溶胶-凝胶法制备生物玻璃陶瓷涂层的发展

介绍了目前制备生物玻璃陶瓷涂层的方法,总结了溶胶-凝胶技术的优缺点,重点介绍了国内外关于溶胶-凝胶法在制备生物玻璃陶瓷涂层中研究的现状.     

生物微晶玻璃的最新进展

生物微晶玻璃是很有前途的一类生物材料,各国对其研究非常活跃.目前,生物材料正向分子水平设计的方向发展,本文试图对最近几年的国内外生物微晶玻璃的研究状况和今后发展趋势予以介绍.     

CaO-P2O5-SiO2系统生物活性纳米粒子形貌和粒径分布影响因素探讨

制备了TritonX-100／正辛醇／环己烷／水微乳液,并研究了该微乳液系统稳定相行为与制备条件的关系。在稳定的微乳液系统中制备出CaO-P2O5-SiO2系统生物玻璃纳米粒子。采用X射线衍射、透射电子显微镜(TEM)和氮气吸附-解吸(BET)技术并结合测量统计法对样品的晶相、形貌、粒度进行表征。研究表明：粒子尺寸与工艺参数σ(表面活性剂与助表面活性剂的质量比)、ω(水与表面活性剂的摩摩尔比)、γ(水与醇盐的摩尔比)等有关。在σ为1．2,ω为6,7为8条件下可制得平均粒径为25nm的球形无定形态生物玻璃粒子。     

The studies of cytotoxicity and antibacterial activity of composites with ZnO-doped bioglass

The paper presents results of the studies on porous composites obtained using lyophilization method based on the solutions of the following polymers: chitosan, sodium alginate and polylactide, as well as ZnO-doped CaO–SiO₂–P₂O₅ bioglass. The researchers took the advantage of zinc ions demonstrating the bactericidal, immune-stimulating, and tissue-regenerating functions in the organism. The cytotoxicity of the composites was tested on L929 cells by means of the direct and the indirect contact method. The antibacterial properties were determined against the gram-negative bacteria Pseudomonas aeruginosa and the gram-positive bacteria Staphylococcus aureus at 24, 48 hours, and 7 days. The study demonstrated that changes due to cytotoxicity effect of the composites depend on the type of polymer and on the duration of contact with cells. The composite with polylactide was found to be the least toxic for L929 cells. ZnO added to the chemical composition of bioglass ensured bactericidal effects. The antibacterial properties of the composites depended on the ZnO content, bioglass grain size, polymer type, and composite microstructure. The composites presented in this paper are innovative as biomaterials for filling bone cavities because they can be a matrix for cells and have an antibacterial effect while supporting the regeneration of damaged tissue.     

生物玻璃陶瓷骨支架光固化3D打印及降解性能

利用光固化技术制备的生物玻璃陶瓷骨植入物在骨修复领域具有许多优势,然而生物玻璃陶瓷受粉体粒度的影响,在光固化打印工艺、结构、力学性能和生物性能等方面存在较大的差异。本文以光固化3D打印过程中粒度的变化为切入点,制备了两种不同粒度粉体的生物玻璃陶瓷浆料,分别对生物玻璃陶瓷浆料的稳定性、流变特性和固化特性进行了表征,根据TG-DSC曲线绘制了脱脂烧结曲线并对骨支架的表面质量、结构和力学性能进行了评价,最后通过颅骨修复试验对降解性能进行了分析。结果表明:小粒度粉体的浆料稳定性较好,黏度较高,对应的固化厚度和过固化宽度也较小;小粒度粉体制备的骨支架表面质量、结构致密化程度和弯曲强度均优于大粒度粉体制备的骨支架,但降解速率较低,植入体内2个月后有新骨长入骨支架孔隙。本研究对不同粒度粉体的生物玻璃陶瓷骨支架制备具有指导意义,有助于推动基于粒度分布的梯度可控降解骨支架的开发和应用。     

用硅烷偶联剂处理生物玻璃表面及其复合支架的制备

为了改善溶胶-凝胶生物活性玻璃与高分子材料的相容性,用硅烷偶联剂氨丙基三乙氧基硅烷对生物活性玻璃进行表面处理,并用X射线光电子能谱对处理后的生物活性玻璃的表面进行元素分析.结果表明:偶联剂通过Si-O-Si键被引入到生物活性玻璃表面.用处理后的生物活性玻璃与壳聚糖-明胶复合制备了多孔支架.扫描电子显微镜观察发现:复合多孔支架的两相相容性好,界面结合紧密;支架的孔隙连通、排列规则.力学测试表明:改性后的溶胶-凝胶生物活性玻璃与壳聚糖-明胶制备的复合支架力学性能得到明显改善.     

