Polydopamine‐Decorated PLCL Conduit to Induce Synergetic Effect of Electrical Stimulation and Topological Morphology for Peripheral Nerve Regeneration

Abstract

Due to the limited self‐repairing capacity after peripheral nerve injuries (PNI), artificial nerve conduits are widely applied to facilitate neural regeneration. Exogenous electrical stimulation (ES) that is carried out by the conductive conduit regulates the biological behavior of Schwann cells (SCs). Meanwhile, a longitudinal surface structure counts to guide axonal growth to accelerate the end‐to‐end connection. Currently, there are no conduits equipped with both electrical conduction and axon‐guiding surface structure. Herein, a biodegradable, conductive poly(l‐lactide‐co‐caprolactone)/graphene (PLCL/GN) composite conduit is designed. The conduit with 20.96 ± 1.26 MPa tensile strength has a micropatterned surface of 20 µm groove fabricated by microimprint technology and self‐assembled polydopamine (PDA). In vitro evaluation shows that the conduits with ES effectively stimulate the directional cell migration, adhesion, and elongation, and enhance neuronal expression of SCs. The rat sciatic nerve crush model demonstrates that the conductive micropatterned conduit with ES promotes the growth of myelin sheath, faster nerve regeneration, and 20‐fold functional recovery in vivo. These discoveries prove that the PLCL(G)/PDA/GN composite conduit is a promising tool for PNI treatment by providing the functional integration of physical guidance, biomimetic biological regulation, and bioelectrical stimulation, which inspires a novel therapeutic approach for nerve regeneration in the future.

Developing conductive hydrogels for biomedical applications

“…Jiang et al fabricated a conductive composite conduit with alignment structure for nerve regeneration. 116 It was shown from an in vivo rat sciatic nerve crush experiment that when applied with electrical stimulation, the myelin sheath was induced to grow and nerve tissues were promoted to regenerate with a faster recovery rate (Figure 7B), indicating the remarkable value of electrical stimulation on nerve regeneration.…”

“…(B) Images of the conductive composite conduit for sciatic nerve crush model. Source: Reproduced with permission 116. Copyright 2023, John Wiley and Sons.…”

Facilitation of Cell Cycle and Cellular Migration of Rat Schwann Cells by O‐Carboxymethyl Chitosan to Support Peripheral Nerve Regeneration

“…Nerve conduction velocity (NCV) was assessed to investigate the functional recovery of the injured nerves. [43] The hollow NGC group had the worst NCV among all the groups at 20 weeks post-implantation (Figure S1, Supporting Information). The C-CM-chitosan NGC showed better NCV than that of the hollow NGC group, similar to that of the autograft group (p > 0.05).…”

Interaction of graphene and WS2 with neutrophils and mesenchymal stem cells: implications for peripheral nerve regeneration

“…5,13,[44][45][46][47] In fact, graphene-based conduits have been used in combination with exogenous electrical stimulation. 46,48,49 In particular graphene-based materials combined with electrical stimulation showed improved cell differentiation and proliferation, 50,51 neurite extension 46 and Schwann cell migration, proliferation and myelination, 49,52 and functional recovery comparable to the gold standard autograft. 48 However, there is a great experimental and commercial variability in GBMs that leads to materials with different compositions and structures that may elicit completely different biological responses.…”