scholarly journals A laser microdissection-based axotomy model incorporating the use of biomimicking fiber scaffolds reveals that microRNAs promote axon regeneration over long injury distances

2020 ◽  
Vol 8 (22) ◽  
pp. 6286-6300
Author(s):  
Na Zhang ◽  
Junquan Lin ◽  
Jiah Shin Chin ◽  
Kunyu Zhang ◽  
Sing Yian Chew
Keyword(s):  
Axon Regeneration ◽  
Laser Microdissection ◽  
Electrospun Fiber ◽  
Cell Soma ◽  
Injury Site ◽  
Fiber Scaffolds

A laser microdissection-based axotomy model coupled with an aligned electrospun fiber platform was developed, with which the distance of injury site from the cell soma can be precisely controlled.

scholarly journals Electrospun Fiber Scaffolds for Engineering Glial Cell Behavior to Promote Neural Regeneration

2020 ◽  
Vol 8 (1) ◽  
pp. 4
Author(s):  
Devan L. Puhl ◽  
Jessica L. Funnell ◽  
Derek W. Nelson ◽  
Manoj K. Gottipati ◽  
Ryan J. Gilbert
Keyword(s):  
Nervous System ◽  
Glial Cell ◽  
Cell Response ◽  
Electrospun Fiber ◽  
Neural Regeneration ◽  
Cell Phenotype ◽  
Comprehensive Overview ◽  
Fiber Alignment ◽  
Wide Range ◽  
Fiber Scaffolds

Electrospinning is a fabrication technique used to produce nano- or micro- diameter fibers to generate biocompatible, biodegradable scaffolds for tissue engineering applications. Electrospun fiber scaffolds are advantageous for neural regeneration because they mimic the structure of the nervous system extracellular matrix and provide contact guidance for regenerating axons. Glia are non-neuronal regulatory cells that maintain homeostasis in the healthy nervous system and regulate regeneration in the injured nervous system. Electrospun fiber scaffolds offer a wide range of characteristics, such as fiber alignment, diameter, surface nanotopography, and surface chemistry that can be engineered to achieve a desired glial cell response to injury. Further, electrospun fibers can be loaded with drugs, nucleic acids, or proteins to provide the local, sustained release of such therapeutics to alter glial cell phenotype to better support regeneration. This review provides the first comprehensive overview of how electrospun fiber alignment, diameter, surface nanotopography, surface functionalization, and therapeutic delivery affect Schwann cells in the peripheral nervous system and astrocytes, oligodendrocytes, and microglia in the central nervous system both in vitro and in vivo. The information presented can be used to design and optimize electrospun fiber scaffolds to target glial cell response to mitigate nervous system injury and improve regeneration.

Axon Regeneration in Peripheral Nerves

2021 ◽  
Author(s):  
Arthur English
Keyword(s):  
Nerve Injury ◽  
Peripheral Nerves ◽  
Axon Regeneration ◽  
Axon Growth ◽  
Injury Site ◽  
Genetic Manipulations ◽  
Novel Treatments ◽  
The Central Nervous System ◽  
Experimental Treatments ◽  
Axonal Protein

Despite the intrinsically greater capacity for axons to regenerate in injured peripheral nerves than after injury to the central nervous system, functional recovery after most nerve injuries is very poor. A need for novel treatments that will enhance axon regeneration and improve recovery is substantial. Several such experimental treatments have been studied, each based on part of the stereotypical cellular responses that follow a nerve injury. Genetic manipulations of Schwann cells that have transformed from a myelinating to a repair phenotype that either increase their production of axon growth-promoting molecules, decrease production of inhibitors, or both result in enhanced regeneration. Local or systemic application of these molecules or small molecule mimetics of them also will promote regeneration. The success of treatments that stimulate axonal protein synthesis at the site of the nerve injury and in the growing axons, an early and important response to axon injury, is significant, as is that of manipulations of the types of immune cells that migrate into the injury site or peripheral ganglia. Modifications of the extracellular matrix through which the regenerating axons course, including the stimulation of new blood vessel formation, promotes the navigation of nascent regenerating neurites past the injury site, resulting in greater axon regeneration. Experimental induction of expression of regeneration associated gene activity in the cell bodies of the injured neurons is especially useful when regenerating axons must regenerate over long distances to reinnervate targets. The consistently most effective experimental approach to improving axon regeneration in peripheral nerves has been to increase the activity of the injured neurons, either through electrical, optical, or chemogenetic stimulation or through exercise. These activity-dependent experimental therapies show greatest promise for translation to use in patients.

scholarly journals Poly-ε-Caprolactone/Halloysite Nanotube Composites for Resorbable Scaffolds: Effect of Processing Technology on Homogeneity and Electrospinning

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3772
Author(s):  
Muriel Józó ◽  
Róbert Várdai ◽  
Nóra Hegyesi ◽  
János Móczó ◽  
Béla Pukánszky
Keyword(s):  
Electrospun Fiber ◽  
Fiber Spinning ◽  
Film Casting ◽  
Melt Mixing ◽  
Indirect Methods ◽  
Nanotube Composites ◽  
Simple Compression ◽  
Fiber Scaffolds ◽  
Direct And Indirect Methods