Vancomycin loaded-mesoporous bioglass/hydroxyapatite/chitosan coatings by electrophoretic deposition

In the current research, vancomycin loaded-mesoporous bioglass/hydroxyapatite whiskers/chitosan composite coatings with drug delivery capability were fabricated on titanium substrate via electrophoretic deposition. Hydroxyapatite with whisker morphology demonstrated improvement in microhardness of the coatings. Among different initial vancomycin concentrations of 1, 5, 15, 25 and 50 mg/ml to load mesoporous bioglass particles, maximum loading efficiency and drug content (95%) were achieved at 25 mg/ml. Based on the quality of the coatings, bioglass loaded with initial concentrations of 1, 5 and 15 mg/ml drug were chosen as optimal samples for further investigations. Synergistic effect of bioglass and hydroxyapatite caused the composition with 20% and 50%Wt MBG to have faster bioactivity response. Regarding the drug delivery capability of the composite coatings, sample containing 50%Wt bioglass encapsulated with 15 mg/ml drug exhibited rapid and maximal drug release due to the facile diffusion of the solved bioglass particles. The achieved results showed the acceptable antibacterial potency of vancomycin-loaded coating to prevent infection. Moreover, existence of antibiotic did not have any toxic effect over the osteoblast cells cultured on the coatings.     

Thermal and mechanical properties of UHMWPE/HDPE/PCL and bioglass filler: Effect of polycaprolactone

Polymeric composites based on polyethylene, high-density polyethylene (HDPE) and ultra-high-molecular-weight polyethylene (UHMWPE) with polycaprolactone (PCL) and a ceramic filler (bioglass type) were studied in terms of their thermal and mechanical behavior. Two polyethylene ratios (10/90 and 30/70% wt/wt of UHMWPE/HDPE) and two PCL content ratios (5% and 10% wt/wt) were used. The obtained composites were characterized by differential scanning calorimetry, melt flow index, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The results indicate a nonchemical interaction between polyethylene, especially the UHMWPE, and PCL and that the composites' thermal transitions vary from the parent polymers and depend on the PCL concentration. The PCL's melting temperature in the composite was reduced, showing a new one. Also, the melting enthalpy of polyethylene was reduced when the concentration of PCL increased. The mechanical behavior depends on both the polyethylene ratio and the PCL content. The composite with 30% wt/wt of UHMWPE and 10% wt/wt of PCL showed the highest toughness value due to the good interaction between polymers. These new composites may be attractive for biomedical applications and could be evaluated, for example, as materials for prostheses.     

Y-TZP对生物微晶玻璃涂层组织结构的影响

为了弥补生物微晶玻璃力学性能较差,脆性大的不足之处,试验采用亚音速火焰喷涂方法及涂层处理技术,以Ti6Al4V为基体喷涂制备生物微晶玻璃涂层,并添加一定量Y-TZP,研究其对涂层组织与结构的影响.结果表明：Y-TZP有抑制生物微晶玻璃涂层裂纹的能力,同时其在热喷涂及晶化处理过程中表现出良好的相稳定性能,涂层为四方氧化锆与羟基磷灰石微晶的混合相,这保证了涂层的生物性能,同时有利于提高涂层的韧性.     

Mechanical properties and aging behaviour of Y-TZP with 64S bioglass additions for dental restorations

Yttria-partially stabilised zirconia (Y-TZP) of 3?mol-% with 5.4, 10.5 and 19.9 vol.-% 64S bioglass compacts was sintered at 1300–1500°C. The influence of 64S content and sintering temperature on the mechanical properties and aging behaviour of Y-TZP ceramics were studied. Among Y-TZP ceramics with 64S additions, maximum hardness and flexural strength values were found for Y-TZP with 10.5 vol.-% 64S at 1400°C. Y-TZP with 19.9 vol.-% 64S at 1500°C presented the highest fracture toughness; crack deflection and pinning by ZrSiO₄ particles combined with zirconia microcracking contributed to the fracture toughness. Y-TZP at 1500°C was extremely susceptible to hydrothermal degradation and its flexural strength markedly decreased after aging. On the contrary, Y-TZP with 10.5 vol.-% 64S at 1400°C remained almost unaltered; it maintained its flexural strength at a high level during aging, becoming the most promising ceramic in terms of mechanical properties and aging behaviour.