电纺漏斗网蜘蛛丝纤维性能及体外细胞生物学性能

目的：近年来，蜘蛛丝在基因识别、人工合成以及基因表达上取得的成果，引发了广大研究者模拟天然蜘蛛丝优秀性能的兴趣。采用静电纺技术对制备的漏斗网蜘蛛丝再生纤维膜进行性能检测，为静电纺蜘蛛丝纳米纤维应用于组织工程和生物医学领域提供前期研究。方法：实验于2006—07／2007—03在东华大学生物研究所生物材料室完成。采用电纺技术制备了漏斗网蛛丝再生纤维膜，对纤维膜的表面形态分析，水解性能，热性能，力学性能进行检测。体外与猪动脉内皮细胞共培养，采用MTT法检测对纤维膜细胞的增殖活性，以相差显微镜和扫描电镜观察细胞的形态变化。结果：再生蛛丝纤维膜热分解起始温度为279℃；在单轴拉伸时断裂强度和断裂伸长率分别为（3．61±0．18）MPa和（33．20±4．86）％；内皮细胞能够在纤维表面黏附并显示良好的生长形态；MTT结果显示内皮细胞在材料上增殖活跃，培养7d后，纤维膜上的细胞增殖为对照组的两倍多。结论：漏斗网蜘蛛丝再生纤维膜显示出稳定的热性能和高的延展性，并能有效促进内皮细胞的黏附和增殖，具育良好的生物相容性。     

静电纺壳聚糖/胶原蛋白复合纳米纤维的细胞相容性

目的:静电纺是一种使带电荷的聚合物溶液或熔体在静电场中射流来制备聚合物纳米级纤维的加工方法,采用此种技术制备壳聚糖/胶原蛋白复合纳米纤维,并观察其细胞相容性.方法:实验于2006-11/2007-10在东华大学化学化工与生物工程学院生物材料与组织工程实验室完成.①支架材料制备:以六氟异丙醇/三氟乙酸为溶剂体系,采用静电纺制备复合纳米纤维,其中壳聚糖/胶原蛋白的质量比分别为100:0,80:20,50:50,20:80与0:100.②细胞相容性观察:体外接种猪髋动脉内皮细胞,苏木精-伊红染色法观察细胞形态,MTT法检测细胞黏附和增殖情况.结果:猪髋动脉内皮细胞在壳聚糖/胶原蛋白复合纤维表面贴附牢固,外形饱满,多呈长梭形,具有良好的生长形态;MTT法结果显示纳米纤维能够有效地促进内皮细胞在材料表面的黏附和增殖,质量比为20:80材料组细胞黏附、增殖能力最强,其次为50:50组.结论: 静电纺壳聚糖/胶原蛋白复合纳米纤维具有良好的细胞相容性,可望成为一种新型的组织工程支架材料.     

电纺胶原和蛛丝纳米纤维膜的制备、表征及生物安全性比较

目的:制备胶原和蜘蛛丝两种纳米纤维膜,进行理化性能表征和生物相容性比较,以期将蜘蛛丝纳米纤维用于组织工程支架材料.方法:实验于2006-07/2007-08在上海市东华大学生物科学与技术研究所完成.将胶原和蜘蛛丝分别以80 g/L溶于六氟异丙醇,采用高15 kV压静电纺制成纳米纤维膜,真空干燥后对其理化性能进行表征.扫描电镜观察超微结构,并进行水接触角测量和水解稳定性测量;并采用MTT实验比较猪大动脉内皮细胞在两种纤维膜表面的黏附、生长和增殖等情况.结果:①静电纺胶原和蛛丝纳米纤维膜均具有良好三维多孔结构,但蛛丝纤维直径更均匀.蛛丝膜具有较大的水接触角,在水解稳定性测试中质量损失较少.②MTT实验表明,种植6 h后血管内皮细胞在胶原和蛛丝膜上都能黏附,但蛛丝膜上细胞增殖速度较快,2 d后超过胶原膜,7 d后蛛丝膜上细胞多于胶原膜表面40%以上.结论:胶原和蛛丝都能促进血管内皮细胞黏附、生长.蛛丝膜具有较强的疏水性和水解稳定性,在体外培养过程中蛛丝更有利于细胞增殖,有望作为血管组织工程支架材料.     

