Supplementary MaterialsSupplementary methods, figures and tables. characterize the secondary structures, microscopic structures, and morphologies of self-assembling nanofiber hydrogels. Then the SC adhesion, myelination and neurotrophin secretion were evaluated on the hydrogels. Finally, the SAP hydrogels were injected into hollow chitosan tubes to bridge a 10-mm-long sciatic nerve defect in rats, and gene expression at 1 week, axonal regeneration, target muscular re-innervation, and functional recovery at 12 weeks were assessed. Results: The bioactive peptide motifs were covalently linked to the C-terminal of the self-assembling peptide and the functionalized peptides could form well-defined nanofibrous hydrogels capable of providing a 3D microenvironment similar to native extracellular matrix. SCs displayed improved cell adhesion on hydrogels with both IKV and RGI, accompanied by improved cell distributing and elongation relative to additional organizations. RSCs cultured on hydrogels with IKV and RGI showed enhanced gene manifestation of NGF, BDNF, CNTF, PMP22 and NRP2, and decreased gene manifestation of NCAM compared with those cultured on additional three organizations after a 7-day time incubation. Additionally, the secretion of NGF, BDNF, and CNTF of RSCs was significantly improved on dual-functionalized peptide hydrogels after 3 days. At 1 week after implantation, the expressions of neurotrophin and Mianserin hydrochloride myelin-related genes in the nerve grafts in SAP and Autograft organizations were higher than that in Hollow group, and the manifestation of S100 in organizations comprising both Mianserin hydrochloride IKV and RGI was significantly higher than that in organizations comprising either IKV or RGI hydrogels, suggesting enhanced SC proliferation. The morphometric guidelines of the regenerated nerves, their electrophysiological overall performance, the innervated muscle mass weight and redesigning of muscle materials, and engine function showed that RAD/IKV/RGI and RAD/IKV-GG-RGI hydrogels could markedly improve axonal regeneration with enhanced re-myelination and engine practical recovery through the synergetic effect of IKV and RGI practical motifs. Conclusions: We found that the dual-functionalized SAP hydrogels advertised RSC adhesion, myelination, and neurotrophin secretion and successfully bridged a 10-mm space representing a sciatic nerve defect in rats and and capable of easy conjugation to SAPs 23, 24. The practical peptide motif IKVAV is commonly used in neurotrophin liberating and stem cell loading during treatment of traumatic brain injury, spinal cord injury, and sciatic nerve injury due to its ability to enhance cell survival and adhesion, neurite outgrowth, and even angiogenesis 25-27. BDNF is definitely a member of the neurotrophin family and enhances myelination in SCs, promotes neuronal survival and neurite outgrowth, and helps prevent neural death 28, 29. Studies show that BDNF promotes axonal regrowth after sciatic nerve injury and is closely related to engine recovery following PNI UVO 30-33. Hassannejad et al. fabricated an IKVAV-functionalized peptide amphiphile (PA) hydrogel to release BDNF for spinal cord repair, resulting in substantial axon preservation and reduced astrogliosis at 6 weeks without any inflammatory response 26. However, the use of growth factors and neurotrophic factors is sometimes limited because of the high cost, short half-life, Mianserin hydrochloride controversial sources, and vulnerability 34. Moreover, BDNF concentration directly influences axonal regeneration, with low exogenous BDNF doses enhancing engine neuron axon regeneration, whereas high levels inhibiting regeneration 35. To address this issue, we previously reported that Mianserin hydrochloride a neurotrophic peptide sequence RGIDKRHWNSQ (RGI) derived from BDNF advertised rat sciatic nerve regeneration 36, 37. The BDNF-mimetic peptide motif designed based on solvent-exposed loops 3 and 4 of BDNF simulated neurite outgrowth and survival by binding to the TrkB and p75 neurotrophin receptor 38. The previous study proposed an SAP nanofiber hydrogel functionalized with BDNF mimicking peptide RGI to improve axon regeneration and engine practical recovery; however, its regenerative effect was not as good as that of autografting, indicating a limitation in the use of a single factor in fixing nerve injury 36. Other studies showed that combined use of RGI and additional peptide motifs derived from growth factors, such as NGF and VEGF, advertised nerve regeneration 13, 37. Consequently, we expanded our previous attempts to establish synergetic scaffolds harboring LN and BDNF mimicking peptide motifs to simulate effects of the extracellular matrix and neurotrophic factors at the same time for evaluation inside a rat model Mianserin hydrochloride of sciatic nerve injury. In this.