负载鸢尾素微溶胶静电纺丝促进神经干细胞分化

目的 探究负载鸢尾素微溶胶的静电纺丝支架对神经干细胞分化的影响.方法 用微溶胶静电纺丝技术制备负载鸢尾素的静电纺丝支架(PLLA),使用透射电镜(TEM)检测纤维支架的内部结构,使用扫描电镜(SEM)检测纤维支架的形貌特征.通过等离子技术将鸢尾素枝接于静电纺丝支架,并测定其释放曲线.提取SD大鼠胎鼠海马区神经干细胞,通...     

应用石墨烯改良PLCL/Gel纳米纱支架材料的可行性分析

目的探索应用石墨烯(Gr)改良聚-L-丙交酯-己内酯/明胶(PLCL/Gel)纳米纱支架材料的可行性。方法采用自制的静电纺丝装置分别制备PLCL-Gel和Gr-PLCL-Gel水纺纳米纱支架材料。使用体视显微镜、扫描电子显微镜观察支架材料形态结构;通过拉伸试验观察该材料机械强度;采用CCK-8实验评价支架生物相容性,并将支架植入大鼠皮下,观察细胞浸润情况。结果拉伸试验显示,加入石墨烯可明显提高支架的力学性能。两组支架都无明显细胞毒性,在体内外实验中均表现出良好的生物相容性,体内实验表明石墨烯在一定程度上减轻了炎症反应。结论应用石墨烯改良PLCL/Gel纳米纱支架材料,可以获得具有合适力学性能、亲水性、生物相容性的纳米纱支架材料,在组织工程皮肤等方面具有应用潜能。     

静电纺丝壳聚糖-明胶复合纤维的制备和体外生物相容性评价

目的采用静电纺丝技术制备壳聚糖-明胶复合纤维,体外评价其生物相容性。方法采用扫描电镜(SEM)观察纤维支架的表面形貌,考察纺丝溶液浓度、黏度以及壳聚糖/明胶质量比对纤维直径和结构的影响。将人成纤维细胞接种在纤维支架表面,绘制细胞生长曲线,观察细胞在支架表面的形态。结果通过静电纺丝技术,制备的壳聚糖-明胶复合纤维均匀、光滑,无珠状结构,纤维平均直径为600 nm～1.6μm。随着纺丝溶液浓度和黏度增加,纤维平均直径增大;随着壳聚糖/明胶质量比增加,纤维直径也随之增大。成纤维细胞在复合纤维支架上生长良好,增殖快,并且保持较好的成纤维细胞形态。结论通过静电纺丝技术制备的壳聚糖-明胶复合纤维具有良好的生物相容性,有望作为皮肤组织工程的支架材料。     

静电纺丝纳米纤维在骨组织工程中的应用

静电纺丝纳米纤维技术在生物医学领域有着广泛的应用研究,其在骨组织工程应用中仍未解决的问题是同时满足材料的生物相容性、可降解性、生物活性和力学性能。骨组织工程主要构成要素是支架、细胞和生长因子。静电纺丝复合纳米纤维支架材料具有纳米级别的天然骨分级结构和天然骨的多孔结构,改进复合支架材料可促进细胞的浸润生长、干细胞分化和组织形成。本文重点探讨通过静电纺丝技术改进复合支架的性能,及其在动物实验研究方面的最新进展。     

静电纺丝技术在纤维环组织工程支架中的应用进展

采用静电纺丝技术制备的组织工程支架具有高表面积比和高孔隙率,因此近年来广泛用于纤维环组织工程的研究。聚己内酯等多种材料已被成功用于制备成各种纤维环组织工程支架,在纤维环缺损修复中取得良好效果,而静电纺丝技术则为纤维环组织工程支架材料的制备提供了新途径。随着该技术的日益完善,其在纤维环组织工程支架制备领域的应用前景将更为广阔。该文就近年静电纺丝技术在纤维环组织工程支架中的应用作一综述。     

取向蚕丝蛋白支架与间充质干细胞的复合培养

目的探讨不同表面结构的蚕丝蛋白纳米纤维对间充质干细胞生长增殖及分化的影响。方法运用静电纺丝技术制备具有不同取向度的蚕丝蛋白纳米纤维支架,检测不同材料结构的力学性质,分离并纯化骨髓间充质干细胞与取向／非取向纳米纤维支架共培养,以纯蚕丝蛋白膜作对照。测定其细胞毒性及细胞增殖率;扫描电镜观察细胞形态、生长、分布及与材料黏附情况。免疫荧光显微镜观察细胞核形态及细胞骨架排列情况。结果扫描电镜观察显示采用静电纺丝法制备的取向蚕丝蛋白纳米纤维支架呈交互编织的多孔网状结构,取向及非取向两种纳米材料生物相容性好,可促进骨髓间充质干细胞的稳定增殖,并沿纤维长轴分布排列。力学测试中取向蚕丝蛋白纳米纤维材料展示出较强的力学各向异性。结论取向蚕丝蛋白纳米纤维具有独特的生物学和力学性质,是一种在骨缺损修复方面具有潜力的组织支架材料。     

