Mechano-morphological studies of aligned nanofibrous scaffolds of polycaprolactone fabricated by electrospinning
Mechano-morphological studies of aligned nanofibrous scaffolds of polycaprolactone fabricated by electrospinning
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DOI：
10.1163/156856206778366022
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发表时间：
2006-01-01
影响因子：
3.6
通讯作者：
Vohra, Yogesh K.
中科院分区：
文献类型：
--
作者：
Thomas, Vinoy;Jose, Moncy V.;Vohra, Yogesh K.
报道了在不同收集器转速（0，3000和6000 rpm）下通过静电纺丝制备的聚（E-己内酯）（PCL）的定向纳米纤维网作为骨组织支架的力学和形态学研究。采用SEM、XRD和DSC对纳米纤维的形貌进行了表征。支架具有纳米纤维形态，纤维（大多数）直径在550-350 nm范围内（取决于纤维吸收率）和互连的孔结构。随着收集器旋转速度的增加，纳米纤维变得更加对齐和取向垂直于旋转轴。在较高的纤维收集速度下沉积纤维对单个纤维的形态和机械性能以及大块纤维网具有深远的影响。纳米压痕用于测量支架的单个纤维的纳米级机械性能。通过纳米压痕测量的取向纤维的硬度和杨氏模量随着收集器旋转速度而降低。这揭示了在较高速度下沉积的纤维的局部微观结构的差异。三种纤维的纳米力学性能（硬度和模量）的顺序为：0 rpm时的PCL> 3000 rpm时的PCL> 6000 rpm时的PCL。这可能是由于在较高的吸收速率下纤维的结晶度降低而解释的。然而，（散装）支架的单轴拉伸性能（拉伸强度和模量）随着收集器旋转速度的增加而增加。支架的平均极限抗拉强度（沿着纤维排列）从吸收速率为0 rpm时的2.21 +/- 0.23 MPa（PCL）增加到吸收速率为3000 rpm时的4.21 +/- 0.35 MPa（PCL），最终增加到9.58 +/- 0.71 Mpa（6000 rpm时）。类似地，拉伸模量从PCL在0 rpm的吸收速率下的6.12 +/-0.8 MPa逐渐增加到PCL在3000 rpm的吸收速率下的11.93 +/-1.22 MPa和PCL在6000 rpm下的33.20 +/-1.98 MPa。三种纤维的宏观力学性能（拉伸强度和模量）从高到低的顺序为0 rpm时的PCL <3000 rpm时的PCL <6000 rpm时的PCL。这归因于在较高的吸收速率下增加的纤维排列和填充以及纤维间孔径的减小。
Mechanical and morphological studies of aligned nanofibrous meshes of poly(E-caprolactone) (PCL) fabricated by electrospinning at different collector rotation speeds (0, 3000 and 6000 rpm) for application as bone tissue scaffolds are reported. SEM, XRD and DSC analyses were used for the morphological characterization of the nanofibers. Scaffolds have a nanofibrous morphology with fibers (majority) having a diameter in the range of 550-350 nm (depending on fiber uptake rates) and an interconnected pore structure. With the increase of collector rotation speed, the nanofibers become more aligned and oriented perpendicular to the axis of rotation. Deposition of fibers at higher fiber collection speeds has a profound effect on the morphology and mechanical properties of individual fibers and also the bulk fibrous meshes. Nanoindentation was used for the measurement of nanoscopic mechanical properties of individual fibers of the scaffolds. The hardness and Young's modulus of aligned fibers measured by nanoindentation decreased with collector rotation speeds. This reveals the difference in the local microscopic structure of the fibers deposited at higher speeds. The sequence of nanoscopic mechanical properties (hardness and modulus) of three fibers is PCL at 0 rpm > PCL at 3000 rpm > PCL at 6000 rpm. This may be explained due to the decrease in crystallinity of fibers at higher uptake rates. However, uni-axial tensile properties of (bulk) scaffolds (tensile strength and modulus) increased with increasing collector rotation speed. The average ultimate tensile strength of scaffolds (along the fiber alignment) increased from 2.21 +/- 0.23 MPa for PCL at uptake rate of zero rpm, to a value of 4.21 +/- 0.35 MPa for PCL at uptake rate of 3000 rpm and finally to 9.58 +/- 0.71 MPa for PCL at 6000 rpm. Similarly, the tensile modulus increased gradually from 6.12 +/- 0.8 MPa for PCL at uptake rate of zero rpm, to 11.93 +/- 1.22 MPa for PCL at uptake rate of 3000 rpm and to 33.20 +/- 1.98 MPa for PCL at 6000 rpm. The sequence of macroscopic mechanical properties (tensile strength and modulus) of three fibers, from highest to lowest, is PCL at 0 rpm < PCL at 3000 rpm < PCL at 6000 rpm. This is attributed to the increased fiber alignment and packing and decrease in inter-fiber pore size at higher uptake rates.