胶原对TTCP/MCPM骨水泥性能的影响

以混合后钙磷比为1.67的磷酸四钙(TTCP)和一水磷酸二氢钙(MCPM)粉体为原料,按固液比3∶1分别用水和5.24 mg/ml自制Ⅰ型胶原溶胶作固化液制备骨水泥试样,测定其凝结时间和抗压强度。结果显示,用胶原作固化液可使TTCP/MCPM骨水泥的抗压强度由17.8±1.9 MPa增至22.7±1.6 MPa,对凝结时间则没有明显影响;两种试样经模拟体液(SBF)浸泡抗压强度均有增加,尤以胶原溶胶固化的试样增幅较大,SBF浸泡4 d和14 d,抗压强度分别增至31.8±3.9 MPa(胶原溶胶)/19.5±1.3 MPa(水)和38.1±3.1 MPa/21.9±2.2 MPa。对比胶原矿化前后的红外谱图发现,矿化后胶原的酰胺Ⅰ带特征峰红移,酰胺Ⅱ带、Ⅲ带几乎消失,提示在胶原与羟基磷灰石(HA)之间发生了明显的化学作用,这应是胶原对TTCP/MCPM骨水泥增强作用的基础;而SBF浸泡前后试样表面的SEM和XRD图谱则显示,SBF浸泡在使透钙磷石(DCPD)转化为HA的同时,又沉积生成了大量新的HA,使试样表面更加致密、光滑,这既是SBF浸泡增强的机理,也揭示TTCP/MCPM骨水泥的凝结硬化是先生成DCPD...     

R2O—A12O3—B2O3—SiO2系统玻璃、超细α—Al2O3对羟基磷灰石陶瓷的烧结和相变的影响

系统地研究了R2O-A12O3-B2O3-SiO2系统玻璃和超细α—Al2O3对羟基磷灰石(HAP)陶瓷的烧结和相变及机械性能的影响。结果表明α—Al2O3对HAP的烧结有阻碍作用，使烧结温度提高；在烧结过程中能抑制玻璃与羟基磷灰石作用，使羟基磷灰石在烧结温度下避免脱去羟基而分解。同时使用超细α—Al2O3和玻璃复合增强HAP可以取得较好的效果，当α-Al2O3含量为10％(wt)，玻璃含量为20％(wt)时，在1200℃下烧结1h可以获得弯曲强度高达106MPa的复相HAP陶瓷。     

Na_2O-CaO-SiO_2-P_2O_5系统生物玻璃析晶对其生物活性及强度的影响

Na2 O- Ca O- Si O2 - P2 O5系统生物活性玻璃具有较高的生物活性 ,是一种理想的骨缺损填充材料。为了提高该生物玻璃的力学强度 ,对其进行了微晶化处理 ,并利用 XRD、SEM、FTIR分析及 SBF浸泡等技术对其生物活性与母体玻璃进行了分析比较 ,并测定和比较了晶化前后材料的抗折强度和断裂韧性 ,对材料的生物活性机理进行了理论分析     

仿生法制备纯镁/羟基磷灰石复合涂层的研究

通过酸碱两步法活化纯镁基体表面，用CaCl2和K2HPO4溶液对其进行预钙化处理，将处理过的纯镁试样浸泡于模拟体液中，仿生沉积得到羟基磷灰石涂层。利用X射线衍射和扫描电子显微镜对形成的涂层进行表征。试验结果表明，4周后可在镁基体表面得到了均匀致密、结晶良好的羽毛状羟基磷灰石涂层。     

高纯镁在体内定量载荷下的降解行为

目的定量研究力学载荷对高纯镁在体内降解的影响。方法将直径2 mm、长14 mm的圆柱状高纯镁(99. 99 wt.%)试件装配到聚醚醚酮(PEEK)制成的圆环上。PEEK环可使镁试件分别处于3种应力状态:无应力、压应力[(6. 2±0. 6) MPa]和拉应力[(4. 6±0. 1) MPa]。将不同应力状态的试件植入SD大鼠背部皮下4周后取出。通过试件失重、剩余体积、表面形貌和周围软组织染色分析高纯镁的降解行为。结果植入大鼠皮下的高纯镁试件均出现降解,并且被胶原纤维囊包裹。受到压、拉应力的试件与无应力试件在失重和剩余体积上无显著差别。在各应力状态下的试件都趋于均匀腐蚀。结论在体内皮下环境中,PEEK环对高纯镁施加4～6 MPa压、拉应力对高纯镁降解行为无明显影响。研究结果为镁基可降解植入物的设计与临床应用提供理论依据。     

