Sharpe Jacquelyn M, Lee Hyunsu, Hall Adam R, Bonin Keith, Guthold Martin
Department of Physics, Wake Forest University, Winston-Salem, NC 27109, USA.
School of Biomedical Engineering and Sciences, Wake Forest School of Medicine, Virginia Tech-Wake Forest University, Winston-Salem, NC 27101, USA.
Nanomaterials (Basel). 2020 Sep 15;10(9):1843. doi: 10.3390/nano10091843.
Electrospun nanofibers manufactured from biocompatible materials are used in numerous bioengineering applications, such as tissue engineering, creating organoids or dressings, and drug delivery. In many of these applications, the morphological and mechanical properties of the single fiber affect their function. We used a combined atomic force microscope (AFM)/optical microscope technique to determine the mechanical properties of nanofibers that were electrospun from a 50:50 fibrinogen:PCL (poly-ε-caprolactone) blend. Both of these materials are widely available and biocompatible. Fibers were spun onto a striated substrate with 6 μm wide grooves, anchored with epoxy on the ridges and pulled with the AFM probe. The fibers showed significant strain softening, as the modulus decreased from an initial value of 1700 MPa (5-10% strain) to 110 MPa (>40% strain). Despite this extreme strain softening, these fibers were very extensible, with a breaking strain of 100%. The fibers exhibited high energy loss (up to 70%) and strains larger than 5% permanently deformed the fibers. These fibers displayed the stress-strain curves of a ductile material. We provide a comparison of the mechanical properties of these blended fibers with other electrospun and natural nanofibers. This work expands a growing library of mechanically characterized, electrospun materials for biomedical applications.
由生物相容性材料制成的电纺纳米纤维被用于众多生物工程应用中，如组织工程、制造类器官或敷料以及药物递送。在许多这些应用中，单根纤维的形态和机械性能会影响其功能。我们使用原子力显微镜（AFM）/光学显微镜联合技术来测定由50:50纤维蛋白原:聚己内酯（PCL）共混物电纺而成的纳米纤维的机械性能。这两种材料都广泛可得且具有生物相容性。将纤维纺丝到具有6μm宽凹槽的条纹状基底上，用环氧树脂固定在脊上，并用AFM探针拉伸。这些纤维表现出显著的应变软化，模量从初始值1700MPa（应变5 - 10%）降至110MPa（应变>40%）。尽管有这种极端的应变软化，这些纤维非常具有延展性，断裂应变为100%。这些纤维表现出高能量损失（高达70%），且应变大于5%会使纤维永久变形。这些纤维呈现出韧性材料的应力 - 应变曲线。我们将这些共混纤维的机械性能与其他电纺和天然纳米纤维进行了比较。这项工作扩展了用于生物医学应用的、具有机械特性的电纺材料的不断增长的文库。
