微纳米生物玻璃的体外成骨性能研究

微纳米生物活性玻璃因其具有特殊的形态结构和理化性能目前引起众多研究者的关注,但是目前对微纳米生物活性玻璃的结构及形态对细胞性能的影响研究的较少。本文通过溶胶-凝胶法结合模板仿生技术合成了具有特殊结构和形态的微纳米生物活性玻璃,并通过体外细胞实验,研究了这种微纳米结构对人骨髓间充质干细胞成骨性能(ALP,Runx2,Col1a1和OPN)的影响,结果证明具有规则形态的生物活性玻璃(SBG)相比不规则形态的生物活性玻璃(IBG)更能促进细胞的体外成骨性能,为将来设计具有特定结构的生物活性玻璃提供了参考依据。     

溶胶–凝胶生物活性玻璃的结构特征及其对糖尿病创面修复作用的研究

采用熔融法和溶胶-凝胶法分别制备了生物活性玻璃45S5和SGBG,通过SEM、BET及XRD等方法对它们的微观结构进行了表征,并建立了SD大鼠糖尿病皮肤创面模型,通过对创面愈合时间、创面愈合率以及HE染色分析,探讨了生物活性玻璃对促进糖尿病难愈创面愈合的效果。结果表明,与凡士林组相比,生物活性玻璃组能加速创面愈合,且SGBG具有纳米结构,其比表面积更大,与45S5相比能缩短糖尿病创面的愈合时间,提高愈合速度。组织学分析表明生物活性玻璃能促进肉芽组织的生长。由此表明生物活性玻璃能促进大鼠糖尿病创面的修复,且具有纳米结构的SGBG效果更好。     

钙磷硅系生物活性玻璃的溶胶-凝胶法制备与表征

采用溶胶-凝胶法制备了CaO—P2O5-SiO2生物活性玻璃，研究了原料的加入顺序的影响，确定了溶胶-凝胶生物玻璃的制备工艺；利用差热分析、X射线衍射（XRD）分析、原子吸收光谱（IR）和扫描电镜（SEM）等手段，研究了溶胶-凝胶玻璃的热演变过程及微观结构和形貌。将该生物玻璃粉与柠檬酸混合，调和固化后于模拟体液申浸泡。研究其生物活性。结果表明，所制备的生物玻璃具有良好的生物活性，能有效地诱导钙、磷离子沉积。     

磷灰石-硅灰石多孔玻璃陶瓷的制备与晶相结构研究

采用溶胶-凝胶法制备磷灰石-硅灰石(AW)生物活性玻璃陶瓷纳米前驱体粉末,前驱体粉末经热处理后,采用有机泡沫漫渍成型,烧结制备了多孔AW生物活性玻璃陶瓷.通过差热和热重分析、X射线衍射分析、红外图谱分析、扫描电镜、透射电镜等分析测试方法,对AW前驱体粉末的微观结构,及其在煅烧过程中的晶相转变进行了研究,确定了制备纳米级AW前驱体粉的最佳工艺条件,推测出微晶玻璃体中各晶相的析出温度,确定了溶胶-凝胶法制备多孔AW玻璃陶瓷的煅烧工艺,体外模拟体液浸泡实验表明材料具有较高的矿化功能和生物活性.     

电致变色纳米氧化镍薄膜的溶胶-凝胶法制备与表征

以无水氯化镍、乙醇为前驱液,加入适量的丁醇和柠檬酸为稳定剂,通过回流、水解得到稳定的溶胶;采用浸渍-提拉的方法在ITO导电玻璃上形成均匀的膜层;分析了溶胶制备中加水量的影响;研究了热处理温度对制备膜层的结构、光透过率的影响;对经过不同处理的膜层进行X射线衍射、透射电子显微镜、扫描电子显微镜、热重分析等研究表明:在空气中加热到350℃、保温30min薄膜分解为稳定的具有立方结构的NiO纳米晶;以氢氧化钾水溶液为电解质的循环伏安、电致变色实验结果表明制备的纳米氧化镍薄膜具有良好的电致变色特性.     

