Fabrication and evaluation of microgrooved polymers as peripheral nerve conduits

Hsu, Shan‐hui; Lu, Po Seng; Ni, Hsiao-Chiang; Su, Chien-Hsiang

doi:10.1007/s10544-007-9068-0

Cited by 50 publications

(46 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During in vivo experiments, this would result in increased migration of Schwann cells from the nerve stump, resulting in the improved regeneration seen in this study, consistent with previous findings. 35 The topographical modifications of PCL/PLA conduits, mimicking the architectural surface topography of the natural tissue, may act to induce cellular responses from both the endogenous Schwann cells and regenerating neurons, resulting in the significant improvement of nerve regrowth observed for the microgrooved PCL/PLA conduits when compared with the nongrooved PCL/PLA conduit controls. These observations would be explained by the fact that in vitro dASCs have also been observed to align in a highly polarized manner along the grooves, which may also happen for Schwann cells in the inner lumen of the conduits, possibly due to the topographical guidance cues in the material surfaces.…”

Section: Discussionmentioning

confidence: 99%

Polymer Scaffolds with Preferential Parallel Grooves Enhance Nerve Regeneration

Mobasseri

Faroni

Minogue

et al. 2015

Tissue Engineering Part A

View full text Add to dashboard Cite

We have modified the surface topography of poly e-caprolactone (PCL) and polylactic acid (PLA) blended films to improve cell proliferation and to guide the regeneration of peripheral nerves. Films with differing shaped grooves were made using patterned silicon templates, sloped walls (SL), V-shaped (V), and square-shaped (SQ), and compared with nongrooved surfaces with micropits. The solvent cast films were tested in vitro using adult adipose-derived stem cells differentiated to Schwann cell-like cells. Cell attachment, proliferation, and cell orientation were all improved on the grooved surfaces, with SL grooves giving the best results. We present in vivo data on Sprague-Dawley rat sciatic nerve injury with a 10-mm gap, evaluating nerve regeneration at 3 weeks across a polymer nerve conduit modified with intraluminal grooves (SL, V, and SQ) and differing wall thicknesses (70, 100, 120, and 210 mm). The SL-grooved nerve conduit showed a significant improvement over the other topographical-shaped grooves, while increasing the conduit wall thickness saw no positive effect on the biological response of the regenerating nerve. Furthermore, the preferred SL-grooved conduit (C) with 70 mm wall thickness was compared with the current clinical gold standard of autologous nerve graft (Ag) in the rat 10-mm sciatic nerve gap model. At 3 weeks postsurgery, all nerve gaps across both groups were bridged with regenerated nerve fibers. At 16 weeks, features of regenerated axons were comparable between the autograft (Ag) and conduit (C) groups. End organ assessments of muscle weight, electromyography, and skin reinnervation were also similar between the groups. The comparable experimental outcome between conduit and autograft, suggests that the PCL/PLA conduit with inner lumen microstructured grooves could be used as a potential alternative treatment for peripheral nerve repair.

show abstract

Section: Discussionmentioning

confidence: 99%

Polymer Scaffolds with Preferential Parallel Grooves Enhance Nerve Regeneration

Mobasseri

Faroni

Minogue

et al. 2015

Tissue Engineering Part A

View full text Add to dashboard Cite

show abstract

“…6 We have also optimized the microgroove dimensions for aligning Schwann cells in vitro. 24,25 A combination of the two structural features, microporosity and microgrooves, could be achieved in one step by controlling the fabrication parameters of the conduit. To the best of our knowledge, this is the first study to combine the two design concepts, the high outflow permeability and the ability to align cells, in one conduit and to compare their effects on peripheral nerve regeneration in vivo.…”

Section: Discussionmentioning

confidence: 99%

“…24 Briefly, a poly(dimethylsiloxane) (PDMS) submaster mold was created by pouring Dow Corning Silastic MDX4-4210 on the photoresist patterned glass. Ten percent solution of PLA (8300D; Cargill Dow, Minneapolis, MN) in 1,4-dioxane was prepared.…”

Section: Creation Of the Micropatternmentioning

confidence: 99%

Fabrication of the Microgrooved/Microporous Polylactide Substrates as Peripheral Nerve Conduits and In Vivo Evaluation