云母基高强度可切削微晶玻璃的研究

着重研究了以钙氟金云母为主相的可切削微晶玻璃的组成、结构和性能。 XRD和 EDS的分析结果表明 ,微晶玻璃以钙氟金云母、t- Zr O2 为主相 ,另有 Kx Ca( 1 - x) /2 Mg2 Si4 O1 0 F2 和 m- Zr O2 存在。微晶玻璃强度达 2 35MPa,比目前临床用同类材料强度提高近一倍 ;断裂韧性最高为 2 .17MPa· m1 /2 ;显微结构对材料性能影响尤为显著。理论分析和实验结果表明 ,具有大量细小晶粒的材料 ,其强度较高。本研究研制的微晶玻璃具有典型的可切削微晶玻璃的显微结构和良好的可切削性     

K2O-B2O3-Al2O3-SiO2-MgO-F系统可切削生物微晶玻璃

目的 可切削微晶玻璃的制备温度高达1500 ℃以上,此特性严重制约其产业化发展.本文设计制备了K2O-B2O3-Al2O3-SiO2-MgO-F系统低温云母生物微晶玻璃,并探讨制备工艺对材料结构和性能的影响.方法 采用1300 ℃熔化工艺与600～750 ℃晶化热处理工艺制备微晶玻璃,通过X射线衍射分析方法研究微晶玻璃的晶相组成,利用扫描电子显微镜观察微晶玻璃的形貌,并通过显微硬度分析、高速砂轮切削实验考察微晶玻璃的可切削性能.结果 分别经过600 ℃、650 ℃、700 ℃、750 ℃晶化热处理2 h、4 h、8 h后,玻璃中均形成了主晶相为氟金云母的微晶玻璃,微晶玻璃的显微硬度为3～8 GPa.且随着晶化温度的升高,微晶玻璃层状结构逐渐明晰,但硬度不断下降,其可切削性持续提高.结论 低温下熔化K2O-B2O3-Al2O3-SiO2-MgO系统玻璃工艺降低了可切削微晶玻璃的制备温度和成本,利于产业化生产和推广应用.     

钙磷生物陶瓷多孔骨修复材料的制备*

以适量的Mg(H2PO4)2-(NaPO3)6为粘结剂,HA和-TCP粉末为原料,用有机泡沫浸渍法制备钙磷多孔生物陶瓷坯体,并在850℃烧成,探索在较低烧结温度下制备钙磷多孔生物陶瓷的工艺。采用X射线衍射(XRD)、扫描电镜(SEM)、能谱(EDS)等方法对多孔生物陶瓷的物相组成、显微结构、物理性能进行了分析。烧成后的钙磷生物陶瓷多孔支架主要由-TCP、-Ca2P2O7和CaO-MgO-Na2O-P2O5磷酸盐玻璃组成。烧结过程中,HA发生了向-TCP的转化,部分-TCP转化为-Ca2P2O7。多孔支架具有良好三维连通性的孔隙结构,孔径为200～500m,孔隙率达81%,抗压强度为1.1～1.5MPa。     

新型掺铕多孔磷灰石/硅灰石磁性生物活性玻璃陶瓷的研究

通过溶胶-凝胶工艺制备了一种掺铕磷灰石/硅灰石多孔磁性生物活性玻璃陶瓷材料。采用DTA、XRD、SEM、能谱(Energy dispersive spectroscopy,EDS)、诱导耦合等离子体原子发射光谱(Inductive couple plasma atomic emission spectrometry,ICP-AES)、振动磁强计(Vibrating sample magnetometer,VSM)等方法分析材料的制备工艺、晶相组成、显微结构、磁性、生物活性和降解性。结果表明:材料的主晶相除了包括氟氧磷灰石、β-硅灰石相外,掺入的稀土元素Eu进入硅酸钙晶核内部形成Ca2Eu8(SiO4)6O2物相。当Eu2O3的掺入量为2%(质量百分比)时,充磁至10000Oe材料的饱和磁化强度达到2.18emu/g。材料在模拟体液(Simulated body fluid,SBF)中浸泡,短期内可在表面形成羟基磷灰石层,显示出良好的生物活性。是一类十分具有发展潜力的骨修复材料、骨组织工程支架材料及骨癌的热治疗修复材料。     