仿生合成梯度含锶磷酸钙骨水泥的体外细胞生物学性能检测

目的:通过在仿生理条件下构建梯度含锶磷酸钙骨水泥,并应用L929成纤维细胞和幼兔成骨细胞检测含锶磷酸钙骨水泥的体外生物学性能.方法:实验于2006-11/2007-04在解放军第四军医大学口腔医院颌面外科和西安交通大学金属材料强度国家重点实验室完成.①实验材料:仿生理条件下合成梯度含锶磷酸钙骨水泥.②实验方法:应用了L-929成纤维细胞和成骨细胞两种细胞,将不同浓度的梯度含锶磷酸钙骨水泥分别与两种细胞接触.③评估指标:采用MTT检测法,对细胞增殖活性进行检测,计算细胞相对增殖率,用6级毒性分类法评级:并应用相差显微镜、扫描电镜进行形态学观察.用碱性磷酸酶测定试剂盒检测浸提液对兔成骨细胞功能表达的影响;检测其细胞毒性、促成骨细胞黏附、增殖及表达能力以及生物降解潜能.结果:仿生理条件下合成的梯度含锶磷酸钙骨水泥无细胞毒性,表面成骨细胞的黏附性良好,增殖活跃,并显示出可能存在良好的生物降解能力.结论:含锶磷酸钙骨水泥体外细胞生物相容性良好,是安全的新型骨组织工程支架材料.     

In vivo analysis of vascularization and biocompatibility of electrospun polycaprolactone fibre mats in the rat femur chamber

In orthopaedic medicine, connective tissues are often affected by traumatic or degenerative injuries, and surgical intervention is required. Rotator cuff tears are a common cause of shoulder pain and disability among adults. The development of graft materials for bridging the gap between tendon and bone after chronic rotator cuff tears is essentially required. The limiting factor for the clinical success of a tissue engineering construct is a fast and complete vascularization of the construct. Otherwise, immigrating cells are not able to survive for a longer period of time, resulting in the failure of the graft material. The femur chamber allows the observation of microhaemodynamic parameters inside implants located in close vicinity to the femur in repeated measurements in vivo. We compared a porous polymer patch (a commercially available porous polyurethane‐based scaffold from Biomerix?) with electrospun polycaprolactone (PCL) fibre mats and chitosan (CS)‐graft‐PCL modified electrospun PCL (CS‐g‐PCL) fibre mats in vivo. By means of intravital fluorescence microscopy, microhaemodynamic parameters were analysed repetitively over 20 days at intervals of 3 to 4 days. CS‐g‐PCL modified fibre mats showed a significantly increased vascularization at Day 10 compared with Day 6 and at Day 14 compared with the porous polymer patch and the unmodified PCL fibre mats at the same day. These results could be verified by histology. In conclusion, a clear improvement in terms of vascularization and biocompatibility is achieved by graft‐copolymer modification compared with the unmodified material.     

Wetting of electrospun nylon-11 fibers and mats

Wetting of electrospun mats plays a huge role in tissue engineering and filtration applications. However, it is challenging to trace the interrelation between the wetting of individual nano-sized fibers and the macroscopic electrospun mat. Here we measured the wetting of different nylon-11 samples – solution-cast films, electrospun fibers deposited onto a substrate, and free-standing mats. With electrospun nylon-11 on aluminium foil, we traced the dependence of the wetting contact angle on the fibers'' surface density (substrate coverage). When the coverage was low, the contact angle increased almost linearly with it. At ∼17–20% coverage, the contact angle achieved its maximum of 124 ± 7°, which matched the contact angle of a non-woven electrospun mat, 126 ± 2°. Our results highlight the importance of the outermost layer of fibers for the wetting of electrospun mats.

When the surface density of electrospun nylon-11 fibers on aluminium increases, it causes a two-stage change in the wetting behaviour.     

Aqueous-based electrospun P(NIPAAm-co-AAc)/RSF medicated fibrous mats for dual temperature- and pH-responsive drug controlled release

This paper presents a green method for fabricating dual temperature- and pH-responsive electrospun fibrous mats from an aqueous-based blend poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAAm-co-AAc)) and regenerated silk fibroin (RSF) by employing electrospinning technique. P(NIPAAm-co-AAc) was synthesized by free radical solution polymerization and its low critical solution temperature (LCST) was in the physiological range (38.8 °C). The P(NIPAAm-co-AAc)/RSF fibers were prepared by electrospinning technology in the presence of the crosslinking agents (EDC·HCl and NHS) with water as solvent. After in situ crosslinking and water-annealing process, the water-stable composite fibrous mats were obtained. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to analyze the crosslinking process. Temperature and pH dual stimuli-responsive swelling-shrinking behavior of the fibrous mats were observed when the temperature was below and above the LCST of the copolymer at different pHs. In addition, rhodamine B-loaded the fibrous mats also showed dual temperature and pH controlled release behavior, demonstrating the potential use of the fibrous mats for “smart” controlled drug delivery applications.

This paper presents a green friendly method for preparing dual temperature- and pH-responsive electrospun P(NIPAAm-co-AAc)/RSF fibrous mats for drug release.     

