In Vivo Neural Tissue Engineering: Cylindrical Biocompatible Hydrogels That Create New Neural Tracts in the Adult Mammalian Brain

Migration and Differentiation of Neural Stem Cells Diverted From the Subventricular Zone by an Injectable Self-Assembling β-Peptide Hydrogel

“…While a number of previous studies have utilised matrices to promote neuroblast migration, the length of migration has been limited to the first quarter of the implant length (Fon et al, 2014a; Clark et al, 2016). Our previous work using injectable gelatin hydrogels was degraded quickly and was cleared after 3 weeks, and therefore was unable to promote neuroblast migration over longer periods.…”

“…The scaffolds were implanted into the brain in a way to impinge on the SVZ, and promoted neuroblast migration in all studies in comparison to injury only controls. Other studies have also demonstrated the possibility to redirect neuroblasts from RMS and SVZ by implanted scaffolds with specific signal cues such as β1 integrin, N-cadherin, VEGF, and nerve growth factor (Clark et al, 2016; Fujioka et al, 2017; Jinnou et al, 2018) being incorporated. However, to develop viable therapies to treat brain injuries, it is important to develop new injectable scaffolds that dramatically increase: (1) the number of migrating neuroblasts, (2) the migration distance, and (3) the persistency of migration over time.…”

Mechanical properties of the spinal cord and brain: Comparison with clinical-grade biomaterials for tissue engineering and regenerative medicine

“…Consequently, they have enabled considerable progress in the development of potential new treatments for a range of CNS disorders, including spinal cord injury [10], stroke [11], traumatic brain injury [12], and neurodegenerative diseases such as Alzheimer's and Parkinson's [13,14]. Indeed, the structural support provided by biomaterials may be essential for facilitating effective axonal regrowth after human spinal cord injury [15], and the combination of biomaterial-based approaches with cell therapies has been used to ameliorate neurodegeneration in animal models of Parkinson's disease [16,17].…”

Extracellular Matrix‐Mimetic Hydrogels for Treating Neural Tissue Injury: A Focus on Fibrin, Hyaluronic Acid, and Elastin‐Like Polypeptide Hydrogels

“…[85] This MSC-seeded material not only facilitated host neuronal migration into the gel but also induced neuronal differentiation of the donor MSCs, which produced axonal bundles that crossed the injury site. Additional electrophysiological examination and analysis of locomotor recovery using Animal model Significant finding(s) Fibrin Fibronectin -Rat SCI Fibronectin supplement better supports axon ingrowth compared to fibrin or fibronectin hydrogels alone [89] Fibrin a ) chABC -Rat SCI Fibrin prolongs chABC release which reduces glycosaminoglycan content compared to chABC injections [96] Fibrin --Rat SCI MSC-loaded hydrogel improved neurite extension and functional recovery [88] Fibrin chABC-loaded lipid microtubes and NEP1-40-loaded PLGA microspheres -Rat SCI Drug-loaded composite improved axon growth, reduced astrocyte scarring, and reduced the presence of CSPGs around the injury site Fibrin a ) Laminin, VEGF, and NGF -Rat cortical implantRat hemi-Parkinson Protein-immobilized hydrogels recruit endogenous neuronal cells and enhance neurite ingrowthProtein-immobilized hydrogels correct parkinsonian behavior [95] AFG -1.6 Rat SCI AFGs promote neuronal cell migration and guide axonal invasion [84] AFG -1.6 Rat PNI AFGs advance injury gap bridging and improve functional recovery [86] Fibrin a ) T1, HYD1, or A5G81 synthetic ligands 0.25-0.32 Rat SCI HYD1-immobilization boosts growth cone formation and functional recovery [90] Fibrin Tacrolimus-loaded PLGA microparticles -Rat PNI Slowed drug release from microparticles improves neurogenesis [99] AFG -1.6 Rat SCI MSC-loaded AFGs produce nerve bundles that cross the injury site and improve functional recovery [85] a) Inclusion of aprotinin, an enzyme inhibitor that reduces fibrin degradation; b) Storage (elastic) modulus.…”