R2O-Al2O3-B2O3-SiO2系统玻璃、超细α-Al2O3对羟基磷灰石陶瓷的烧结和相变的影响

系统地研究了 R2 O- Al2 O3- B2 O3- Si O2 系统玻璃和超细α- Al2 O3对羟基磷灰石 (HAP)陶瓷的烧结和相变及机械性能的影响。结果表明α- Al2 O3对 HAP的烧结有阻碍作用 ,使烧结温度提高 ;在烧结过程中能抑制玻璃与羟基磷灰石作用 ,使羟基磷灰石在烧结温度下避免脱去羟基而分解。同时使用超细α- Al2 O3和玻璃复合增强 HAP可以取得较好的效果 ,当α- Al2 O3含量为 10 % (wt) ,玻璃含量为 2 0 % (wt)时 ,在 12 0 0℃下烧结 1h可以获得弯曲强度高达 10 6 MPa的复相 HAP陶瓷     

In vitro mineralization of a glass-ceramic of the MgO-3CaO x P2O5-SiO2 system: wettability studies

The calcium phosphate deposition on the surface of a bioactive glass-ceramic of the MgO-3CaO. P(2)O(5)-SiO(2) system during a 1-week immersion in biological model fluids, was investigated through wettability studies. Two model fluids with chemical composition similar to the human blood plasma were tested: Hanks' balanced salt solution (HBSS) and a simulated body fluid (SBF) with a higher calcium content. The effect of the presence of albumin, both in solution or previously adsorbed to the surface, was assessed. The behavior observed using two SBF solutions prepared with and without TRIS buffer was compared. The surface free energy of the glass-ceramic samples was determined, before and after immersion, and dynamic contact angle analysis was performed using the biological model fluids as scanning liquids. Scanning electron microscope observations and x-ray photoelectron spectroscopy (XPS) analysis were performed to complement the wettability studies. The experimental results led to the conclusion that the precipitation of a calcium phosphate film in HBSS occurred mainly when the immersion solution was renewed daily or in the presence of adsorbed albumin. In SBF, the addition of TRIS buffer seemed to inhibit the formation of the calcium phosphate film.     

模拟体液中生物大分子对类骨磷灰石矿化的影响

为考察体内生物大分子对羟基磷灰石（hydroxyapatite,HA）基底表面矿化物形成的影响,将牛血清白蛋白（bovine serum albumin,BSA）和硫酸软骨素（chondroitin sulfate,CS）大分子分别浸入模拟体液（SBF）中制备成2种矿化介质,再将HA浸入上述矿化介质中3d观察类骨磷灰石形成过程.结果 发现HA基底表面均沉积有Na＋和CO2-3取代的类骨磷灰石（Ca3.78Na0.02）（Ca5.22Na0.48）（CO3）1.5（OH）.BSA在2SBF中的存在促进了类骨磷灰石晶体在基材表面沉积,有利于其沿（300）晶面择优取向生长.CS对类骨磷灰石晶体的生长呈阻碍作用,获得的晶粒尺寸较小.模拟体液中BSA和CS大分子对类骨磷灰石晶体生长和形貌等均有一定的作用.     

Phase composition and in vitro bioactivity of porous implants made of bioactive glass S53P4

This work studied the influence of sintering temperature on the phase composition, compression strength and in vitro properties of implants made of bioactive glass S53P4. The implants were sintered within the temperature range 600-1000°C. Over the whole temperature range studied, consolidation took place mainly via viscous flow sintering, even though there was partial surface crystallization. The mechanical strength of the implants was low but increased with the sintering temperature, from 0.7 MPa at 635°C to 10 MPa at 1000°C. Changes in the composition of simulated body fluid (SBF), the immersion solution, were evaluated by pH measurements and ion analysis using inductively coupled plasma optical emission spectrometry. The development of a calcium phosphate layer on the implant surfaces was verified using scanning electron microscopy-electron-dispersive X-ray analysis. When immersed in SBF, a calcium phosphate layer formed on all the samples, but the structure of this layer was affected by the surface crystalline phases. Hydroxyapatite formed more readily on amorphous and partially crystalline implants containing both primary Na(2)O·CaO·2SiO(2) and secondary Na(2)Ca(4)(PO(4))(2)SiO(4) crystals than on implants containing only primary crystals.     