静电纺丝制备PLGA纤维支架的初步研究

目的 以PLGA为材料,采用静电纺丝方法制备了纤维支架,考察制备参数对纤维支架结构的影响规律.方法 本实验以氯仿为溶剂,调节PLGA溶液浓度和流量分别制备了具有不同表面形貌的纤维支架.通过扫描电镜(SEM)研究了纺丝溶液的浓度、流量对纤维形貌和直径的影响.结果 随着纺丝溶液浓度的增加,纤维直径增大,支架结构中纤维比例增加.而随着流量的增加,纤维直径略有增大,液滴增多且逐渐聚集成团.结论 当其他参数一定时,溶液浓度过低或流速过大均无法得到理想的纤维结构.     

新型3D打印PLCL/Col多孔复合支架的制备及初步表征

背景:组织工程支架为组织缺损修复提供了一种可供选择的新方法。低温快速成型技术(LDM)是一种3D打印支架成型技术,具有显著的优势,可用于制备新型的多孔支架。目的:采用LDM制备新型3D打印PLCL/Col多孔复合支架。方法:采用新溶剂系统六氟异丙醇/1,4-二氧六环(HFIP/DIO)同时溶解天然材料Ⅰ型胶原蛋白(Col)和合成材料左旋乳酸-己内酯共聚物(PLCL),配置的溶液被LDM打印成PLCL/Col复合材料支架。通过扫描电子显微镜表征支架形貌结构,红外光谱检测支架组分,并对其进行初步力学观测。结果:通过形态结构表征证实3D打印复合支架有规则的相互连通的一级大孔隙,并且在所打印的线条内还有微米级的次级孔隙。虽然所打印支架有收缩,但其孔径尺寸较大,孔隙率均在85%左右。通过红外光谱检测证实Col的存在,证实所打印支架为复合材料支架。初步的力学观测表明所打印支架具有良好的力学性能和形变恢复能力。结论:所制备新型3D打印多孔PLCL/Col支架有良好的结构和力学性能,有用于组织缺损修复的潜能。     

静电纺丝的主要参数对PLGA纤维支架形貌和纤维直径的影响

目的 以聚乳酸-羟基乙酸共聚物(PLGA)为材料,采用静电纺丝方法制备纤维支架,考察制备参数对纤维支架结构及纤维直径的影响规律.方法 本实验以四氢呋喃(THF)和N,N-二甲基甲酰胺(DMF)的混合液为溶剂,调节PLGA溶液浓度、流量及电场强度分别制备了具有不同表面形貌的纤维支架.通过扫描电镜(SEM)观察了纺丝溶液的浓度、流量及电场强度对纤维形貌和直径的影响.结论 随着纺丝溶液浓度的增加,纤维直径逐渐增大,纤维直径的分布也随之增大.随着流量的增加,纤维直径略有增大.随着电场强度的增大,纤维直径没有明显的变化.但是电压和浓度的增大有助于减少珠丝的产生.     

小口径聚乳酸-己内酯/纤维蛋白原管形支架的构建及生物相容性评价

目的探索静电纺丝技术制备小口径聚乳酸-己内酯[P(LLA-CL)]/纤维蛋白原管形支架的方法,评价支架的生物相容性,探讨其作为血管组织工程材料的可行性。方法以P(LLA-CL)、纤维蛋白原为原料,制备小口径复合管形支架,观察支架的大体形态,并用扫描电镜观察三维结构;利用溶血试验、细胞毒性试验、皮下植入试验,评价支架材料的生物相容性。结果管形支架表面呈网格状三维结构,并有大小不等、互相交通的孔隙,孔径平均直径为(4.56±1.23)μm,表面纤维平均直径(318±56)nm;P(LLA-CL)/纤维蛋白原浸提液溶血率为2.87%±0.49%;细胞毒性实验示P(LLA-CL)/纤维蛋白原浸提液较阴性对照组无明显差异(P>0.05);皮下植入试验显示P(LLA-CL)/纤维蛋白原支架炎症反应轻微,材料逐渐降解。结论通过静电纺丝技术可以构建小口径P(LLA-CL)/纤维蛋白原管形支架,并具有良好的生物相容性,可作为组织工程血管的支架材料。     

