Neural Pathfinding on Uni- and Multidirectional Photopolymerized Micropatterns
| Autor: | Andrew M. Erwood, Marlan R. Hansen, Scott P. White, Alison E. Seline, Linjing Xu, C. Allan Guymon, Bradley W. Tuft |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Materials science
Neurite Neural Prostheses Retinal implant Nanotechnology Biocompatible Materials 02 engineering and technology pattern Signal 03 medical and health sciences otorhinolaryngologic diseases medicine Neurites Animals General Materials Science Inner ear Spiral ganglion Cells Cultured 030304 developmental biology 0303 health sciences neurite Neural Prosthesis 021001 nanoscience & nanotechnology Nerve Regeneration Rats contact guidance medicine.anatomical_structure photopolymerization microsurface topography Axon guidance sense organs Schwann Cells 0210 nano-technology Pathfinding Spiral Ganglion neural prosthesis Biomedical engineering Research Article |
| Zdroj: | ACS Applied Materials & Interfaces |
| ISSN: | 1944-8252 1944-8244 |
| Popis: | Overcoming signal resolution barriers of neural prostheses, such as the commercially available cochlear impant (CI) or the developing retinal implant, will likely require spatial control of regenerative neural elements. To rationally design materials that direct nerve growth, it is first necessary to determine pathfinding behavior of de novo neurite growth from prosthesis-relevant cells such as spiral ganglion neurons (SGNs) in the inner ear. Accordingly, in this work, repeating 90° turns were fabricated as multidirectional micropatterns to determine SGN neurite turning capability and pathfinding. Unidirectional micropatterns and unpatterned substrates are used as comparisons. Spiral ganglion Schwann cell alignment (SGSC) is also examined on each surface type. Micropatterns are fabricated using the spatial reaction control inherent to photopolymerization with photomasks that have either parallel line spacing gratings for unidirectional patterns or repeating 90° angle steps for multidirectional patterns. Feature depth is controlled by modulating UV exposure time by shuttering the light source at given time increments. Substrate topography is characterized by white light interferometry and scanning electron microscopy (SEM). Both pattern types exhibit features that are 25 μm in width and 7.4 ± 0.7 μm in depth. SGN neurites orient randomly on unpatterned photopolymer controls, align and consistently track unidirectional patterns, and are substantially influenced by, but do not consistently track, multidirectional turning cues. Neurite lengths are 20% shorter on multidirectional substrates compared to unidirectional patterns while neurite branching and microfeature crossing events are significantly higher. For both pattern types, the majority of the neurite length is located in depressed surface features. Developing methods to understand neural pathfinding and to guide de novo neurite growth to specific stimulatory elements will enable design of innovative biomaterials that improve functional outcomes of devices that interface with the nervous system. |
| Databáze: | OpenAIRE |
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