Polydopamine-coated polycaprolactone/carbon nanotube fibrous scaffolds loaded with brain-derived neurotrophic factor for peripheral nerve regeneration

Abstract

Carbon nanotubes (CNTs) have attracted increasing attention in the field of peripheral nerve tissue engineering owing to their unique structural and physical characteristics. In this study, a novel type of aligned conductive scaffolds composed of polycaprolactone (PCL) and CNTs were fabricated via electrospinning. Utilizing the mussel-inspired polydopamine (PDA) surface modification, brain-derived neurotrophic factor (BDNF) was loaded onto PCL/CNTs fibrous scaffolds to obtain PCL/CNTs-PDA-BDNF fibrous scaffolds capable of the sustained release of BDNF over 28 days. Schwann cells were cultured on these scaffolds, and the effects of the scaffolds on peripheral nerve regeneration in vitro were assessed by studying cell proliferation, morphology and the expressions of myelination-related genes S100, P0 and myelin basic protein (MBP). Furthermore, the effects of these scaffolds on peripheral nerve regeneration in vivo were investigated using a 10-mm rat sciatic nerve defect model. Both the in vitro and in vivo results indicated that PCL/CNTs-PDA-BDNF fibrous scaffolds could effectively promote sciatic nerve regeneration and functional recovery. Therefore, PCL/CNTs-PDA-BDNF fibrous scaffolds have great potential for peripheral nerve restoration.

Schwann cell-matrix coated PCL-MWCNT multifunctional nanofibrous scaffolds for neural regeneration

“…These observations are in line with previous works highlighting the importance of surface topography and polarity on cell behaviour including proliferation, adhesion and differentiation. 12,21,25,26,42 However, again the change did not reach signicance. Taken together, fabricated scaffolds exhibited high biocompatibility with prominent cell proliferation over time.…”

“…They outlined that efficacy of developed scaffold was due to the combination of factors including aligned topography, electrical conductivity of MWCNT, PDA surface modification (polarity) and sustained BDNF release. 26 Taken together from these studies, it is not clear if scaffold morphology along with surface properties can sufficiently promote peripheral nerve regeneration in multicomponent electrospun scaffolds.…”

“…Further, MWCNT loaded PCL/collagen electrospun scaffold and silicone conduits performed significantly better than autografted nerve four months after implantation. Recently, Pi et al 26 developed brain-derived neurotrophic factor (BDNF) loaded and polydopamine (PDA) surface modified PCL/MWCNT electrospun scaffolds (PCL/MWCNT/PDA/BDNF) and explored their efficacy in a Schwann cells in vitro and in a rat sciatic nerve defect in vivo model. In vitro studies revealed significant proliferation of Schwann cells cultured on the PCL/MWCNT/PDA/BDNF scaffold along with significant increase in the expression of myelination-related genes (S100, P0, MBP).…”

Simultaneous Presentation of Dexamethasone and Nerve Growth Factor via Layered Carbon Nanotubes and Polypyrrole to Interface Neural Cells

“…cultured neurons on the PEDOT/CNT substrate, and the neuronal networks were well established, indicating healthy neuronal growth on the PEDOT/CNT substrate . Besides, it has been frequently reported that the cytotoxicity of CNTs associated with cellular uptake could be ameliorated when neurotrophic factors and functionalized CNTs are used in combination . A study carried out on neurite outgrowth stimulated by the coupling of low concentrations of amino-modified CNTs with NGF suggested that CNTs may stimulate neurite outgrowth in dorsal root ganglion neurons by the activation of the extracellular signal-regulated kinase signaling pathway .…”

A critical review on polydopamine surface-modified scaffolds in musculoskeletal regeneration

“…Afrash et al (2021) fabricated PCL/chitosan nanofibers with PDA and found that coated DA layer conjugated NGF onto the scaffold, improved cell adhesion and proliferation by immobilizing NGF (Figure 6C). Recently, Pi et al (2022) modified PCL/carbon nanotube fibrous scaffolds with PDA in order to obtain scaffolds that release sustained levels of brain-derived neurotrophic factor (BDNF). These scaffolds were used to culture SCs in-vitro, and they enhanced peripheral nerve regeneration, stimulating cell proliferation and myelinationrelated gene expression.…”