Characterization and biocompatibility of a fibrous glassy scaffold

Bioactive glasses (BGs) are known for their ability to bond to living bone and cartilage. In general, they are readily available in powder and monolithic forms, which are not ideal for the optimal filling of bone defects with irregular shapes. In this context, the development of BG‐based scaffolds containing flexible fibres is a relevant approach to improve the performance of BGs. This study is aimed at characterizing a new, highly porous, fibrous glassy scaffold and evaluating its in vitro and in vivo biocompatibility. The developed scaffolds were characterized in terms of porosity, mineralization and morphological features. Additionally, fibroblast and osteoblast cells were seeded in contact with extracts of the scaffolds to assess cell proliferation and genotoxicity after 24, 72 and 144 h. Finally, scaffolds were placed subcutaneously in rats for 15, 30 and 60 days. The scaffolds presented interconnected porous structures, and the precursor bioglass could mineralize a hydroxyapatite (HCA) layer in simulated body fluid (SBF) after only 12 h. The biomaterial elicited increased fibroblast and osteoblast cell proliferation, and no DNA damage was observed. The in vivo experiment showed degradation of the biomaterial over time, with soft tissue ingrowth into the degraded area and the presence of multinucleated giant cells around the implant. At day 60, the scaffolds were almost completely degraded and an organized granulation tissue filled the area. The results highlight the potential of this fibrous, glassy material for bone regeneration, due to its bioactive properties, non‐cytotoxicity and biocompatibility. Future investigations should focus on translating these findings to orthotopic applications. Copyright © 2015 John Wiley & Sons, Ltd.     

丝素蛋白/壳聚糖复合支架材料的细胞相容性

背景:大量研究表明丝素蛋白、壳聚糖为天然高分子材料,具有良好的细胞生物相容性.目的:探讨丝素蛋白/壳聚糖复合支架材料与诱导的兔骨髓间充质干细胞的生物相容性.方法:将兔骨髓间充质干细胞分离培养、诱导后,与丝素蛋白/壳聚糖三维支架材料体外共培养,以材料的细胞毒性、细胞增殖活力、材料细胞黏附率及扫描电镜等检测评价材料的细胞相容性.结果与结论:经诱导后的骨髓间充质干细胞在支架材料上黏附、生长良好,保持正常的分裂增殖速度;随时间的增加,细胞黏附率增加,材料组较对照组黏附率强,差异有显著性意义(P<0.05).扫描电镜观察发现细胞接种48 h 后细胞生长良好,与支架黏附紧密,增殖分裂活跃.说明丝素蛋白/壳聚糖三维支架材料具有良好的细胞相容性.     

丝素蛋白/壳聚糖复合支架材料的细胞相容性

背景：大量研究表明丝素蛋白、壳聚糖为天然高分子材料,具有良好的细胞生物相容性。目的：探讨丝素蛋白/壳聚糖复合支架材料与诱导的兔骨髓间充质干细胞的生物相容性。方法：将兔骨髓间充质干细胞分离培养、诱导后,与丝素蛋白/壳聚糖三维支架材料体外共培养,以材料的细胞毒性、细胞增殖活力、材料细胞黏附率及扫描电镜等检测评价材料的细胞相容性。结果与结论：经诱导后的骨髓间充质干细胞在支架材料上黏附、生长良好,保持正常的分裂增殖速度;随时间的增加,细胞黏附率增加,材料组较对照组黏附率强,差异有显著性意义（P〈0.05）。扫描电镜观察发现细胞接种48h后细胞生长良好,与支架黏附紧密,增殖分裂活跃。说明丝素蛋白/壳聚糖三维支架材料具有良好的细胞相容性。     

电纺纳米羟基磷灰石/聚酯酰胺复合支架材料的制备及其细胞相容性

背景:采用静电纺丝技术将功能性无机纳米微粒复合高分子超细纤维,形成类细胞外基质结构和功能的复合支架材料是骨组织工程支架领域一个新的研究方向。目的:通过静电纺丝法构建纳米羟基磷灰石/脂肪族聚酯酰胺复合纤维支架材料,并初步考察其细胞相容性。方法:以静电纺丝法制备纳米羟基磷灰石/脂肪族聚酯酰胺超细纤维支架材料,通过扫描电镜、原子能谱等表面形貌的物相分析,进行细胞在复合材料上的形态学观察。结果与结论:通过静电纺丝法成功制备出纳米羟基磷灰石/脂肪族聚酯酰胺超细纤维复合材料,成骨细胞直接培养于材料上呈现良好生长行为,初步证实了复合支架材料的细胞相容性。说明静电纺丝技术在构建类骨细胞外基质结构和功能的仿生复合材料方面具有独特优势,电纺超细纤维复合材料有望成为新型的骨组织工程支架。