半乳糖酰化壳聚糖衍生物包复的5-氟尿嘧啶白蛋白微球的制备

目的:制备肝靶向的半乳糖酰化壳聚糖衍生物包复的5-氟尿嘧啶白蛋白微球.方法:采用乳化-交联固化法制备了5-氟尿嘧啶白蛋白微球,分别以均匀设计和单因素处方分析优化了该制备工艺,然后在其表面通过静电作用力包裹壳聚糖衍生物,采用正交实验设计确定最佳包裹条件,得到壳聚糖衍生物包复的5-氟尿嘧啶白蛋白微球.结果:优化后的制备条件为:5-氟尿嘧啶浓度10 μg/ml,w/o体积比1/20,戊二醛加入量1.0 ml/100 mg牛血清白蛋白,固化时间4 h,衍生物包复时包裹时间10 min,衍生物浓度2%,冰醋酸浓度2%.结论:本法简便、易操作,实验设计方案经济有效.     

Evaluation of different mannan polysaccharide usage in enzyme-linked immunosorbent assay for specific antibodies determination

Polysaccharides as antigens impose the problem of the proper ELISA assay. The indirect coating using biotin-avidin or lectins are therefore used. We tried to clarify the efficiency of different approaches to this problem. Our experiments clearly demonstrate that direct coating with mannan polysaccharide on high binding ELISA plates is superior to any other combination using any intermediate protein. On the other hand, the direct coating of the normal ELISA plate with mannan was of significantly lower (P=0.008) efficiency. The use of protein cannot be avoided in normal microplates. All previous statements are supported by experimental data in the paper.     

Fabrication and in vitro characterization of magnetic hydroxycarbonate apatite coatings with hierarchically porous structures

Hydroxycarbonate apatite/Fe(3)O(4) composite coatings (MHACs) with hierarchically porous structures were fabricated by electrophoretic deposition of CaCO(3)/Fe(3)O(4) particles on Ti6Al4V substrates followed by treatment with phosphate buffer solution (PBS) at 37 degrees C. The effects of Fe(3)O(4) on the conversion rate of calcium carbonate to hydroxycarbonate apatite and the porous structures and in vitro bioactivity of MHACs were investigated. After soaking CaCO(3)/Fe(3)O(4) coatings in PBS, hydroxycarbonate apatite nucleates heterogeneously on the surfaces of CaCO(3)/Fe(3)O(4) particles and forms a plate-like structure. Fe(3)O(4) increases the velocity of nucleus formation of hydroxycarbonate apatite. After soaking for 1day, the percentage of unreacted calcium carbonate for MHACs is approximately 9.1%, lower than the approximately 41.0% for hydroxycarbonate apatite coatings (HCACs). As the CaCO(3)/Fe(3)O(4) coatings are converted to MHACs, macropores with a pore size of approximately 4mum on the coatings and mesopores with a pore size of approximately 3.9nm within the hydroxycarbonate apatite plates are formed. The mesopores remain in the MHACs after treatment with PBS for 9 days, while they disappear in the HCACs. Simulated body fluid immersion tests reveal that Fe(3)O(4) improves the in vitro bioactivity of biocoatings. The amount of bone-like apatite precipitated on the surfaces of MHACs is greater than that on the surfaces of HCACs.     

Tribological characterization of a biocompatible thin film of UHMWPE on Ti6Al4V and the effects of PFPE as top lubricating layer

Ultra-high molecular weight polyethylene (UHMWPE) thin film was coated onto Ti6Al4V alloy specimens using dip coating method. Tribological performance of this coating (thickness of 19.6±2.0 μm) was evaluated using 4 mm diameter Si₃N₄ ball counterface in a ball-on-disk tribometer. Tests were carried out for different normal loads (0.5, 1.0, 2.0 and 4.0 N) and rotational speeds of the disk (200 and 400 rpm). UHMWPE coating formed in this study exhibits high hydrophobicity with water contact angle of 135.5±3.3° and meets the requirements of cytotoxicity test using the ISO 10993-5 elution method. This coating shows low coefficient of friction (0.15) and high wear durability (>96,000 cycles) for the tested conditions. PFPE overcoat on UHMWPE has further increased the wear durability of UHMWPE coating as evaluated at even higher rotational speed of 1000 rpm.     

钛基植人物生物陶瓷涂层的研究进展

医用钛合金材料属于生物惰性材料,广泛应用于硬组织的替换与修复领域.采用表面改性技术在钛基材料表面制成生物陶瓷涂层可改善钛基材料的生物活性和生物相容性.羟基磷灰石涂层已在临床上获得应用,但使用效果仍然受其较低的结合强度和结晶度所制约.为了获得综合性能更好的植入材料,制备了多种新型生物陶瓷涂层,其具有良好的生物活性、较好的...     