微纳米生物活性玻璃的细胞基因激活性能研究

微纳米生物材料目前已成为生物医用材料领域一个研究热点和难点。大量研究表明具有微纳米结构特征的生物材料表现出了积极的生物学响应。生物活性玻璃(BG)具有较高的生物活性、生物相容性,是一类重要的骨修复材料。而微纳米生物活性玻璃(MNBG)因其具有特殊的形态结构和理化性能,引起众多研究者的关注。但是目前对MNBG的研究还主要集中在制备、表征以及其表面类骨羟基磷灰石矿物在SBF溶液中的形成活性等方面,关于MNBG的细胞相容性以及基因激活性能方面的研究还鲜有报道。通过溶胶-凝胶法结合模板仿生技术合成了具有特殊微纳米结构和形态的MNBG,并将其浸提液与MG-63细胞共培养,研究生物玻璃溶出物对细胞增殖,成骨相关基因和蛋白表达的影响,结果证明相比于传统的熔融法制备的生物玻璃(45S5)浸提液,MNBG浸提液能够明显促进细胞增殖,激活细胞成骨相关基因,上调相关蛋白的表达,为设计和制备具有基因介导作用的新型生物活性玻璃骨修复材料提供了理论依据。     

溶胶–凝胶法制备高比表面积铝磷钙生物活性玻璃（英文）

采用溶胶–凝胶法,在不使用模板剂的情况下制备出高比表面积的介孔CaO-Al_2O_3-P_2O_5生物活性玻璃(MBGs),用BET、XRD、DTA以及FTIR对MBGs的结构进行了表征,并用生物模拟体液(SBF)在36.5℃对生物玻璃进行了体外活性测试,测试时间为1 d、3 d、7 d和14 d。介孔玻璃的比表面积最高达到461.1 m2/g,随着CaO的含量从5mol%增加到30mol%,介孔玻璃的比表面积呈降低趋势。用XRD和FTIR验证了材料的玻璃结构。然而,在生物模拟体液(SBF)实验中,当CaO摩尔含量达到20mol%时,介孔玻璃表现出较高生物活性。这种特殊的高比表面积的介孔铝磷钙生物活性玻璃在生物医药方面有潜在的应用价值。本文的实验结果对优化生物玻璃的介孔结构和CaO含量来提升玻璃的生物活性有一定的指导意义。     

溶胶-凝胶法制备高比表面积铝磷钙生物活性玻璃

采用溶胶-凝胶法, 在不使用模板剂的情况下制备出高比表面积的介孔CaO-Al₂O₃-P₂O₅生物活性玻璃(MBGs), 用BET、XRD、DTA以及FTIR对MBGs的结构进行了表征, 并用生物模拟体液(SBF)在36.5℃对生物玻璃进行了体外活性测试, 测试时间为1 d、3 d、7 d和14 d。介孔玻璃的比表面积最高达到461.1 m²/g, 随着CaO的含量从5mol%增加到30mol%, 介孔玻璃的比表面积呈降低趋势。用XRD和FTIR验证了材料的玻璃结构。然而, 在生物模拟体液(SBF)实验中, 当CaO摩尔含量达到20mol%时, 介孔玻璃表现出较高生物活性。这种特殊的高比表面积的介孔铝磷钙生物活性玻璃在生物医药方面有潜在的应用价值。本文的实验结果对优化生物玻璃的介孔结构和CaO含量来提升玻璃的生物活性有一定的指导意义。     

溶胶-凝胶法制备的纳米介孔材料研究进展

纳米介孔材料具有大的比表面积和孔体积、均一可调的孔道结构,已经被广泛应用在酶的固定吸附、生物催化、免疫亲和色谱、药物控释放和生物物理研究模型等方面。综述了溶胶-凝胶法制备的纳米介孔材料的最近研究进展,介绍了纳米介孔材料的种类和溶胶-凝胶制备方法,详细阐述了纳米介孔材料在固定生物活性蛋白方面的研究,并展望了纳米介孔材料在生物领域的应用。     

