Crimped Nanofibrous Biomaterials Mimic Microstructure and Mechanics of Native Tissue and Alter Strain Transfer to Cells

Abstract

To fully recapitulate tissue microstructure and mechanics, fiber crimping must exist within biomaterials used for tendon/ligament engineering. Existing crimped nanofibrous scaffolds produced via electrospinning are dense materials that prevent cellular infiltration into the scaffold interior. In this study, we used a sacrificial fiber population to increase the scaffold porosity and evaluated the effect on fiber crimping. We found that increasing scaffold porosity increased fiber crimping and ensured that the fibers properly uncrimped as the scaffolds were stretched by minimizing fiber−fiber interactions. Constitutive modeling demonstrated that the fiber uncrimping produced a nonlinear mechanical behavior similar to that of native tendon and ligament. Interestingly, fiber crimping altered strain transmission to the nuclei of cells seeded on the scaffolds, which may account for previously observed changes in gene expression. These crimped biomaterials are useful for developing functional fiberreinforced tissues and for studying the effects of altered fiber crimping due to damage or degeneration.

A mini review on the generation of crimped ultrathin fibers via electrospinning: Materials, strategies, and applications

“…Up to now, electrospun crimped ultrathin fibers have been produced from various polymers, including polyurethane (PU), polyacrylonitrile (PAN), polyamide‐6 (PA6), polycaprolactone (PCL), acrylic, polylactide (PLA), polyvinylidene fluoride (PVDF), poly (L‐lactide‐co‐ε‐caprolactone) (P(LLA‐CL)), poly (L‐lactide‐co‐acryloyl carbonate) (P(LLA‐AC)), poly(lactic‐ co ‐glycolic) acid (PLGA), poly‐L‐lactide (PLLA), and poly(ε‐caprolactone‐co‐acryloyl carbonate) (P(ε‐CL‐AC)), The polymer solutions of these polymers are summarized in Table .…”

“…Szczesny et al fabricated crimped PLLA nanofibers using poly(ethylene oxide) (PEO) as the sacrificial fiber population. PEO was added to alter the mechanical properties of the PLLA fibers.…”

“…B, Scanning electron microscope (SEM) images of electrospun crimped nanofibers webs obtained from Dual PLLA/poly (ethylene oxide). C, SEM images of electrospun crimped nanofibers webs obtained from only PLLA [Colour figure can be viewed at wileyonlinelibrary.com]…”

“…Szczesny et al found that electrospun crimped PLLA nanofibers can be used successfully for the rational design of engineered constructs for the replacement of diseased or damaged tissue. Furthermore, they can alter the nuclear morphology of cells seeded on nanofibrous scaffolds.…”

3D Microfibrous Scaffolds Selectively Promotes Proliferation and Glial Differentiation of Adult Neural Stem Cells: A Platform to Tune Cellular Behavior in Neural Tissue Engineering

“…We demonstrated that by changing the flow rate ratio between the core and sheath fluids, as well as PCL concentration (in the core fluid), we were able to achieve wavy and straight fibers with different sizes. These architectures have been previously fabricated using various techniques and in different size ranges; however, for our specific application of creating a 3D microenvironment to enhance neural progenitor cell differentiation into glial cells, using fibers in similar size range of cells is preferred . After culturing the AHPCs on the microfibrous scaffolds of various diameters and topographies, we found that the larger diameter microfibers appear to guide the differentiation to mature neurons, whereas all PCL microfibers promoted astrocyte differentiation.…”