of one’s life. The strategy to prevent the development of caries is the effective treatment of early lesions. Currently, enamel defects are frequently refilled with unstructured substitutes. The problems involved in this repair when it is applied to ear...学位：工学硕士院系专业：材料学院材料科学与工程系_材料学学号：2072008115061