Hsu

2009

Tissue Engineering Part A

Self Cite

View full text Add to dashboard Cite

An innovative technique combining phase transition and microprinting in one step was applied to fabricate the nerve conduits used in peripheral nerve regeneration. The asymmetric microporosity served to generate asymmetric permeability, and the surface microgrooves were introduced to achieve cell alignment in vitro. The symmetric/asymmetric porous poly(D,L-lactide) (PLA) substrates with microgrooves on the surface were tested for their ability to repair 10 mm sciatic nerve transection defects in rats. The in vivo results showed that porous PLA conduits maintained a stable supporting structure during the entire regeneration process. The myelin sheaths of the regenerated nerve in asymmetric conduits were thicker than in symmetric groups at 4 weeks. Moreover, the regenerated nerves in the asymmetric conduits with surface microgrooves had the highest degree of myelination at 4 weeks and the most number of vessels at 6 weeks. The walking track analysis also implied that the asymmetric conduits with surface microgrooves had the highest degree of functional recovery. Based on the study, the combination of microgrooves and asymmetric microporous structure could be employed in the design of nerve conduits for peripheral nerve regeneration in the future.

show abstract

“…42 Again, about 70% of glial cells aligned parallel (≤10°) to biodegradable poly(D,L-lactide) (PLA) microchannels that were patterned into 20 × 20 μm plateau and channel dimensions with a 3 μm depth using a PDMS mold. 43 Additionally, spiral ganglion neurons achieved over 70% alignment (≤20°) on topographical patterns with 25 μm channel and plateau widths with 7 μm depths. 44 Even though our channel and plateau dimensions are similar to these studies, we did not achieve this high of a percentage of cell process alignment.…”

Section: Process Alignment To Micropatterned Channelsmentioning

confidence: 97%

Micropatterned Coumarin Polyester Thin Films Direct Neurite Orientation

McCormick

Maddipatla²,

Shi

et al. 2014

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Guidance and migration of cells in the nervous system is imperative for proper development, maturation, and regeneration. In the peripheral nervous system (PNS), it is challenging for axons to bridge critical-sized injury defects to achieve repair and the central nervous system (CNS) has a very limited ability to regenerate after injury because of its innate injury response. The photoreactivity of the coumarin polyester used in this study enables efficient micropatterning using a custom digital micromirror device (DMD) and has been previously shown to be biodegradable, making these thin films ideal for cell guidance substrates with potential for future in vivo applications. With DMD, we fabricated coumarin polyester thin films into 10×20 μm and 15×50 μm micropatterns with depths ranging from 15 to 20 nm to enhance nervous system cell alignment. Adult primary neurons, oligodendrocytes, and astrocytes were isolated from rat brain tissue and seeded onto the polymer surfaces. After 24 h, cell type and neurite alignment were analyzed using phase contrast and fluorescence imaging. There was a significant difference (p<0.0001) in cell process distribution for both emergence angle (from the body of the cell) and orientation angle (at the tip of the growth cone) confirming alignment on patterned surfaces compared to control substrates (unpatterned polymer and glass surfaces). The expected frequency distribution for parallel alignment (≤15°) is 14% and the two micropatterned groups ranged from 42 to 49% alignment for emergence and orientation angle measurements, where the control groups range from 12 to 22% for parallel alignment. Despite depths being 15 to 20 nm, cell processes could sense these topographical changes and preferred to align to certain features of the micropatterns like the plateau/channel interface. As a result this initial study in utilizing these new DMD micropatterned coumarin polyester thin films has proven beneficial as an axon guidance platform for future nervous system regenerative strategies.

show abstract

Fabrication and evaluation of microgrooved polymers as peripheral nerve conduits

Cited by 50 publications

References 40 publications

Polymer Scaffolds with Preferential Parallel Grooves Enhance Nerve Regeneration

Polymer Scaffolds with Preferential Parallel Grooves Enhance Nerve Regeneration

Fabrication of the Microgrooved/Microporous Polylactide Substrates as Peripheral Nerve Conduits and In Vivo Evaluation

Micropatterned Coumarin Polyester Thin Films Direct Neurite Orientation

Contact Info

Product

Resources

About