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81.
背景:近年来聚乳酸、羟基磷灰石类复合材料支架具有良好的生物降解性和生物相容性而被广泛的研究,但是这类复合材料在增强材料界面的结合、调节材料的降解速率、改善材料的强度等方面仍不能满足理想的组织工程支架材料的要求。 目的:探讨电纺丝法制备纳米纤维的结构形态及表面亲水性。 方法:分别将聚乳酸、聚3羟基丁酸酯共聚4羟基丁酸酯和聚碳酸亚丙酯通过静电纺丝法制备纳米纤维膜,扫描电镜对纤维膜的结构形态进行分析,并观察在人体环境相近的磷酸盐缓冲溶液(37 ℃,pH 7.4)中浸泡不同时间的表面亲水性。 结果与结论:通过静电纺丝技术可以将聚乳酸、聚3羟基丁酸酯共聚4羟基丁酸酯和聚碳酸亚丙酯3种材料制备成微纳米纤维结构,控制制备参数可以获得不同直径的纤维,样品随着在培养液中的浸泡时间延长,总体显示出接触角比初始降低,亲水性增强。 关键词:聚乳酸;聚3羟基丁酸酯共聚4羟基丁酸酯;聚碳酸酯;电纺丝;亲水性 doi:10.3969/j.issn.1673-8225.2010.12.046  相似文献   
82.
The demand for lightweight, high-modulus, and temperature-resistant materials for aerospace and other high-temperature applications has contributed to the development of ceramic fibers that exhibit most of the favorable properties of monolithic ceramics. This review demonstrates preceramic-based polymer fiber spinning and fiber classifications. We discuss different types of fiber spinning and the advantages of each. Tuning the preceramic polymer chemical properties, molar mass, functional chemistry influences, and incorporation with fillers are thoroughly investigated. Further, we present the applications of preceramic-based polymer fibers in different fields including aerospace, biomedical, and sensor applications. This concise review summarizes recent developments in preceramic fiber chemistry and essential applications.  相似文献   
83.
静电喷射是一种简易的获得纳米粒子或纤维状物质的方法。利用这种技术能够将药物封装在聚合物纳米颗粒或纤维材料之中,从而提高药物的分散性与稳定性,延长药物的作用时间,降低毒副作用,并可制成靶向性制剂。通过选择不同的聚合物体系,调节静电喷射工艺参数,可以控制药物的释放速度和释放周期,从而设计制备出具有快速、缓慢、持续或阶段性等不同释药特性的制剂。本文旨在讨论静电喷射技术的基本原理及其在制备纳米控释材料的研究进展,并对静电喷射技术应用于制备纳米中药缓/控释给药系统的前景进行展望。  相似文献   
84.
In this study, nanofibers of poly (acrylic acid) (PAAc), polyacrylamide (PAAm) and poly (vinyl alcohol) (PVOH) were prepared using the electrospinning technique. Based on the Taguchi DOE (design of experiment) method, the effects of electrospinning parameters, i.e., needle tip to collector distance, polymer solution concentration, applied voltage, polymer solution feed rate and polymer type, on the diameter and morphology of polymer nanofibers were evaluated. Analyses of the experiments for the diameters of the polymer nanofibers showed that the type of polymer was the most significant factor. The optimal combination to obtain the smallest diameters with minimum deviations for electrospun polymer nanofibers was also determined. For this purpose, the appropriate factor levels were determined as follows: polymer PAAm, applied voltage 10 kV, delivery rate 0.1 mL/h, needle tip to collector distance 10 cm, and polymer solution concentration 8%, to obtain the thinnest nanofibers. This combination was further validated by conducting a confirmation experiment, and the average diameter of the polymer nanofibers was found to be close to the optimal conditions estimated by the Taguchi DOE method.  相似文献   
85.
Conventional manufacturing of pharmaceutical tablets often involves single processes such as blending, granulation, milling and direct compression. A process that minimizes and incorporates all these in a single continuous step is desirable. The concept of omitting milling step followed by direct-molding of tablets utilizing a twin-screw extruder in a melt granulation process using thermoplastic binders was explored. The objective of this study was to investigate the effect of combining hydrophilic binder (HPMC K4M, PEO 1M), and hydrophobic binder (Compritol® ATO 888, Precirol® ATO 5) on the release profiles of direct-molded tablets and direct-compressed tablets from milled extrudates using a quality-by-design approach. It was identified that hydrophilic binder type and process significantly affects (p = 0.005) the release profiles of verapamil. Moreover, two-way interaction analysis demonstrated that the combination of process with type of hydrophilic polymer (p = 0.028) and the type of hydrophilic polymer with polymer ratio (p = 0.033) significantly affected the release profiles. The formulation release kinetics correlated to Higuchi release model and the mechanism correlated to a non-Fickian release mechanism. The results of the present study indicated that direct-molded tablets with different release profiles can be manufactured without milling process and through a continuous melt granulation using twin-screw extruder with appropriate thermoplastic binder ratio.  相似文献   
86.
This perspective involves two types of functional nanomaterials, amyloid fibrils and metal oxide nanowires and nanogrids. Both the protein and the inorganic nanomaterials rely on their polymorphism to exhibit diverse properties that are important to sensing and catalysis. Several examples of novel functionalities are provided from biomarker sensing and filtration applications to smart scaffolds for energy and sustainability applications.  相似文献   
87.