络合剂对溶胶凝胶制备纳米铜及其催化性能影响

为研究络合剂对纳米铜粉体的制备及其催化性能的影响,分别以柠檬酸、葡萄糖为络合剂,采用溶胶-凝胶法制备纳米铜.考察了两种络合剂对制备过程以及产物结构的影响,通过催化苯氧化合成苯酚的反应考察制得的纳米铜粉的催化性能.研究表明:葡萄糖为络合剂制得的纳米铜(G-Cu)平均粒径较小(30 nm),比表面积为5.203 m2/g,在催化苯制苯酚反应时,具有较高的苯转化率(50.30%),但对苯酚的选择性较差;而柠檬酸为络合剂制得的纳米铜(C-Cu)平均粒径为55 nm,比表面积19.517 m2/g,催化苯转化率为21.95%,选择性为38.46%.此外,通过对溶胶凝胶法制备机理分析可知,在形成的胶体结构中,柠檬酸和葡萄糖中的羧基和羟基分别与铜离子进行配位.     

Fabrication of porous bioactive glass particles by one step sintering

In this study, we reported a facile method to prepare porous bioactive glass microparticles. Porous particles were synthesized by sintering hollow bioactive glass microspheres obtained using a sol-gel co-template technology. The results showed that porous bioactive glass particles possessed a narrow particle size distribution, a relatively porous surface morphology and a hollow structure. It is worth to say that the resulting microparticles present an amorphous structure although the sintering temperature was improved compared to hollow microspheres. The presence of macropore on the shell may provide an efficient method to carry drugs in the hollow cores. Considering the high deposit rate of nanoscale apatite for bioactive glass materials, the porous microparticles should have potential applications in drug and bioactive molecules delivery, in addition to bone tissue regeneration.     

竹基多孔炭上生长一维纳米炭

采用CVD法,以二甲苯为炭源,二茂铁、氯化铁等为催化剂在竹基多孔炭上生长一维纳米炭。采用扫描电镜、透射电镜及氮吸附仪等对一维纳米炭/竹基多孔炭的形貌、微结构与比表面积进行了表征。结果表明:采用CVD法可以在不同比表面积的竹基多孔炭上生长一维纳米炭(包括炭纳米管和炭纳米纤维),竹基多孔炭的比表面积越高,所获得的一维纳米炭/竹基多孔炭复合物的比表面积越大。     

Influence of acid washing on the surface morphology of ionomer glasses and handling properties of glass ionomer cements

Acid washing is known to influence the handling properties of ionomer glasses used in glass ionomer cements due to the production of an ion depleted-zone on the surface of the glass particles. The influence of acid washing on the particle size distribution and surface area of four glasses was examined by scanning electron microscopy (SEM), particle size analysis (PSA) and accelerated surface area porosimetry (ASAP) and the working and setting times of cements, produced from the glasses, correlated to changes in surface morphology. A linear relationship was found between the specific surface area of acid-washed SiO₂–Al₂O₃–XF₂–P₂O₅ glasses (X being either calcium or strontium) and their cement working and setting times. These changes directly correlated with increases in the mesopore volume. However, the influence of acid washing on the surface morphology was also found to be glass composition-dependant with the addition of sodium into the glass network resulting in no significant change in the surface area or mesopore volume despite changes in the working and setting time. Through examination of the influence of acid washing and glass composition on the specific surface area improvements in the control of the working and setting times of glass ionomer cements may be achieved.     