基于室内自然光源的色差校正方法在舌象苔色中的应用研究

目的:评价拓扑剖分影射(TRM)方法在临床舌苔图像颜色校正中的应用价值。方法:本实验运用TRM方法对临床410例苔色进行色彩还原和分析,尝试进行舌象颜色特征分类。结果:舌象的人工分类与Fisher's判别分类一致性检验结果:395例白苔、淡黄苔、正黄苔一致性检验结果K=0.544;395例白苔和黄苔一致性检验结果K=0.665。结论:TRM校正方法能明显校正室内自然光源下的舌象图像色差,并且使用方便,在舌象信息采集与分析、远程诊断等方面具有较强的实用价值。     

Application of starch-albumen powder as breading material in fried foods: An optimization study

The potential of using starch-albumen powder (SAP) as solid coating powder for fried food application was studied. Egg albumen was mixed with 10–30% dried starch and dried at 40–60°C air velocity of 4.5 m/s to produce SAP. SAP was used to coat wet yam chips prior to frying at 180°C for 3 min. The drying temperature and starch content in SAP significantly affected the oil uptake and moisture of fried chips. The increased amount of albumen (or reduced starch) content significantly reduced oil uptake. The sensory attributes influenced the overall acceptability of the fried chips in the order of taste > flavor > texture > appearance. To minimize oil uptake and moisture content and maximize acceptability of the fried chips, SAP dried at temperature of 40°C with starch content of 11.3% should be used. The study further indicates the potential of using SAP as coating in some other food products.     

Hydrophobicity of graphene as a driving force for inhibiting biofilm formation of pathogenic bacteria and fungi

Objective

To evaluate the surface and wettability characteristics and the microbial biofilm interaction of graphene coating on titanium.

Influence of implant properties and local delivery systems on the outcome in operative fracture care

Fracture fixation devices are implanted into a growing number of patients each year. This may be attributed to an increase in the popularity of operative fracture care and the development of ever more sophisticated implants, which may be used in even the most difficult clinical cases. Furthermore, as the general population ages, fragility fractures become more frequent. With the increase in number of surgical interventions, the absolute number of complications of these surgical treatments will inevitably rise. Implant-related infection and compromised fracture healing remain the most challenging and prevalent complications in operative fracture care. Any strategy that can help to reduce these complications will not only lead to a faster and more complete resumption of activities, but will also help to reduce the socio-economic impact. In this review we describe the influence of implant design and material choice on complication rates in trauma patients. Furthermore, we discuss the importance of local delivery systems, such as implant coatings and bone cement, and how these systems may have an impact on the prevalence, prevention and treatment outcome of these complications.     

新型肝素化聚氨酯涂层三氧化二砷洗脱支架的初步研究

目的研究新型三氧化二砷洗脱支架(AES)的涂层材料的生物相容性及其药物释放的特征及初步功效。方法以肝素化聚氨酯为药物支架涂层材料,三氧化二砷(As2O3)为药物,成功制备新型AES,研究其在(37±0.5)℃、体外磷酸盐缓冲溶液(PBS,pH值=7.4)中的释放规律。在体内比较AES与金属裸支架(BMS)植入4周时的相关组织反应及血管内膜增生的情况,观察支架表面的内皮化进程及内皮功能恢复情况。结果支架所载药物在1周内全部释放。支架植入1周后,AES植入处的冠状动脉平滑肌细胞凋亡率为(62.6±9.6)%,显著高于BMS及单聚合物涂层支架(PCS)植入处的(18.1±3.3)%及(21.2±5.3)%(P值均<0.05)。AES植入处血管的管腔面积较BMS及PCS植入处显著增加(P值均<0.05),而内膜面积、支架内再狭窄(ISR)发生率及内膜厚度均显著减少(P值均<0.05)。支架植入4周后,BMS及AES植入处表面均内皮化完全。以60mg/mL的速度注入乙酰胆碱,BMS、PCS、AES植入处血管的平均收缩率分别为(21.7±4.5)%、(20.4±3.7)%、(23.3±4.2)%,3种支架间的差异无统计学意义(P>0.05)。结论新型聚氨酯涂层的AES具有良好的生物相容性,其药物释放在动物冠状动脉支架植入模型中可有效抑制内膜增生,并具有较好的内皮覆盖性能。该支架的深入研究及优化有望为临床提供一种在减少ISR发生的同时,可降低不良事件发生率的新型内皮友好型支架。