单层组织工程纤维环取向纳米纤维支架的构建和初步验证

目的 使用静电纺丝技术构建取向纳米纤维支架,观测其结构,测试其力学特点,观察支架与细胞之间的相互作用,探讨其作为纤维环组织工程支架的可能性.方法 使用高速滚轴作为收集装置制备聚左旋乳酸聚己内酯[poly（lactic acid-co-caprolactone,P（LIA-CL）]取向纳米纤维支架.以P（LLA-CL）无规纳米纤维支架作为对照,观察取向纳米纤维支架的纤维直径、角度分布、孔径等表观指标;测试其拉伸力学行为;体外接种骨髓间充质干细胞观察其体外增殖和生长形态情况.结果 P（LLA-CL）取向纳米纤维支架纤维取向性良好,平行于纤维方向上的拉伸力学性能得到明显增强.接种细胞后,支架可促进细胞增殖,并诱导细胞沿着纤维方向拉伸并定向排列.结论 取向纳米纤维支架的力学强度在取向方向上得到了明显增强,具有和单层纤维环相似的各向异性力学特点,并可以诱导细胞沿纤维方向定向排列,细胞分布与纤维环细胞排列方式相似,可用于纤维环组织工程研究.     

Electrospinning approaches toward scaffold engineering--a brief overview

Tissue engineering involves the in vitro seeding of cells onto scaffolds which assume the role of supporting cell adhesion, migration, proliferation, and differentiation, and which define the three-dimensional shape of the tissue to be engineered. Among the various types of scaffold architectures available, scaffolds based on nanofibers mimicking to a certain extent the structure of the extracellular matrix offer great advantages. Electrospinning is the technique of choice for the preparation of such scaffolds. Investigations have revealed that the nanofibrous structure promotes cell adhesion, proliferation, and differentiation. Parameters relevant for these processes such as fiber diameters, surface topology, porosity, mechanical properties, and the fibrous architecture of the scaffold can be controlled by electrospinning in a broad range.     

Meniscus tissue engineering using a novel combination of electrospun scaffolds and human meniscus cells embedded within an extracellular matrix hydrogel

Meniscus injury and degeneration have been linked to the development of secondary osteoarthritis (OA). Therapies that successfully repair or replace the meniscus are, therefore, likely to prevent or delay OA progression. We investigated the novel approach of building layers of aligned polylactic acid (PLA) electrospun (ES) scaffolds with human meniscus cells embedded in extracellular matrix (ECM) hydrogel to lead to formation of neotissues that resemble meniscus‐like tissue. PLA ES scaffolds with randomly oriented or aligned fibers were seeded with human meniscus cells derived from vascular or avascular regions. Cell viability, cell morphology, and gene expression profiles were monitored via confocal microscopy, scanning electron microscopy (SEM), and real‐time polymerase chain reaction (PCR), respectively. Seeded scaffolds were used to produce multilayered constructs and were examined via histology and immunohistochemistry. Morphology and mechanical properties of PLA scaffolds (with and without cells) were influenced by fiber direction of the scaffolds. Both PLA scaffolds supported meniscus tissue formation with increased COL1A1, SOX9, and COMP, yet no difference in gene expression was found between random and aligned PLA scaffolds. Overall, ES materials, which possess mechanical strength of meniscus and can support neotissue formation, show potential for use in cell‐based meniscus regeneration strategies. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:572–583, 2015.     

Preliminary experience with tissue engineering of a venous vascular patch by using bone marrow-derived cells and a hybrid biodegradable polymer scaffold

OBJECTIVE: Currently available synthetic polymer vascular patches used in cardiovascular surgery have shown serious shortcomings, including thrombosis, calcification, infection, and lack of growth potential. These problems may be avoided by vascular patches tissue-engineered with autologous stem cells and biodegradable polymeric materials. The objective of this study was to develop a tissue-engineered vascular patch by using autologous bone marrow-derived cells (BMCs) and a hybrid biodegradable polymer scaffold. METHODS: Hybrid biodegradable polymer scaffolds were fabricated from poly(lactide-co-epsilon-caprolactone) (PLCL) copolymer reinforced with poly(glycolic acid) (PGA) fibers. Canine bone marrow mononuclear cells were induced in vitro to differentiate into vascular smooth muscle cells and endothelial cells. Tissue-engineered vascular patches (15 mm wide x 30 mm long) were fabricated by seeding vascular cells onto PGA/PLCL scaffolds and implanted into the inferior vena cava of bone marrow donor dogs. RESULTS: Compared with PLCL scaffolds, PGA/PLCL scaffolds exhibited tensile mechanical properties more similar to those of dog inferior vena cava. Eight weeks after implantation of vascular patches tissue-engineered with BMCs and PGA/PLCL scaffolds, the vascular patches remained patent with no sign of thrombosis, stenosis, or dilatation. Histological, immunohistochemical, and scanning electron microscopic analyses of the retrieved vascular patches revealed regeneration of endothelium and smooth muscle, as well as the presence of collagen. Calcium deposition on tissue-engineered vascular patches was not significantly different from that on native blood vessels. Immunofluorescent double staining confirmed that implanted BMCs survived after implantation and contributed to regeneration of endothelium and vascular smooth muscle in the implanted vascular patches. CONCLUSIONS: This study demonstrates that vascular patches can be tissue-engineered with autologous BMCs and hybrid biodegradable polymer scaffolds.     