Synthesis of novel tricalcium phosphate-bioactive glass composite and functionalization with rhBMP-2

A functionalization is required for calcium phosphate-based bone substitute materials to achieve an entire bone remodeling. In this study it was hypothesized that a tailored composite of tricalcium phosphate and a bioactive glass can be loaded sufficiently with rhBMP-2 for functionalization. A composite of 40 wt% tricalcium phosphate and 60 wt% bioactive glass resulted in two crystalline phases, wollastonite and rhenanite after sintering. SEM analysis of the composite’s surface revealed a spongious bone-like morphology after treatment with different acids. RhBMP-2 was immobilized non-covalently by treating with chrome sulfuric acid (CSA) and 3-aminopropyltriethoxysilane (APS) and covalently by treating with CSA/APS, and additionally with 1,1′-carbonyldiimidazole. It was proved that samples containing non-covalently immobilized rhBMP-2 on the surface exhibit significant biological activity in contrast to the samples with covalently bound protein on the surface. We conclude that a tailored composite of tricalcium phosphate and bioactive glass can be loaded sufficiently with BMP-2.     

燃料对溶液燃烧合成ZnO纳米棒微观形貌和光催化性能的影响

以蔗糖、柠檬酸、乙二醇和尿素为燃料, Zn(NO₃)₂为氧化剂/锌源, 采用溶液燃烧法合成ZnO纳米棒。借助XRD、SEM、比表面分析和光谱吸收等测试方法, 考察了不同燃料对粉体的物相组成、微观形貌、比表面积和光催化性能的影响。结果表明: 在点燃温度500℃下, 各燃料配制的前驱体溶液均可发生燃烧反应合成六方相ZnO纳米棒, 其平均径向尺寸小于100 nm, 且以尿素为燃料合成的ZnO晶形更完整, 以蔗糖为燃料合成的ZnO粉体具有最大的比表面积(24.83 m²/g)。光催化实验表明, 以蔗糖为燃料合成的ZnO粉体光催化能力最佳, 在高压汞灯照射60 min条件下, 其对甲基橙溶液(10 mg/L)的降解率可达98.2%, 且光催化反应符合一级动力学方程。     

Surface modification of titanium for load-bearing applications

Titanium and its alloys are extensively used in load-bearing metallic devices. They are bioinert material and, therefore, get encapsulated after implantation into the living body by a fibrous tissue that isolates them from the surrounding tissues. Here we report modification of titanium surface using bioactive tricalcium phosphates (TCP) and nanoscale TiO2 to enhance cell-materials interaction. We have introduced bioactivity in Ti using laser-assisted coating of TCP and by anodization to grow surface TiO2 at room temperature using a mixed aqueous solution of sodium fluoride, citric acid and sulfuric acid as electrolyte. TCP coating showed a columnar Ti grains at the substrate side of the coating and transitioned to an equiaxed grains at the outside. Coating hardness increased from 882 +/- 67 to 1029 +/- 112 Hv as the volume fraction of TCP increased in the coating. For TiO2 nanotubes, microscopic analysis showed tubes of 50 nm in diameter with wall thickness of 15 nm and typical length between 200 nm and 1 micron based on anodization times. Effects of TCP and nanoscale TiO2 coating on bone cell-material interaction were examined by culturing osteoprecursor cells (OPC1) on coated surfaces. Antibacterial activity analysis using metallic Ag via electrodeposition showed over 99% antibacterial activity against the growth of colonies of Pseudomonas aeruginosa.     