In vitro studies of plasma-sprayed hydroxyapatite/Ti-6Al-4V composite coatings in simulated body fluid (SBF)

The bioactivity of plasma-sprayed hydroxyapatite (HA)/Ti-6Al-4V composite coatings was studied by soaking the coatings in simulated body fluid (SBF) for up to 8 weeks. This investigation was aimed at elucidating the biological behaviour of plasma-sprayed HA/Ti-6Al-4V composite coatings by analyzing the changes in chemistry, and crystallinity of the composite coating in a body-analogous solution. Phase composition, microstructure and calcium ion concentration were analyzed before, and after immersion. The mechanical properties, such as tensile bond strength, microhardness and Young's modulus were appropriately measured. Results demonstrated that the tensile bond strength of the composite coating was significantly higher than that of pure HA coatings even after soaking in the SBF solution over an 8-weeks period. Dissolution of Ca-P phases in SBF was evident after 24h of soaking, and, a layer of carbonate-apatite covered the coating surface after 2 weeks of immersion. The mechanical properties were found to diminish with soaking duration. However, slight variation in mechanical properties was found after supersaturation of the calcium ions was attained with the precipitation of the calcium phosphate layers.     

Gel-derived materials of a CaO-P(2)O(5)-SiO(2) system modified by boron, sodium, magnesium, aluminum, and fluorine compounds

Bioactive glass-ceramic materials of the CaO-P(2)O(5)-SiO(2) system modified by adding boron, magnesium, sodium, fluorine, and aluminum were obtained using the sol-gel method. Gel-derived materials were produced in the pellet form obtained by compression of powders as well as in coatings on glass slides. The materials obtained were examined in vitro with regard to the ability of calcium phosphate layer to form on the material surface as the result of contact with simulated body fluid (SBF). SBF pH changes and calcium solubility in this solution were determined and scanning electron microscopy, energy-dispersive X-ray analysis, and infrared spectroscopy studies were conducted before and after contact of the materials with SBF. The gels modified by aluminum were amorphous, whereas the sodium and fluorine additives promoted the bulk crystallization of gel-derived materials. The ability of calcium phosphates to crystallize on the surface of gel-derived materials depended only slightly on the types of additives applied, and the character of this dependence was different from that observed in melted glasses. Moreover, to estimate the biocompatibility of gel-derived coatings, we examined the proliferation, collagen synthesis, adhesion, and morphology of fibroblasts (NRK cells) cultured in the presence of gel-derived materials. The results of these experiments showed that none of the tested materials significantly reduced any cell function.     

在动态模拟体液中致密CaP陶瓷表面形貌对类骨磷灰石层形成的影响研究

磷酸钙陶瓷植入体内后其表面类骨磷灰石层的形成是诱导成骨的先决条件。本实验在模拟体液 (Simu-lated body fluid,SBF)以人体骨骼肌组织的正常生理流率 (2 ml/ 10 0 m l· min)下 ,研究在动态 SBF中致密磷酸钙陶瓷表面形貌对类骨磷灰石层形成的影响。结果表明 :在生理流速条件下 ,材料的粗糙表面有利于类骨磷灰石层的形成 ,加大 SBF中 Ca2 +、HPO4 2 -离子浓度 ,类骨磷灰石层的形成速度加快。本研究进一步证实了材料的几何形貌对类骨磷灰石形成的影响 ,加深了对磷酸钙陶瓷在体内诱导成骨机理的理解     