纳米化左旋聚乳酸有序膜的细胞亲和性研究

目的 制备具有较好细胞亲和性、利于内皮生长晕细胞(EOCs))黏附增殖的纳米左旋聚乳酸有序膜,为构建组织工程血管材料提供理论依据.方法 改性后纳米纤维膜与细胞复合培养,观察细胞与材料牛物亲和性.结果 纳米纤维孔径在300～400 nm,孔隙率>90%.有序和超级有序膜组吸光度,4值与无序膜、单纯细胞组差异有显著统计学意义(P<0.05).无序膜细胞生长较散在、杂乱;有序及超级有序纤维膜有利于细胞沿纤维定向附着、增殖.结论 EOCs是理想的组织工程血管种子细胞来源.有序及超级有序膜是一种理想的组织工程血管材料.     

Nanofiber-based scaffolds for tissue engineering

For successful tissue engineering, it is essential to have as many biomimetic scaffolds as possible. With increasing interest in nanotechnology, development of nanofibers (n-fibers) by using the technique of electrospinning is having a new momentum. Among important potential applications of n-fiber-based scaffolds for tissue engineering represent an important advancing front. Nanoscaffolds (n-scaffolds) mimic natural extracellular matrix (ECM) and its nanoscale fibrous structure. With electrospinning, it is possible to develop submicron fibers from biodegradable polymers and these can also be used for developing multifunctional drug-releasing and bioactive scaffolds. Developed n-scaffolds are tested for their cytocompatibility using various cell models. In addition, they were seeded with cells for engineering tissue constructs. There is a large area ahead for further applications and development of these scaffolds. For instance, multifunctional scaffolds that can be used as controlled delivery system do have a potential and have yet to be investigated for improved engineering of various tissues. So far, there are only very few in vivo studies on n-scaffolds, but in the future many are expected to emerge. With the convergence of the fields of nanotechnology, drug release, and tissue engineering, new solutions could be found for the current limitations of tissue engineering. In this paper, nanoscaffolds developed by using electrospinning, used polymers so far, cytocompatibility and applications in tissue engineering are reviewed.     

软骨脱细胞基质仿生支架的制备及其对骨髓基质干细胞成软骨分化的影响

目的探讨软骨脱细胞基质(ACM)仿生支架的制备及其对骨髓基质干细胞(BMSCs)成软骨分化的影响。方法将软骨组织粉碎后脱细胞处理,并以不同的比例与明胶(GT)溶液混合并交联,冷冻干燥制成多孔仿生支架。用扫描电镜(SEM)观察不同交联比例制成的ACM/GT支架,并对其孔径、孔隙率、生物力学、降解速率进行评估,从而选取最优组用于体外软骨构建。分离并培养山羊BMSCs,接种于单纯GT和ACM/GT支架上,SEM观察培养1、7、14 d后细胞在支架上的黏附、分布与基质分泌情况,并通过实时定量聚合酶链反应(qRT-PCR)评估成软骨分化能力。结果制备的ACM无细胞残留。随着ACM占比增加,孔径逐渐增大,降解速率逐渐增快,力学强度逐渐降低。其中G2A2组在孔径、孔隙率、生物力学和降解速率方面均适宜体外构建软骨组织。SEM显示细胞在单纯GT和G2A2支架上均匀分布,增殖显著,基质分泌明显。qRT-PCR显示G2A2显著促进了BMSCs的成软骨分化。结论ACM可以制备成适宜软骨再生的支架材料,并可促进BMSCs的成软骨分化。     

Fabrication of a Novel Hybrid Heart Valve Leaflet for Tissue Engineering: An In Vitro Study

The objective of this study was to fabricate biomatrix/polymer hybrid heart valve leaflet scaffolds using an electrospinning technique and seeded by mesenchymal stem cells. Mesenchymal stem cells were obtained from rats. Porcine aortic heart valve leaflets were decellularized, coated with basic fibroblast growth factor/chitosan/poly-4-hydroxybutyrate using an electrospinning technique, reseeded, and cultured over a time period of 14 days. Controls were reseeded and cultured over an equivalent time period. Specimens were examined biochemically, histologically, and mechanically. Recellularization of the hybrid heart valve leaflet scaffolds was significantly improved compared to controls. Biochemical and mechanical analysis revealed a significant increase of cell mass, 4-hydroxyproline, collagen, and strength in the hybrid heart valve leaflets compared to controls. This is the first attempt in tissue-engineered heart valves to fabricate hybrid heart valve leaflets using mesenchymal stem cells combined with a slow release technique and an electrospinning technique.