Polymer/bioactive glass nanocomposites for biomedical applications: A review

Nanoscale bioactive glasses have been gaining attention due to their reported superior osteoconductivity when compared to conventional (micron-sized) bioactive glass materials. The combination of bioactive glass nanoparticles or nanofibers with polymeric systems enables the production of nanocomposites with potential to be used in a series of orthopedic applications, including scaffolds for tissue engineering and regenerative medicine. This review presents the state of art of the preparation of nanoscale bioactive glasses and corresponding composites with biocompatible polymers. The recent developments in the preparation methods of nano-sized bioactive glasses are reviewed, covering sol–gel routes, microemulsion techniques, gas phase synthesis method (flame spray synthesis), laser spinning, and electro-spinning. Then, examples of the preparation and properties of nanocomposites based on such inorganic bionanomaterials are presented, obtained using various polymer matrices, including polyesters such as poly(hydroxybutyrate), poly(lactic acid) and poly(caprolactone), and natural-based polymers such as polysaccharides (starch, chitin, chitosan) or proteins (silk fibroin, collagen). The physico-chemical, mechanical, and biological advantages of incorporating nanoscale bioactive glasses in such biodegradable nanocomposites are discussed and the possibilities to expand the use of these materials in other nanotechnology concepts aimed to be used in different biomedical applications are also highlighted.     

Application of response surface methodology with a Box–Behnken design for struvite precipitation

Struvite crystals were precipitated by the reaction of magnesium chloride hexahydrate and ammonium dihydrogen phosphate using different concentrations of citric acid as the additive (100, 300, and 500 ppm). The structure, morphology, functional groups and particle size of the crystals were evaluated experimentally by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR) and particle size analysis. The experimental results demonstrated that citric acid exerted a significant influence on the struvite precipitation and the crystal morphology changed from rod-like to tubular shaped with a larger size and hollow bodies. The average particle size changed from 17.60 to 33.60 μm with increasing citric acid concentration. The results of FTIR suggested that the citric acid adsorbed on the crystal surface. Following the characterization of the crystals prepared using different concentrations of citric acid, the response surface methodology coupled with Box-Behnken design were applied as a statistical tool to determine the effects of the key parameters affecting the precipitation process (temperature, pH and additive concentration) on the responses (namely, particle size and specific cake resistance of struvite). Second-order polynomial equations for both responses were improved to correlate the parameters. Analysis of variance (ANOVA) showed a significant quadratic regression model with high coefficients of the determination values. The optimum conditions for particle size were found to be 60 °C, pH 8 and 500 ppm additive concentration.     

A novel way for preparing high surface area silica monolith with bimodal pore structure

The crack-free silica monolith with macropores and mesopores has successfully been achieved in the presence of citric acid as nonsurfactant via sol-gel reactions of tetramethoxysilane (TMOS). Citric acid was removed by calcination to afford monolithic bodies with high specific surface area of 648 m²/g, pore volume of 0.9 cm³/g. Poly (ethyl glycol) has been used together with citric acid to control the particle aggregation and internal structure. Macropores in the micrometer range originate from the spinodal phase separation and gelation kinetics. Textural mesopores in the 2–8 nm range are controlled through adding citric acid and postsynthesis treatment in ammonia solution. By employing the glycerol as drying control chemical additives (DCCA), cracks of the materials can be successfully avoided.     

Effect of nanoparticulate bioactive glass particles on bioactivity and cytocompatibility of poly(3-hydroxybutyrate) composites

This work investigated the effect of adding nanoparticulate (29 nm) bioactive glass particles on the bioactivity, degradation and in vitro cytocompatibility of poly(3-hydroxybutyrate) (P(3HB)) composites/nano-sized bioactive glass (n-BG). Two different concentrations (10 and 20 wt %) of nanoscale bioactive glass particles of 45S5 Bioglass composition were used to prepare composite films. Several techniques (Raman spectroscopy, scanning electron microscopy, atomic force microscopy, energy dispersive X-ray) were used to monitor their surface and bioreactivity over a 45-day period of immersion in simulated body fluid (SBF). All results suggested the P(3HB)/n-BG composites to be highly bioactive, confirmed by the formation of hydroxyapatite on material surfaces upon immersion in SBF. The weight loss and water uptake were found to increase on increasing bioactive glass content. Cytocompatibility study (cell proliferation, cell attachment, alkaline phosphatase activity and osteocalcin production) using human MG-63 osteoblast-like cells in osteogenic and non-osteogenic medium showed that the composite substrates are suitable for cell attachment, proliferation and differentiation.