Modification, crosslinking and reac

Modification, crosslinking and reactive electrospinning of a thermoplastic medical polyurethane for vascular graft applications
Thermoplastic polyurethanes are used in a variety of medical devices and experimental tissue engineering scaffolds. Despite advances in polymer composition to improve their stability, the correct balance between chemical and mechanical properties is not always achieved. A model compound (MC) simulating the structure of a widely used medical polyurethane (Pellethane®) was synthesized and reacted with aliphatic and olefinic acyl chlorides to study the reaction site and conditions. After adopting the conditions to the olefinic modification of Pellethane®, processing into flat sheets, and crosslinking by thermal initiation or ultraviolet radiation, mechanical properties were determined. The modified polyurethane was additionally electrospun under ultraviolet light to produce a crosslinked tubular vascular graft prototype. Model compound studies showed reaction at the carbamide nitrogen, and the modification of Pellethane with pentenoyl chloride could be accurately controlled to up to 20% (correlation: ρ = 0.99). Successful crosslinking was confirmed by insolubility of the materials. Initiator concentrations were optimized and the crosslink densities shown to increase with increasing modification. Crosslinking of Pellethane containing an increasing number of pentenoyl groups resulted in decreases (up to 42%, p < 0.01) in the hysteresis and 44% in creep (p < 0.05), and in a significant improvement in degradation resistance in vitro. Modified Pellethane was successfully electrospun into tubular grafts and crosslinked using UV irradiation during and after spinning to render them insoluble. Prototype grafts had sufficient burst pressure (>550 mmHg), and compliances of 12.1 ± 0.8 and 6.2 ± 0.3%/100 mmHg for uncrosslinked and crosslinked samples, respectively. It is concluded that the viscoelastic properties of a standard thermoplastic polyurethane can be improved by modification and subsequent crosslinking, and that the modified material may be electrospun and initiated to yield crosslinked scaffolds. Such materials hold promise for the production of vascular and other porous scaffolds, where decreased hysteresis and creep may be required to prevent aneurismal dilation.

結果 (中文) 1:

改性、 交联和无功静电纺丝的热塑性医用聚氨酯血管移植应用程序热塑性聚氨酯用于各种医疗设备和实验的组织工程支架材料。尽管聚合物组成是提高其稳定性研究进展，化学和力学性能之间的正确平衡是不总能实现。模拟系统广泛使用的医用聚氨酯 (Pellethane ®) 的结构模型化合物 (MC) 与脂肪族和烯酰氯研究反应场所和条件反应，合成。采用 Pellethane ®，加工成薄片和由热引发或紫外线辐射交联烯烃改性条件后力学性能测定。改性后的聚氨酯另外是纺在紫外光灯下产生交联管状血管原型。模型化合物研究表明反应在尿素氮，和 Pellethane 戊烯酰氯化改性可以准确地控制到高达 20%(相关: ρ = 0.99)。成功的交联证实了不溶性的材料。引发剂浓度进行了优化和交联密度增加而增加修改所示。交联的 Pellethane 含有戊烯酰团体越来越多，结果导致体外降解抵抗跌幅达 42%(p < 0.01) 中的迟滞和 44%在蠕变 (p < 0.05)，和在一个重大的改进。改性的 Pellethane 成功纺出管状移植和交联使用 UV 照射期间和之后旋转，使其不溶。原型移植了足够的爆裂压力 (> 550 毫米汞柱)，和顺应性 12.1 ± 0.8 和 6.2 ± 0.3%/100 毫米汞柱为未交联体系和交联样品，分别。它被结束修改和随后的交联，可以提高标准的热塑性聚氨酯的粘弹性和改性的材料可能是静电纺丝和发起产生交联支架。这种材料有望生产的血管和其他多孔支架，降低的迟滞和蠕变可能需要防止动脉瘤样扩张。

結果 (中文) 3:

改性、交联反应的血管移植物的应用
热塑性聚氨酯热塑性聚氨酯静电纺丝技术用于各种医疗设备和实验的组织工程支架材料。尽管聚合物组合物的进展，以提高它们的稳定性，化学和机械性能之间的正确的平衡并不总是实现。模型化合物（MC）模拟一个广泛使用的医用聚氨酯的结构（PELLETHANE®）合成脂肪族和烯酰氯的反应研究现场条件反应。采用条件对®PELLETHANE烯烃改性后，加工成平板，并通过热引发或紫外线辐射交联，机械性能进行了测定。改性聚氨酯加静电在紫外线下产生交联管状血管的原型。模型化合物的研究表明，尿素氮反应，与氯化pentenoyl PELLETHANE修改可以被精确地控制到20%（相关：ρ= 0.99）。成功是由不溶性的交联材料的确认。引发剂浓度进行了优化，证明随着改性的交联密度增加。含有越来越多的pentenoyl组PELLETHANE交联导致减少（42%，P＜0.01）的迟滞和蠕变的44%（P＜0.05），并在体外抗降解能力的显著改善。改进的PELLETHANE成功电纺成管状移植和交联使用UV照射期间和之后的旋转使他们不溶。原型移植有足够的爆破压力（大于550毫米汞柱），和12.1±0.8和6.2±0.3% / 100毫米汞柱，未交联的和交联的样品的柔性，分别。它的结论是，一个标准的热塑性聚氨酯的粘弹性特性，可以通过修改和随后的交联改性材料的改进，这可能是静电，引发产生交联的支架。这种材料有保证血管和其他多孔支架的生产，在降低迟滞和蠕变可能需要防止动脉瘤样扩张。