Bioinspired Multichannel Nerve Guidance Conduit Based on Shape Memory Nanofibers for Potential Application in Peripheral Nerve Repair

Abstract

Repairing peripheral nerve injury, especially long-range defects of thick nerves, is a great challenge in the clinic due to their limited regeneration capability. Most FDA-approved nerve guidance conduits with large hollow lumen are only suitable for short lesions, and their effects are unsatisfactory in repairing long gaps of thick nerves. Multichannel nerve guidance conduits have been shown to offer better regeneration of long nerve defects. However, existing approaches of fabricating multichannel nerve conduits are usually complicated and time-consuming. Inspired by the intelligent responsive shaping process of shape memory polymers, in this study, a self-forming multichannel nerve guidance conduit with topographical cues was constructed based on a degradable shape memory PLATMC polymer. With an initial tubular shape obtained by a high-temperature molding process, the electrospun shape memory nanofibrous mat could be temporarily formed into a planar shape for cell loading to realize the uniform distribution of cells. Then triggered by a physical temperature around 37 °C, it could automatically restore its permanent tubular shape to form the multichannel conduit. This multichannel conduit exhibits better performance in terms of cell growth and the repair of rat sciatic nerve defects. These results reveal that self-forming nerve conduits can be realized based on shape memory polymers; thus, the fabricated bioinspired multichannel nerve guidance conduit has great potential in peripheral nerve regeneration.

Nerve Guidance Conduits with Hierarchical Anisotropic Architecture for Peripheral Nerve Regeneration

“…Conduits containing fillers with hierarchical anisotropic architectures stimulated axon extensions and functional recovery for the regeneration of long nerve defects. [36][37][38][39][40] However, these technologies are usually time-consuming, complex and challenging to control. Here, a modular assembly strategy was used to fabricate nerve conduits with hierarchical anisotropic architectures, providing a flexible and controllable option (Scheme 1).…”

Electrospun Shape Memory Polymer Micro-/Nanofibers and Tailoring Their Roles for Biomedical Applications

“…The electrospun SMP nanofibers mat was initially prepared in a plane form suitable for cell loading and then triggered by a physical temperature to transform to its final tubular form automatically to make a multichannel conduit (Figure 7). The promising results of the cell proliferation and repair of rat sciatic nerve defects evidenced the considerable potential of smart fibers in peripheral nerve regeneration [154]. Many micro-/nanostructures developed as ECM replacements are almost static (although they degrade over time) and thus, fail to match the dynamic physiological conditions in vivo.…”

3D printing of functional nerve guide conduits

“…In general, the biomimic structure of NGCs can be classified as hollow [ 56 ], multi-channel [ 57–59 ] or porous [ 60 ]. Hollow conduits with the simplest structure are the most widely used in peripheral nerve repair, some of which have been approved in clinic.…”