Precision microchannel scaffolds for central and peripheral nervous system repair
In previous studies, we demonstrated the ability to linearly guide axonal regeneration using scaffolds comprised of precision microchannels 2 mm in length. In this work, we report our efforts to augment the manufacturing process to achieve clinically relevant scaffold dimensions in the centimeter-scale range. By selective etching of multi-component fiber bundles, agarose hydrogel scaffolds with highly ordered, close-packed arrays of microchannels, ranging from 172 to 320 μm, were fabricated with overall dimensions approaching clinically relevant length scales. Cross-sectional analyses determined that the maximum microchannel volume per unit volume of scaffold approached 80%, which is nearly twice that compared to our previously reported study. Statistical analyses at various points along the length of the microchannels also show a significant degree of linearity along the entire length of the scaffold. Two types of multi-component fiber bundle templates were evaluated; polystyrene and poly(methyl methacrylate). The scaffolds consisting of 2 cm long microchannels were fabricated with the poly(methyl methacrylate) fiber-cores exhibited a higher degree of linearity compared to those fabricated using polystyrene fibers. It is believed that the materials process developed in this study is useful for fabricating high aspect ratio microchannels in biocompatible materials with a wide range of geometries for guiding nerve regeneration.
KeywordsPMMA Propylene Carbonate Average Wall Thickness Agarose Hydrogel Relevant Length Scale
This study was supported by the Veterans Administration and the Christopher Reeve Paralysis Foundation. The authors would also like to thank Dr. Mark Tuszynski at the University of California, San Diego for his insightful interaction and assistance with characterizing the in vivo efficacy of the scaffolds described in this study.
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