硅酸钙-磷酸盐复合骨水泥的制备及其性能研究

分别以α-磷酸三钙（α—TCP）、磷酸四钙（TTCP）为基本原料，添加羟基磷灰石（HAP）、磷酸氢钙（DCPD）、碳酸钙（CaCO2）、氧化钙（CaO）等其它辅料，并与一定量的无定形硅酸钙（CaSiO3）进行复合，确定了钙磷比均为1．50的六种骨水泥配方，对其基本性能进行了研究。对固化骨水泥样品进行了Ringer’S模拟液浸泡实验，研究了浸泡液pH值、样品的抗压强度随浸泡时间的变化。结果表明：调和液0．25MK2HPO4／KH2PO4和无定形CaSiO3对骨水泥有促凝作用，缩短骨水泥的终凝时间，其中初凝时间为4～5．5min，终凝时间为18～19．5min；同时添加适量无定形CaSiO3可以显著提高骨水泥的抗压强度，其中添加适量无定形CaSiO3的以α—TCP为主要原料的骨水泥Ringer’s模拟液浸泡两周后抗压强度可达45．3MPa。     

用于放射性核素铼标记的fac-[^188Re（CO）3（H2O）3]^＋的制备研究

目的：探讨放化中间体fac-[188Re（CO）3（H2O）3]＋的合成条件,并对其进行优化研究。方法：参照Schibli介绍的方法进行放化中间体fac-[188Re（CO）3（H2O）3]＋的合成,分别从反应温度、反应时间和反应物BH3.NH3的用量对合成fac-[188Re（CO）3（H2O）3]＋产率的影响进行观察。结果：合成放化中间体fac-[188Re（CO）3（H2O）3]＋的最佳反应条件为：反应时间为15min,反应温度为70℃,BH3.NH3的用量为5mg;pH值〈2。在最佳的反应条件下,产物的放化产率为85%,经Sep-Pak（硅胶柱分离后,放化纯度〉95%。结论：本文结果为放化中间体fac-[188Re（CO）3（H2O）3]＋标记生物分子作为新一代治疗药物的发展提供了有力的实验基础。     

In vitro calcium phosphate growth over surface modified PMMA film

In vitro nucleation of calcium phosphate phase was studied over functionalized polymethyl methacrylate (PMMA) films using Fourier transform infrared spectroscopy, electron spectroscopy, scanning electron microscopy and energy dispersive X-ray analysis. PMMA films were prepared by dissolving commercial grade pellets in chloroform and cast into thin sheets. The films were immersed in a methanol solution of sodium hydroxide before treating with 1.5% solution of adenosine triphosphate (ATP) at a pH of 5.2 for 24 h. ATP treated films were then soaked in saturated lime solution for 4 days to initiate formation of calcium phosphate precursor phase over their surface. The above films immersed in simulated body fluid solution (1.5 x SBF) for more than 5 days led to the nucleation of apatitic calcium phosphate phase all over the film surface. The ATP coupled film not subjected to lime treatment did not show calcium phosphate nucleation behaviour upon immersion in SBF solution. The Ca/P ratio of the calcium phosphate phase increase with increase in soaking time in SBF solution.     

Effect of the substitution of M2O3 (M = La, Y, In, Ga, Al) for CaO on the bioactivity of 2.5CaO x 2SiO2 glass.

Glasses were prepared whose compositions are defined by the following general formula: (2.5 - x)CaO x x/3M2O3 x 2SiO2 (0 < or = x < or = 0.6) (M = Ga, Al, In). Their bioactivity was studied "in vitro" by soaking the glasses in a simulated body fluid (SBF). The consequent formation of calcium phosphate layer was studied by means of electron microscopy (EM) equipped with an energy-dispersive system (EDS) for elemental analysis and Infrared (IR) spectroscopy. The results are compared to the literature relative to the substitution of La2O3 and Y2O3 for CaO. It is observed that, in general, the substitution of M2O3 for CaO in the binary CaO-SiO2 glass composition progressively reduces the ability to form a calcium phosphate layer on the surfaces exposed to simulated body fluid (SBF). The composition limit can be related to the ionic field strength of the substituting cation and to the CaO content of the base glass. According to the mechanism reported in the literature a silica gel-like surface layer initially forms on the surfaces exposed to SBF. The observed results can be attributed to the effect of the substitution of M2O3 for CaO on the acidic properties of the silanolic groups.