Natural Flammulina velutipes-Based Nerve Guidance Conduit as a Potential Biomaterial for Peripheral Nerve Regeneration: In Vitro and In Vivo Studies

Abstract

The treatment and repair of serious peripheral nerve injuries remain challenging in the clinical practice, while the application of multifunctional nerve guidance conduits (NGCs) based on naturally derived polymers has attracted much attention in recent years because of their excellent physicochemical properties and biological characteristics. Flammulina velutipes (Curt. ex FV) is a popular edible mushroom characterized by hollow tubular structures, antibacterial activities, and high nutritional properties. In this study, FV is utilized to construct NGCs (labeled FVC) via a freeze-drying technique without chemical modifications. The morphology, physical properties, cellular biocompatibility, antibacterial properties, and nerve regeneration capacity of FVC were assessed both in vitro and in vivo. FVC is composed of hollow tubes and evenly irregular interconnected micropores with 73.8 ± 5.5% porosity and 476.1 ± 12.9 μm hollow tube diameter. The inner surface of the FVC presents multiple microgrooves elongated parallel to the long axis. Moreover, FVC possessed strong antibacterial activity and could inhibit Gram-positive Staphylococcus aureus growth by up to 96.0% and Gram-negative Escherichia coli growth by up to 94.8% in vitro. FVC exhibited excellent biocompatibility and effectively promoted PC-12 cell proliferation and elongation in vitro. When applied to repair critical-sized sciatic nerve defects, FVC could effectively stimulate nerve functional recovery and axonal outgrowth in a rat model. Interestingly, Western blot analysis indicated that growth-associated protein 43 (GAP-43) had increased expression levels in the FVC group compared with the autograft group. This result suggested that by activating the Janus activated kinase2 (JAK2)/Phosphorylation ofsignal transducer and activator of transcription-3 (STAT3) signaling pathway, FVC upregulated Phosphorylation of signal transducer and activator of transcription-3 (P-STAT3) in vivo, resulting in the secretion of GAP-43. Collectively, a natural NGC FVC was fabricated based on FV without chemical modifications. The morphology, physical properties, cellular biocompatibility, antibacterial properties, and nerve regeneration capacity of FVC provide new insights for its further optimization and application in the field of nerve tissue engineering.

Biocompatible and antibacterial Flammulina velutipes-based natural hybrid cryogel to treat noncompressible hemorrhages and skin defects

“…Based on the previous experimental results, HFV70 with loose and interconnected pores provides the most convenient environment for the attachment and growth of L929 cells. In our previous two studies on biomaterials based on FV extracts, the seedbed-like FV polysaccharide–derived scaffolds apparently promoted L929 cell growth relative to the blank control ( Chen et al, 2021a ), and the natural FV-based nerve guidance conduit could be beneficial for the proliferation of PC-12 cells ( Chen et al, 2021b ). In addition, cells presented favorable adhesion, as confirmed via observation.…”

“…Many studies have proved that the main active substances of FV are polysaccharides and glycoprotein, which have a variety of bioactivities, such as anti-oxidation, immune regulation, anti-inflammation, liver protection, anti-tumor effect, anti-hyperlipidemia, improving memory, and resisting decrepitude ( Wu et al, 2010 ; Shi et al, 2012 ; Wang et al, 2018 ; Zhang et al, 2018 ; Chen et al, 2019 ; Wang and Zhang, 2021 ). Previously, we demonstrated that the natural FV nerve guide catheter is a potential biomaterial for peripheral nerve regeneration ( Chen et al, 2021b ). In our previous research, we used FV as raw material and fabricated a novel seedbed-like scaffold by the frozen slicing method.…”

3D Printing rGO/PCL/Mel Bionic Conduit for Peripheral Nerve Regeneration

“…The resultant 3D rGO/PCL/Mel hybrid conduit exhibits a lightweight density of (144.3 ± 1.27) mg/cm 3 and the highest reported porosity of (98.5 ± 0.24)% (Figure S9), surpassing that of other natural or synthetic conduits (Fig. 3k) [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] . This remarkable achievement is attributed to the precise regulation of the rGO conduit's microstructural features, from the microscale to macroscopic dimension, by controlling the GO ink's owing state and fabrication parameters such as freeze-casting temperature.…”

“…Masson's trichrome staining was conducted to assess the differences in muscle ber recovery among three groups by comparing the muscle ber area and mean diameter. rGO/PCL/Mel conduit and another previously reported polymer scaffolds [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] . l, The tensile stress-strain curve of rGO/PCL conduit fabricated using varying concentrations of PCL precursor solution (70 mg/mL, 100 mg/mL, and 120 mg/mL).…”

Integration of genetically engineered virus nanofibers and fibrin to form injectable fibrous neuron-rich hydrogels and enable neural differentiation

“…Some novel biomaterials have been reported to replace ANGs and improve the PNI treatment, such as decellularized allografts, 10,11 artificial polymers and scaffolds, 12,13 and natural materials. 14 However, some drawbacks are found for these biomaterials for the repair of damaged nerves, such as immunological rejection, immune response, poor biodegradability, high complexity of the synthesis process, and more importantly, an unsatisfactory axon-promoting effect. Thus, novel biomaterials that can efficiently induce neural regeneration for large nerve injury with good biocompatibility and few side effects are urgently needed in clinical applications.…”