Polycaprolactone (PCL)/halloysite composites were prepared to compare the effect of homogenization technology on the structure and properties of the composites. Halloysite content changed from 0 to 10 vol% in six steps and homogeneity was characterized by various direct and indirect methods. The results showed that the extent of aggregation depends on technology and on halloysite content; the size and number of aggregates increase with increasing halloysite content. Melt mixing results in more homogeneous composites than the simple compression of the component powders or homogenization in solution and film casting. Homogeneity and the extent of aggregation determines all properties, including functionality. The mechanical properties of the polymer deteriorate with increasing aggregation; even stiffness depends on homogeneity. Strength and deformability decreases drastically as the number and size of aggregates increase. Not only dispersed structure, but also the physical state and crystalline structure of the polymer influence homogeneity and properties. The presence of the filler affects the preparation of electrospun fiber scaffolds as well. A part of the filler is excluded from the fibers while another part forms aggregates that complicates fiber spinning and deteriorates properties. The results indicate that spinning is easier and the quality of the fibers is better if a material homogenized previously by melt mixing is used for the production of the fibers.

Biointerface control of electrospun fiber scaffolds for bone regeneration: Engineered protein link to mineralized surface

2014 ◽  
Vol 10 (6) ◽  
pp. 2750-2761 ◽  
Author(s):  
Jae Ho Lee ◽  
Jeong-Hui Park ◽  
Ahmed El-Fiqi ◽  
Joong-Hyun Kim ◽  
Ye-Rang Yun ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Electrospun Fiber ◽  
Fiber Scaffolds

scholarly journals Modular assembly of thick multifunctional cardiac patches

2017 ◽  
Vol 114 (8) ◽  
pp. 1898-1903 ◽  
Author(s):  
Sharon Fleischer ◽  
Assaf Shapira ◽  
Ron Feiner ◽  
Tal Dvir
Keyword(s):  
Cardiac Tissue ◽  
Electrospun Fiber ◽  
Signal Propagation ◽  
Electrical Signal ◽  
Modular Assembly ◽  
Cardiac Tissues ◽  
Structure Morphology ◽  
Biomaterial Scaffolds ◽  
Fiber Scaffolds ◽  
And Function

In cardiac tissue engineering cells are seeded within porous biomaterial scaffolds to create functional cardiac patches. Here, we report on a bottom-up approach to assemble a modular tissue consisting of multiple layers with distinct structures and functions. Albumin electrospun fiber scaffolds were laser-patterned to create microgrooves for engineering aligned cardiac tissues exhibiting anisotropic electrical signal propagation. Microchannels were patterned within the scaffolds and seeded with endothelial cells to form closed lumens. Moreover, cage-like structures were patterned within the scaffolds and accommodated poly(lactic-co-glycolic acid) (PLGA) microparticulate systems that controlled the release of VEGF, which promotes vascularization, or dexamethasone, an anti-inflammatory agent. The structure, morphology, and function of each layer were characterized, and the tissue layers were grown separately in their optimal conditions. Before transplantation the tissue and microparticulate layers were integrated by an ECM-based biological glue to form thick 3D cardiac patches. Finally, the patches were transplanted in rats, and their vascularization was assessed. Because of the simple modularity of this approach, we believe that it could be used in the future to assemble other multicellular, thick, 3D, functional tissues.

scholarly journals Mueller Matrix Measurement of Electrospun Fiber Scaffolds for Tissue Engineering

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2062 ◽  
Author(s):  
Dierk Fricke ◽  
Alexander Becker ◽  
Lennart Jütte ◽  
Michael Bode ◽  
Dominik de Cassan ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Fiber Orientation ◽  
Electrospun Fiber ◽  
Mueller Matrix ◽  
Relative Orientation ◽  
Sem Images ◽  
Production Parameters ◽  
Fiber Scaffolds ◽  
Non Destructive

Electrospun fiber scaffolds are gaining in importance in the area of tissue engineering. They can be used, for example, to fabricate graded implants to mimic the tendon bone junction. For the grading of the tensile strength of the fiber scaffolds, the orientation of the fibers plays a major role. This is currently measured by hand in scanning electron microscope (SEM) images. In this work, a correlation between polarimetric information generated by measuring the Mueller matrix (MM) and the orientation of the fibers of electrospun fiber scaffolds is reported. For this, the MM of fiber scaffolds, which were manufactured with different production parameters, was measured and analyzed. These data were correlated with fiber orientation and mechanical properties, which were evaluated in an established manner. We found that by measurement of the MM the production parameters as well as the relative orientation of the fibers in space can be determined. Thus, the MM measurement is suitable as an alternative tool for non-contact, non-destructive determination of the production parameters and, thus, the degree of alignment of electrospun fiber scaffolds.

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