This paper examines the electrochemical and microstructural features of SrCo0.8Fe0.1Ga0.1O3−δ (SCFG) with a fibrous structure infiltrated by an SDC electrolyte for use as a cathode in solid oxide fuel cells (SOFCs). An electrospinning process is used to produce SCFG fibers. In a symmetrical cell, Sm0.2Ce0.8O1.9 (SDC) nanoparticles are infiltrated into the porous fibrous SCFG cathode layer after it was applied to the SDC dense electrolyte. Electrochemical impedance spectroscopy (EIS) analysis reveals that the polarization resistance of the SCFG cathode with fiber morphology is significantly lower than that of the same combination with powder morphology. In addition, it is shown that infiltration of SDC oxygen ion conductor nanoparticles enhanced electrochemical performance. The lowest value of polarization resistance, 0.03 Ω cm2 at 800 °C, is attained by the SCFG with a fibrous structure containing 14 wt% SDC nanoparticles.  相似文献   
88.
布洛芬聚乙二醇-b-聚L-乳酸电纺超细纤维毡的药物释放   总被引:1,自引:0,他引:1  
目的 通过静电纺丝制备同时包载有布洛芬的聚乙二醇-b-聚L-乳酸纤维毡,并在纤维中添加月桂酸,考察月桂酸是否对纤维中药物的释放行为有影响。方法以聚乙二醇嵌段聚乳酸为载体材料,有机溶液高压静电法纺丝法制得同时包载布洛芬和月桂酸的纤维毡,采用ESEM、WAXD和DSC对其进行表征研究,采用HPLC法测定布洛芬在含有蛋白酶K的磷酸缓冲盐溶液中的释放行为。结果ESEM结果显示得到添加有月桂酸的聚乙二醇聚乳酸纤维药物释放体系,WAXD扫描显示纤维表面无药物结晶析出,说明其对布洛芬和月桂酸完全包封,药物体外释放表明添加月桂酸后,药物释放速率加快明显。结论在聚乙二醇-聚乳酸超细纤维添加月桂酸可加快纤维中布洛芬的释放,蛋白酶K的降解也可加快布洛芬的释放。  相似文献   
89.
A capability for effective tissue reparation is a living requirement for all multicellular organisms. Bone exits as a precisely orchestrated balance of bioactivities of bone forming osteoblasts and bone resorbing osteoclasts. The main feature of osteoblasts is their capability to produce massive extracellular matrix enriched with calcium phosphate minerals. Hydroxyapatite and its composites represent the most common form of bone mineral providing mechanical strength and significant osteoinductive properties. Herein, hydroxyapatite and fluorapatite functionalized composite scaffolds based on electrospun polycaprolactone have been successfully fabricated. Physicochemical properties, biocompatibility and osteoinductivity of generated matrices have been validated. Both the hydroxyapatite and fluorapatite containing polycaprolactone composite scaffolds demonstrated good biocompatibility towards mesenchymal stem cells. Moreover, the presence of both hydroxyapatite and fluorapatite nanoparticles increased scaffolds’ wettability. Furthermore, incorporation of fluorapatite nanoparticles enhanced the ability of the composite scaffolds to interact and support the mesenchymal stem cells attachment to their surfaces as compared to hydroxyapatite enriched composite scaffolds. The study of osteoinductive properties showed the capacity of fluorapatite and hydroxyapatite containing composite scaffolds to potentiate the stimulation of early stages of mesenchymal stem cells’ osteoblast differentiation. Therefore, polycaprolactone based composite scaffolds functionalized with fluorapatite nanoparticles generates a promising platform for future bone tissue engineering applications.  相似文献   
90.
目的:探讨搭载不同浓度紫杉醇脂质体的聚乳酸-羟基乙酸共聚物(PLGA)静电纺丝膜对神经干细胞(NSCs)增殖和分化的影响,评价载有紫杉醇脂质体的PLGA静电纺丝膜在脊髓损伤组织工程修复中应用的可行性。方法:将紫杉醇脂质体和PLGA以不同比例混合,利用静电纺丝技术分别构建1、5和10 μg·L-1紫杉醇脂质体PLGA静电纺丝膜。从胎鼠大脑组织中分离纯化NSCs。扫描电镜(SEM)检测各组紫杉醇脂质体PLGA静电纺丝膜纤维直径,免疫荧光染色鉴定分离纯化所得的NSCs。将NSCs分别培养在含有不同浓度(0、1、5和10 μg·L-1)紫杉醇脂质体PLGA静电纺丝膜的培养基中(作为纯PLGA静电纺丝膜组和1、5及10 μg·L-1紫杉醇脂质体PLGA静电纺丝膜组),MTT法检测各组NSCs增殖活性,RT-PCR法检测各组NSCs中Tuj-1和GFAP mRNA表达水平。结果:紫杉醇脂质体PLGA静电纺丝膜呈白色薄膜状。SEM检测,各组紫杉醇脂质体PLGA静电纺丝膜纤维直径比较差异无统计学意义(P>0.05)。免疫荧光染色,从胎鼠脑组织中分离出的细胞呈球状,所有细胞均有Nestin蛋白阳性表达。MTT法检测,5 μg·L-1紫杉醇脂质体PLGA静电纺丝膜组NSCs增殖活性高于其他3组(P<0.05)。RT-PCR检测,与纯PLGA静电纺丝膜组比较,5 μg·L-1紫杉醇脂质体PLGA静电纺丝膜组NSCs中Tuj-1 mRNA表达水平升高(P<0.05),GFAP mRNA表达水平降低(P<0.05)。结论:中等浓度紫杉醇能够促进NSCs增殖,诱导NSCs向神经元分化。载有中等浓度紫杉醇脂质体的PLGA静电纺丝膜在脊髓损伤修复中有一定的应用价值。  相似文献   
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